Abstracts from the 30th Bárány Society meeting Uppsala, Sweden, June 10-13, 2018

OP01: Clinical vestibular testing VEMP (I) 2

OP01-1 - Role of oVEMP and cVEMP tests in relation to oscillopsia 2

OP01-2 - Ocular and cervical VEMPs to air conducted sound and bone conducted vibration in Meniere’s Disease 2

OP01-3 - Eliciting ocular VEMPs by first order bone vibration and second order resonance effect 3

OP01-4 - Temporal Dynamics of Eye Movements Elicited by Combined Otolith and Semicircular Canal Stimulation 3

OP01-5 - Altered soleus VEMP may be a prognostic marker of progressive spinal cord damage 4

OP01-6 - The clinical significance of waveform morphology in OVEMP testing 4

OP01-7 - The effects of different sound stimuli when performing OVEMPs 5

OP02: Superior Canal Dehiscence Syndrome 5

OP02-1 - Cervical and ocular VEMPs to 4000Hz show Superior Semicircular Canal Dehiscence 5

OP02-2 - Efficacy of vestibular function tests post-canal plugging for superior canal dehiscence syndrome 6

OP02-3 - Heterogeneity in Reported Outcome Measures after Surgery in Superior Canal Dehiscence Syndrome 6

OP02-4 - Management of hearing and balance problems in SCDS 7

OP02-5 - Skull vibration induced nystagmus in patients with unilateral semicircular canal dehiscence 7

OP02-6 - Spontaneous plugging of superior canal: two possible natural evolutions of an unstable dehiscence 8

OP02-7 - The diagnostic value of vestibular evoked myogenic potentials in superior canal dehiscence syndrome 9

OP03: Spatial orientation 9

OP03-1 - Hearing & postural control: what is the impact of hearing loss and what role can hearing aids play? 9

OP03-2 - Towards a clinically useful test for vestibular perception 10

OP03-3 - The role of vection and velocity storage in visually induced motion sickness 10

OP03-4 - The role of temporo-parietal cortex in upright perception and the link with torsional eye position 11

OP03-5 - Spatial navigation, sense of direction, and vestibular function in young deaf individuals 11

OP03-6 - Functional and mechanistic link between sensory cue integration and self-motion perception 12

OP03-7 - A Computational Model of Self-Motion Perception and Vestibular Cognition 12

OP04: Traumatic Brain Injury 13

OP04-1 - Benign Paroxysmal Positional Vertigo in acute traumatic brain injury 13

OP04-2 - Concussion Balance Test: Assessment and Treatment Effectiveness After Sports Related Concussion 13

OP04-3 - Does the Vestibular/Ocular Motor Screening (VOMS) Tool Predict Recovery in Collegiate Athletes? 14

OP04-4 - Is it clinically feasible to run a multi-modal battery of tests in a virtual reality goggle? 14

OP04-5 - Linking traumatic brain injury (TBI) severity, vestibular agnosia, and vestibular symptom load. 15

OP04-6 - VEMP latency predict precision of subjective visual vertical in acute traumatic brain injury (TBI). 15

OP05: Acute vertigo 16

OP05-1 - Acute Dizziness without Nystagmus: Incidence and Predictors of Stroke 16

OP05-2 - False negative stroke in acute dizziness 16

OP05-3 - Prospective evaluation of cerebral lesion localization in acute vestibular and ocular motor stroke 17

OP05-4 - Spontaneous nystagmus characteristics in posterior circulation stroke 18

OP05-5 - Truncal Ataxia in the Differential Diagnosis of Acute Vestibular Syndrome 18

OP05-6 - VOG vs MRI-All for Stroke Diagnosis of Vertigo in Emergency Departments: Cost Effectiveness Analysis 19

OP06: Vestibular Prosthesis 19

OP06-1 - First-in-human Safety and Preliminary Efficacy Results for the MVI Multichannel Vestibular Implant 19

OP06-2 - Multichannel Vestibular Implant Early Feasibility Study: Gait and Posture Outcomes 20

OP06-3 - Multichannel Vestibular Implant Early Feasibility Study: Safety and Audiometric Outcomes 20

OP06-4 - Multichannel Vestibular Implant: Continuous Restoration of the Human Vestibulo-Ocular Reflex 21

OP06-5 - The vestibular implant input interacts with residual natural function 22

OP06-6 - Combined stimulation of multiple canals to map a vestibular prosthesis. 22

OP06-7 - Electrically Evoked Compound Action Potentials in Patients with a Hybrid Cochlear-Vestibular Implant 23

OP08: Rehabilitation of vestibular disorders (I) 24

OP08-1 - The effect of darkness on human head impulse catch-up saccades 24

OP08-2 - Sensory Substitution quantified via the Oculus Rift in Patients with Vestibular Dysfunction 24

OP08-3 - Accel. and velocity vHIT gains after unilateral vestibular loss: Insights into neural compensation 25

OP08-4 - Assessment of vestibulo-ocular reflex gain and catch-up saccades during Vestibular Rehabilitation 25

OP08-5 - Behavioral Evidence for Independently Modifiable Neural Circuits Mediating Concurrent VOR Adaptation 26

OP08-6 - Effects of saccular function on recovery of subjective dizziness after vestibular rehabilitation 26

OP08-7 - Efficacy of Gaze Stabilisation Exercises in Vestibular Dysfunction: A Systematic Review 27

OP09: BPPV (I) 27

OP09-1 - A new numerical model : speed of migration of otonia under gravity action depending of their size. 27

OP09-2 - Association between serum vitamin D levels and BPPV in elderly patients 28

OP09-3 - Clinical investigation and analysis of the risk factors of benign paroxysmal positional vertigo 28

OP09-4 - Correlations between scores of Eysenck Personality questionnaire and DHI in patients with BPPV 29

OP09-5 - Establishment of clinical diagnosis procedure in patients with benign paroxysmal positional vertigo 29

OP09-6 - Horizontal canal benign paroxysmal positional vertigo: Lempert vs Gufoni 30

OP10: Functional and Psychiatric Vestibular Disorders 30

OP10-1 - Altered functional brain connectivity in patients with visually induced dizziness 30

OP10-2 - Alternatives to Treat Associated Symptoms of Mal de Debarquement Syndromes (MdDS) 31

OP10-3 - Decreased Spontaneous Functional Activity of left PIVC in Persistent Postural-Perceptual Dizziness 31

OP10-4 - Integrating mental and physical health assessment in neuro-otology 32

OP10-5 - Interaction of Time Pressure and Anxiety upon Spatial orientation judgments 32

OP10-6 - The cognitive-behavioural correlates of dizziness related interference 33

OP10-7 - Vestibulo-cortical Hemispheric Dominance: the link between Anxiety and the Vestibular System? 33

OP11: Cochlear implantation 34

OP11-1 - CI and vestibular assessment: controversies, measurement bias and ostensible clinical impact ..... 34

OP11-2 - Intralabyrinthine schwannomas: vestibular function after surgery with/without cochlear implantation 34

OP11-3 - Music May Improve Gait Pattern in Cochlear Implant Patients with Bilateral Caloric Areflexia. 35

OP11-4 - Preservation of vestibular function after cochlear implantation with round window approach 35

OP11-5 - Vestibular and Balance Function is Impaired in Children with Unilateral Sensorineural Hearing Loss 36

OP11-6 - Vestibular function after cochlear implantation in partial deafness treatment. 36

OP11-7 - Vestibular function pre and post Cochlear implant in 71 patients 37

OP12: Clinical vestibular testing VEMP (II) 37

OP12-1 - Spatial Selectivity of Eye Movements Elicited by Combined Otolith and Semicircular Canal Stimulation 37

OP12-2 - Clinical evaluation of a new bone conduction transducer for VEMP 38

OP12-3 - oVEMP: A novel tool for non-invasive intracranial pressure monitoring 38

OP12-4 - Repetitive oVEMP stimulation for myasthenia gravis: optimization of stimulus parameters 39

OP12-5 - What kind of information can be provided using chirp sound in VEMP? 39

OP12-6 - VEMP a simple, portable and affordable vestibular evoked myogenic potential test device. 40

OP12-7 - VEMP triggered by galvanic stimulation may reveal a subclinical myelopathy 41

OP12-8 - Simultaneous recording of bilateral cervical/ocular vestibular-evoked myogenic potentials 41

OP13: Ménière’s disease (I) 42

OP13-1 - Low-frequency vibration induced vestibular reactions and benefits in Meniere’s disease patients 42

OP13-2 - Intratympanic Steroid is an Economic and Effective Treatment for Intractable Meniere’s Disease 42

OP13-3 - Follow-up of a randomised, double-blind, trial of methylprednisolone vs gentamicin in unilateral MD 43

OP13-4 - Exploring Fluctuating Sensorineural Hearing Loss In Meniere’s Disease Using iPad-Based Audiometry 43

OP13-5 - Endolymphatic hydrops diagnosis at 3T MRI: Reproducibility and correlation with Meniere’s disease. 44

OP13-6 - Endogenous Ouabain in Menire’s Disease 44

OP13-7 - Acoustic absorbance in wideband tympanometry of Meniere’s Disease is greater in affected side 45

OP14: Clinical vestibular testing HIT (II) 45

OP14-1 - Video-Head-Impulse testing in infants younger than 24 months 45

OP14-2 - Video head impulse test data in subjects with and without vascular risk factors and vertigo 46

OP14-3 - Viewing-target distance influences the VOR gain when assessed using the vHIT 46

OP14-4 - Dissociation between caloric test and video head impulse test: device factor vs stimulus factor 47

OP14-5 - Changes in vestibulo-ocular reflex during video Head Impulse Test in patients with cerebellar ataxia 47

OP14-6 - vHIT VOR-gain is not yet a reliable measure for bilateral vestibulopathy 48

OP14-7 - Problems with vertical Video Head Impulse Test (vHIT) 48

OP15: Imaging 49

OP15-1 - Meniere’s disease affected inner ears are distinct from healthy controls with MRI and Radiomics 49

OP15-2 - MRI in Meniere patients: reliability of standard and additional diagnostic imaging criteria. 49

OP15-3 - The human vestibular cortex 50

OP15-4 - Head tap stimulus to image the vestibular cortex on fMRI-- a pilot study 50

OP15-5 - MR volumetric measurement of endolymphatic space in patients without vertigo or hearing loss 51

OP15-6 - PET visualized stimulation of the vestibular organ 52

OP15-7 - The Ups and Downs of Endolymphatic Hydrops Imaging 52

OP15-8 - Neuroinflammation along the vestibular nerve and nucleus in acute unilateral vestibulopathy 53

OP16: Miscellaneous 53

OP16-1 - DIZZYNET - a European network initiative for vertigo and balance research: visions and aims 53

OP16-2 - Cochlear cooling for neuroprotection: The Cool-cochlea Project 54

OP16-3 - Vestibular dysfunction in mitochondrial disease: a common, treatable cause of dizziness or imbalance 55

OP16-4 - Otoconial loss a new important diagnosis - explanation for residual dizziness and chronic imbalance 55

OP16-5 - Amelioration of hyperacusis impacts vestibular symptoms and binocular vision dysfunction symptoms 56

OP16-6 - Correlations with hearing recovery and vestibular testing in sudden sensorineural hearing loss 56

OP16-7 - A reappraisal supported by functional and morphological assessments of delayed endolymphatic hydrops 57

OP17: Labyrinthine fistula/Vestibular schwannoma 58

OP17-1 - Detecting Perilymphatic Fistula by Variation of 3D Reconstruction Thresholds on CT scan 58

OP17-2 - Postoperative recurrence of perilymphatic fistula 58

OP17-3 - The change of hearing and positional nystagmus after surgery in barotraumatic perilymph fistula(PLF) 59

OP17-4 - The results of a nationwide study of PLF using a novel ELISA for human CTP detection test. 59

OP17-5 - What are the serious symptoms of chronic perilymph fistula (PLF)? 60

OP17-6 - Specificity and sensitivity of two video Head Impulse Test systems in Vestibular Schwannoma patients 60

OP17-7 - Preoperative determination of nerve of origin in patients with vestibular schwannoma 61

OP18: Central Vestibular Disorders 61

OP18-1 - Apogeotropic Central Positional Nystagmus: Characteristics and Mechanism 61

OP18-2 - Combined Central & Peripheral Vestibular Disorders: CANVAS, iCABV & Other Differential Diagnoses 62

OP18-3 - Mal de Debarquement Syndrome: motion-triggered versus spontaneous/other onsets. 62

OP18-4 - The mystery of conversion of upbeat to downbeat nystagmus in thiamine deficiency 63

OP18-5 - Uncommon causes of episodic vertigo and imbalance: Ictal characteristics 64

OP18-6 - Vestibular Paroxysmia: Not Always As Simple As It Seems 64

OP18-7 - How to diagnose ataxia 65

OP19: Postural control 65

OP19-1 - Can Sensory Condition affect the Modified CTSIB relative to the SOT? 65

OP19-2 - Visual priming inducing expectational mismatch distorts sense of instability during postural control 66

OP19-3 - Sensitivity and specificity of 3 Hz tremor in patients with cerebellar ataxia 66

OP19-4 - Validity & kinematic outcomes of New Balance Test 67

OP19-5 - DHI score variation in vestibular rehabilitation patients, regardless of pathology 67

OP19-6 - Balanci: Improving balance in children with bilateral cochleovestibular loss using cochlear implants 68

OP19-7 - Balance, Gait and Dizziness in Adult Patients post Cochlear Implant 68

OP20: Basic vestibular science/Animal models (I) 69

OP20-1 - Endolymphatic fluid absorption in the developing inner ear 69

OP20-2 - Application of Gene Therapy to a Mouse Model of Vestibular Dysfunction 70

OP20-3 - Assessment of D-methionine Protecting Gentamicin-induced Otolith Toxicity 70

OP20-4 - What is the insulin signaling system doing in the inner ear?- implications for diabetes 71

OP20-5 - Biocompatibility and therapeutic effect of three intra-tympanic drug-delivery vehicles 71

OP20-6 - The effects of electrical vestibular stimulation on neurochemical release in the rat striatum. 72

OP20-7 - Is it time for optical coherence tomography to be part of our vestibular workup? 72

OP21: Rehabilitation of vestibular disorders (II) 73

OP21-1 - Pain a common finding in patients with persistent dizziness 73

OP21-2 - Individualized vibrotactile neurofeedback training in bilateral vestibular loss patients 73

OP21-3 - Multi-sensory training and wrist fractures. A randomized controlled trial 74

OP21-4 - Vestibular rehabilitation exercises as a form of neural priming to regain motor control of the arm 74

OP21-5 - The reliability and validity of the Life Space Assessment in persons with vestibular disorders 75

OP21-6 - Histamine H1 receptor contributes to vestibular compensation 75

OP22: Gait, Posture and locomotion 76

OP22-1 - Balance control impairments in Fabry disease 76

OP22-2 - Body sway is mediated by vestibular cortical dominance 77

OP22-3 - Changes in Cortical Activity during Dual-task Walking in Individuals with and without Visual Vertigo 77

OP22-4 - Influence of hearing on postural control and stability in healthy subjects 78

OP22-5 - The auditory influence on postural control in stance and gait conditions 78

OP22-6 - Vestibular loss effects on standing balance during postural threat 79

OP22-7 - Virtual Reality for Vestibular and Balance Rehabilitation A Preliminary report 79

OP23: Perception and Central Vestibular function 80

OP23-1 - Exposure to an extreme environment comes at a sensorimotor cost 80

OP23-2 - Sensation and functional balance in elderly - low efficacy using the 256 Hz tuning fork 80

OP23-3 - Paroxysmal positional ocular flutter associated with middle cerebellar peduncle demyelination 81

OP23-4 - Main sequence of torsional saccade under videooculography recordings. 81

OP23-5 - Structural connectome of the human vestibular cortex 82

OP24: Vestibular migraine 83

OP24-1 - Abnormal Visuo-vestibular Interactions in Vestibular Migraine 83

OP24-2 - Errors of Upright Perception in Patients with Vestibular Migraine 83

OP24-3 - Living with Vestibular Migraine; A qualitative investigation of patients perspectives 84

OP24-4 - Severe motion sickness - a possible rare presentation of vestibular migraine 84

OP24-5 - Vertigo in Pediatric population. Migraine prevalence 85

OP24-6 - Vestibular migraine: reference to International Classification of Headache Disorders 3rd edition. 85

OP24-7 - Benign Recurrent Spontaneous Vertigo with Interictal Head-Shaking Nystagmus 86

OP25: Clinical Vestibular testing HIT (II) 86

OP25-1 - Video-head impulse test results in Meniere’s disease related to duration and stage of disease 86

OP25-2 - Acute video-oculography for vertigo in emergency rooms for rapid triage (avert) Trial: pilot results 87

OP25-3 - Different vHIT results of sudden deafness with vertigo and vestibular neuritis 87

OP25-4 - Enhanced VOR suppression in dancers during passive high velocity head impulses 88

OP25-5 - Investigating Mechanisms of Overt and Covert Saccades Using a Computer Model of Head Impulse Test 88

OP25-6 - Bedside examinations distinguish central from peripheral causes of vertigo 89

OP25-7 - Oral glycerol reduces the enhanced eye velocity in vHIT testing of patients with probable hydrops 89

OP26: Epidemiology of vestibular disorders 90

OP26-1 - A retrospective cross-sectional study in an emergency department of a tertiary referral centre 90

OP26-2 - Health Burden of Balance Problems and Falling: 2016 United States Health Survey of 33,028 Adults 90

OP26-3 - Prevalence of Dizziness and Balance Problems and Significant Head Injuries in United States Children 91

OP26-4 - Sensory impairments and wrist fractures. A case-control study. 92

OP26-5 - Stroke Risk after Diagnosis of Benign Vertigo is Lower in Specialty Care than General Practice 92

OP27: Ménière’s disease (II) 93

OP27-1 - Symptom severity and fluctuations in 192 patients with Hydropic Ear Disease 93

OP27-2 - Outcomes after Surgical Treatment of Meniere’s Disease: Experience from Shanghai Xinhua Hospital 94

OP27-3 - Prediction of unilateral Meniere’s disease attack using inner ear test battery 94

OP27-4 - Shift of the frequency tuning on Ocular Vestibular-Evoked Myogenic Potentials in Meniere’s disease 95

OP27-5 - Simultaneous triple semicircular canal plugging and cochlear implantation in Meniere’s disease 95

OP27-6 - Slow-phase velocity of thermally-induced nystagmus is early reduced in Meniere’s Disease 96

OP28: BPPV (II) 96

OP28-1 - Isolated positional vertigo of vascular origin 96

OP28-2 - Positional Downbeating Nystagmus due to BPPV variants: our experience 97

OP28-3 - Probable benign paroxysmal positional vertigo, spontaneously resolved: incidence and natural course. 97

OP28-4 - Significance of repeated positional maneuver in the diagnosis of benign positional vertigo 98

OP28-5 - Supplementation of Vitamin D and Calcium May Prevent Recurrences of BPPV 98

OP28-6 - Upright Head Pitch Test to diagnose Posterior Canal Benign Paroxysmal Positional Vertigo. 99

OP28-7 - Vestibular evoked myogenic potentials in posterior canal benign paroxysmal positional vertigo 100

OP29: Basic vestibular science/Animal models (II) 100

OP29-1 - Effects of Selective Electrical Vestibular Stimulation on the Rat Hippocampus 100

OP29-2 - Biomechanical Origins of Tullio Phenomena 101

OP29-3 - How does 500Hz sound or vibration cause VEMPs 101

OP29-4 - Development of a non-human primate model for the cervical vestibular evoked myogenic potential 102

OP29-5 - Probing the role of the efferent vestibular system using direct monosynaptic viral tracing 102

OP29-6 - Visual Suppression has Minimal Effect on Adaptation to Magnetic Vestibular Stimulation 103

OP29-7 - Sound-evoked vestibular projections to the trapezius muscles in humans 104

OP30: Nystagmus and visual stabilization 104

OP30-1 - Discussion on the significance of nystagmus detection for continuous variable positional nystagmus 104

OP30-2 - Gaze Stability in Elite Athletes 105

OP30-3 - Comorbid inner ear disorders in patients with congenital nystagmus 105

OP30-4 - Utility Of Positional Testing In Acute Vestibular Syndrome: A Transversal And Longitudinal Study 106

OP30-5 - Video ocular counter-roll (vOCR): A new clinical test of otolith-ocular function 106

OP30-6 - The clinical utility of vibration-induced nystagmus and its role in the vestibular examination 107

OP30-7 - Accuracy of Automated Nystagmus Velocity Calculation by Video-oculographyImplications for Eye ECG 107

OP31: Bilateral Vestibulopathy 108

OP31-1 - Impaired spatial orientation in 30 patients with bilateral vestibulopathy 108

OP31-2 - Etiology and hearing status of 129 patients with bilateral vestibulopathy 108

OP31-3 - Cognitive impairment in patients with bilateral vestibulopathy with and without hearing loss 109

OP31-4 - Extensive exploration of symptoms of bilateral vestibulopathy 110

OP31-5 - Hierarchical cluster analysis of semicircular canal and otolith deficits in bilateral vestibulopathy 110

OP31-6 - On the effect of noisy galvanic vestibular stimulation on dynamic visual acuity. 111

OP31-7 - Vestibular perception in patients with bilateral vestibulopathy 111

Exhibition and poster viewing (poster session 1) 114

PP1-1 - 3D Visualization and Position of Human Inner Ear Graviceptors A Synchrotron Imaging Study 114

PP1-2 - A multifaceted tailored randomised-controlled trial to reduce the burden of dizziness in middle aged and older people 114

PP1-3 - Developing a Model for Quantification of Heat Transfer to the Vestibular System 115

PP1-4 - Distribution of extracellular matrix in vestibular nuclei of developing mouse brain stem 115

PP1-5 - Ion Transport Proteins and Claudin 11 Barrier in the Lateral Wall of the Human Cochlea 116

PP1-6 - Is there a Neuroimmunoaxis in the Human Inner Ear - Role in Disease and Repair? 116

PP1-7 - Microcomputed Tomography Analysis of the the Fundus of the Human Internal Acoustic Canal 117

PP1-8 - A new procedure of labyrinthectomy in mice by means of transtympanic injection of p-arsanilic acid 117

PP1-9 - Altered circadian locomotor activity after acute otovestibular failure in rodents. 118

PP1-10 - Effect of thioperamide on vestibular compensation in rats with immunohistochemistry 119

PP1-11 - Evaluating an kinase inhibitor library for effects on hair cells using the zebrafish lateral line 119

PP1-12 - Extracellular matrix in vestibular compensation 120

PP1-13 - Locomotor hyperactivity in bilateral vestibulopathic rats: a consequence of spatial disorientation? 120

PP1-14 - Macrophages in the Human Endolymphatic Sac - Molecular Expression and Interaction 121

PP1-15 - Neural Correlates of Galvanic Vestibular Stimulation in the Alert and Behaving Macaque 121

PP1-16 - Photobiomodulation for peripheral vestibular dysfunction induced by aminoglycoside in animal model 122

PP1-17 - Tissue optical clearing of the mouse temporal bone for downstream applications 122

PP1-18 - Selective otolith organ dysfunction in patients with non-spinning vertigo 123

PP1-19 - The effect of distraction on motion sickness 123

PP1-20 - Efficacy of the Gufoni maneuver for treating the horizontal canal BPPV 124

PP1-21 - 25 (OH) D3 levels, incidence and recurrence of different clinical forms of BPPV 124

PP1-22 - Accuracy of Questionnaire-Based Diagnosis of Benign Paroxysmal Positional Vertigo 125

PP1-23 - Apogeotropic variant of posterior semicircular canal benign paroxysmal positional vertigo 125

PP1-24 - Asking about dizziness when turning in bed predicts benign paroxysmal positional vertigo 126

PP1-25 - Canalith jam of the horizontal canal masquerading as acute vestibular loss: role of the video-HIT 126

PP1-26 - Characteristics of the Recurrence of Idiopathic Benign Paroxysmal Positional Vertigo 127

PP1-27 - Characteristics and recurrent risks of Benign Paroxysmal Positional Vertigo in young and elder group 127

PP1-28 - Characteristics of Benign Positional Vertigo Tested on the Epley Omniax Chair 128

PP1-29 - Clinical analysis of benign paroxysmal positional vertigo with multiple canal involvement 128

PP1-30 - Clinical characteristic and risk factor of canal conversion in benign paroxysmal positional vertigo 129

PP1-31 - Demographics of patients with BPPV and treatment efficacy in the Singapore population 129

PP1-32 - Diagnosis and Treatment of Anterior Canal Benign Paroxysmal Positional Vertigo 130

PP1-33 - Effect of Intratympanic Steroid Injection in Light Cupula 130

PP1-34 - Efficacy of Gufoni maneuver and head-shaking for treating apogeotropic horizontal BPPV 131

PP1-35 - Frequency tuning of ocular vestibular evoked myogenic potential in BPPV 131

PP1-36 - Idiopathic benign paroxysmal positional vertigo in the elderly: A long-term follow-up study 132

PP1-37 - Immediate efficacy of Gufoni maneuver for HC-BPPV:a meta-analysis 132

PP1-38 - Objective Characteristics of Nystagmus in Posterior Semicircular Canal BPPV 133

PP1-39 - Optimal reassessment timing after treatment in posterior canal benign paroxysmal positional vertigo 133

PP1-40 - Positional downbeat nystagmus in posterior canal benign paroxysmal positional vertigo 134

PP1-41 - Relationship between clinical features and therapeutic approach in benign BPPV outcomes 134

PP1-42 - Residual dizziness after repositioning in BPPV with preexisting central neurologic disorders 135

PP1-43 - The discussing between premier solution of Roll Test and Dix-Hallpike Test inBPPV 135

PP1-44 - Trial of a two-item questionnaire for identifying patients with Benign Paroxysmal Positional Vertigo 136

PP1-45 - TRV Chair For Diagnosis and Treatment of BPPV 136

PP1-46 - Use of the Brny Society criteria to diagnose benign paroxysmal positional vertigo 137

PP1-47 - Utility of Bow and Lean Test in Predicting Subtype of Benign Paroxysmal Positional Vertigo 137

PP1-48 - Vitamin D deficiency and Benign Paroxysmal Positional Vertigo recurrence. 138

PP1-49 - Cogans syndrome: An autoimmune inner ear disease 138

PP1-50 - Etiology analysis and vestibular assessment of bilateral vestibulopathy 138

PP1-51 - Frequency properties of postural sway in bilateral vestibulopathy and somatosensory disorder 139

PP1-52 - Impact of Bilateral Vestibulopathy on Spatial and non-Spatial Cognition: a Systematic Review 139

PP1-53 - Progressive central and peripheral vestibulopathy in superficial siderosis 140

PP1-54 - Are gonadal hormones involved in the pathophysiology of Mal de Debarquement Syndrome? 141

PP1-55 - Central Positional Vertigo 141

PP1-56 - Dissociation between semicircular canals and saccular function in Machado-Joseph Disease 142

PP1-57 - Evaluation of gravitational recognition in patients with spinocerebellar degeneration 143

PP1-58 - Long term observation of slow saccades and caloric response in a SCA2 patient 143

PP1-59 - Metabolic and Visuospatial Memory Function Changes in Transient Mal de Debarquement Syndrome 144

PP1-60 - Nystgamus and vestibular loss in autoimmune and paraneoplastic ataxia syndromes 144

PP1-61 - Positional tests under Videonistagmography for Central Positional Vertigo Diagnosis 145

PP1-62 - Subjective visual vertical in typical Alzheimer’s disease and posterior cortical atrophy 145

PP1-63 - The Semicircular Canal Coordinate System and Its Relation to Neural Circuits for Saccades 146

PP1-64 - Tumor size of vestibular schwannoma impair vestibular function and compensation 146

PP1-65 - Use of proprioception differentiates postural control in peripheral and central vestibular patients 147

PP1-66 - Vestibular dysfunction in Wernickes encephalopathy: selective impairment of the horizontal canals 147

PP1-67 - Visual fixation suppression of caloric nystagmus in progressive supranuclear palsy 148

PP1-68 - 3D analysis of VOR and spatial orientation during eccentric rotation while right ear downwards 148

PP1-69 - A normative study of the Dynamic Visual Acuity test, with comparison of two vertical test methods 149

PP1-70 - Analysis of the result of normal youth sinusoidal harmonic acceleration test by NKI rotation chair 149

PP1-71 - Anxiety, depression, and visual dependence assessment in neuro-vestibular physical therapy 150

PP1-72 - Balance and Eye Movement Responses to Electrical Vestibular stimulation in Vestibular Schwannoma 150

PP1-73 - Can HIT and oVEMP evaluate the superior vestibular nerve function in substitution for caloric test? 151

PP1-74 - Cervico-Ocular Reflex Induced by Manual stimulus of the Sternocleidomastoid Muscle: The First Report 151

PP1-75 - Clinical features of otolith organ-specific vestibular dysfunction 152

PP1-76 - Clinical study of the new three dimensional rotating equipment in vestibular function detection 152

PP1-77 - Clinical usefulness of dizziness diagnosis in the foam posturography analysis system 153

PP1-78 - Comparing the video Head Impulse to the Suppression Head Impulse as target distance is varied 153

PP1-79 - Comparison of video Head Impulse Test with Head Impulse Test and calorics: a retrospective study 154

PP1-80 - Comparison of video-head impulse, rotatory chair and bithermal caloric test in vestibular disease 154

PP1-81 - Development of real-time video-oculography using high quality infrared video Frenzel. 155

PP1-82 - Differences of VOR gain in the conventional head impulse test and the suppression head impulse test 155

PP1-83 - Effect of gaze direction on vertical VOR gain during the video head impulse test 156

PP1-84 - Effect of intratympanic gentamicin injection on lateral and vertical canals using HIMPs and SHIMPs 156

PP1-85 - Eliciting cVEMPs and oVEMPs from newborns through the elderly-a review 157

PP1-86 - Eye tracking during caloric nystagmus: a sensitive test to identify central vestibular disorder 157

PP1-87 - Functional Measure of Gaze Shifting in Healthy and Unilateral Vestibular Hypofunction Individuals 158

PP1-88 - Head Movement During Functional Gait Assessment Predicts Clinical Measures in Vestibular Patients 158

PP1-89 - High-frequency VOR in certain Hydropic Ear Disease 159

PP1-90 - Horizontal ocular deviation on brain MRI in acute vertigo patients 159

PP1-91 - How many sweeps are needed for Clincal OVEMP testing 160

PP1-92 - How well does clinical history correlate with results of vestibular assessment? 160

PP1-93 - Isolated posterior canal hypofunction on video-HIT: association with additional inner ear deficits 161

PP1-94 - New protocol to optimize ocular-VEMP stimulation and recording with High-Force Level Bone Conductors 161

PP1-95 - Non compensation in the vestibular patient 162

PP1-96 - Normal values of video-head impulse test for healthy people in different age 162

PP1-97 - Outcome prediction of sudden sensorineural hearing loss using neurotological tests 163

PP1-98 - Postural control, vestibular restoration and disability perception in vestibular neuritis 163

PP1-99 - Posturographic pattern of patients with peripheral vestibular dysfunction at vertigo interval period 164

PP1-100 - Preliminary results of video Head Impulse Testing (vHIT) in children with dizziness or vertigo 164

PP1-101 - Quantitative analysis of smooth pursuit eye movement by video-oculography (VOG) 165

PP1-102 - Relationship of Vestibulo Ocular Reflex and Gait in Patients with Vestibular Schwannoma 165

PP1-103 - Reliability of the Suppression Head Impulse Test and Role of Test Predictability 166

PP1-104 - Simultaneous recording of cervical and ocular vestibular-evoked myogenic potentials 166

PP1-105 - Splenius capitis: Target for the cVEMP in older and neurodegenerative patients 167

PP1-106 - Suppression head impulse paradigm in normal adults: values and parameters 167

PP1-107 - Systemic Aminoglycosides-Induced Vestibulotoxicity in Humans 168

PP1-108 - The analysis of the value ofspontaneous nystagmus in peripheral vestibular hypofunction. 168

PP1-109 - The diagnostic value of the bone-conduction cervical vestibular evoked myogenic potentials (cVEMP) 169

PP1-110 - The Role of Predictability in the Suppression Head Impulse Test 169

PP1-111 - The use of virtual reality in the assessment BPPV-related otolithic dysfunction a pilot study. 170

PP1-112 - Updated screening tests of balance for vestibular disorders 170

PP1-113 - Variacin del dhi en pacientes de rehabilitacion vestibular, independientemente de la patologa 171

PP1-114 - Variation of v-hit in patients with vestibular neuritis pre and post treatment. 171

PP1-115 - VEMP characteristics of vestibular paroxysm 172

PP1-116 - VEMP using a new low frequency bone conduction transducer 172

PP1-117 - Vestibular function in children with congenital cytomegalovirus infection: A two-year follow-up 173

PP1-118 - Vestibular Infant Screening-Flanders (VIS-Flanders): the start of an exciting project. 173

PP1-119 - Vestibular testing results in a world-famous extreme tightrope walker 174

PP1-120 - VHIT and the influence of daily use of spectacles to correct a refractive error 175

PP1-121 - vHIT using a smart phone. 175

PP1-122 - VVOR and VORS tests as a tool in the diagnosis of unilateral and bilateral vestibular hypofunction 175

PP1-123 - Assessment of horizontal semicircular canal after cochlear implantation by vHIT and caloric test 176

PP1-124 - Assessment of the otolith function of the cochlear implant surgery using eccentric rotation test 176

PP1-125 - Correlation between hearing and vestibular function preservation after cochlear implantation 177

PP1-126 - Effects of Cochlear Implantation on Visual, Postural and Haptic Verticality Perceptions 177

PP1-127 - Intra-cochlear Figuration of Implant Electrodes using Synchrotron Phase Contrast Imaging 178

PP1-128 - Long term effects of cochlear implantation on vestibular evoked myogenic potentials 179

PP1-129 - Long-term evaluation of the vestibular function after cochlear implantation(CI) in children 179

PP1-130 - The Effect of Cochlear Implant on Postural Control 179

PP1-131 - A questionnaire for the patient with benign paroxysmal positional vertigo: a pilot study 180

PP1-132 - Epidemiology of acute isolated vertigo in an italian emergency department: a retrospective study 180

PP1-133 - Multicenter databanking in management of dizzy patients first results from the DizzyNet registry 181

PP1-134 - The prevalence of persistent tinnitus and dizziness in an elderly population in southern Taiwan 182

PP1-135 - Cognitive impairment in persistent postural-perceptual dizziness: working vs. non-working patients 182

PP1-136 - Dr 183

PP1-137 - Influence of Visual and Vestibular Hypersensitivity on Depersonalization/Derealization in Dizziness 183

PP1-138 - Persistent Postural-Perceptual Dizziness in the Light of New Diagnostic Criteria 184

PP1-139 - Selective serotonin reuptake inhibitor (SSRI) and vestibular function 184

PP1-140 - Sensory Organization Test Profile for Patients with Persistent Postural-Perceptual Dizziness 185

PP1-141 - Structure Changes of Superior longitudinal fasciculus in Persistent Postural-Perceptual Dizziness 185

PP1-142 - A study on auto-scoring algorithm for balance assessment 186

PP1-143 - Assessment of vestibular compensation in static posturography tests. 186

PP1-144 - Balance disorder of patients with Mnire’s disease: assessing with posturography and gait analysis 187

PP1-145 - Correlations between multiplane vHIT and balance control after acute unilateral vestibular deficit. 187

PP1-146 - Disordered gait pattern after craniocervical trauma a case study 188

PP1-147 - Dissociated objective and subjective stability in the elderly due to postural anxiety 188

PP1-148 - Does the sensory organization test discriminate between athletes and non-athletes? 189

PP1-149 - Effects of visuo-ocular state on vestibular-evoked behaviors during standing balance 189

PP1-150 - Evaluation of balance performance in vestibular loss patients using virtual reality system 190

PP1-151 - Influence of arteriosclerosis on balance function Data from Iwaki health promotion project 191

PP1-152 - Postural control instability caused by virtual reality 191

PP1-153 - Postural instability according to the Virtual Reality program 192

PP1-154 - Relationship between cognitive function and balance in a community-dwelling population in Japan. 192

PP1-155 - Spatiotemporal parameters and variability with changes in gait velocity in bilateral vestibulopathy 193

PP1-156 - Stabilogram of patients with otolithic vertigo 193

PP1-157 - The characteristics of balance sensory weight of sudden hearing loss with vertigo 194

PP1-158 - Episodic ataxia type 2 characterized by recurrent dizziness/vertigo: a report of four cases 194

PP1-159 - Genome-wide association study in downbeat nystagmus 195

PP1-160 - Molecular genetic studies of Familial Menieres disease: a systematic review 195

PP1-161 - Regenerative medicine for vestibular disorders 196

PP1-162 - Voltage-gated Ion Channels in the Developing Human Inner Ear 196

Exhibition and poster viewing (poster session 2) 197

PP2-1 - Auditory-Vestibular Integration at the Posterior Superior Temporal Gyrus and Posterior Insula Gyrus 197

PP2-2 - Imaging analysis of patients with Menieres disease treated with endolymphatic sac shunt surgery 197

PP2-3 - Multiplanar visualization of vestibular endolymphatic hydrops 198

PP2-4 - New strategy for diagnosis of Menieres disease using three dimensional MRI 198

PP2-5 - Progression of Hydrops in Meniere’s disease continues over time though the symptoms are relieved 199

PP2-6 - The Feasibility of MRI in the Differential Diagnosis of a patient with Acute Audiovestibular Loss 199

PP2-7 - Usefulness of intravital multi-photon microscopy in visualizing study of the scala media 200

PP2-8 - Antigen in the Endolymphatic Duct results in Chronic Hydrops and an Enlarged Endolymphatic Duct. 200

PP2-9 - Bilateral Meniere’s disease or autoimmune inner ear disease presenting to the Emergency Department 201

PP2-10 - Cervical and Ocular Vestibular-evoked Myogenic Potentials in Patients with Menieres Disease 201

PP2-11 - Clinical application of glycerol test with endolymphatic sac decompression in Meniere ‘s disease 202

PP2-12 - Clinical features of symptom and audiovestibular test for Menieres disease and vestibular migraine 202

PP2-13 - Delayed contrast 3-dimensional MRI and regional hydrops in Meniere’s disease and variants. 203

PP2-14 - Delayed effect and gain restoration after intratympanic gentamicin for Menieres Disease. 203

PP2-15 - Detecting endolymphatic hydrops with posterior tympanic medial wall Gd-DTPA delivery and 8 min-MRI 204

PP2-16 - Diagnostic Diversity of Acute Vestibular Syndrome with Negative Video Head Impulse Test 205

PP2-17 - Diagnostic Value of the Multifrequency Tympanometry in the Patients with Menieres Disease 205

PP2-18 - Discrepancies between vHIT and caloric tests in congenital and acquired endolymphatic hydrops 206

PP2-19 - Discrepancy between results of vHIT and those of caloric test in the cases with Menieres disease 206

PP2-20 - Dissociated vestibular tests result in patients with Menieres is not due to central dysfunction 207

PP2-21 - Eye Movement Response Patterns during vHIT in Menieres Disease or Migraine Related Vertigo 207

PP2-22 - Fn14 and NF-B underlying inflammation in peripheral blood mononuclear cells in Meniere disease 208

PP2-23 - Incidence of progression Into Mnires Disease from idiopathic sudden sensorineural hearing loss 209

PP2-24 - Intratympanic latanoprost for Menires - A randomized, double-blind, placebo-controlled study 209

PP2-25 - Low- & high-frequency VOR disparity may differentiate Menires disease from vestibular migraine 210

PP2-26 - Menire and friends: Classification of Hydropic Ear Disease 210

PP2-27 - Menires disease: combined pharmacotherapy with betahistine and the MAO B inhibitor selegiline 211

PP2-28 - P.M34T variant on GJB2 gene associated to familial deafness and Ménières disease 211

PP2-29 - Pressure therapy of intractable Menieres disease using transtympanic membrane massage device. 212

PP2-30 - Prognostic value of glycerol test of ECochG in patients undergoing sac decompression surgery 212

PP2-31 - Pure-tone follow-up study of Meniere’s disease 213

PP2-32 - Revision surgery after triple semicircular canal plugging 214

PP2-33 - The Detection of Endolymph Hydrops in the Patients using a Multifrequency Tympanometry 214

PP2-34 - The Effect of Intratympanic Dexamethasone for Sudden Sensorineural Hearing Loss 215

PP2-35 - The effect of transtympanic ventilation tube insertion in people with intractable 215

PP2-36 - The effect of transtympanic ventilation tube insertion in people with intractable Meniere’s disease 215

PP2-37 - The importance of temporal 3T MRI in the diagnostics of menieres disease in Lithuania 216

PP2-38 - Treatment for intractable delayed endolymphatic hydropstriple semicircular canal plugging 216

PP2-39 - Unilateral Menieres disease with downbeat nystagmus in 2 cases 217

PP2-40 - Vertical nystagmus during attacks of menieres disease or delayed endolymphatic hydrops. 217

PP2-41 - Vertigo and istamine: atopic reactions and histamin intolerance (HIT) 217

PP2-42 - Vestibular findings in patients with persistent apogeotropic nystagmus 218

PP2-43 - A Case of Pendular Nystagmus: Delayed onset congenital nystagmus or acquired form by head trauma 218

PP2-44 - An Algorithm as a Diagnostic Tool for Central Ocular Motor Disorders 219

PP2-45 - Living in the dark: self-induced visual deprivation leading to pendular nystagmus. 219

PP2-46 - Long-term course of progression of clinical ocular motor signs in progressive supranuclear palsy 220

PP2-47 - Rebound nystagmus, a window to the oculomotor integrator 221

PP2-48 - Vertical Component of Horizontal Nystagmus due to Impairment of Vertical Semicircular Canals 221

PP2-49 - Two case reports of perilymphatic fistula after nose blowing with review of possible mechanisms 222

PP2-50 - A prospective study of Cochlin-tomoprotein detection test in sudden sensorineural hearing loss cases 222

PP2-51 - Proposal of the diagnostic criteria for barotraumatic perilymph fistula (PLF) 223

PP2-52 - Oxidative stress in leukoaraiosis dizziness patients, effect of a polyphenol supplementation 223

PP2-53 - Acute topographical disorientation due to right-sided hippocampal haemorrhage 224

PP2-54 - Astronauts Gaze Behavior during Visual Target Acquisition during and after Space Shuttle Flights 224

PP2-55 - Body-based spatial reasoning selectively disrupted by vertigo after a decelerating velocity step 225

PP2-56 - Changes in Heart Rate Variability due to Continuous Stimulation in the Head with a mini-Vibrator 225

PP2-57 - Comparison of Haptic and Visual Perception of Upright and the Effect of Handedness 226

PP2-58 - Cortical integration of vestibular and visual inputs during forward self-motion 226

PP2-59 - Effects of space perception on unilateral vestibular loss mice 227

PP2-60 - Effects of vestibular disorders on vestibular reflex and imagery 227

PP2-61 - Impact of alcohol on self-motion perception and reflexive eye movements: the role of the cerebellum 228

PP2-62 - Subjective cognitive dysfunction in patients with dizziness and vertigo 228

PP2-63 - Treatment of Mal de Debarquement Syndrome (MdDS) by readaptation of the vestibuloocular reflex (VOR) 229

PP2-64 - Vestibular Function and Hippocampal Volume in the Baltimore Longitudinal Study of Aging 229

PP2-65 - Visual dependency in spatial orientation: The effect of body tilt and hemispheric lateralization 230

PP2-66 - Visual gravitational motions affect estimation of subjective visual vertical (SVV). 230

PP2-67 - A diagnostic dilemma: beyond high resolution computed tomography (CT) scan, thinning versus fistula. 231

PP2-68 - Aggregating the symptoms of superior semicircular canal dehiscence syndrome. 231

PP2-69 - Correlation of neuroradiological and post-mortem autopsy findings in SCDS 232

PP2-70 - Fremitus Nystagmus - a simple and objective clinical sign for SCDS 232

PP2-71 - Hearing eyeball and/or eyelid movements on the side of a unilateral superior canal dehiscence 233

PP2-72 - Improving the Specificity of VEMP testing in Superior Canal Dehiscence: Trial by oVEMP 233

PP2-73 - Management of Dehiscences Involving Superior Canal and Tegmen 234

PP2-74 - New issues within the third windows spectrum abnormalities impacting diagnosis and treatment. 234

PP2-75 - Ocular Vestibular Evoked Myogenic Potential Waveform Morphology: Signs of Superior Canal Dehiscence 235

PP2-76 - Outcome of surgical plugging in superior canal dehiscence syndrome 236

PP2-77 - Vestibular suppression of normal bodily sounds 236

PP2-78 - VOG and VEMPs in Superior Semicircular Canal Dehiscence and Perilymfatic Fistula 237

PP2-79 - Mild blast wave leads intensity-dependent sequential changes in MMP2 expression in rat brains 237

PP2-80 - Temporal bone fracture in acute traumatic brain injury: Vestibular consequences 238

PP2-81 - The utility of the Sports Concussion Assessment Tool in hospitalized traumatic brain injury patients 238

PP2-82 - Vestibular and optokinetic responses in post-concussive syndrome 239

PP2-83 - Why is routine vestibular screening not undertaken by trauma ward staff? A qualitative study 239

PP2-84 - Acute dizziness/vertigo in the telestroke network TEMPiS: frequency and telemedical decision making 240

PP2-85 - Canal and otolith test characteristics in vestibular neuritis and posterior circulation stroke 240

PP2-86 - Diagnosing dizziness of vascular origin: are there safer options than arteriography? 241

PP2-87 - Eye movements and vestibular function in patients with posterior circulation infarction 241

PP2-88 - HINTS vs ABCD2 to predict cerebrovascular cause in acute vestibular syndrome patients at the ED 242

PP2-89 - Transient vertigo preceding vestibular neuritis 242

PP2-90 - A novel study on the relationship between dizziness or vertigo symptoms and nystagmus intensity 243

PP2-91 - Efficiency of non-invasive cooling of the vestibular system 243

PP2-92 - Impact of visual stimuli on cervical vestibular evoked myogenic potentials (cVEMPs) 244

PP2-93 - Is there any difference between clockwise and counter clockwise dynamic subjective visual vertical? 244

PP2-94 - Pulsed infrared vestibular stimulation: evoked eye movement and cardiovascular responses 245

PP2-95 - The Activity of Vestibular Pukinje Cells is Attenuated During Self-Generated Head Movements 245

PP2-96 - Case study: benefits of integrated vestibular rehabilitation in neurosarcoidosis 246

PP2-97 - Case study: Reduction of intercranial hypertension-induced vestibular symptoms 246

PP2-98 - Case study: Resolution of centrally maintained vestibular symptoms secondary to BBPV 247

PP2-99 - Do sinusoidal gaze stabilising exercises result in adaptation of the transient (head impulse) VOR? 247

PP2-100 - Efficacy of vestibular rehabilitation exercises in acute unilateral peripheral vestibulopathy 248

PP2-101 - HTC Vive to improve balance and dizziness in unilateral peripheral hypofunction: 2 case reports 248

PP2-102 - Impact of Vestibular Rehabilitation on Patients with Chronic Vestibular Hypofunction 249

PP2-103 - Is Static Acuity Pre-requisite for Dynamic Visual Acuity: Case Series Failed Vestibular Rehab 249

PP2-104 - Manifestation and Prognostic Factors of Dizziness due to Long-Term Use of Vestibular Suppressant 250

PP2-105 - Noisy galvanic stimulation improves vestibular perception 250

PP2-106 - PEDIATRIC VESTIBULAR REHABILITATION: A CASE STUDY 251

PP2-107 - Prognosis after Acute Unilateral Vestibulopathy: the importance of video Head Impulse Test. 251

PP2-108 - Smartphone-based Virtual Reality Vestibular Therapy App for Motion Sickness 252

PP2-109 - Subsensory Neuromodulation Improves Vestibular Function in Bilateral or Unilateral Hypofunction 252

PP2-110 - The effect of consolidation on human vestibulo-ocular reflex adaptation and retention. 253

PP2-111 - The role of physiotherapy in managing vestibular migraine: A critical literature review 253

PP2-112 - Therapy of impaired upright body orientation using a 3D device 254

PP2-113 - Training time affects human vestibulo-ocular reflex adaptation. 254

PP2-114 - Changes CGRP serological parameters in patients with vestibular migraine 255

PP2-115 - Clinical characteristics of vestibular migraine based on Barany diagnostic criteria 255

PP2-116 - Differences between patients who have vestibular migraine and those who migraine only 256

PP2-117 - Do the inflammatory factors contribute to the pathogenesis of vestibular migraine? 256

PP2-118 - Is it possible to differentiate vestibular migraine from Meniere’s disease neurophysiologically? 257

PP2-119 - Postural instability evoked by visual motion stimuli in patients with vestibular migraine 257

PP2-120 - The differences of clinical characteristics between Vestibular migraine and Meniere’s Disease 258

PP2-121 - The Research of Cognitive Change and Imaging Features in patients with (vestibular) migraine 258

PP2-122 - Unique findings of video head impulse test during the ictal period of vestibular migraine 259

PP2-123 - Vestibular Migraineurs journey from symptom to diagnosis; long frustrating and often disappointing 259

PP2-124 - VHIT in Vestibular migraine - Overt and covert saccades with increased gain. 260

PP2-125 - Diagnosing peripheral vestibular dysfunction by assessing 3D body tracking via Kinect v2 260

PP2-126 - Diplopia from skew deviation in peripheral vestibulopathy 261

PP2-127 - Disability and neuritis, prognostic factors 261

PP2-128 - Functional MR Spectroscopy of the Primary vestibular Cortex in Patients with vestibular neuritis 261

PP2-129 - Genome-wide Association Study in Vestibular Neuritis 262

PP2-130 - Steroids for acute vestibular neuronitis - the earlier the treatment, the better the outcome? 262

PP2-131 - The clinical efficacy of vestibular function tests in patients with acute peripheral vestibulopathy 263

PP2-132 - Vestibular function features and prognosis of vestibular neuritis in children 263

PP2-133 - Video Head Impulse Test and Cervical Vestibular Evoked Myogenic Potential in Vestibular Neuritis 264

PP2-134 - Controlled postural responses upon electrical stimulation with a vestibular implant in humans 264

PP2-135 - Effects of long-term noisy vestibular stimulation on body balance in bilateral vestibulopathy 265

PP2-136 - Immediate efficacy of Gufoni maneuver for HC-BPPV: a meta-analysis 265

PP2-137 - A Novel Tele-Dizzy Consultation Program in the Emergency Department using Portable Video-oculography 266

PP2-138 - A Retrospective Study of a Multidisciplinary Chronic Dizziness Clinic and an Acute Dizziness Clinic 267

PP2-139 - Brain tissue volume changes in astronauts after six months of exposure to microgravity 267

PP2-140 - Central Vestibular Sensitivity affects Motion Sick Susceptibility through the Velocity Storage. 268

PP2-141 - Challenge and Limitation of the Emergent Care of Dizziness in a Hospital without Specialists 268

PP2-142 - Clinical characteristics of 26 cases with recurrent low frequency sensorineural hearing loss 269

PP2-143 - Cobalt-induced ototoxicity from metal-on-metal hip prostheses: preliminary results 269

PP2-144 - Description of otoneurological findings in peripuberal females 270

PP2-145 - Direct Observational Procedural Skills in Otolaryngology Training 271

PP2-146 - Distorted own-body representations and out-of-body experience in 350 patients with dizziness 271

PP2-147 - Dizziness related to patulous eustachian tube 272

PP2-148 - EEG Correlates of Postural Control and Balance 272

PP2-149 - Etiologic evaluation and risk factor profile of childhood hearing loss 273

PP2-150 - Influence of vestibular stimulation on executive functions 273

PP2-151 - Influence of vestibular stimulation on phantom limb pain after supracondylar amputation 274

PP2-152 - Interaction between Vestibulo Ocular Reflex and Optokinetic Nystagmus in virtual reality worlds 274

PP2-153 - Mastoid Obliteration with Middle Temporal Artery and Inferior Musculoperiosteal Flaps 275

PP2-154 - Metabolic syndrome among patients with different type of peripheral vestibular vertigo 275

PP2-155 - Predictive capability of an iPad based medical device for the diagnosis of vertigo and dizziness 276

PP2-156 - Prevalence of and factors related to mild and substantial dizziness in older adults 276

PP2-157 - Recovery of Ocular and Cervical Vestibular Evoked Myogenic Potentials after Vertigo Attacks 277

PP2-158 - Sub-clinical symptoms of postural-perceptual dizziness are associated with general sensory avoidance 277

PP2-159 - The central nervous system complications accompanied by Ramsay-Hunt syndrome 278

PP2-160 - The ototoxic effect of cisplatin on vestibular hair cells in vitro 278

PP2-161 - Vestibular Neuropathy in Auditory Neuropathy: Detected by Vestibular Evoked Myogenic Potentials 279

PP2-162 - Vestibular Symptoms and Function in Veterans with Post Traumatic Stress Disorder 279

PP2-163 - Voluntary eye closure disrupts the vestibulo-ocular response to head rotation in man and monkey 280

PP2-164 - Walking to the Toilet in Impatient with Vertigo (5th report)-An Evaluation Using the DHI 280

PP2-165 - When on earth a patient with congenital nystagmus experiences oscillopsia? -A case report- 281

OP01-1 - Role of oVEMP and cVEMP tests in relation to oscillopsia

7. Clinical Testing for Vestibular Function

Shuo-Yen Hsu¹

Yi-Ho Young¹

¹ Department of Otolaryngology, National Taiwan University Hospital, Taiwan

Purpose: The term oscillopsia means a symptom of jumbling eye movements, manifested as blurred vision when walking or running. It occurs primarily from loss of vestibulo-ocular reflex (VOR) or ocular oscillations. This study investigated whether ocular and cervical vestibular-evoked myogenic potential (oVEMP and cVEMP) tests related to the occurrence of oscillopsia.

Methods: From 2012 to 2017, 26 patients with caloric areflexia on both ears underwent dynamic visual acuity (DVA) test subsequently. Half of them who had oscillopsia and failed to pass the DVA test were assigned to Group A, including 9 males and 4 females, with mean age of 67 years. The remaining 13 patients without oscillopsia and passed the DVA test were assigned to Group B, consisting of 5 men and 8 women, with mean age of 64 years.

Results: Groups A and B did not significantly differ in the abnormality rates of pursuit, saccade, optokinetic nystagmus, and caloric tests. Likewise, Romberg quotients of sway area on foam posturography were 1.96 and 2.36 in Groups A and B, respectively, exhibiting non-significant difference. For the oVEMP test, 81% vs. 85 % abnormalities, no significant difference was identified between the two groups. However, Group A (96%) had significantly higher cVEMP abnormality than Group B (65%).

Conclusions: In patients with VOR loss, oscillopsia may occur depending on whether compensatory eye movements arise or not. In such condition, presence of cVEMP, but not oVEMP, may help compensate VOR loss via cervico-ocular reflex.

OP01-2 - Ocular and cervical VEMPs to air conducted sound and bone conducted vibration in Meniere’s Disease

7. Clinical Testing for Vestibular Function

Leonardo Manzari¹

Maria Sofia Manzari¹, Domenico Graziano¹, Giulio Dehesh¹

¹ MSA ENT ACADEMY CENTER CASSINO

Purpose: In definite Meniere’s Disease, to investigate Air Conducted Sound and Bone Conducted Vibration results in cervical evoked myogenic potentials recorded over contracted SCM and ocular evoked myogenic potentials recorded beneath both eyes while the subjects is looking up

Methods: 50 definite Meniere’s Disease were tested at MSA ENT clinic in Cassino (Italy) using a hand-held Bruel & Kjaer 4810 minishaker for BCV stimulation. Surface EMG electrodes beneath both eyes were used, to record oVEMP n10 and over SCM, to record cVEMP p13-n23. The stimulus BCV at Fz of the skull were tone bursts at 500 Hz, the stimulus ACS were tone bursts at 500 – 750 and 1000 Hz. 40 healthy subjects were tested in the same paradigm.

Results: In 50 patients with Meniere’s Disease, the n10 responses to ACS and Fz BCV showed results that appear to show dissociation between ACS and BCV stimulation.In response to ACS stimuli MD patients showed aberrant results; i.e. in some patients there was no detectable oVEMP n10 to 500Hz ACS, although oVEMP n10 was clearly present to 500Hz Fz BCV stimulation. ACS p13 – 23 to 500 Hz – 750 Hz – 1000 Hz are absent or reduced over the ipsilateral SCM. This may reflect a change in frequency tuning to ACS stimuli since the n10 to ACS stimulation was absent to 500Hz but present to 750Hz (mainly) or 1000 Hz.

Conclusions: The dissociation between the results to BCV as opposed to ACS stimulation may be due to changes in the endolymph volume. These results are due also to different route of stimulation.

OP01-3 - Eliciting ocular VEMPs by first order bone vibration and second order resonance effect

7. Clinical Testing for Vestibular Function

Kuei-You Lin¹

Te-Huei Yeh², Fu-Shan Jaw³, Yi-Ho Young²

¹ Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan; Department of Otolaryngology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan

² Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan

³ Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan

Purpose: This study investigated ocular vestibular-evoked myogenic potential (oVEMP) tests via Fpz and Fz taps to assess the role of the frontal sinus in mediating oVEMP elicitation.

Methods: Forty healthy subjects and 80 patients with Meniere’s disease (MD) underwent a series of oVEMP tests via a minishaker tapping at the Fpz and Fz sites in a randomized order. Response rates of oVEMP test via various tapping sites were compared. Dimensions of the frontal sinus were measured via CT scan.

Results: A significantly negative correlation between the age and height of the frontal sinus was noted, and the cutoff age for discriminating present and absent Fpz oVEMPs in MD patients was 52 years. Additionally, oVEMPs by Fpz tapping were more efficiently presented in males than females, likely because of greater resonance by the larger height of the frontal sinus in males (3.88 ±0.68 cm) than females (3.42 ±0.67 cm).

Conclusions: The height of the frontal sinus acts in mediating the elicitation of oVEMPs. The oVEMPs could be easily elicited by the first order bone vibration (Fpz/Fz tapping) coupled with the second order resonance effect (a high extent of frontal sinus). Thus, initial tapping at the Fpz site is suggested. If it fails, try the Fz site for screening the oVEMPs.

OP01-4 - Temporal Dynamics of Eye Movements Elicited by Combined Otolith and Semicircular Canal Stimulation

26. Vestibular Prosthesis

Margaret Chow¹

Kristin Hageman¹, Dale Roberts², Charles Della Santina²

¹ Johns Hopkins School of Medicine, Department of Biomedical Engineering, USA

² Johns Hopkins School of Medicine, Department of Otolaryngology - Head and Neck Surgery, USA

Purpose: Efforts to develop a vestibular prosthesis have primarily focused on stimulation of the SCCs; however, the otolith end organs encode head movements with different kinematics and different temporal dynamics. We examined the temporal dynamics of eye movements evoked by individual and combined stimulation of electrodes in SCCs and otolith end organs.

Methods: We fit three chinchillas with head posts and binocular scleral coils for tracking 3D eye movements. We implanted a polyimide vestibular electrode array with 26 otolith and 24 SCC contacts into the left ear. Bipolar current pulses were delivered while the animals were kept still in dark, driving electrically evoked eye movements. Eye movements were recorded during a constant pulse train (encoding a virtual static tilt) delivered via multiple electrode configurations.

Results: The temporal dynamics to reach the final ocular counter-roll position during a virtual static tilt depended on location of the stimulating/reference electrodes. Stimulation with a otolith/distant reference combination resulted in quick onset of eye movement (consistent with the SCCs’ high pass characteristic). Otolith/near reference stimulation resulted in a slower rise-time to final ocular counter-roll position (consistent with the otolith’s low pass characteristic). Combining SCC and otolith stimulation resulted in an eye response like that of a mechanical static head tilt in a normal animal.

Conclusions: Responses differed in temporal dynamics for SCC and otolith stimulation. These results indicate that semi-selective prosthetic stimulation of the otolith end organs is possible and that it may be necessary to restore sensation of low frequency head motion and static tilts.

OP01-5 - Altered soleus VEMP may be a prognostic marker of progressive spinal cord damage

7. Clinical Testing for Vestibular Function

Julia Caporali¹

Anna Paula de Avila Pires², Ludimila Labanca³, Tatiana Rocha⁴, Kyonis Florentino⁴, Denise Utsch Goncalves⁵

¹ Federal University of Minas Gerais, Medical Clinics Department, Brazil

² Federal University of Minas Gerais, Brazil

³ Federal University of Minas Gerais, Audiology and Speech Therapy department, Brazil

⁴ Federal University of Minas Gerais, Graduation Program of Infectology and Tropical Medicine, Brazil

⁵ Federal University of Minas Gerais, Otorhinolaryngology department, Brazil

Purpose: Human T-cell leukemia virus type 1 (HTLV-1) infection causes a spastic paraparesis in around 5% of the HTLV-1-asymptomatic carriers. The purpose was to prospectively investigate the postural reflex of HTLV-1-infected individuals.

Methods: VEMP recorded from the soleus muscle (Soleus-VEMP) triggered by galvanic stimulation (duration: 400ms; intensity: 2mA) was annually applied for three consecutive years in 16 patients with definite HTLV-1-associated myelopathy (HAM), 22 with non-definite (oligosymptomatic) HAM and 20 HTLV-1-asymptomatic carriers. Galvanic stimulation was used to trigger the postural reflex through the vestibulospinal tract. The stimulus was applied in the mastoid processes and VEMP was recorded in the soleus muscle. The outcome analyzed was a changing in Soleus-VEMP from normal to altered.

Results: At baseline, 30% of the HTLV-1-asymptomatic carriers showed altered soleus-VEMP comparing to 55% in non-definite HAM and 75% in definite HAM (p=0.03). After a follow-up of three years, altered soleus-VEMP was 80% in the HTLV-1-asymptomatic carriers, 95% in the olygosymptomatic and 100% in HAM (p=0.26). The comparison of Kaplan-Meier survival curves between groups showed no statistical difference (p=0.13).

Conclusions: High prevalence and incidence of postural reflex alteration were found not only in patients with HAM, as expected, but more importantly, in HTLV-1-asymptomatic carriers, indicating subclinical impairment of spinal cord function. These results indicated a considerable portion of HTLV-1-asymptomatic carriers that are classified as normal despite of a subclinical impairment of neurological function. The follow-up will clarify the risk of the asymptomatic carriers with altered soleus-VEMP to progress to definite HAM. The subclinical diagnosis of the myelopathy has therapeutic implications.

OP01-6 - The clinical significance of waveform morphology in OVEMP testing

7. Clinical Testing for Vestibular Function

Art Mallinson¹

Neil Longridge¹

¹ University of British Columbia, Department of Surgery; Vancouver General Hospital, Vancouver, CANADA

Purpose: The OVEMP is a very delicate low amplitude reflex. Normal subjects have normal OVEMP amplitudes and latencies, but also very well-defined wave morphology. Some patients have “normal” OVEMP parameters but poor waveform morphology, where OVEMPs have an identifiable peak and trough but these are not well defined. We wondered what the meaning was of poor waveform morphology and wondered if it is clinically relevant. We hypothesize that the utricle (i.e. a loosely fixed vibration sensor) may be susceptible to decelerative trauma or other insult. Since the OVEMP is generated by a properly functioning utricle, it follows that a dysfunctional utricle may be able to produce a waveform, but poor morphology due to insult and normal latency. One difficulty with reporting OVEMP amplitudes is that there is a floor effect; there is no such thing as a “low amplitude”. We wondered if trauma to the otolith might prevent proper generation of the waveform. It follows that poor waveform morphology might be a significant observation (regardless of other measured parameters).

Methods: We compared OVEMP results in three groups; patients who had suffered trauma, “regular” vestibular patients, and normal controls. We defined what we called “poor morphology” of OVEMPs, and we looked at the rate of poor morphological waveforms in each group.

Results: It appears that (as is the case with caloric testing) poor morphology does not infer any difference in clinical disease

Conclusions: poor waveform morphology may repesent a clinically significant finding but this significance is as yet not understood.

OP01-7 - The effects of different sound stimuli when performing OVEMPs

7. Clinical Testing for Vestibular Function

Neil Longridge¹

Art Mallinson²

¹ University of British Columbia, Department of Surgery; Vancouver, CANADA

² University of British Columbia, Department of Surgery; Vancouver General Hospital, Vancouver, CANADA

Purpose: We hypothesized that OVEMP reflexes generated by a sound stimulus represent an aphysiological supramaximal intermittent nonspecific response of the maculae of the inner ear to sound stimulation. Care in interpreting results from vibration and sound stimulation has to be undertaken, as the differing results means that with any particular type of stimulus, normative data must be established.

Methods: We used different sound stimuli when performing OVEMPs. Assuming that the supramaximal response is universal, use of sound stimuli at different frequencies, .25, .5, .75 and 1.0 KHz should produce identical responses.

Results: This hypothesis was tested and failed. There was variation in amplitude and latency with respect to the different frequency stimulations at the same decibel loudness.

Conclusions: The physical stimulus for vibration is much stronger than direct cochlear stimulation in terms of energy, and not surprisingly vibration VEMPs are frequently recorded while sound VEMPs are abnormal. The absence of sound VEMPs in a patient with symptoms probably is clinically significant, and caution in inferring that because vibration VEMPs are normal, abnormal sound VEMPs can be ignored. As always, a pathological finding (more than two standard deviations from the normal by ay technique) is significant, a normal response does not mean nothing wrong, and the diagnosis of disease depends on the history.

Variation of response indicates that the maculae responds to strong stimulus and is specific to the stimulus. The organ does not respond as a whole but vibrates variably depending on the stimulus and the neural responses are consistent and specific.

OP02-1 - Cervical and ocular VEMPs to 4000Hz show Superior Semicircular Canal Dehiscence

19. Superior Canal Dehiscence Syndrome

Leonardo Manzari¹

Ann M. Burgess², Ian S. Curthoys²

¹ MSA ENT Academy Center – Cassino, Italy

² Vestibular Research Laboratory, School of Psychology, the University of Sydney, NSW, Australia

Purpose: In patients with CT-verified SSCD and in patients with definite Meniere’s Disease (MD) to investigate the effect of frequency on the n10 component of the ocular vestibular-evoked myogenic potential (oVEMP n10) and on the p13-n23 component of the cervical vestibular-evoked myogenic potential (cVEMP p13-n23) evoked by air conducted sound (ACS) and bone conducted vibration (BCV) at the midline forehead at the hairline (Fz).

Methods: A hand-held Bruel & Kjaer 4810 minishaker provided BCV stimulation and surface EMG electrodes beneath both eyes recorded oVEMP n10 and over SCM recorded cVEMP p13-n23 . The stimulus ACS and BCV at either Fz or at the vertex of the skull (Cz) were tone bursts at 500Hz or 4000Hz with a short rise time (ramp). 27 healthy subjects were tested in the same paradigm.

Results: In response to ACS and Fz BCV at 500 Hz and 4000 Hz in 27 CT-verified SSCD patients the oVEMP n10 beneath the contraSSCD eye was present and the cVEMP p13 – n23 over the ipsi SSCD sternocleidomastoid muscle was also present. In contrast in normals and Meniere’s Disease patients neither oVEMPs or cVEMPs to 4000Hz are present with either ACS or Fz BCV.

Conclusions: Testing cVEMP and oVEMP with high frequency ACS or BCV allows very simple, very fast identification of a probable unilateral SSCD in a manner which is very easy even for junior and senior patients and testing only uses two frequencies, 500 Hz and 4000 Hz.

OP02-2 - Efficacy of vestibular function tests post-canal plugging for superior canal dehiscence syndrome

19. Superior Canal Dehiscence Syndrome

Yvette Reid¹

Jane Lea², Brian Westerberg²

¹ Providence Health Care, Department of Audiology, Canada

² University of British Columbia, Department of Surgery – Division of Otolaryngology Head And Neck Surgery, Canada

Purpose: Dizziness and balance dysfunction is expected temporarily after surgically plugging the superior canal as a treatment for superior canal dehiscence syndrome (SCDS). However, some patients experience residual symptoms even months after surgery. Our aim was to assess the efficacy of vestibular function tests in evaluating surgery outcomes.

Methods: We retrospectively reviewed six patients with residual symptoms after canal plugging surgery. Subjects underwent audiometry, cVEMPs, oVEMPs, vHIT as well as MRI with reconstruction of the superior canal.

Results: MRI imaging demonstrated a persistent dehiscence post-operatively for all six patients. Five subjects with pre-operative air-bone gaps still had air-bone gaps post-operatively. Low threshold cVEMP present in all six ears pre-operatively normalized in four. VEMP asymmetry ratios could only be assessed in three patients with unilateral SCDS. For these three subjects, the cVEMP asymmetry ratio range dropped from 32-45% pre-operatively to 10-21% post-operatively. In the one subject with pre- and post-operative oVEMPs, the asymmetry ratio dropped from 41% to 1%. Four subjects had post-operative vHITs; two had normal gain (0.81 and 0.83) and two abnormal (0.41 and 0.46).

Conclusions: VEMP thresholds and asymmetry ratios often normalize even after incomplete canal plugging. The vHIT results are also not representative of surgery outcomes. The measure that was consistently abnormal after an incomplete plugging surgery was the air-bone gap on the audiogram; however, other studies have demonstrated that the air-bone gap often persists even with successful plugging surgery. Patient complaints and MRI appear to be the best way to assess the outcomes of SCD repair surgery.

OP02-3 - Heterogeneity in Reported Outcome Measures after Surgery in Superior Canal Dehiscence Syndrome

19. Superior Canal Dehiscence Syndrome

Mira Ossen¹

Robert Stokroos², Herman Kingma², Joost van Tongeren², Vincent Van Rompaey³, Yasin Temel⁴, Raymond van de Berg²

¹ Faculty of Medicine, Maastricht University, Maastricht, Netherlands

² Department of Otorhinolaryngology and Head & Neck Surgery, Maastricht University Medical Center, Maastricht, Netherlands

³ Department of Otorhinolaryngology and Head & Neck Surgery, Antwerp University Hospital, Edegem, Belgium

⁴ Department of Neurosurgery, Maastricht University Medical Center, Maastricht, Netherlands

Purpose: To assess available evidence on the comparative effectiveness and risks of different surgical treatments for superior canal dehiscence syndrome (SCDS), regarding: (1) symptom improvement; (2) objectively measurable auditory and vestibular function; (3) adverse effects; (4) length of hospitalization.

Methods: A systematic search according to PRISMA statement was conducted on Pubmed, Embase, and Cochrane library. Reference lists were searched. Retrospective and prospective cohort studies were included when they investigated the association between a surgical treatment method and the relief of vestibular and/or auditory symptoms. Only studies including quantitative assessment of the pre- to postoperative success rate of a surgical treatment method were included. Case reports, reviews, meta-analysis, and studies not published in English, Dutch, or German were excluded.

Results: Seventeen studies (354 participants, 367 dehiscences) were grouped according to surgical approach. Seven combinations of surgical approaches were identified: plugging, resurfacing, or a combination of both through the middle fossa (middle fossa approach); plugging, resurfacing, or a combination of both through the mastoid (transmastoid approach); round window reinforcement through the ear canal (transcanal approach). Several studies showed high internal validity, but quality was often downgraded due to study design. Outcome measures and timing of postsurgical assessment varied among studies, making it unfeasible to pool data to perform a meta-analysis.

Conclusions: A standardized protocol including outcome measures and timeframes is needed to compare the effectiveness and safety of SCDS treatments. It should include symptom severity assessments and changes in vestibular and auditory function before and after treatment.

OP02-4 - Management of hearing and balance problems in SCDS

19. Superior Canal Dehiscence Syndrome

Arne Ernst¹

Phillipp Mittmann², Dietmar Basta³

¹ Dept. Otolaryngology at ukb, Hospital of the Univ of Berlin (Charité)

² Dept. Otolaryngology at ukb (Berlin)

³ Dept. Otolaryngology at ukb, Charité (Berlin)

Purpose: SCDS is a disorder with varying symptoms. The management is complicated by the need to offer the patient a realistic outcome with either conservative or surgical measures.

Methods: In our prospective, non-randomized series, 52 patients (31 female, 21 male, average age 48.8 yr) with radiologically confirmed SCDS were counselled, 41 agreed to undergo a surgical therapy. The surgical therapy consisted of canal occlusion via a transmastoid approach. In addition, all patients were given a hearing implant (CI or VSB) for auditory rehab. The patients were followed up for 14 months (6 – 24 months) on average (DHI, neurotological testing- c/oVEMPs, excentric rotation, HIT and PTA).

Results: A positive outcome (n = 28, i.e. significant improvement in DHI, normalisation of cVEMP thresholds) was correlated to the severity of vertigo preoperatively, to the parallel implantation of a CI, to the age at implantation (younger than 45 yrs).

A negative outcome (n = 13; i.e., non-significant improvement in DHI, no normalization of cVEMP thresholds) was correlated to the co-morbidity of vestibular migraine and/or Menière’s disease, the bilateral occurrence of SCDS, SCDS defect size (larger than 4 mm), old age (55 yrs). In those 13 patients, 5 were revised which significantly improved the DHI outcome and led to a normalization of cVEMP amplitudes.

The 10 patients who declined surgery were treated by antivertiginous drugs, which lead to a reduction of vertigo, but no significant improvement in DHI.

Conclusions: In essence, canal occlusion in SCDS can be highly effective when considering co-morbidity and adding hearing implants for auditory rehab.

OP02-5 - Skull vibration induced nystagmus in patients with unilateral semicircular canal dehiscence

19. Superior Canal Dehiscence Syndrome

Georges Dumas¹

Alexis Lion², Ian Curthoys³, Philippe Perrin⁴, Laurent Dumas⁵, Sébastien Schmerber⁶

¹ Department of Oto-Rhino-Laryngology, Head and Neck Surgery, University Hospital, Grenoble, France

² Sports Medicine Research Laboratory, Luxembourg Institute of Health, L-1460 Luxembourg

³ Vestibular Research Laboratory, School of Psychology, the University of Sydney, NSW, Australia

⁴ EA 3450 DevAH, Development, Adaptation and Disadvantage, Faculty of Medicine and UFR STAPS, University of Lorraine, Villers-lès-Nancy, France

⁵ INSERM S 1039 Bioclinic-Radiopharmaceutics-Laboratory-Grenoble

⁶ INSERM BrainTec Lab UMR 1205; Grenoble, France

Purpose: bone conducted vibration applied to the mastoid in severe unilateral vestibular loss (SUVL) patients usually elicits a skull vibration induced nystagmus (SVIN) beating away from the affected side. In unilateral superior semicircular canal dehiscences (uSCD) SVIN beats toward the affected side. This study sought to establish the optimum stimulus frequency and location for these populations.

Methods: SUVL (n = 18); superior semicircular canal (SCD) patients (n= 40; 27 unilateral, 13 bilateral). The control group consisted of 11 cases.

Results: In SUVL, SVIN was always beating away from the lesion side and the optimal frequency was 100Hz for the horizontal and torsional components VIN-SPV. In uSCD SVIN beat toward the lesion side in 92%, a wider range of frequencies elicited SVIN (up to 800Hz) with optimal frequency being around 500Hz. In SUVL mastoid stimulation was significantly more efficient than vertex stimulation at 60 and 100Hz [p<0.01]. Conversely in uSCD SVIN SPV was significantly higher on vertex stimulation at 100 and 300Hz [p=0.04]. A VIN was significantly more often observed in uSCD than bSCD [p=0.009] and with a higher SPV [p=0.008]. In SUVL the optimal frequency is 100Hz and SVIN beats toward the intact side. In uSCD,

Conclusions: SVIN beats toward the lesion side with a greater sensitivity to higher frequencies. Vertex stimulations are more efficient in uSCD than in SUVL. SVINT reveals instantaneously a characteristic VIN and acts as a vestibular Weber test. It is more sensitive to reveal uSCD than bSCD. SVIN test should be considered as a useful indicator for uSCD diagnosis.

OP02-6 - Spontaneous plugging of superior canal: two possible natural evolutions of an unstable dehiscence

19. Superior Canal Dehiscence Syndrome

Andrea Castellucci¹

Cristina Brandolini², Gianluca Piras³, Valeria Del Vecchio², Giovanni Carlo Modugno², Angelo Ghidini⁴, Antonio Pirodda²

¹ 1. ENT & Audiology Unit, DIMES, Sant’Orsola – Malpighi University Hospital, Bologna, Italy. 2. ENT Unit, Department of Surgery, AUSL – IRCCS, Reggio Emilia, Italy.

² 1. ENT & Audiology Unit, DIMES, Sant’Orsola – Malpighi University Hospital, Bologna, Italy.

³ 1. ENT & Audiology Unit, DIMES, Sant’Orsola – Malpighi University Hospital, Bologna, Italy. 3. Department of Otology and Skull Base Surgery, Gruppo Otologico, Piacenza, Italy.

⁴ 2. ENT Unit, Department of Surgery, AUSL – IRCCS, Reggio Emilia, Italy.

Purpose: Besides third-mobile window symptoms/signs, superior canal dehiscence (SCD) can lead to unusual clinical pictures. As well as asymptomatic patients, Ménière-like attacks have been occasionally described though poorly explained. Moreover, while surgical occlusion of superior canal (SC) in symptomatic patients generally induces transient vestibulo-cochlear symptoms with a selective SC hypofunction, loss of SC function in patients with wide-sized dehiscence and poor symptomatology can be sporadically detected. A natural canal plugging by middle fossa dura (MFD) has been offered as possible interpretation for the latter scenario. We aimed to explain acquired spontaneous SC hypofunction with two possible theories.

Methods: Among patients who were followed-up for SCD, we reviewed clinical records of 3 cases who developed spontaneous impairment of SC function on video head impulse testing (vHIT) over time (mean follow-up 106 months). Audiometric, video-oculographic, vibratory, vHIT e VEMPs data were compared with post-operative (PO) findings of patients undergoing SC occlusion.

Results: While in 1 case progressive reduction of symptoms was reported, 2 patients developed recurrent vertigo spells (with auditory symptoms in 1 case) and spontaneous nystagmus similarly to surgical patients during the first PO days. Pure tone average impaired in 1 case. Unlike surgical patients, cervical- and ocular-VEMPs remained abnormal. In 2 cases vibratory nystagmus was mainly horizontal similarly to PO findings.

Conclusions: We hypothesized that, in particular cases with “unstable” wide-sized dehiscence, MFD may either slowly progressively occlude the dehiscent canal without causing symptoms or lead to partial and recurrent canal plugging. This event may induce a transient labyrinthine hydrops, similarly to PO findings.

OP02-7 - The diagnostic value of vestibular evoked myogenic potentials in superior canal dehiscence syndrome

19. Superior Canal Dehiscence Syndrome

Luca Verrecchia¹

Krister Brantberg¹, Magnus Vestin², Maoli Duan¹

¹ Karolinska Institutet, Department of clinical intervention and technology (CLINTEC), ENT section

² Karolinska University Hospital, Trauma and Reparative Medicin, Ear Nose and Throat Patient Area

Purpose: Superior canal dehiscence syndrome (SCDS) shows several idiosyncrasies at vestibular evoked myogenic potentials (VEMP). Specific SCDS markers at VEMP testing have assumed a major role in the SCDS diagnostic work out. Here, we sum up the conclusions of different studies on the VEMP diagnostic accuracy for SCDS conducted at our department in the last decade.

Methods: SCDS markers at VEMP have been investigated in case-control and cohort studies in different conditions: cervical (cVEMP) and ocular VEMP (oVEMP) in response to stimuli at near and suprathreshold levels, with frequency specific or wide band configurations, and delivered with air (AC) or bone (BC) conducted modalities.

Results: VEMP amplitude in response to AC stimulation showed the best diagnostic properties as SCDS marker. At suprathreshold stimulations, oVEMP is superior to cVEMP and AC oVEMP is better than BC oVEMP, particularly in terms of SCDS sensitivity. A better diagnostic accuracy is however obtained with VEMP at near threshold stimulation levels, also here in terms of response amplitude and better for AC VEMP. Moreover, at threshold levels a specific SCDS showed a specific frequency tuning, which can further differentiate this syndrome from other conditions.

Conclusions: VEMP, especially in terms of response amplitude at near threshold AC stimulation, is a valid SCDS marker. This is of clinical relevance considering the variable presentation of other SCDS clinical key features and the suboptimal diagnostic accuracy of the radiological investigations.

OP03-1 - Hearing & postural control: what is the impact of hearing loss and what role can hearing aids play?

18. Spatial Orientation

Jessica Vitkovic¹

Carmen Le¹, Su-Ling Lee¹, Ross Clark²

¹ The University of Melbourne, Dept of Audiology and Speech Pathology, Australia.

² School of Exercise Science, Australian Catholic University, Australia.

Purpose: This study determined the effect of spatial hearing/sound on the postural control of normally hearing, hearing-impaired and vestibular-impaired subjects. We also examined the role of hearing aids in the hearing-impaired subjects.

Methods: Centre of pressure analysis was used to measure the effect of sound on the postural sway of 50 normally hearing subjects, 28 hearing impaired subjects and 19 subjects with vestibular dysfunction. Subjects were asked to stand still for 60 seconds in various acoustic environments that utilised sound cues that were either present or absent. Hearing-impaired participants who were fitted with hearing aids were assessed with and without their hearing aids on.

Results: Sound cues facilitated postural control in normally hearing subjects. This ability was diminished in the hearing-impaired subjects, but appeared to be overcome with the use of a hearing aid. Patients with additional vestibular deficits exploited auditory cues to a greater degree, suggesting that a sensory re-weighting to enhance the use of auditory cues may be applied when there is diminished sensory redundancy.

Conclusions: People with balance problems are best to enrich their environments with sound cues and maximise their audible hearing to better maintain their balance. As the risk of falls and hearing impairment increase with age, the benefit of hearing aids in improving stability is appealing when considering the substantial disability, mortality and socioeconomic burden of falls in the elderly.

OP03-2 - Towards a clinically useful test for vestibular perception

7. Clinical Testing for Vestibular Function

Florence Lucieer¹

Bart Dupuits², Nils Guinand³, Angelica Perez-Fornos³, Jean-Philippe Guyot³, Herman Kingma¹, Raymond van de Berg¹

¹ Department of Otorhinolaryngology and Head & Neck Surgery, Maastricht University Medical Center, Maastricht, Netherlands

² Faculty of Health, Medicine and life Sciences, University of Maastricht, Maastricht, Netherlands

³ Service of Otorhinolaryngology and Head and Neck Surgery, Department of Clinical Neurosciences, Geneva University Hospitals, Geneva, Switzerland

Purpose: Clinical vestibular testing mainly consists of testing reflexes like the vestibulo-ocular reflex and the vestibulo-collic reflex. However, this type of testing does not always detect perceptual symptoms. Objective of this study was to propose a clinically useful test for vestibular perception, to investigate its age-related normative values and to compare these with the normative values of other known perceptual tests.

Methods: Fifty-five healthy subjects were included. Vestibular perceptual thresholds were measured using the MOTEK platform in dark. The subject had to report the correct type and direction of movements. The platform delivered twelve different movements: six translations (forward, backward, right, left, up and down) and six rotations/tilt (yaw left, yaw right, pitch forward, pitch backward, roll left and roll right). A staircase paradigm was used for threshold detection. This test involved shorter testing times and continuous communication between subject and researcher, compared to perception tests performed in previous studies.

Results: Age significantly increased perceptual thresholds for all movements. Gender did not have a significant influence. Within the translations, significantly different thresholds were found between forward-backward translations and translations up-down. Within rotations, significantly different thresholds were found between yaw-rotations left-right and both pitches forward-backward and roll left-right.

Conclusions: The results of this faster and more patient friendly test for vestibular perception showed comparable results to more research oriented tests regarding age-related influences. This opens up new perspectives in examining vestibular perception in clinic.

OP03-3 - The role of vection and velocity storage in visually induced motion sickness

18. Spatial Orientation

Suzanne A.E. Nooij¹

Paolo Pretto¹, Heinrich H. Bülthoff¹

¹ Max Planck Institute for Biological Cybernetics, Dept. of Human Perception, Cognition and Action, Tübingen, Germany

Purpose: Full-field visual rotation around the vertical axis induces a sense of self-motion (vection), optokinetic nystagmus (OKN), and, eventually, also motion sickness (MS). If the lights are suddenly switched off, optokinetic after-nystagmus (OKAN) occurs. This is due to the discharge of the velocity storage mechanism (VSM), a central integrative network that has been suggested to be involved in motion sickness. We previously showed that visually induced motion sickness (VIMS) following optokinetic stimulation is dependent on vection intensity. To shed light on this relationship, the current study investigates whether vection intensity affects VSM activity, and thus, the OKAN.

Methods: In repetitive trials (8 per condition), 15 participants were exposed to 120s of visual yaw rotation (60 deg/s), followed by 90s in darkness. The visual stimulus either induced strong vection (i.e., scene rotating normally) or weak vection (central and peripheral part moving in opposite directions). Eye movements and subjective vection intensity were continuously measured.

Results: OKAN occurred less frequent and with lower initial magnitude in the weak-vection condition as compared to the strong-vection condition. Decay time constants were not significantly different.

Conclusions: The results suggest that the occurrence of vection enhances the charging of the VSM. As VSM activity has been found to be a factor in motion sickness, the enhanced VSM activity in our strong vection condition could explain why visual stimuli producing a strong sense of vection also elicit high levels of motion sickness.

OP03-4 - The role of temporo-parietal cortex in upright perception and the link with torsional eye position

18. Spatial Orientation

Jorge Otero-Millan¹

Ariel Winnick²,

Amir Kheradmand³

¹ Johns Hopkins, Department of Neurology, USA

² Johns Hopkins, Departments of Neurology, USA

³ Johns Hopkins, Departments of Neurology and Otolaryngology & Head and Neck Surgery, USA

Purpose: Upright perception is a key aspect of orientation constancy, as we maintain a stable perception of the world despite continuous movements of our eyes, head and body. Torsional position of the eyes can impact perception of upright by changing orientation of the images on the retina relative to gravity. Here we investigated the role of temporo-parietal cortex in upright perception with respect to ocular torsion, by means of the inhibitory effect of continuous theta burst transcranial magnetic stimulation (TMS).

Methods: We used a subjective visual vertical (SVV) paradigm to track changes in upright perception, and a custom video method to track ocular torsion simultaneously. Twelve participants were tested during lateral head tilt of 20^° to the left.

Results: TMS at the posterior aspect of the supramarginal gyrus (SMGp) resulted in an average SVV shift in the opposite direction of the head tilt compared to sham stimulations (1.8^°). Ocular torsion following TMS at SMGp showed no significant change compared to sham stimulations (-0.1^°). Thus, changes in upright perception at SMGp was dissociated from ocular torsion.

Conclusions: This finding suggests that perception of upright at SMGp is primarily related to processing sensory inputs, as opposed to subcortical regions that have direct influence over ocular torsion.

OP03-5 - Spatial navigation, sense of direction, and vestibular function in young deaf individuals

18. Spatial Orientation

Chizuko Tamaki¹

Kristen Maul¹, Sarah Sparks¹, Emalee Danner¹, Noelle Allemang¹

¹ Gallaudet University

Purpose: Literature suggests that vestibular impairment impacts visuo-spatial and cognitive functions, including spatial navigation and mental imagery. Hearing loss, and potentially acquired vestibular dysfunction, has been linked to cognitive decline in older adults, but spatial and cognitive abilities of young deaf adults, who are likely to have vestibular dysfunction, has not been studied. This study examines young deaf adults’ navigational abilities and perceived sense of direction in relation to their vestibular and balance functions.

Methods: Young adults, ages 18-36 years, with hearing levels greater than 50dBHL in the better ear, and with normal middle ear function (Jerger Type A tympanogram), have been included. All reported either congenital or childhood onset of deafness. Navigational ability was assessed through an object-finding task in a virtual reality first-person avatar maze. Sense of direction was assessed with the Santa Barbara Sense of Direction Scale (SBSOD). Hearing levels, vestibular function status (vHIT, VEMP, modified Clinical Test of Sensory Integration of Balance, Activities-specific Balance Confidence Scale [ABC]), and language use (spoken vs. sign) were obtained.

Results: Virtual reality maze completion time was negatively correlated with otolitic functions (VEMP thresholds) and with self-reported sense of direction (SBSOD). Self-reported confidence in balance (ABC) was correlated with SBSOD.

Conclusions: Results suggest a strong relationship between otolithic function, sense of direction, and the ability to efficiently locate objects in a VR maze, in a group of young deaf individuals. Otolithic impairment may hinder development of route-learning abilities in deaf individuals.

OP03-6 - Functional and mechanistic link between sensory cue integration and self-motion perception

18. Spatial Orientation

Qadeer Arshad¹

¹ Imperial College

Purpose: Navigating our environment successfully requires the ability to integrate multi-sensory cues, which in-turn facilitates appropriate self-motion perception. Despite advances in the macaque monkey, the neural mechanism underpinning multi-sensory cue integration in humans remains largely unknown. Considering the specific topic of how much we rely on visual as opposed to vestibular cues during sensory integration (i.e. visual dependence), two hypotheses can be constructed: it may reflect either the level of visual cortex excitability, or alternatively, reduced vestibulo-cortical dominance.

Methods: Accordingly, we explored the relationship between, (i) visual cortical excitability - assessed using transcranial magnetic stimulation (TMS)-induced phosphenes and, (ii) vestibulo-cortical dominance - assessed using a measure of vestibular-nystagmus suppression following transcranial direct current stimulation over the parietal cortex – with the degree of visual dependence during a sensory integration task.

Results: We observed that visual dependence was unrelated to either the early (V1/V2) or late (V5/MT) visual cortex excitability, however was related to the degree of vestibulo-cortical dominance. We proceeded to assess the functional significance of vestibulo-cortical dominance upon vestibular-behaviour by assessing the time taken to experience self-motion during opto-kinetic stimulation. We observed that the degree of visual dependence was correlated with the time taken to experience circular-vection.

Conclusions: Utilising a multi-method approach, we demonstrate that vestibulo-cortical dominance functionally and mechanistically link sensory integration and self-motion perception, two fundamental components that mediate human spatial orientation.

OP03-7 - A Computational Model of Self-Motion Perception and Vestibular Cognition

18. Spatial Orientation

Fred W. Mast¹

Andrew W. Ellis¹

¹ University of Bern, Department of Psychology, Switzerland

Purpose: Numerous studies in vestibular patients and healthy participants have demonstrated that sensory information provided by the vestibular system is involved in cognitive processes such as mental rotation, body representation, numerical tasks and affective control. Despite these interesting empirical findings, the underlying mechanisms are not well understood. The key to a better understanding of vestibular involvement in cognition is to consider the probabilistic computations performed by the vestibular system, rather than focus solely on the sensory signals.

Methods: We use a probabilistic model capable of processing sequential vestibular data. This model is a dynamic latent variable model, in which the latent variables represent the dynamics of the head. The same model can be applied when movement of the head is due to an external disturbance (passive), or when the movement is self-initiated (active). Besides information obtained via efference copy, our model can incorporate knowledge from multiple sources, including higher-level knowledge to predict the dynamics of the latent variables.

Results: Cognitive tasks (e.g., perceptual decision-making, meta-cognitive evaluation in self-motion perception, mental rotation of self-motion) use the probabilistic model with higher-level knowledge. For example, imagined self-motion is performed by running a Monte Carlo sampling algorithm; this amounts to sampling from the prior. Not only do the simulations serve to demonstrate that cognitive mechanisms are part of sensory inference, but they can also explain impaired self-motion perception in vestibular patients.

Conclusions: Mechanisms used for sensory inference are used in offline operations. By investigating interactions between online and offline usage we can better conceptualize the vestibulo-cognitive interplay.

OP04-1 - Benign Paroxysmal Positional Vertigo in acute traumatic brain injury

20. Traumatic Brain Injury

Rebecca Smith¹

Elena Calzolari¹, Barry Seemungal¹

¹ Imperial College London

Purpose: Benign paroxysmal positional vertigo (BPPV) is a common vestibular disorder following traumatic brain injury (TBI). Previous studies evaluating type and frequency of BPPV in TBI have been limited to the sub-acute population, or have employed dizziness screening tools prior to study inclusion. Currently there is no data pertaining to the frequency and type of BPPV in acute TBI. This prospective observational study aimed to provide such data.

Methods: Patients at a major trauma centre (St Mary’s Hospital, London, UK) were screened for a prospective study evaluating markers of balance recovery in TBI. Patients meeting the inclusion criteria were assessed using a standardised neuro-otological examination. Details pertaining to BPPV frequency, type and treatment rates were recorded.

Results: 359 acute TBI patients were screened. Of those 359 patients, 42 were assessed for inclusion in the study. 52% of 42 patients (22) had a positive Dix-Hallpike test (Mean age 47±17 years; 68% Male). All patients had posterior canal BPPV, 86% had unilateral BPPV whilst 14% had bilateral BPPV. Critically, just over a third of patients did not complain of vertigo symptoms prior to the diagnosis, or during diagnostic or treatment manoeuvres.

Conclusions: Our data is the first to demonstrate the frequency and type of BPPV in acute TBI. Higher rates of BPPV were noted among our sample in comparison to previous data. Given that over 50% of patients were diagnosed with BPPV and a significant number did not complain of vertigo, we recommend a screening approach be utilised in all TBI patients.

OP04-2 - Concussion Balance Test: Assessment and Treatment Effectiveness After Sports Related Concussion

20. Traumatic Brain Injury

Shelly Massingale¹

Amy Alexander¹, Richard Allred¹, Steven Erickson¹, Richard Gerkin², Elizabeth McQueary¹, Sarah Schodrof¹, Jamie Pardini¹

¹ Banner University Sports Medicine and Concussion Center

² Banner University Medical Center Phoenix

Purpose: The Concussion Balance Test (COBALT) is an eight-condition postural control measure that assesses high-level balance skills necessary to successfully and safely return to play, with conditions 7 and 8 (C7 and C8) challenging these systems through a headshake (C7) and visual motion sensitivity (C8) task on a foam surface. The purpose of this study was to explore the utility of COBALT to assess treatment progress in a concussed athlete population

Methods: Subjects (age 10-25) were 84 concussed adolescent athletes (mean age = 15) referred for treatment of vestibular dysfunction at an outpatient concussion clinic, and 132 uninjured athletes (mean age = 14.8) who presented for baseline assessment. Postural control was assessed via COBALT at the initial visit (median = 13 days from time of injury) and at the conclusion of treatment for concussed athletes, and at one time point (pre-season screening) for uninjured athletes.

Results: Comparison of pre- to post-treatment data in concussed athletes revealed a positive effect for the most complex conditions (C7, C8). For C7, a significant improvement in sway scores was observed from initial to final assessment (t=3.63, p<0.01). Sway scores for C8 also improved substantially (t=6.25, p<0.01). Following treatment completion, the concussed group demonstrated significantly better sway scores than non-injured athletes for C7 (t=3.63, p<0.001), and demonstrated similar sway scores to the control sample in C8 (p>0.05).

Conclusions: COBALT is a useful measure to evaluate dysfunction and recovery of postural control in athletes following sports related concussion.

OP04-3 - Does the Vestibular/Ocular Motor Screening (VOMS) Tool Predict Recovery in Collegiate Athletes?

20. Traumatic Brain Injury

Susan Whitney¹

Gregory Marchetti², Anne Mucha³, Michael Collins⁴, Anthony Kontos⁴

¹ University of Pittsburgh Departments of Physical Therapy and Otolaryngology, USA

² Duquesne Univesity Department of Physical Therapy, USA

³ Centers for Rehab Services, Univeristy of Pittsburgh Medical Center, USA

⁴ University of Pittsburgh Department of Orthopedics, USA

Purpose: Following sport-related concussion (SRC), it is common for athletes to experience vestibular and/or oculomotor impairments and symptoms. The Vestibular/Ocular Motor Screening (VOMS) is a screening tool that evaluates vestibular and oculomotor symptom provocation and impairment following SRC. Research has yet to explore which components of the VOMS predict recovery time following SRC. The purpose was to determine if a total VOMS symptom score predicts recovery time, and determine if the individual VOMS component scores are better at predicting recovery time than the total score.

Methods: Division I and II collegiate student-athletes (n=68) with restricted participation post-injury completed self-reported demographic and medical history and the VOMS at preseason physical examinations. Variables reported to be significant univariate predictors of recovery were used to develop a Cox proportional hazards model with hazard ratio (HR) to identify the VOMS scores associated with recovery time. VOMS scores that optimally predicted recovery time for initial and multiple injuries were identified with Receiver Operating Characteristic (ROC) Area Under Curve (AUC) analysis.

Results: The likelihood of recovery after concussion at any time point was associated with VOMS vertical vestibular ocular reflex testing (VOR-V, HR = .94, P = .002) and total headache (HA) score (HR = 0.98, P =.006). Recovery at 7 and 14 days after injury was optimally predicted by VOR vertical score (cut point < 3 points) and total HA score (cut point £<16 points).

Conclusions: Visual motion sensitivity, VOR-vertical and total headache symptom scores are key components of the VOMS for clinicians to consider in the prognosis of collegiate student-athletes following concussion.

OP04-4 - Is it clinically feasible to run a multi-modal battery of tests in a virtual reality goggle?

20. Traumatic Brain Injury

Alexander Kiderman¹

Michael Hoffer², Hillary Snapp², Alexandr Braverman³, Carey Balaban⁴

¹ Neuro Kinetics, Inc., Pittsburgh, Pennsylvania, USA

² University of Miami, Miller School of Medicine, Department of Otolaryngology, Miami, Florida, USA

³ Hebrew University of Jerusalem, Israel

⁴ University of Pittsburgh, Department of Otolaryngology, Pittsburgh, Pennsylvania, USA

Purpose: Comparison of oculomotor, vestibular, and reaction time (OVRT) test results using the clinical stationary Neuro Otologic Test Center (I-Portal® NOTC) vs. Portable Head Mounted Goggle with 3D Display and Integrated Eye Tracking System (I-PAS™).

Methods: A battery of OVRT tests were run using stationary and portable systems including: saccade horizontal and vertical; smooth pursuit horizontal and vertical; gaze horizontal and vertical; optokinetic; subjective visual vertical and horizontal. A total of 82 variables were evaluated using Bland-Altman and Deming regression methods. Participants consisted of 69 controls and four mTBI subjects. All subjects were tested on both systems. Test sequence order was randomized, with 49% tested on NOTC first, 51% tested on I-PAS first.

Results: The effect of gender, age, and sequence of tests and assessment of Slopes and Biases were evaluated. It was determined that gender, age, or sequence of tests had no effect. The Bland Altman and Deming regression results demonstrated significant agreement between variables using the stationary NOTC system and the portable I-PAS device. No significantly different bias from zero and slope from 1 were observed for 78 variables.

Conclusions: Results and statistical analysis demonstrate that testing on the Portable Head-Mounted Goggle is equivalent to that of standard clinical stationary systems. I-PAS can successfully be used for accurate and efficient assessment of mTBI outside of the clinical environment. Note; FDA clearance for I-PAS has been obtained.

OP04-5 - Linking traumatic brain injury (TBI) severity, vestibular agnosia, and vestibular symptom load.

20. Traumatic Brain Injury

Elena Calzolari¹

Rebecca Smith¹, Mariya K. Chepisheva¹, Mark Wilson², David J. Sharp³, Barry M. Seemungal¹

¹ Brain and Vestibular Group, Neuro-Otology Unit, Division of Brain Sciences, Imperial College London, Charing Cross Hospital, London W6 8RF, UK.

² St Mary’s Hospital Major Trauma Centre, Imperial College Healthcare NHS Trust, London W2 1NY

³ C3NL, Imperial College London, W12 0NN

Purpose: Dizziness and imbalance affect over 80% of TBI patients. We observed TBI patients with acute vestibular activation (e.g. BPPV) without complaint of vertigo. We hypothesised that acute TBI attenuates vertigo perception – i.e. vestibular agnosia – measured via laboratory tests of vestibular perception. This predicts (i) a non-linear change in vestibular symptom load over time; (ii) TBI severity is inversely related to vestibular symptom load acutely.

Methods: In this ongoing, prospective study, patients with a closed head injury were consented from an acute major trauma unit and were examined, completed questionnaires (vestibular symptoms, functional ability, cognition), neuro-imaging and laboratory testing.

Results: There was no significant linear relationship between symptoms and TBI severity. Vestibular perceptual thresholds (in yaw) were elevated initially particularly in patients with low vestibular symptom scores. At three months, vestibular perception improved (lower) and symptoms increased.

Conclusions: These data support our predictions of a non-linear relationship between vestibular symptoms, TBI severity and vestibular perception. Important clinical implications include the masking of active vestibular diagnoses (e.g. BPPV) since patients may not report symptoms but still fall or manifest nausea and vomiting. This suggests that acute TBI patients should be screened routinely for vestibular dysfunction irrespective of symptoms. In conclusion, we show a non-linear, but predictable relationship between subjective vestibular symptoms and (i) TBI severity and (ii) degree of vestibular agnosia.

OP04-6 - VEMP latency predict precision of subjective visual vertical in acute traumatic brain injury (TBI).

20. Traumatic Brain Injury

Elena Calzolari¹

Rebecca Smith¹, Mariya K. Chepisheva¹, Mark Wilson², David J. Sharp³,

Barry M. Seemungal¹

¹ Brain and Vestibular Group, Neuro-Otology Unit, Division of Brain Sciences, Imperial College London, Charing Cross Hospital, London W6 8RF, UK

² St Mary’s Hospital Major Trauma Centre, Imperial College Healthcare NHS Trust, London W2 1NY

³ C3NL, Imperial College London, W12 0NN

Purpose: Vestibular Evoked Myogenic Potentials (VEMPs) interrogate the integrity of otolith reflexes involving either the saccule (cervical VEMP) or the utricle (ocular VEMP). Traumatic brain injury (TBI) commonly impairs postural control and one element may be damage to the peripheral vestibular organ, or its brainstem connections controlling reflex functions. It is not known however, if the VEMP can provide a convenient marker of TBI or predict TBI-related imbalance.

Methods: In this ongoing, prospective study, patients with a closed head injury were consented from an acute major trauma unit. We assessed the subjective visual vertical (measured using a QUEST algorithm) and VEMPs (ocular and cervical) at bedside of 6 patients so far.

Results: There was no significant difference in VEMP amplitudes or degree of asymmetry in patients versus controls and there was no link between VEMP amplitude, latency or symmetry and SVV bias. In contrast, we found a significant correlation between SVV precision and latencies for p1 (r.sq 0.41) and n1 (r.sq. 0.32) for cVEMP and also for n1 for the oVEMP (r.sq 0.79) but not for p1 oVEMP.

Conclusions: These data suggest that slowing of conduction in otolithic pathway may impair performance of the SVV (i.e. increased uncertainty of responses). Combining prospective behavioural and neuroimaging assessments may enable us to isolate the neural correlates of the observed behavioural measures. Whether these VEMP measures are associated with balance performance and tilt perception in acute TBI are as yet unknown.

OP05-1 - Acute Dizziness without Nystagmus: Incidence and Predictors of Stroke

21. Vascular Vertigo

Kwangdong Choi¹

Jae-Hwan Choi², Seo Young Choi¹, Eun Hye Oh², Ji Yun Park³

¹ Department of Neurology, Pusan National University Hospital, South Korea

² Department of Neurology, Pusan National University Yangsan Hospital, South Korea

³ Department of Neurology, Ulsan University Hospital, South Korea

Purpose: The present study aimed to investigate the prevalence of stroke and clinical predictors for diagnosing stroke in acute dizziness without nystagmus where HINTS (Head Impluse, Nystagmus, Test of Skew) examination can be hardly applied.

Methods: We performed a prospective, single-center, observational study that had consecutively recruited patients presenting acute dizziness without nystagmus who did not have an obvious causes. All patients received a constructed evaluation and brain MRIs, and patients without a definite cause further received perfusion-weighted imaging (PWI). Multivariable logistic regression was used to determine clinical parameters to identify stroke in acute dizziness without nystagmus.

Results: The prevalence of stroke was approximately 60% in acute dizziness without nystagmus which mostly comprised posterior circulation infarctions involving the cerebellum and brainstem, and anterior circulation infarctions in some. A few patients showed hypoperfusion of the cerebellum, brainstem, or the territory of internal carotid artery on PWI without an infarction on diffusion-weighted image. The higher risk of stroke in acute dizziness without nystagmus was found in association with craniocervical pain and focal neurologic symptoms/signs.

Conclusions: Acute dizziness without nystagmus harbours higher incidence of stroke. However, bedside examination have a limitation in diagnosing strokes in acute dizziness without nystagmus. Perfusion imaging may help to indentify strokes in some of unknown etiology. Associated craniocervical pain and focal neurological symptoms/signs are the useful clues for strokes in acute dizziness without stroke.

OP05-2 - False negative stroke in acute dizziness

21. Vascular Vertigo

Jae-Hwan Choi¹

Eun Hye Oh¹, Han-Jin Cho², Min-Gyu Park¹, Seo-Young Choi², Kwang-Dong Choi²

¹ Pusan National University Yangsan Hospital, Neurology, South Korea

² Pusan National University Hospital, Neurology, South Korea

Purpose: To elucidate the characteristics of false negative stroke causing acute dizziness.

Methods: Among patients with acute stroke presenting with vestibular symptoms, we recruited 29 patients who showed initially negative diffusion weighted image (DWI). Patients received a constructive neurological examination including HINTS “plus” (head impulse, nystagmus, test-of-skew plus hearing), perfusion-weighted image (PWI), and follow-up DWI. We analyzed the clinical features, anatomical location and perfusion status.

Results: Time from onset of symptoms to initial and follow-up DWI was 14.9 ± 13.2 and 79.4 ± 49.6 hours, respectively. The most frequently affected location was the lateral medulla (n=14, 48%), followed by the cerebellum (n=6, 21%), the pons (n=4, 14%), the lateral medulla and cerebellum (n=4, 14%), and the midbrain (n=1, 3%). Eleven patients showed a perfusion defect in unilateral cerebellum or lateral medulla which confirmed as acute stroke in follow-up DWI. About half of patients presented with isolated vestibular syndrome and 17 (59%) did not have any nystagmus. Although the HINTS “plus” battery identified false negative stroke with greater sensitivity (92%) than focal neurological signs (52%) or severe imbalance (48%), six patients missed by bedside examinations and three of them could be identified by only PWI.

Conclusions: Our study shows that false negative stroke in acute dizziness can occur commonly in the lateral medullary lesion. Some patients can present with isolated vestibular syndrome without nystagmus, resulting in the limited application of bedside examinations. PWI may help to identify false negative stroke in acute dizziness.

OP05-3 - Prospective evaluation of cerebral lesion localization in acute vestibular and ocular motor stroke

21. Vascular Vertigo

Andreas Zwergal¹

Ken Möhwald¹, Elvira Lopez-Salazar², Hristo Hadzhikolev³, Thomas Brandt⁴, Marianne Dieterich⁵, Klaus Jahn⁶

¹ Ludwig-Maximilians-University Munich, Department of Neurology, German Center for Vertigo and Balance Disorders (DSGZ)

² Ludwig-Maximilians-University Munich, Department of Neurology

³ Ludwig-Maximilians-University Munich, German Center for Vertigo and Balance Disorders (DSGZ)

⁴ Ludwig-Maximilians-University Munich, Clinical Neurosciences, German Center for Vertigo and Balance Disorders (DSGZ)

⁵ Ludwig-Maximilians-University, Munich, Department of Neurology, German Center for Vertigo and Balance Disorders (DSGZ)

⁶ Schön Klinik Bad Aibling, German Center for Vertigo and Balance Disorders (DSGZ)

Purpose: To prospectively investigate cerebral lesion localization in patients with acute isolated vertigo, dizziness or double vision due to acute stroke.

Methods: 342 adult patients submitted to the emergency room with acute vertigo, dizziness or double vision of unclear etiology were enrolled prospectively in the EMVERT trial and underwent a standardized protocol of clinical, video-oculographic and posturographic measurements as well as a MRI within 7d after symptom onset. The MRI protocol included DWI-/FLAIR-/T2-/T2*-/3D-T1-weighted sequences and a TOF-angiography. MRIs with acute DWI lesions were further processed using SPM-based algorithms for lesion mapping.

Results: In 47 of the patients the MRI indicated acute stroke (13.6%). The most frequent chief complaint was dizziness (44.7%), followed by vertigo (38.3%) and double vision (17.0%). In patients with dizziness the lesions were found mostly in the lateral PICA and SCA territories (involving the flocculus/superior vermis), and the pontomesencephalic brainstem tegmentum (involving the ocular motor centers for the pitch/role plane). Patients with vertigo frequently had lesions in the medial PICA territory (including the vermis/nodulus/uvula), the pontomedullary brainstem (involving the vestibular nuclei) and the parieto-insular vestibular cortex. Patients with double vision had pontomesencephalic and mesodiencephalic lesions. Lesion volume in patients with intratentorial strokes correlated with subjective estimation of symptoms on a visual analog scale.

Conclusions: Prospective evaluation of lesion localization in acute vertigo and dizziness showed that mostly the cerebellum was affected by strokes, with some preference towards the medial cerebellar structures accociated with vertigo and lateral hemispherical structures accociated with dizziness. In the brainstem pontomedullary lesions induced vertigo, pontomesencephalic rather dizziness.

OP05-4 - Spontaneous nystagmus characteristics in posterior circulation stroke

21. Vascular Vertigo

Luke Chen¹

Michael Todd², Michael Halmagyi², Swee Aw²

¹ Faculty of Medicine, University of New South Wales, Sydney

² Department of Neurology, Royal Prince Alfred Hospital, Sydney

Purpose: To characterize and compare spontaneous nystagmus (SN) characteristics in posterior circulation stroke (PCS) and acute unilateral peripheral vestibulopathy (AUPV).

Methods: Eye movement was recorded ≤7 days from vertigo onset with search coils in 41 PCS involving anterior inferior, posterior inferior and superior cerebellar artery (13 AICA, 17 PICA, 3 SCA, and lateral medulla (8 LM) confirmed by MRI and 20 AUPV. We determined the three-dimensional magnitude of SN velocity (|SPV|) with and without visual fixation in the neutral position, and on viewing ipsilesional and contralesional horizontal 20^° targets.

Results: Following removal of visual fixation, |SPV| increase was universal in AUPV (+4.7^°/s), but variably present in AICA (+2.3^°/s), PICA/SCA (+0.9^°/s) and LM (+0.5^°/s). On ipsilesional to contralesional horizontal gaze change, |SPV| always increased in AUPV (+2.9^°/s), but was inconsistent in PICA/SCA (+ 0.1^°/s), AICA (-0.2^°/s) and LM (-1.2^°/s). Whilst no AUPV had direction changing nystagmus, this was present in AICA (15%), PICA/SCA (35%) and LM (13%). None of the AUPV had ipsilesional beating SN, though this was found in PICA/SCA (55%), AICA (15%) and LM (12.5%). SN, whether with or without visual fixation, was absent in 30% of PICA/SCA, 39% of AICA and 12.5% of LM.

Conclusions: Contrary to conventional view, removal of visual fixation can increase SN in PCS, albeit less strongly than in AUPV. SN changes variably on contralesional horizontal gaze shift, but always increases in AUPV. These findings have potential diagnostic implication and quantitative SN analysis should be further explored in future video-oculography study.

OP05-5 - Truncal Ataxia in the Differential Diagnosis of Acute Vestibular Syndrome

21. Vascular Vertigo

Sergio Carmona¹

Guillermo Zalazar¹, Carlos Martínez², Marcela Moro²

¹ Neuro-otology. Fundacion San Lucas. Rosario. Argentina

² Neurology. Cullen Hospital. Santa Fe. Argentina

Purpose: To demostrate the utility of vestibulo-spinal signs to differentiate posterior fossa stroke from vestibular neuritis in Acute Vestibular Syndrome

Methods: HINTS protocol set a new paradigm to differentiate peripheral vestibular disease from stroke in patients with acute vestibular syndrome (AVS). The relationship between degree of truncal ataxia and stroke has not been systematically studied. We studied a group of 114 patients who were admitted to a General Hospital due to AVS, 72 of them with vestibular neuritis (based on positive head impulse, abnormal caloric tests, and negative MRI) and the rest with stroke: 32 in the posterior inferior cerebellar artery (PICA) territory (positive HINTS findings, positive MRI) and 10 in the anterior inferior cerebellar artery (AICA) territory (variable findings and grade 3 ataxia, positive MRI).

Results: Truncal ataxia was measured: grade 1, mild to moderate imbalance with walking independently; grade 2, severe imbalance with standing, but cannot walk without support; and grade 3, falling at upright posture. With HINTS protocol to our sample, we obtained 100% sensitivity and 94.4% specificity. Only those patients with stroke presented with grade 3 ataxia. With grade 2 ataxia (n = 38), 11 had cerebellar stroke and 28 had vestibular neuritis. Grade 2–3 ataxia was 92.9% sensitive and 61.1% specific to detect AICA/PICA stroke in patients with AVS, with 100% sensitivity to detect AICA stroke. In turn, two signs (nystagmus of central origin and grade 2–3 Ataxia) had 100% sensitivity and 61.1% specificity.

Conclusions: Ataxia is less sensitive than HINTS but much easier to evaluate.

OP05-6 - VOG vs MRI-All for Stroke Diagnosis of Vertigo in Emergency Departments: Cost Effectiveness Analysis

21. Vascular Vertigo

Maningbe Keita¹

William Padula¹,

David Newman-Toker²

¹ Johns Hopkins Bloomberg School of Public Health

² Johns Hopkins University School of Medicine

Purpose: 4.4 million US emergency department (ED) visits occur annually for acute vertigo/dizziness (cost: 10 billion USD). Approximately 5% of these patients have strokes, yet one-third are misdiagnosed. Current care uses computerized tomography scans, despite low sensitivity. Magnetic resonance imaging (MRI) has a higher sensitivity but may increase costs. Eye movement-based bedside diagnosis accurately differentiates strokes from ear disease but requires clinical expertise. This abstract compares the cost effectiveness of VOG-guided vs. MRI-all diagnostic methods relative to current diagnostic care for ED patients presenting acute vertigo/dizziness.

Methods: One year, decision tree, cost-effectiveness analysis of diagnostic evaluation among ED patients presenting dizziness of a neuro-vestibular cause (stroke, vestibular neuritis, benign paroxysmal positional vertigo, and vestibular migraine/Menière’s disease). Probability, utility, and cost parameters were determined through literature review supplemented by expert opinion. Outcomes were measured in units of cost (USD, 2016) and effectiveness (health utility ranging from 0 to 1 in quality-adjusted life years [QALYs]) to calculate incremental cost-effectiveness ratios (ICERs).

Results: Compared to current care ($4183, 0.69), VOG-guided care incurred significantly lower cost and higher health utility ($3683, 0.73), while the MRI-all pathway resulted in higher costs for the same health utility ($4602, 0.69). VOG-guided care dominates both current care (ICER: -$12,497) and MRI-all (ICER: -$22,981) strategies, translating to 88,000 QALYs gained and >1 billion USD saved each year if routinely implemented in ED clinical practice nationwide.

Conclusions: VOG-guided diagnosis could save lives and reduce costs. Future research should focus on prospective validation of VOG-guided diagnosis and barriers to its dissemination.

OP06-1 - First-in-human Safety and Preliminary Efficacy Results for the MVI Multichannel Vestibular Implant

26. Vestibular Prosthesis

Peter J Boutros¹

Desi Schoo¹, Mehdi Rahman², Nicolas S Valentin², Margaret Chow¹, Yoav Gimmon¹, Stephen Bowditch¹, Andreas Hofner³, Aitor Morillo Rascon³, Andreas Marx³, Ross Deas³, Stefan Strasser³, Gene Y Fridman¹, Natan S Davidovics², Dale C Roberts¹, Brian Morris¹, Andrianna Ayiotis¹, Kelly Lane¹, Abderrahmane Hedjoudje¹, Bryan K Ward¹, Carolina Treviño¹, Michael C Schubert¹, John P Carey¹, Andreas Jaeger³,

Charles C Della Santina¹

¹ Vestibular NeuroEngineering Laboratory, Johns Hopkins School of Medicine, USA

² Labyrinth Devices, LLC, USA

³ Med-El GmbH, Austria

Purpose: In rodents and nonhuman primates with bilateral vestibular hypofunction, we previously demonstrated that motion-modulated current pulses delivered via electrodes in the ampullae can partially restore the 3D angular vestibulo-ocular reflex (VOR) while partially preserving hearing. Based on those studies, we initiated a first-in-human clinical trial of continuous motion-modulated prosthetic stimulation using the MVI™ Multichannel Vestibular Implant system developed by Labyrinth Devices LLC and MedEl GmbH.

Methods: Four subjects underwent unilateral implantation; two were observed overnight and two were discharged the same day. VOR responses to 0.5-5 Hz passive head or whole-body rotation and prosthetic stimulation; pure tone and speech audiometry; and metrics of posture, gait, dynamic visual acuity and quality of life were assessed during 2-14 months of continuous MVI™ use.

Results: Electrically-evoked VOR responses typically ranged from 5-40°/s and aligned approximately with the stimulated canal for ≥1 electrode in each of 3 canals in each implanted ear. VOR responses were typically smaller than those for similar currents in animals, but significantly greater with motion-modulated stimulation than without. Motion perception thresholds are below VOR thresholds. Hearing sufficient for unaided communication was preserved in all subjects. At >6 mos postop, subjects 1-3 have preserved hearing except for high-frequency SNHL; at 8wks postop, subject 4 has a HFSNHL and 25dB speech reception threshold change.

Conclusions: The MVI™ system can be implanted in outpatient surgery, generates motion percepts and 3D binocular VOR responses consistent with selective stimulation of 3 implanted canals, and can be implanted with preservation of useful hearing.

OP06-2 - Multichannel Vestibular Implant Early Feasibility Study: Gait and Posture Outcomes

26. Vestibular Prosthesis

Margaret Chow¹

Yoav Gimmon², Desi Schoo², Carolina Trevino², Peter Boutros¹, Mehdi Rahman³, Nicolas Valentin³, Andreas Hofner⁴, Aitor Morillo Rascon⁴, Andreas Marx⁴, Ross Deas⁴, Gene Fridman², Andreas Jaeger⁴, Michael Schubert², John Carey², Charles Della Santina²

¹ Johns Hopkins School of Medicine, Department of Biomedical Engineering, USA

² Johns Hopkins School of Medicine, Department of Otolaryngology - Head and Neck Surgery, USA

³ Labyrinth Devices LLC, USA

⁴ Med-El GmbH, Austria

Purpose: The Labyrinth Devices MVI™ Multichannel Vestibular Implant system is intended to treat severe-to-profound bilateral vestibular loss (BVL) in individuals who remain severely symptomatic despite vestibular rehabilitation by encoding head rotation information via pulsatile electrical stimulation to the vestibular afferent nerve. We investigated the efficacy of the MVI™ system on gait and balance of four study participants enrolled in the Multichannel Vestibular Implant Early Feasibility Study.

Methods: Devices were implanted in the left ears of the four participants. After onset of chronic, motion-modulated stimulation, subjects wore their MVI™ systems 24 hr/day and were evaluated at 10 timepoints within 1-45 weeks after activation. We quantified performance using the Modified Romberg Test, Bruininks-Oseretsky Test Edition 2, Subtest 5 (BOT™), Timed Up and Go (TUG), Dynamic Gait Index (DGI) and gait metrics collected by a GAITRite™ system while the MVI™ system delivered either motion-modulated or constant-rate stimulation. We fit a linear mixed-effect model to quantify outcomes as functions of subject, condition (modulation vs. baseline) and time.

Results: All subjects reported improvement in activity level. BOT™ score improved compared to preimplantation. Gait metrics did not exhibit consistent changes. DGI improved more than the clinical minimal detectable change (3.2 points) in three patients. One subject exhibited a clinically significant increase in time-to-failure during a modified Romberg test with eyes closed, standing on foam. TUG scores improved significantly (p<0.05) for two of the four participants.

Conclusions: These data demonstrate that motion-modulated prosthetic input from the MVI™ system provides sensory input that may influence gait and balance in subjects with BVL.

OP06-3 - Multichannel Vestibular Implant Early Feasibility Study: Safety and Audiometric Outcomes

26. Vestibular Prosthesis

Desi Schoo¹

Peter Boutros², Margaret Chow², Yoav Gimmon¹, Stephen Bowditch¹, Mehdi Rahman³, Nicolas Valentin³, Dawn Marsiglia¹, Bryan Ward¹, Natan Davidovics³, Carolina Treviño¹, Andreas Hofner⁴, Aitor Morillo Rascon⁴, Andreas Marx⁴, Ross Deas⁴, Gene Fridman¹, Michael Schubert¹, Andreas Jaeger⁴, John Carey¹, Charles Della Santina¹

¹ Johns Hopkins School of Medicine, Department of Otolaryngology-Head and Neck Surgery, USA

² Johns Hopkins School of Medicine, Department of Biomedical Engineering, USA

³ Labyrinth Devices, LLC, USA

⁴ Med-El GmbH, Austria

Purpose: The Labyrinth Devices MVI™ Multichannel Vestibular Implant system is an investigational device which intends to continuously provide a motion-modulated electrical stimulus to unilateral afferent vestibular nerve branches driving the vestibulo-ocular reflex in patients with bilateral vestibular loss (BVL). This report aims to characterize safety outcomes, including measurements of cochlear function, in this first-in-human clinical trial.

Methods: Four participants with BVL confirmed by clinical history and caloric testing were consented and underwent implantation with the MVI™ device. We recorded safety outcomes including adverse events (AE), serious adverse events (SAE), pure-tone audiometry, and ear specific speech audiometry.

Results: Intralabyrinthine position of MVI™ electrodes near their target ampullae was confirmed in all 4 participants (MVI001-MVI004). We observed a favorable AE profile related primarily to stimulation errors. No SAE related to implantation or stimulation have been encountered.

Hearing in the implanted ear was mostly, but not completely, preserved and has remained stable up to 11 months postimplantation for MVI001-MVI003. Air conduction pure tone thresholds are within 10dBHL of pre-implantation (0.125-8kHZ) in MVI001. MVI002-MVI003 retained hearing in the normal range for 125-2000Hz and exhibited a new 40-70dBHL high-frequency sensorineural hearing loss (SNHL) at 4-8kHz. At six weeks postimplantation, MVI004 demonstrated a new moderate low-frequency SNHL for range 125-2000Hz and a 75-85dBHL high-frequency SNHL from 4000-8000Hz.

Conclusions: While a larger sample size is needed for a statistically robust estimation of risk, this data demonstrates that implantation of MVI™ electrodes can be performed safely while preserving hearing to a degree sufficient to support unaided communication.

OP06-4 - Multichannel Vestibular Implant: Continuous Restoration of the Human Vestibulo-Ocular Reflex

26. Vestibular Prosthesis

Peter Boutros¹

Desi Schoo MD², Mehdi Rahman³, Nicolas Valentin³, Margaret Chow¹, Yoav Gimmon PhD², Andreas Hofner⁴, Aitor Morillo Rascon⁴, Andreas Marx⁴, Ross Deas PhD⁴, Gene Fridman PhD⁵, Natan Davidovics PhD³, Bryan Ward MD², Carolina Trevino MD², Stephen Bowditch², Dale Roberts², Michael Schubert PhD², Andreas Jaeger PhD⁴, John Carey MD², Charles Della Santina PHD MD⁶

¹ Johns Hopkins University, Department of Biomedical Engineering, USA

² Johns Hopkins School of Medicine, Department of Otolaryngology – Head & Neck Surgery, USA

³ Labyrinth Devices LLC, USA

⁴ Med-El GmbH, Austria

⁵ Johns Hopkins University, Department of Biomedical Engineering, USA; Johns Hopkins School of Medicine, Department of Otolaryngology – Head & Neck Surgery, USA

⁶ Johns Hopkins University, Department of Biomedical Engineering, USA; Johns Hopkins School of Medicine, Department of Otolaryngology – Head & Neck Surgery, USA; Labyrinth Devices LLC, USA

Purpose: Individuals with bilateral vestibular loss (BVL) suffer poor visual acuity during head motion, chronic disequilibrium and postural instability. Electrical stimulation of vestibular afferent neurons to partially restore the vestibulo-ocular reflex (VOR) has been effective in animal models of BVL. The Labyrinth Devices MVI™ Multichannel Vestibular Implant (manufactured by Med-El GmbH) was designed to sense 3D head motion and continuously provide artificial stimulation to the branches of the vestibular nerve to encode different components of head motion.

Methods: Four subjects with BVL were implanted in the left ear with MVI™ stimulators, with an array of electrodes inserted into each semicircular canal (SCC). An earth-vertical rotary chair provided en bloc sinusoidal rotations in darkness over 0.1–2Hz at 100°/s peak velocity. Additionally, head velocity waveforms were encoded via electrical stimulation with the subject’s head stationary to directly observe the electrically-evoked VOR. 3D eye movements were recorded using 3DBinoc™ video-oculography goggles (Labyrinth Devices, LLC) pre-operatively, post-op/pre-activation and up to 8 weeks post-activation.

Results: Subjects activated with the MVI^TM compensated to the prosthetic stimulation in ~35 minutes. Post-activation, all subjects reported improvements in visual and postural stability. Electrical stimulation of individual SCC branches produced conjugate 3D eye movements aligned with the intended SCC axis. Rotary chair testing produced greater VOR gains during motion-modulated stimulation than with placebo stimulation for all subjects.

Conclusions: Coupled with durable and significant subjective benefit, VOR responses measured in humans during whole-body rotation with and without motion-modulated MVI™ stimulation support the hypothesis that prosthetic vestibular nerve input effectively drives vestibulo-cerebellar VOR circuits.

OP06-5 - The vestibular implant input interacts with residual natural function

26. Vestibular Prosthesis

Raymond van de Berg¹

Nils Guinand², Maurizio Ranieri², Samuel Cavuscens², Khoa Nguyen³, Jean-Philippe Guyot², Florence Lucieer¹, Dmitrii Starkov⁴, Herman Kingma¹, Marc van Hoof¹, Angelica Perez-Fornos²

¹ Division of Balance Disorders, Department of Otorhinolaryngology and Head and Neck Surgery, Faculty of Health Medicine and Life Sciences, Maastricht University Medical Center, Maastricht, Netherlands

² Service of Otorhinolaryngology and Head and Neck Surgery, Department of Clinical Neurosciences, Geneva University Hospitals, Geneva, Switzerland

³ Translational Neural Engineering Lab, Center for Neuroprosthetics, Interfaculty Institute of Bioengineering , EPF, Lausanne, Switzerland

⁴ Faculty of Physics, Tomsk State University, Russian Federation

Purpose: To investigate how “artificial” VI-input is integrated with residual “natural” input by the central vestibular system.

Methods: Five vestibular electrodes in 4 BV-patients implanted with a vestibular implant were available. This involved electrodes with a predominantly horizontal response and electrodes with a predominantly vertical response. Responses to predominantly horizontal residual “natural” input and predominantly horizontal and vertical “artificial” VI-input were separately measured first. Then, inputs were combined in conditions where both would hypothetically collaborate or counteract. Each condition involved 60 cycles of 1Hz sinusoidal stimulation. Gain, asymmetry, phase and angle of eye responses were calculated.

Results: Combining residual “natural” input and “artificial” VI-input resulted in an interaction in which characteristics of the resulting eye movement responses could significantly differ from those observed when responses were measured for each input separately (p<0.0013). In the total eye response, inputs with a stronger vector magnitude seemed to have stronger weights than inputs with a lower vector magnitude, in a non-linear combination. “Artificial” VI-input was able to significantly influence and counteract the response to residual “natural” input.

Conclusions: In the acute phase of VI-activation, residual “natural” input and “artificial” VI-input interact to generate eye movement responses in a non-linear fashion. This implies that different stimulation paradigms and more complex signal processing strategies will be required unless the brain is able to optimally combine both sources of information after adaptation during chronic use. Next to this, these findings could pave the way for using the VI as “vestibular pacemaker”.

OP06-6 - Combined stimulation of multiple canals to map a vestibular prosthesis.

26. Vestibular Prosthesis

James Phillips¹

Leo Ling¹, Christopher Phillips¹, Amy Nowack¹, Kaibao Nie², Jay Rubinstein¹

¹ University of Washington/Otolaryngology-HNS/USA

² University of Washington/Bioengineering/USA

Purpose: Vestibular prosthesis technology is rapidly advancing, and techniques to optimize stimulation with such devices are being developed. Still, most controlled stimulation with such devices are performed by rotation in canal planes with observation of slow phase eye movement. Typically, this stimulation results in activation of single electrode arrays, targeting the afferents of single canals. In these experiments, we performed systematic combinations of stimulations across multiple semicircular canals to see if there was a strict algebraic addition of the eye movement velocities associated with single canal stimulation.

Methods: Rhesus monkeys were unilaterally implanted with a vestibular prosthesis based on a cochlear implant. Eye movements were recorded with surgically implanted scleral coils during head restraint in complete darkness. 2s trains of fixed current amplitude and pulse frequency monopolar stimuli were used to drive slow phase eye movements. Pseudorandomly, combinations of such pulse trains were also performed to produce eye movements resulting from stimulation of 2 or more canals together.

Results: Consistent responses were evoked from either single or multiple canal stimulation. Single canal stimulation yielded eye movements that were predominately in the plane of the stimulated canal. However, combined stimulation of multiple canals did not result in the vector sum of the velocities elicited by single canal stimulation.

Conclusions: Multiple canal stimulation may produce temporal integration of activations resulting from current spread between electrodes in different canals, which are activated sequentially during combined stimulation. Programming strategies may need to take such interactions into account for optimal stimulation during natural behaviors.

OP06-7 - Electrically Evoked Compound Action Potentials in Patients with a Hybrid Cochlear-Vestibular Implant

26. Vestibular Prosthesis

T. A. Khoa Nguyen¹

Konrad Schwarz², Samuel Cavuscens³, Maurizio Ranieri³, Jean-Philippe Guyot³, Raymond van de Berg⁴, Silvestro Micera⁵, Herman Kingma⁴, Nils Guinand³,

Angelica Perez Fornos³

¹ Department of Neurosurgery, University Hospital Bern, Bern, Switzerland

² MED-EL, Innsbruck, Austria

³ Cochlear Implant Center for French Speaking Switzerland, Service of Otolaryngology-Head & Neck Surgery, Geneva University Hospitals, Geneva, Switzerland

⁴ Division of Balance Disorders, Department of Otorhinolaryngology and Head and Neck Surgery, Maastricht University Medical Center, Maastricht, Netherlands

⁵ Bertarelli Foundation Chair in Translational Neural Engineering, Center for Neuroprosthetics, EPF Lausanne, Switzerland

Purpose: To characterize electrically evoked compound action potentials (eCAPs) using electrodes implanted in the cochlea and in the peripheral vestibular system.

Methods: Patients with bilateral vestibular loss and severe hearing loss received a hybrid cochlear-vestibular implant (MED-EL, Austria). We recorded eCAPs in 4 implanted patients for three setups: i) a cochlear setup, where stimulation and recording electrode were in the cochlear array; ii) a mixed setup, where the stimulation electrode was in the cochlear array and the recording electrode in a vestibular branch or vice versa; and iii) a trans-canal setup, where the stimulation electrode was in one vestibular branch and the recording electrode in another vestibular branch. In one subject, we additionally measured eCAPs during continuous stimulation to investigate potential adaptation mechanisms.

Results: We successfully recorded eCAPs for all setups. Cochlear-vestibular and vestibular-vestibular eCAPs exhibited similar morphology as cochlear-cochlear eCAPs with two peaks. However, peak-to-peak voltages for cochlear-cochlear eCAPs were markedly larger than for the other setups. Amplitude growth functions for all setups displayed sigmoidal shape with distinct segments below and above threshold. Recovery functions for cochlear-cochlear eCAPs had a clearer exponential shape than the other setups. The investigation of eCAPs during continuous stimulation revealed very fast adaptation of the responses.

Conclusions: Our findings suggest that eCAP recordings with a vestibulo-cochlear implant could be used to reduce erroneous activation of non-target neurons by primarily guiding electrode placement during surgery. Post-operatively, the recordings could be leveraged to aid implant programming and as supplemental information about neuronal activation during chronic use.

OP08-1 - The effect of darkness on human head impulse catch-up saccades

23. Vestibular Compensation and Rehabilitation

Jacob M Pogson¹

Leigh McGarvie², Rachael L Taylor², Andrew Bradshaw², G Michael Halmagyi², Miriam S Welgampola²

¹ Sydney Medical School, University of Sydney, Camperdown Australia

² Institute of Clinical Neuroscience, Royal Prince Alfred Hospital, Camperdown, Australia

Purpose: In health, a rapid passive head-impulse generates an equal and opposite smooth eye-movement, driven by the vestibulo-ocular reflex (VOR). In vestibular loss, this smooth eye-movement is impaired and a compensatory ‘catch-up’ saccade maintains the eyes on target. We sought to determine the vestibular and visual contributions to catch-up saccades in health and disease.

Methods: We studied 18 normal controls, 22 subjects after total unilateral vestibular-deafferentation (UVD) and 10 subjects with bilateral vestibular loss (BVL). All subjects were tested in bright light and total darkness with the video head impulse test (vHIT, GN Otometrics), head and eye velocity data were processed offline (LabView, NI). Statistical analysis used GLM and GEE models and Fischer’s exact test.

Results: In normals we detected a higher prevalence of small (0.6-1.3°, p=0.01) overt-saccades in the light (59%) compared with the dark (29%, p<0.000) while covert-saccades were very rare (0.5-1%, p=0.04). In UVD subjects, ipsilesional impulses conducted in light and dark generated covert-saccades of similar frequency (69 and 65%, p=0.08), magnitude (6.9 and 6.6°, p=0.68), and onset-latency (123 and 117ms, p=0.06). In contrast, in BVL subjects, covert-saccades were more frequent (56 vs 30%, p=0.00) of larger magnitudes (7.8 vs 4.3°, p=0.00) in light compared with darkness, but occurred at similar onset-latencies (135 and 131ms, p=0.51). Saccade peak velocities greater than 100°/s were lower in darkness (p<0.01).

Conclusions: Our results indicate that ipsilesional covert-saccades in UVD are a conditioned response to contralateral vestibular input. Covert-saccades in BVL however are light-dependant. These multisensory catch-up saccades could prove useful in tracking vestibular-rehabilitation.

OP08-2 - Sensory Substitution quantified via the Oculus Rift in Patients with Vestibular Dysfunction

23. Vestibular Compensation and Rehabilitation

Anat Lubetzky¹

Jennifer Kelly², Bryan Hujsak²

¹ New York University, Department of Physical Therapy, USA

² The New York Eye and Ear Infirmary of Mount Sinai, The Ear Institute, Hearing and Balance Center, Vestibular Rehabilitation, USA

Purpose: Patients with vestibular dysfunction typically employ a sensory substitution strategy by overly relying on visual or somatosensory cues. Our aims were: 1) assess the direct/inverse relationship of the sensory integration process, i.e., whether the weight of one sensory system decreases when the weight of another increases; 2) test whether these sensory substitution strategies are associated with self-reported disability via the Dizziness Handicap Inventory (DHI) and Activities-Specific Balance Confidence (ABC).

Methods: Twenty individuals with peripheral vestibular dysfunction and 16 age-matched controls (age range 24-81 and 24-79 respectively) were wearing the Oculus Rift and observed a 3-wall display of moving spheres in 2 scenes: (1) anterior-posterior movement (large 32mm amplitude, frequency 0.2Hz) and (2) medio-lateral movement (small 4.5mm amplitude, 0.48Hz). We quantified visual dependence via gains and postural sway directional-path in the anterior-posterior plane in scene (1), and somatosensory dependence via differences in directional-path for scene (2) between compliant and stable surfaces.

Results: Both visual and somatosensory dependence increased with age and this effect was more pronounced in patients with vestibular dysfunction. Among the patients, 4 were more visually dependent, 3 more somatosensory dependent and the rest were high or low on both. Visual dependence was significantly and negatively correlated at -0.7 (gains) and -0.6 (directional-path) with ABC but not with DHI. Somatosensory dependence was not significantly correlated with ABC or DHI.

Conclusions: The sensory weighting process was not inversely dependent in all patients. Patients who were visually dependent displayed reduced balance confidence in their daily living but not increased dizziness-related disability.

OP08-3 - Accel. and velocity vHIT gains after unilateral vestibular loss: Insights into neural compensation

23. Vestibular Compensation and Rehabilitation

John H.J. Allum¹

Taylor W Cleworth², Paul Kessler³, Flurin Honegger¹, Mark G Carpenter²

¹ Department of ORL, University of Basel Hospital, Basel, Switzerland

² School of Kinesiology, University of British Columbia, Vancouver, BC, Canada

³ Department ofORL, Cantonal Hospital of Basel-Land, Switzerland

Purpose: An acute unilateral peripheral vestibular deficit (aUPVD) causes deficient vestibular ocular reflex (VOR) control. The subsequent improvement of VOR deficit and contra-deficit side gains could be due to a greater increase in acceleration (phasic) than velocity (tonic) sensitive neural compensation (Minor and Lasker, JVR 2009). We examined this hypothesis using lateral video head impulse tests (vHIT).

Methods: 60 patients with vestibular neuritis were examined at aUPVD onset, 3 and 6 weeks later. Acceleration gain was computed as eye/head velocity over ±12ms around peak head acceleration. Velocity gain was calculated as eye/head velocity over ±12ms around peak head velocity with eye velocity shifted 8ms because it lags head velocity.

Results: Deficit side acceleration gains increased (p<0.01) from 0.46 at onset to 0.69 at both 3 and 6 weeks, and contra-deficit side acceleration gains from 0.88 to 0.96 respectively. Deficit side velocity gains increased (p<0.01) from 0.28 to 0.55 at both 3 and 6 weeks, and contra-deficit side velocity gains (p<0.05) from 0.82 to 0.90 respectively. Deficit side acceleration gain was significantly (p<0.01) higher than velocity gain at onset and at 3 weeks. Contra-deficit side velocity gains were still <1.0 at 6 weeks. Contra-deficit side acceleration gains were not different from 1.0 at 3 weeks. Improvement for both gains types post onset was similar.

Conclusions: These results indicate that greater acceleration rather than velocity sensitive compensatory neural mechanisms are active during the first 6 weeks of compensation for an aUPVD. The weaker velocity compensation is also apparent in contra-deficit side responses.

OP08-4 - Assessment of vestibulo-ocular reflex gain and catch-up saccades during Vestibular Rehabilitation

23. Vestibular Compensation and Rehabilitation

Augusto Pietro Casani¹

Elena Navari¹, Niccolò Cerchiai¹

¹ Pisa University Hospital, Italy

Purpose: to assess, in patients referred to vestibular rehabilitation (VR) for persistence of disability after acute unilateral vestibulopathy (AUV), whether the video Head Impulse Test (VHIT) can be a useful technique in order to define patients’ recovery.

Methods: 30 patients were prospectively evaluated; the main outcome measures included Dizziness Handicap Inventory score (DHI), high-velocity vestibulo-oculomotor reflex gain, asymmetry index, and catch-up saccade parameters. The tests were all performed at the beginning (4 and 8 weeks from the onset of the AUV), and after 10 weeks (end of the VR program).

Results: all patients reported a clear clinical improvement after VR, also demonstrated by better DHI scores (p < .001). A consistent increased gain and decreased asymmetry index were also observed (p < .001 for both). Patients did not show any change in covert saccades, while a statistically significant reduction of the number and amplitude of the overt saccades was interestingly detected (p=.009 and p=.030, respectively).

Conclusions: VR is a valid approach for patient with residual disability after AUV. A reduction in number and amplitude of overt saccades seems to be related to clinical improvement.

OP08-5 - Behavioral Evidence for Independently Modifiable Neural Circuits Mediating Concurrent VOR Adaptation

23. Vestibular Compensation and Rehabilitation

Yoav Gimmon¹

Americo Migliaccio², Chris Todd², Will Figtree²,

Michael Schubert¹

¹ Laboratory of Vestibular NeuroAdaptation, OHNS, Johns Hopkins University, USA

² Balance and Vision Laboratory, Neuroscience Research Australia

Purpose: Patients with unilateral damage to the Vestibulo-Ocular Reflex (VOR) typically also have a slightly reduced VOR gain (eye/head velocity) during contra-rotational head rotation due to loss of afference from the crossed inhibitory commissural vestibular pathway. Here, we conduct behavioral experiments to examine whether motor learning in the VOR is supported by separate and independently modifiable neural circuits. We sought to examine if the VOR could be driven simultaneously in opposite directions, i.e., increase for rotations to one side and decrease to the other.

Methods: Fourteen healthy subjects were each tested over three separate days to three randomly-applied paradigms of concurrent (right and left head rotation) VOR adaptation: 1) Up-gain bilaterally; 2) Down-gain bilaterally, or 3) Mixed (one side up, opposite side down). We used the unilateral incremental VOR adaptation technique with horizontal active head impulses as the vestibular stimulus. Active and passive VOR gains were measured before and after training.

Results: All three adaptation sessions caused significant Pre to Post VOR gain change (p<0.001) for both active and passive head rotation. Significant correlation between post training gain values and training condition was found (Pearson’s r=0.663). Linear regression predicted 51% of our result. There was no difference in the magnitude of VOR gain change between Up-gain to Mixed-Up (side) and Down-gain to Mixed-Down (side) trainings.

Conclusions: The right and left VOR can be driven concurrently in opposite directions, suggesting mediation from at least two independently modifiable neural circuits. This may be useful for developing rehabilitation strategies that reduce the VOR asymmetry in vestibular hypofunction.

OP08-6 - Effects of saccular function on recovery of subjective dizziness after vestibular rehabilitation

23. Vestibular Compensation and Rehabilitation

Junhui Jeong¹

Dae Bo Shim², Jinsei Jung³, Sung Huhn Kim³

¹ National Health Insurance Service Ilsan Hospital, Department of Otorhinolaryngology, Republic of Korea

² Myongji Hospital, Department of Otorhinolaryngology, Republic of Korea

³ Yonsei University College of Medicine, Department of Otorhinolaryngology, Republic of Korea

Purpose: We attempted to investigate whether the integrity of saccular function influences the severity of subjective dizziness after vestibular rehabilitation in vestibular neuritis.

Methods: Forty-six patients with acute unilateral vestibular neuritis were included and analyzed retrospectively. All patients completed vestibular rehabilitation therapy until their computerized dynamic posturography and rotary chair test results were significantly improved. The rehabilitation patients were classified into the normal to mild subjective dizziness and moderate to severe subjective dizziness groups according to the dizziness handicap inventory score (cut-off of 40). Differences between the two groups were analyzed.

Results: After rehabilitation, 32.6% of the patients still complained of moderate to severe dizziness. Age, gender distribution, the presence of comorbidities, caloric weakness, pre- and post-rehabilitation gain values in rotary chair test, post-rehabilitation composite scores in posturography, and the duration of rehabilitation were not significantly different between the two groups. However, initial DHI score and composite score in dynamic posturography were worse and the proportion of patients with absent cervical vestibular-evoked myogenic potential in the moderate to severe group was much higher (93.3% vs. 35.5%, p <0.001). After multiple regression analysis of those factors, initial DHI score and absent cVEMP response were identified as being associated with higher post-rehabilitation DHI score.

Conclusions: Saccular dysfunction in acute vestibular neuritis can contribute to persistent subjective dizziness, even after the objective parameters of vestibular function tests have been improved by vestibular rehabilitation.

OP08-7 - Efficacy of Gaze Stabilisation Exercises in Vestibular Dysfunction: A Systematic Review

23. Vestibular Compensation and Rehabilitation

Dara Meldrum¹

Evan Farrell², Regina Halpin², Colm O’Hare², Mark Wahba², Olive Lennon²

¹ School of Medicine, Trinity College Dublin

² School of Public Health, Physiotherapy and Sports Science, University College Dublin

Purpose: This systematic review examined evidence for efficacy of gaze stabilisation (GS) exercises as a stand-alone treatment or part of multimodal treatments for vestibular dysfunction. Comparators were sham/placebo, usual care or vestibular rehabilitation (VR) excluding GS exercises. Primary outcomes evaluated were dynamic visual acuity (DVA) and self-reported dizziness.

Methods: Electronic databases were searched from inception to January 1^st 2017. Randomised controlled trials of adults with confirmed vestibular disease where VR (including or comprising solely of GS exercises) in comparison to sham/placebo, usual care or VR excluding GS exercises were tested . Records were assessed by two independent reviewers.

Results: 22 studies, n=765 adults, were included with n=9 providing data for meta-analysis. When VR (including GS exercises) was compared with sham/no treatment, no DVA outcomes could be evaluated, but promising effects on Dizziness Handicap Inventory Scores (DHI) were noted from 2 studies with mixed and unspecified dysfunction (n=65 subjects; MD: -13.85; p=0.008 I² 68%). When VR (including GS exercises) was compared with VR (excluding GS exercises), no effect and high heterogeneity was noted in n=2 peripheral dysfunction studies on DVA (n=19 subjects; SMD: 0.84; p=0.14; I² 82%). Similarly, from n=5 studies, no effect on DHI total was observed (n=114 subjects; SMD: -0.13; p=0.50 I² 47%).

Conclusions: When considered as a stand-alone intervention or in addition to VR, insufficient data exist to conclusively address by meta-analysis, the efficacy of GS exercises on DVA in vestibular disease. Individual small RCTs demonstrated efficacy but could not be included in the MA due to heterogenous outcomes. Larger RCTs are required.

OP09-1 - A new numerical model : speed of migration of otonia under gravity action depending of their size.

4. Benign Paroxysmal Position Vertigo

THOMAS RICHARD-VITTON¹

AMITA TRIPATHI²

¹ Private Clinic of Marignane-France

² Fluidyn Computational Fluid Dynamics Saint-Denis-France

Purpose: Canaliths disorders are probably a larger group than the BPPVs, including these lasts but also a part of the dizziness with some symptoms that are not positional vertigo. We will present the results of the numerical model of the spontaneous migration of otoconia into a semi-circular canal under gravity action depending of their size. Secondary we will apply some hypergravity environment to reproduce the effect of mechanical assisted manoeuvres with the TRV CHAIR® that is used to help to treat canaliths disorders, and to measure its effects on particles migration.

Methods: We built a mathematical model of a canal with the same size that a posterior canal, 20 millimeters long and 150 micrometers diameter. Various sizes of particles were reproduced. Only gravity, then 0,75; 1 and 1,5 G deceleration were tested.

Results: The smallest particles (3,5 micrometers) take 70 minutes to make the trip of 20 millimeters from the cupula to the exit when the biggest (30 micrometers) make it within 30 seconds and it takes 6 minutes for a middle sized one (10 micrometers). The application of one G deceleration vetcor to the 3,5 sized particle makes its instantaneous speed 500 time faster.

Conclusions: The size of the particles have a very important influence to the sensivity of these lasts to gravity. It leads to consider that the canaliths disorders should have some very various expression depending of the size of the particles, and their number. The use of some mechanical assistance could be interesting to improve the canaliths disorders management.

OP09-2 - Association between serum vitamin D levels and BPPV in elderly patients

4. Benign Paroxysmal Position Vertigo

Wang Liyi¹

¹ ENTdepartment, Beijing hospital, China

Purpose: To investigate the association between serum vitamin D levels and benign paroxysmal positional vertigo in elderly patients.

Methods: 64 cases of elderly patients over 60 years old with BPPV as BPPV group and 100 cases of elderly people who got physical examination at the same period as the control group. The serum 25-hydroxyvitamin D₃ concentration of the two groups was analyzed.

Results: The 25-hydroxyvitaminD₃ was significant lower in BPPV group than in control P0.01The serum 25-hydroxyvitamin D₃ concentration was no significant difference between male BPPV patients and female BPPV patients. There was higher prevalence of vitamin D deficiency and severe deficiency in BPPV group than in control groupP0.01.

Conclusions: Vitamin D deficiency may be a risk factor for the onset of BPPV in elderly patients.

OP09-3 - Clinical investigation and analysis of the risk factors of benign paroxysmal positional vertigo

4. Benign Paroxysmal Position Vertigo

Zhan-guo Jin¹

Xiao-xu Chen¹, Jian-chang Wang¹

¹ General Hospital of Air Force, Aerospace Balance Medical Center, Beijing, China

Purpose: To investigate the risk factors of the recurrent reason of the benign paroxysmal positional vertigo.

Methods: A total of 175 elderly patients with primary BPPV confirmed our center who underwent repositioning therapy and were followed up for 12 months were retrospectively analyzed. The follow-up results were divided into 61 cases of recurrent BPPV patients and 141 cases of non-recurrent BPPV patients. During the same period, 73 young middle-aged patients were randomly selected as control group. The influencing factors of the recurrent BPPV was analyzed by Logistic regression method.

Results: There was no significant difference in age (68.03 / 66.71, P=0.107), sleep disturbance (48/127, P=0.129) and hypertension (96/79, P=0.065), but the difference was statistically significant in diabetes (40/135, P=0.003), migraine (61/114, P=0.004) and hyperlipidemia (104/71, P=0.025) between the recurrent BPPV elderly patients and the non-recurrent BPPV elderly patients.There was no significant difference between the middle-aged group recurrent and non-recurrent BPPV patients among gender (2.286/1.632, P=0.531), age (41.92/42.17, P=0.482), sleep disorders (32/41, P=0.29), diabetes(0), hypertension (10/63, P=0.715), hyperlipidemia (16/57, P=0.559), and cervical spondylosis (20/53, P=0.337), but the difference was statistically significant in tiredness (32/41, P=0.013), migraine(24/49, P<0.001).There was no significant difference in the recurrent rate of BPPV at 12 months (36.9%/31.5%, P=0.611), the type of BPPV (55/23, P=0.99), and the responsible semicircular canal (1.77/1.86, P=0.49) and the times of recurrence (94.83%/97.26%, P=0.398) also had no statistical significance.

Conclusions: Hyperlipidemia, diabetes mellitus and migraine are risk factors in the recurrent BPPV elderly patients, but fatigue, migraine are the risk factors of the recurrent BPPV young middle-aged patients.

OP09-4 - Correlations between scores of Eysenck Personality questionnaire and DHI in patients with BPPV

4. Benign Paroxysmal Position Vertigo

Yanmei Feng¹

Yuanyuan Sun¹, Hui Wang¹, Dongzhen Yu¹, Shankai Yin¹

¹ Shanghai Jiaotong University Affiliated Sixth People’s Hospital

Purpose: To evaluate whether there is a possible correlation between scores of Eysenck Personality Questionnai (EPQ) and Dizziness Handicap Inventory (DHI) in patients with benign positional paroxysaml vertigo.

Methods: 35 cases of BPPV patients confirmed by manual reduction were included in our research. They were investigated with EPQ and DHI in the first visit, 1 week after manual rehabitation.

Results: The mean values were 58.34±12.14, 47.97±12.95, 46±6.52; 58.2±6.71 for E, N, P, L, respectively. DHI scores were 50.85±25.31 before treatment, and 35.76±32.67 1 week after manual reduction. The mean courses of disease were 17.08±10.74 days. Correlation analysis showed no significant correlations between E, N, P, L and DHI scores both before and after treatment and the improvement of DHI scores (all p>0.05). There were also no significant correlations between scores of E, N, P, L and courses of disease (all p>0.05).

Conclusions: There were no significant correlations between E, N, P, L and DHI scores both before and after treatment.

OP09-5 - Establishment of clinical diagnosis procedure in patients with benign paroxysmal positional vertigo

4. Benign Paroxysmal Position Vertigo

Xu Yang¹

Xia Ling¹

¹ Department of Neurology, Aerospace Center Hospital, Peking University Aerospace School of Clinical Medicine, Beijing, China.

Purpose: To establish a clinical diagnosis procedure of benign paroxysmal positional vertigo (BPPV).

Methods: 331 patients with BPPV were included. All patients underwent positional tests(PT), including Dix-Hallpike test, straight head hanging test and Roll test in the naked eye and videonystagmography examinations. Patient’s hearing and vestibular function were also evaluated. Patients with an unclear diagnosis were followed-up until a definitive diagnosis was obtained.

Results: 407 patients were initially included because of transient dizziness/vertigo caused by changes in head position. 27 patients with orthostatic hypotension, 18 patients with vestibular migraine, and 12 patients with central paroxysmal positional vertigo were excluded, thus 331 patients with BPPV were included. Medical history: positional vertigo was observed in 221 (66.8%) patients, positional dizziness in 56 (16.9%) patients, stumbling in 36 (10.9%) patients, and blurred vision in 18 (5.4%) patients. Physical examinations: typical BPPV was confirmed in 209 (63.1%) patients in the naked eye examination, with single PT examination in 152 patients and twice PT in 57 patients. Atypical BPPV was confirmed in 122 (36.9%) patients, with twice PT in 28 patients in naked eye, videonystagmograpy examination in 57 patients, and experience-based repositioning and follow up in 37 patients. Hearing and vestibular evaluation: 81 (24.5%) patients had vestibular dysfunction and 87 (26.3%) patients had impaired hearing. Primary/secondary BPPV: 205 (61.9%) patients primary BPPV and 126 (38.1%) patients secondary BPPV.

Conclusions: Typical and primary BPPV is easy to diagnose, but atypical and secondary/concomitant BPPV often require further layered diagnosis based on medical history, physical examination, vestibular evaluation and dynamic follow-up.

OP09-6 - Horizontal canal benign paroxysmal positional vertigo: Lempert vs Gufoni

4. Benign Paroxysmal Position Vertigo

Isaura Rodríguez-Montesdeoca¹

Gloria Guerra-Jiménez¹, Antonio Espinel-León¹, Barbara Mentado Sosa¹, Julieta Portiglia², Ángel Ramos Macías¹

¹ Complejo Hospitalario Insular Materno Infantil de Las Palmas de Gran Canaria, Spain

² Argentina

Purpose: Benign paroxysnal positional vértigo (BPPV) is a frequent and disabling entity. Horizontal canal (HSC) is the second canal most affected. There is little evidence about compared effectiveness of Lempert (LM) vs Gufoni (GM) repositioning maneuvers. The aim of this study is to compare the different maneuvers and to expose our results.

Methods: We present an observational retrospective study over HSC-BPPV outpatients of a tertiary hospital with results between January 2015 and January 2017 . Complete personal and vestibular history and clinical evaluation have been recorded. The exclusion criteria include: anterior, posterior or multicanal BPPV.;atypical nystagmus;other vestibular or neurological disease.

Results: 50 (28%) outpatients were diagnosed of BPPV. 16 (32%) HSC-BPPV patients (2:1, women:men) of 61 years on average; 11 Canalolithiasis and 5 Cupulolithiasis. Among canalolithiasis, LM (n = 6) or GM (n = 5) were performed: it were observed a higher resolution percentage in Gufoni’s group both in first (n=4, 80%; n=2, 33%; p=0.175) and second maneuver (n=1, 100%; n=1, 25%; p=0.4) without statistical significance. All cupulolithiasis were treated by GM, with a resolution percentage of 60% after the first maneuver and 50% after the second. Recurrence was higher in cupulolithiasis (n=1, 20%-n=2, 9%) and slightly higher for GM (n=1,20%-17%).

Conclusions: Since Lempert and Gufoni maneuvers are effective in the treatment of HSC-BPPV, there is a clinically significant higher success percentage for Gufoni’s one in our sample. It is possible that larger sample sizes studies could find statistical differences.

OP10-1 - Altered functional brain connectivity in patients with visually induced dizziness

10. Functional and Psychiatric Vestibular Disorders

Angelique Van Ombergen¹

Lizette Heine²,

Steven Jillings¹, Edward R. Roberts³, Ben Jeurissen⁴, Vincent Van Rompaey⁵, Viviana Mucci¹, Stefanie Vanhecke⁵, Jan Sijbers⁴, Floris Vanhevel⁶, Stefan Sunaert⁷, Mohamed Ali Bahri⁸, Paul M. Parizel⁶, Paul Van de Heyning⁵, Steven Laureys², Floris Wuyts¹

¹ University of Antwerp, Antwerp University Research center for Equilibrium and Aerospace (AUREA), Belgium

² University of Liège, COMA science group - GIGA consciousness, Belgium

³ Imperial College London, Neuro-otology Department, United Kingdom

⁴ University of Antwerp, iMinds-Vision Lab, Belgium

⁵ Antwerp University Hospital, Department of Otorhinolaryngology, Belgium

⁶ Antwerp University Hospital, Department of Radiology, Belgium

⁷ University of Leuven, Department of Imaging and Pathology - Translational MRI, Belgium

⁸ University of Liège, GIGA-Cyclotron Research Center - In Vivo imaging , Belgium

Purpose: Patients experiencing dizziness caused or aggravated by challenging visual stimuli have now been classified as visually induced dizziness (VID). The pathophysiology of this condition is poorly understood. Hereto, we conducted an explorative resting-state functional MRI study on 10 VID patients to investigate possible changes in functional connectivity in this patient group.

Methods: 10 VID patients and 10 age- and gender-matched healthy controls participated in the study. Data were acquired on a 3T MRI scanner and 280 volumes of functional resting-state data were acquired by a T2* weighted EPI sequence. Data analysis was divided in a hypothesis-free analysis using the intrinsic connectivity contrast (ICC) and a region of interest (ROI) analysis with seeds in vestibular and visual brain areas.

Results: When considering the VID group versus controls, a decreased connectivity between the superior temporal gyrus/posterior insula (primary vestibular area) and the rest of the brain was noted. Increased connectivity was found between the primary visual cortex and the rest of the brain. ROI analysis revealed altered functional connectivity between the visual association area and higher-order brain regions involved in spatial orientation. Also the thalamus revealed altered connectivity with the cerebellum, basal ganglia and primary visual cortex.

Conclusions: This first neuroimaging perspective on VID revealed stronger connectivity within visual areas and weaker connectivity in the primary vestibular area. These findings are in line with the behavioural profile of VID patients, namely increased reliance on visual cues for spatial perception. These findings provided a first framework for future neuroimaging studies and treatment options for VID patients.

OP10-2 - Alternatives to Treat Associated Symptoms of Mal de Debarquement Syndromes (MdDS)

10. Functional and Psychiatric Vestibular Disorders

Mingjia Dai¹

Yakushin Sergei B¹

¹ Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, USA

Purpose: The Mal de Debarquement Syndrome (MdDS) is primarily characterized by a continuous feeling of swaying and rocking (primary symptoms), commonly follows water or air travels. The primary symptoms are also accompanied by many other associated symptoms, such as a static force pulling in a particular direction, floor undulating or bouncing when walking, circular motion of the body, general woozy feeling, head pressure, heaviness or floating of body, elevated visual sensitivity and agoraphobia. We recently demonstrate that primary symptoms could be treated by re-adaptation of the vestibulo-ocular reflex (VOR, Dai et al., 2014, standard treatment). Accompanied symptoms are also decreased after treatment (Dai et al., 2017). Sometimes, however, accompanied symptoms persist.

Methods: Over the last several years while treating more than 400 patients, we have developed and used alternative optokinetic (OKN) stimuli and visual vestibular interactions to treat specific symptoms.

Results: The results of these alternative treatments are promising. Interestingly, the alternative treatment sometimes alone effectively reduces both primary and companion symptoms.

Conclusions: Recently, we have had an increased rate of successful treatment. This may be due to the application of the alternative procedures. The background, hypotheses and outcomes will be presented and discussed.

OP10-3 - Decreased Spontaneous Functional Activity of left PIVC in Persistent Postural-Perceptual Dizziness

10. Functional and Psychiatric Vestibular Disorders

Xu Yang¹

Kangzhi Li¹

¹ Department of Neurology, Aerospace Center Hospital, Peking University Aerospace School of Clinical Medicine, Beijing, China.

Purpose: To investigate the changes of brain spontaneous functional activity in patients with persistent postural-perceptual dizziness (PPPD).

Methods: Seven patients (3 males and 4 females) with PPPD were enrolled. All patients underwent detailed medical history acquisition; cranial MRI, peripheral vestibular function evaluation, internal medicine and laboratory tests were performed to exclude other chronic dizziness lesions. SVDS, CVS, DHI score were performed to assess the patient’s symptoms. The patients confirmed PPPD were further scanned by fMRI. Fractional Amplitude of Low Frequency Fluctuation (fALFF) was calculated to investigate the changes of brain spontaneous functional activity in patients with PPPD.

Results: In PPPD patients, the fALFF values of the left-sided PIVC region were significantly lower than healthy subjects (P < 0.05, FDR corrected). Further correlation analysis showed no significant correlations between SVDS , CVS , DHI score and this area. The length of history had a negative correlation with the spontaneous activity of the brainstem and a positive correlation with inferior occipital gyrus and gray matter near the central sulcus . SVDS score was positively correlated with the occipital lobe, the right PIVC and Supp_motor_area (P < 0.05, FDR corrected).

Conclusions: (1) Spontaneous functional activity in the left PIVC of PPPD patients is often decreased. (2) The severity of subjective symptoms in patients was positively correlated with the spontaneous functional activity of occipital lobe, right PIVC area, and Supp_motor_area. The duration of the medical history was negatively correlated with the functional activity of the brain stem, and positively correlated with suboccipital gyrus and the gray matter near central sulcus.

OP10-4 - Integrating mental and physical health assessment in neuro-otology

10. Functional and Psychiatric Vestibular Disorders

David Herdman¹

Helen Sharma¹, Louisa Murdin¹

¹ Guys & St Thomas’ NHS Foundation Trust, Multidisciplinary Balance Clinic, UK

Purpose: To assess the feasibility and acceptability of a web-based informatics system for collection of patient-reported outcomes, with real-time feedback to guide clinical care in a specialist neuro-otology clinic, and to describe the prevalence of common psychological symptoms.

Methods: Nine hundred and fifty-four consecutive patients (69.6% female, M age 51, range 16-90) completed the web-based questionnaire comprising patient-reported outcome measures at their initial appointment. Data was analysed retrospectively. Condition specific questionnaires included the Dizziness Handicap Inventory, Headache Impact Test, Situational Vertigo Questionnaire and Disability Rating Scale. Psychological symptoms were screened using the Patient Health Questionnaire-9 and Generalised Anxiety Disorder Questionnaire-7. Feasibility was quantified as the proportion of patients who completed the questionnaire. Acceptability was quantified as the proportion of patients declining screening.

Results: The proportion of patients who successfully completed the screen was high (70%).The decline rate was low (7%). The most common reason to decline was lack of confidence in using IT. The prevalence of probable depression was 21% and for probable anxiety was 29%. Suicidal ideation was present in 5%. The proportion of patients who reported either recent or long term severe disability was 11%. The proportion of patients reporting high impact headache was 54%. Anxiety and depression were strongly correlated to dizziness handicap, disability and all other outcome measures (p<0.001).

Conclusions: Patients attending a specialist neuro-otology service are at risk of common mental disorders. Web-based screening is feasible and acceptable to patients in this setting, helping to identify service needs, inform care and monitor outcomes.

OP10-5 - Interaction of Time Pressure and Anxiety upon Spatial orientation judgments

10. Functional and Psychiatric Vestibular Disorders

Qadeer Arshad¹

¹ Imperial College

Purpose: Spatial orientation is achieved via the integration of visual, vestibular and proprioceptive cues. The degree to which an individual relies on visual cues instead of the others is termed visual dependency. Perceptual judgements, such as spatial orientation, are affected by psychological factors, like anxiety and contextual influences like time pressure. However, the impact of time pressure and innate levels of anxiety upon visual dependency have not been investigated. Therefore, we assessed the impact of time pressure on visual dependency and how this relationship is modulated by anxiety.

Methods: In 44 healthy subjects, the effect of time pressure on visual dependency was measured using the rod-disk test, where participants align a rod to their perceived gravitational vertical during background visual motion, in the absence of any visual reference cues to vertical. The experimental procedure was split in two parts; a baseline condition (average completion time 7 seconds) and a time pressure condition where subjects were given a maximum of 3 seconds to complete the task. Non-situational levels of anxiety i.e. trait anxiety and situational levels of anxiety i.e. state anxiety were quantified using the Spielberg State Trait Anxiety Inventory.

Results: Higher trait anxiety levels correlated with reduced visual dependency under time pressure compared to baseline conditions (R²= 0.393, p=5.31x10-6). State anxiety did not influence the levels of visual dependency in either condition.

Conclusions: Levels of trait anxiety influenced the impact of time pressure on visual dependency. Counterintuitively, time pressure reduces inaccuracy in perceptual judgements for individuals with higher trait anxiety.

OP10-6 - The cognitive-behavioural correlates of dizziness related interference

10. Functional and Psychiatric Vestibular Disorders

David Herdman¹

Sam Norton¹, Marousa Pavlou², Louisa Murdin³, Rona Moss-Morris¹

¹ King’s College London, Health Psychological Section, UK

² King’s College London, Centre of Human & Aerospace Physiological Sciences, UK

³ Guy’s & St Thomas’ NHS Foundation Trust, ENT Department, UK

Purpose: To determine the contribution of cognitions, behaviours and emotions to explain the variance in dizziness related handicap (interference) over and above demographic and objective illness measures.

Methods: One-hundred and eighty-five consecutive patients who were on the waiting list to attend an initial diagnostic appointment for dizziness related symptoms completed a cross-sectional survey including valid and reliable psychometric questionnaires. Dizziness handicap was measured using the Dizziness Handicap Inventory and the psychological questionnaires included the Patient Health Questionnaire-9, Generalised Anxiety Disorders-7, Illness Perceptions Questionnaire – Revised, Cognitive and Behavioural Responses to Symptoms Questionnaire, Psychological Vulnerability Questionnaire and the Beliefs About Emotions Scale. Correlations and hierarchical multiple regressions determined the relative contribution of illness severity, psychological distress, cognitions, and behaviours to the prediction of dizziness related handicap.

Results: All psychosocial factors including distress, negative beliefs about dizziness and its consequences, cognitive and behavioural responses to symptoms were related to dizziness outcomes. The total hierarchical regression model explained 70% of the variance in dizziness handicap. Only six percent was explained by demographic factors and a further 43% was explained by illness factors, which included visually triggered dizziness (Situational Vertigo Questionnaire). A further 23% was uniquely accounted for by the psychological factors, which was statistically significant.

Conclusions: The psychosocial factors identified as important in predicting dizziness handicap are potentially modifiable and thus may be useful to address within interventions in the future and highlight the importance of adopting a biopsychosocial approach in this setting.

OP10-7 - Vestibulo-cortical Hemispheric Dominance: the link between Anxiety and the Vestibular System?

10. Functional and Psychiatric Vestibular Disorders

Qadeer Arshad¹

¹ Imperial College

Purpose: Vestibular processing and anxiety networks are functionally intertwined, as demonstrated by reports of reciprocal influences upon each other. Previous findings have also highlighted the involvement of hemispheric lateralisation in processing of both anxiety and vestibular signals. Yet whether there is an underlying neural mechanism relating these two systems remains unknown.

Methods: Accordingly, we explored the interaction between vestibular cortical processing and anxiety by assessing the relationship between anxiety levels and the degree of hemispheric lateralisation of vestibulo-cortical processing in 64 right-handed, healthy individuals. Vestibulo-cortical hemispheric lateralisation was determined by gaging the degree of caloric-induced nystagmus suppression following modulation of cortical excitability using trans-cranial direct current stimulation targeted over the posterior parietal cortex, an area implicated in the processing of vestibular signals. The degree of nystagmus suppression yields an objective biomarker, allowing the quantification of the degree of right vestibulo-cortical hemisphere dominance. Anxiety levels were quantified using the Trait component of the Spielberger State-Trait Anxiety Questionnaire.

Results: Our findings demonstrate that the degree of an individual’s vestibulo-cortical hemispheric dominance correlates with their anxiety levels. That is, those individuals with greater right hemispheric vestibulo-cortical dominance exhibited lower levels of anxiety.

Conclusions: By extension, our results support the notion that hemispheric lateralisation determines an individual’s emotional processing, and hereby we suggest a possible mechanistic link between cortical circuits involved in processing anxiety and vestibular signals respectively.

OP11-1 - CI and vestibular assessment: controversies, measurement bias and ostensible clinical impact .....

8. Cochlear Implant and Vestibular Function

Andy J Beynon¹

¹ Radboud University Medical Centre Nijmegen, The Netherlands

Purpose: Investigating the apparent clinical need and value of semicircular canal assessment in CI candidates and users.

Methods: Pre- vs -postoperative hearing and vestibular function were analyzed in 626 patients. Subjects underwent pre-post caloric irrigational testing, rotary chair testing, vHIT and completed the Dizziness Handicap Inventory. Canal functionality was compared and in contrast to all previous studies, categorical analysis were applied and contralateral (non-implanted) side was also taken into account. Possible deterioration (or complete loss) after CI was defined using a 4 category scale. Objective and subjective vestibular measures of previous studies are compared with recent data.

Results: Present group data show extremely small, although statistically significant, postop vestibular reduction: 3.1 °/s and 4.7 °/s (warm and cold irrigation, respectively). 37.4% of patients dropped 1 or more categories. Similarly, vHIT data also showed small, but significant VOR decrease of -0.057, -0.040 and -0.045 (anterior, lateral and posterior canal gains, respectively). Subjective symptoms (DHI) did not show any postop changes for composite total score, as well for scores on functional and emotional subdomains. The physical subdomain score however, showed small but significant increase. Behaviourally, 9.0% show a deterioration of 1 or more categories.

Conclusions: In contrast to many previous smaller studies (including our own), this study did not show any relevant clinical impact on group level for canal testing (calorics & vHIT) at all, taken into account contralateral ear and categorical deterioration. Nevertheless, on the individual level, CI can still lead to serious individual vestibular changes, still justifying pre- and postop behavioural and objective assessment.

OP11-2 - Intralabyrinthine schwannomas: vestibular function after surgery with/without cochlear implantation

8. Cochlear Implant and Vestibular Function

Stefan Plontke¹

Laura Fröhlich¹, Torsten Rahne¹

¹ Department of Otorhinolaryngology, Head & Neck Surgery, Martin Luther University Halle-Wittenberg, University Medicine Halle, Germany

Purpose: Intralabyrinthine schwannomas (ILS) are a rare differential diagnosis of sudden hearing loss and vertigo. We describe the outcome after surgical tumor removal through subtotal or partial cochleoectomy and/or labyrinthectomy with or without cochlear implantation (CI).

Methods: In an own case series of 24 patients, 11 tumors showed an intracochlear, 3 an intravestibular, 3 an intravestibulocochlear, 3 a transmodiolar, 1 a transmodiolar with CPA, 1 a transotic with CPA and 2 a multilocular location. 16 patients received surgery for tumor removal, 4 patients are scheduled for surgery and 8 patients decided for a “wait-and-test-and-scan (W&T&S)”-strategy.

Results: The 3 intravestibular tumors were removed via labyrinthectomy and patients received a CI in a single stage procedure. Nine intracochlear tumors were surgically removed via an extended cochleostomy with single stage CI (x1), via partial or subtotal cochleoectomy and partial cochlear reconstruction with CI (x6) or implantation of an electrode dummy for follow up with MRI and possible later CI (x2), or via labyrinthectomy and partial cochleoectomy (x2). The transotic and the transmodiolar tumors were removed via a translabyrinthine approach. For the intracochlear tumors, vestibular function could be at least partially preserved after surgery. In all but one case, hearing rehabilitation with CI was successful.

Conclusions: Surgical removal of ILS is recommended before tumor growth leads to a complete filling of the cochlea or before a transmodiolar or transmacular growth complicates surgical removal and prevents cochlear implantation. If done early enough, CI after surgical removal of ILS is an option and an alternative to a “W&T&S” strategy.

OP11-3 - Music May Improve Gait Pattern in Cochlear Implant Patients with Bilateral Caloric Areflexia.

8. Cochlear Implant and Vestibular Function

Vincent Van Rompaey¹

Griet Mertens¹, Paul Van de Heyning¹, Ann Hallemans²

¹ University of Antwerp, Dept. Translational Neurosciences, Belgium

² University of Antwerp, Multidisciplinary Motor Center Antwerp, Belgium.

Purpose: Patients with bilateral caloric areflexia suffer from imbalance, resulting in an increased risk of falling. In case of simultaneous deafness, the lack of auditory feedback results in less auditory scene awareness. Our aim was to explore the relationship between cochlear implant (CI) stimulation, auditory feedback and gait.

Methods: Adults (seven males, one female, mean age 61 ± 14 years), wearing a CI to treat profound sensorineural hearing loss and presenting with bilateral caloric areflexia walked barefoot, over ground, at self-selected speed in three different conditions: CI on, while listening to music and CI off. Spatiotemporal and kinematic parameters were calculated using the conventional gait model.

Results: Removing auditory feedback by turning off the CI decreased stride time (mean difference 0.03 ± 0.15 s) and slightly increased stride length (mean difference 0.5 ± 1.2 cm) compared to the control condition with the CI on. Walking while playing music positively affected gait compared to walking with the CI on but without auditory feedback. By increasing the motion of the pelvis (mean difference 1.3° ± 0.4°), the knee (mean difference 3.9° ± 0.8°) and the ankle (mean difference 2.2° ± 0.2°), stride length increased (7.8 ± 1.2 cm), while stride time decreased (0.059 ± 0.016 s).

Conclusions: This pilot study suggests that playing music while wearing an active CI may improve gait in patients with bilateral otovestibular loss. It remains unclear if the musical cues boost balance control or the CI might produce current spread and electrical stimulation to the vestibular afferents.

OP11-4 - Preservation of vestibular function after cochlear implantation with round window approach

8. Cochlear Implant and Vestibular Function

Katsumi Doi¹

Ko Shiraishi¹, Toru See¹, Takeshi Fujita¹, Kazuya Saito¹

¹ Department of Otolaryngology & HNS, Kindai University Faculty of Medicine

Purpose: Nowadays, the preservation of cochlear function can be highly predicted after cochlear implantation (CI) by using round window approach (RWA) with a combination of systemic and local applications of steroid during the surgery. The preservation of vestibular function might also be possible and highly expected after CI surgery with RWA.

Methods: Caloric response, vHIT response, oVEMP, and cVEMP were recorded before and after CI surgery.

Results: The preservation of vestibular function after CI surgery was compared between two procedures: CI surgery with classic cochleostomy (n=5) and CI surgery with RWA (n=12). All the surgeries were done by a single senior oto-surgeon. Caloric response was preserved in 40% of CI surgery with cochleostomy (n=5), while it was preserved in 83% of CI surgery with RWA (n=12). vHIT response was preserved in 50% of CI surgery with cochleostomy (n=4), while it was preserved in 83% of CI surgery with RWA (n=12). oVEMP was preserved in 50% of CI surgery with cochleostomy (n=2), while it was preserved in 89% of CI surgery with RWA (n=9). cVEMP was preserved in 80% of CI surgery with cochleostomy (n=5), while it was preserved in 92% of CI surgery with RWA (n=12)

Conclusions: These results suggest that CI surgery with RWA should have an advantage over CI surgery with cochleostomy in the preservation of inner ear functions. Systemic and local applications of steroid during the surgery would be strongly recommended to reinforce it.

OP11-5 - Vestibular and Balance Function is Impaired in Children with Unilateral Sensorineural Hearing Loss

8. Cochlear Implant and Vestibular Function

Sharon Cushing¹

Meirav Sokolov¹, Karen Gordon², Melissa Polonenko², Susan Blaser³, Blake Papsin¹

¹ Department of Otolaryngology, Head and Neck Surgery, Hospital for Sick Children, University of Toronto

² Archie’s Cochlear Implant Laboratory, Hospital for Sick Children, University of Toronto

³ Deparment of Diagnostic Imaging, Hospital for Sick Children, University of Toronto

Purpose: Children with unilateral deafness could have concurrent vestibular dysfunction which would be associated with balance deficits and potentially impair overall development. The prevalence of vestibular and balance deficits remains to be defined in these children.

Methods: Twenty children with unilateral deafness underwent comprehensive vestibular and balance evaluation.

Results: More than half of the cohort demonstrated some abnormality of the vestibular end organs (otoliths and horizontal canal), with the prevalence of end organ specific dysfunction ranging from 17-48% depending on organ tested and method used. In most children, impairment occurred only on the deaf side. Children with unilateral deafness also displayed significantly poorer balance function than their normal hearing peers.

Conclusions: The prevalence of vestibular dysfunction in children with unilateral deafness is high and similar to that of children with bilateral deafness. Vestibular and balance evaluation should be routine and the functional impact of combined vestibulo-cochlear sensory deficits considered.

OP11-6 - Vestibular function after cochlear implantation in partial deafness treatment

8. Cochlear Implant and Vestibular Function

Magdalena Sosna¹

Katarzyna Pietrasik¹,

Grażyna Tacikowska¹, Henryk Skarżyński¹, Piotr H. Skarżyński¹, Maria Matuszewska¹

¹ Institute of Physiology and Pathology of Hearing, Warsaw

Purpose: Nowadays, the indications for cochlear implantation have been broadened and include the patients with bilateral profound deafness, partial deafness and unilateral deafness. It requires to put the great emphasis to protect not only the cochlear but also the vestibular function. The aim of the study is to assess the postoperative vestibular function with the application of hearing preservation techniques and to determine whether the type and insertion depth of the electrode have the impact on vestibular status after cochlear implantation in partial deafness treatment.

Methods: The patients who underwent cochlear implantation procedure were divided into three groups according to the type of the electrode applied in cochlear implantation: perimodiolar, straight, flexible electrode. Each patient was assessed with cVEMP, oVEMP, caloric tests, vHIT and fulfilled the questionnaire before and 6 months after the operation.

Results: The vestibular disorders are rare, transient and in early postoperative period. Despite applying hearing preservation techniques, the possibility of vestibular damage still exists. The rate of vestibular function loss was as follows: cVEMP response in 16,3%, oVEMP response in 13,6%, reduction in caloric reponse (change from normal response to unilateral weakness or unilateral weakness to areflexia) in 7,9% of the whole study population. The vestibular function was better preserved after insertion of flexible electrodes than perimodiolar or straight electrodes. No significant difference in postoperative vestibular function was observed between the various length of inserted electrodes.

Conclusions: Application of hearing preservation techniques in partial deafness treatment has significantly diminished the rate of vestibular disorders after cochlear implantation.

OP11-7 - Vestibular function pre and post Cochlear implant in 71 patients

8. Cochlear Implant and Vestibular Function

Sergio Carmona¹

René Márquez¹, Romina Weinschelbaum¹, Patricia Sommerfleck²

¹ Neuro-otology. Instituto Superior de ORL. Buenos Aires. Argentina

² Pediatric Otolaryngology. Garraham Hospital. Buenos Aires. Argentina

Purpose: There is no doubt that cochlear implant has been the most important contribution made by otologic surgery to the disabilities caused by profound hearing loss, both in children and in adults, there is not information about the vestibular function.

Methods: 71 adult and pediatric patients with profound bilateral deafness of different etiologies,were studied. The possible cause of deafness was obtained and a Video Head Impulse Test was performed to all of them pre implant and a month late.

Results: The vestibular function previous to the implant was not significantly affected except in 9.72% of the cases. In most patients, the coclear implant did not significantly modify the VOR function. In the group of patients who previously had a damaged or asymmetric vestibular function, if the best ear is implanted, this could cause a bilateral vestibular failure, so that the ear with the lowest gain should be chosen to be implanted

Conclusions: The implant, when performed by experienced professionals, does not affect vestibular function, except in those cases where it is already damaged or asymmetric

OP12-1 - Spatial Selectivity of Eye Movements Elicited by Combined Otolith and Semicircular Canal Stimulation

26. Vestibular Prosthesis

Kristin Hageman¹

Margaret Chow¹, Dale Roberts², Charles Della Santina²

¹ Johns Hopkins School of Medicine, Department of Biomedical Engineering, USA

² Johns Hopkins School of Medicine, Department of Otolaryngology - Head and Neck Surgery, USA

Purpose: The semicircular canals (SCCs) and otolith end organs encode head movements with different kinematics and temporal dynamics. We examined the spatial selectivity and range of eye movements evoked by individual and combined stimulation of electrodes in SCCs and otolith end organs intended to encode head tilts about different Earth-horizontal axes.

Methods: We fit three chinchillas with head posts and binocular scleral coils for tracking 3D eye movements. We implanted a polyimide vestibular electrode array with 26 otolith and 24 SCC contacts into the left ear. Bipolar current pulses were delivered while the animals were kept still in dark, driving electrically evoked eye movements. Eye movements were recorded during a constant pulse train (encoding a virtual static tilt) delivered via multiple electrode configurations.

Results: Providing a step change in pulse rate to different electrode pairs resulted in an ocular counter-roll for the duration of the virtual static tilt. A linear increase in pulse rate or pulse amplitude on the same pair of electrodes elicited a linear increase of the magnitude of the eye movement. The direction and magnitude of ocular counter-roll responses depended on the relative locations of the pairs of electrodes intended to stimulate different locations on the maculae.

Conclusions: Spatially selective stimulation of different regions within a utricular or saccular macula can repeatedly elicit eye movement responses consistent with those expected for static head tilts about different axes, indicating that stimulation of the utricle and saccule may serve as a useful complement to prosthetic SCC stimulation for encoding head tilt and translation.

OP12-2 - Clinical evaluation of a new bone conduction transducer for VEMP

7. Clinical Testing for Vestibular Function

Karl-Johan Fredén Jansson¹

Bo Håkansson¹, Sabine Reinfeldt¹, Cristina Rigato¹, Tomas Tengstrand², Elisabeth Dahlström³, Måns Eeg-Olofsson³

¹ Chalmers University of Technology, Electrical Engineering, Sweden

² University of Gothenburg,Department of Audiology, Sweden

³ Sahlgrenska University Hospital, Department of Otolaryngology, Sweden

Purpose: The aim of this study is to in clinical vestibular evoked myogenic potential (VEMP) evaluate a prototype version of a new bone conduction (BC) transducer, called B250. Conventionally, VEMP responses has been evoked using air conduction (AC) ear-phones, which requires high sound levels and is limited to patients without conductive hearing loss. By using BC stimuli, the sound level can be decreased and conductive hearing losses by-passed. BC stimuli are today commonly applied with a Minishaker B&K4810 or audiometric transducers neither optimal nor intended for VEMP.

Methods: This study is ongoing and includes otologically normal hearing subjects, patients with conductive hearing loss and vestibular disorders between 18 and 65 years. Cervical (cVEMP) and ocular (oVEMP) responses are compared for AC ear-phones as well as the audiometric BC transducer Radioear B81 and the B250 prototype. Thresholds, peak values and latencies are determined for tone-bursts and click-sound stimuli. Furthermore, the findings are compared with literature data.

Results: Based on three otologically normal test subjects, BC stimuli with B250 were up to 40 dB more efficient than AC-stimuli. Also, BC stimuli with B250 were superior at 250 Hz compared to 500 Hz. One patient with conductive hearing loss, who was unable to evoke a VEMP response for AC stimuli, was tested and found have clinically viable VEMP responses using B250.

Conclusions: Preliminary results suggest B250 as an alternative for clinical VEMP testing. Data from more subjects will be presented at the meeting.

OP12-3 - oVEMP: A novel tool for non-invasive intracranial pressure monitoring

22. Vestibular and Inner Ear Physiology

Robert Gürkov¹

Louis Wittwer², Guillaume Speierer², René Müri², Georgios Mantokoudis³, Claudia Jerin⁴, Roger Kalla²

¹ University of Munich, Otorhinolaryngology, Germany

² University of Bern, Neurology, Switzerland

³ University of Bern, Otorhinolaryngology, Switzerland

⁴ University of Munich, Otorhinolaryngology & German Vertigo Centre, Germany

Purpose: Ocular VEMP (oVEMP) are currently being established as a rapid and simple test for utricular function. Here, we present a novel application for VEMP.

Methods: OVEMP were recorded from controls and from patients with idipathic intracranial hypertension (IIH). Tilt-table experiments with “body-up” inclination angles at 0-30 degrees were performed in controls. The influence of stimulus frequency (500 or 1000 Hz) and type (ACS or BCV) were examined with respect to their sensitivity to intracranial pressure (ICP) changes. Repeated measurements before and after lumbar drainage were performed in patients with IIH. The correlations were examined and the diagnostic accuracy to detect ICP changes was calculated.

Results: Tilt table experiments in 20 controls revealed a highly significant linear correlation between tilt angle and ACS oVEMP amplitude (R=0.999; p < 0.01). This effect was restricted to the ACS stimulus (p=0.001 for ACS oVEMP) and it was restricted to the 500 Hz stimulus (p <0.001 for 500 Hz ACS). Repeated ACS oVEMP measures before and after lumbar drainage in ten patients with IIH confirmed the correlation between the oVEMP amplitude reduction and the CSF pressure reduction. In each individual patient, the oVEMP amplitude was reduced by at least 30% after the lumbar drainage. BCV oVEMP remained unchanged. The diagnostic accuracy for the detection of a change in CSF pressure of 10 cm H₂O was 100%.

Conclusions: These data confirm with direct evidence the principal suitability of ACS oVEMP measurements for monitoring of intracranial pressure.

OP12-4 - Repetitive oVEMP stimulation for myasthenia gravis: optimization of stimulus parameters

15. Ocular Motility: Physiology and Pathology

Magdalena A. Wirth¹

Yulia Valko², Sally M. Rosengren³, Tanja Schmueckle-Meier¹, Christopher J. Bockisch⁴, Dominik Straumann², Klara Landau¹,

Konrad P. Weber⁵

¹ University Hospital Zurich, Department of Ophthalmology, Switzerland

² University Hospital Zurich, Department of Neurology, Switzerland

³ Royal Prince Alfred Hospital Sydney, Department of Neurology, Australia

⁴ University Hospital Zurich, Departments of Ophthalmology, Neurology and ENT, Switzerland

⁵ University Hospital Zurich, Departments of Neurology and Ophthalmology, Switzerland

Purpose: Early diagnosis of myasthenia gravis (MG) is important for the course and outcome of the disease. Recently, repetitive ocular vestibular evoked myogenic potential (oVEMP) stimulation has been developed as a novel diagnostic tool for MG. Quantification of extraocular muscle response decrement after repetitive stimulation facilitates the diagnosis of MG at the predilection site of initial symptoms. We compared different stimulation paradigms to determine the optimal parameters for detecting the characteristic oVEMP decrement.

Methods: Repetitive bone-conducted oVEMPs were elicited in 18 MG patients and 17 healthy subjects. We compared four different repetition rates (20Hz, 30Hz, 40Hz, 50Hz) to determine the most sensitive and specific oVEMP parameters for decrement detection.

Results: Mean age of MG patients and healthy subjects was 62±18 and 30±6 years, respectively. The majority (89%) of MG patients had ocular symptoms at time of measurement, including ptosis (n=14) and diplopia (n=12). Eight patients (44%) had isolated ocular symptoms, 4 (22%) had additional bulbar weakness and 9 (50%) generalized muscle weakness. Repetitive stimulation at 30Hz yielded the best differentiation between MG patients and healthy subjects, with a sensitivity of 82% and a specificity of 83% (area under the curve (AUC) 0.84) when using an overall decrement of ≥9% as cutoff.

Conclusions: Preliminary data of our study suggest that 30Hz repetitive oVEMP stimulation is the most effective stimulus paradigm. Repetitive oVEMP stimulation with optimal parameters facilitates early and accurate diagnosis of ocular MG.

OP12-5 - What kind of information can be provided using chirp sound in VEMP?

7. Clinical Testing for Vestibular Function

TOSHIHISA MUROFUSHI¹

Yukiko Tsuda², Eriko Yoshimura²

¹ Department of Otolaryngology, Teikyo University School of Medicine Mizonokuchi Hospital, Japan

² Yoshimura ENT Clinic, Japan

Purpose: For recording cervical vestibular evoked myogenic potentials (cVEMP), 500Hz and 1000Hz air-conducted short tone bursts (STB) or clicks have been used. Nowadays, 500Hz STBs are used most frequently because the otolith organs, especially the saccular sensory cells, best respond to STBs around 500Hz. Additionally, 1000Hz STBs are used to assess tuning property change of cVEMP due to endolymphatic hydrops (EH). Recently, chirp sound, which can be described as a sound in which frequency varies with time, has been applied in the field of audiology. However, its usefulness in VEMPs is not clear yet. We studied chirp-cVEMP to clarify its usefulness in the field of vestibular research.

Methods: Patients diagnosed with having Meniere’s disease, vestibular migraine or their related disorders were enrolled. Subjects underwent cVEMP testing using STBs (500Hz, 1000Hz) and chirp sound. Myogenic potentials were recorded on the sternocleidmastoid muscle.

Results: The rates of present responses were not significantly different among the 3 types of stimulation. The normalized amplitude was the largest to 500Hz STB. The most interesting result was that the latency of P1 (p13) of chirp-cVEMP showed association with 500-1000Hz cVEMP slope, which is an index of tuning property change due to EH.

Conclusions: The latency of P1 of chirp-cVEMP might reflect tuning property because frequency in chirp sound varies with time. This finding suggests that the latency of P1 of chirp-cVEMP might be used as an index of EH.

OP12-6 - VEMP a simple, portable and affordable vestibular evoked myogenic potential test device.

7. Clinical Testing for Vestibular Function

Hamish MacDougall¹

John Holden¹, Sally Rosengren², Elodie Chiarovano¹

¹ The University of Sydney, School of Psychology, Australia

² Neurology Department, Royal Prince Alfred Hospital and Central Clinical School, The University of Sydney, Australia

Purpose: In 2008, we developed the first useable vHIT (video head impulse test) goggles to simplify the assessment of the six semicircular canals. Testing the remaining four end-organs (otoliths) still requires complicated, bulky and expensive equipment. In this project we aimed to develop a simple portable and affordable VEMP test device which we call the μVEMP.

Methods: Similar to the vHIT development strategy we tried to employ recent advances in electronic component performance and to simplify the VEMP device by implementing the minimum necessary features for effective testing. We used the traditional cVEMP (cervical) and oVEMP (ocular) electrode placements and the simplest bone-conducted tendon hammer taps and air-conducted clicks for stimuli.

The pocket-sized interface connects to phones, tablets, laptops etc. and a first prototype was evaluated in the lab and clinic. Six copies of a second prototype were distributed to colleagues for feedback on usability, durability, etc. A third design is easier to make and more likely to meet strict regulatory requirements (such as 5kV isolation).

Results: Validation data collected simultaneously from the same subject and electrodes using the mVEMP device and ‘gold standard’ research grade commercial equipment shows a strong similarity with an average concordance correlation coefficient of rc = 0.997±0.003. Results recorded with the µVEMP device on patients with audio-vestibular diseases are similar to those typically found in the literature.

Conclusions: It is now possible to assess the function of all ten vestibular end-organs in less than 20 minutes using simple, portable and affordable equipment including vHIT and μVEMP.

OP12-7 - VEMP triggered by galvanic stimulation may reveal a subclinical myelopathy

7. Clinical Testing for Vestibular Function

Ludimila Labanca¹

Anna Paula de Avila Pires², Tatiana Rocha³, Julia Caporali⁴, Sirley Carvalho¹, Fabrice Giraudet⁵, Paul Avan⁵, Denise Utsch Goncalves⁶

¹ Federal University of Minas Gerais, Audiology and Speech Therapy department, Brazil

² Federal University of Minas Gerais, Brazil

³ Federal University of Minas Gerais, Graduation Program of Infectology and Tropical Medicine, Brazil

⁴ Federal University of Minas Gerais, Medical Clinics Department, Brazil

⁵ Clermont Auvergne University, Neurosensory Biophysics department, France

⁶ Federal University of Minas Gerais, Otorhinolaryngology department, Brazil

Purpose: VEMP triggered by galvanic vestibular stimulation (galvanic-VEMP) evaluates the vestibulo spinal tract and the purpose is to use the galvanic-VEMP to test the postural reflex aiming at a precocious diagnosis of the myelopathies that is associated with a vestibular central disorder.

Methods: Dizziness can be the first symptom of the human T lymphotropic virus type 1 (HTLV-1)-associated myelopathy (HAM). This cross-sectional study nested to a 20-years cohort included 25 individuals with HAM, 26 HTLV-1-asymptomatic carriers and 45 HTLV-1-seronegative individuals (controls). Galvanic stimuli (duration: 400ms; intensity: 2mA) were applied bilaterally to the mastoid processes and VEMP was recorded in the gastrocnemius muscle. The electromyographic parameters investigated were the latency and amplitude of the short-latency (SL) and medium-latency (ML) wave responses.

Results: While SL and ML amplitudes were similar, SL and ML latencies were delayed in HTLV-1 groups compared to control group (p<0.001). Using neurological examination as the gold standard, Receiver Operating Characteristic (ROC) curve analysis showed an area under the curve of 0.83 (p<0.001) for SL and 0.86 (p<0.001) for ML to detect altered postural reflex. Sensibility and specificity were, respectively, 76% and 86% for SL and 79% and 85% for ML. Galvanic-VEMP disclosed alterations that were progressive in HTLV-1-neurological disease, ranging from SL delayed latency in HTLV-1-asymptomatic carriers to absence of VEMP response in HAM group.

Conclusions: The worse the galvanic-VEMP response, the more severe the myelopathy. Galvanic-VEMP alteration may be a prognostic marker of progression from HTLV-1-asymptomatic carrier to HAM. The earlier the diagnosis of HAM, the better the therapeutics opportunities.

OP12-8 - Simultaneous recording of bilateral cervical/ocular vestibular-evoked myogenic potentials

7. Clinical Testing for Vestibular Function

Chih-Ming Chang¹

Yi-Ho Young², Po-Wen Cheng¹

¹ Department of Otolaryngology, Far Eastern Memorial Hospital, Taiwan

² Department of Otolaryngology, National Taiwan University Hospital, Taiwan

Purpose: We premised that cervical vestibular-evoked myogenic potential (cVEMP) and ocular VEMP (oVEMP) can be elicited simultaneously using bone-conducted vibration (BCV) stimuli. With the aid of novel four-channel surface electromyography (EMG) recording, the purpose of this study is to investigate the feasibility of performing bilateral cVEMP and oVEMP tests and getting four VEMP waveforms simultaneously.

Methods: Twenty subjects younger than 60 years without previous inner ear diseases were prospectively enrolled in this study. All subjects underwent individual unilateral cVEMP, unilateral oVEMP, and simultaneous bilateral cVEMPs and oVEMPs testing using BCV stimuli at forehead. The response rate and characteristic parameters of VEMP tests such as p13 latency, n23 latency, nI latency, pI latency, p13-n23 amplitude and nI-pI amplitude were further compared and analyzed.

Results: All of 40 ears had clear cVEMP and oVEMP responses, regardless of individual VEMP test or 4-channel simultaneous VEMP test. There were no significant differences between the individual and simultaneous VEMP tests in terms of all VEMP parameters. Furthermore, Pearson’s correlation analyses revealed significant positive correlations between the individual and simultaneous VEMP tests in terms of all VEMP parameters.

Conclusions: Bilateral cVEMP and oVEMP tests can be obtained simultaneously using BCV stimuli with the aid of four-channel surface EMG recordings.

OP13-1 - Low-frequency vibration induced vestibular reactions and benefits in Meniere’s disease patients

14. Meniere’s Disease and Related Disorders

Jing Zou¹

Rishunzi Peng¹, Guiliang Zheng¹, Qing Zhang¹, Esko Toppila², Hongliang Zheng¹, Ilmari Pyykko²

¹ Second Military Medical University/Changhai Hospital, Department of Otolaryngology-Head and Neck Surgery, China

² University of Tampere/School of Medicine, Hearing and Balance Research Unit, Finland

Purpose: To explore the mechanism of low-frequency vibration on interfering vertigo and the efficacy of controlling vertigo in Meniere’s disease (MD) patients using a novel device that generates the defined vibrations.

Methods: The frequency spectrum of vibrations induced by temporal bone drilling in cadavers and that of a rotatory vibrator were analyzed. 13 normal individuals and 14 MD patients were exposed to low-frequency vibrations for 30 min. The audiograms and cervical vestibular evoked myogenic potentials (cVEMPs) were measured at various time points. The complaints in MD patients were followed for 7-19 months.

Results: Drilling of the temporal bone induced vibrations ranging from 4 Hz to 3.2 kHz. The novel device generated vibrations ranging from 42-116 Hz depending on the voltage of power supply. Of the 13 volunteers, 3 experienced transient vestibular stimulating symptoms during exposure to the 68 Hz vibrations. The cVEMP amplitudes were reduced at 30 min and 7 d post-exposure. 12 out of 14 patients felt comfortable within 24 h after exposure except that 2 patients did not show any benefit. The vertigo was significantly controlled after exposure (p<0.01, Wilcoxon signed ranks test). The tinnitus and ear fullness were also significantly improved after exposure (p<0.05, Wilcoxon signed ranks test).

Conclusions: The novel device delivered sufficient vibration to disrupt the vestibular activity by mimicking temporal bone drilling during the ear surgery, which is safe for the auditory system and effective in controlling vertigo, tinnitus, and ear fullness of MD patients. The study was supported by National Natural Science Foundation of China (contract 81771006.

OP13-2 - Intratympanic Steroid is an Economic and Effective Treatment for Intractable Meniere’s Disease

14. Meniere’s Disease and Related Disorders

Bo Liu¹

Su-Lin Zhang¹, Yangming Leng¹, Renhong Zhou¹, Jingjing Liu¹, Dongdong Liu¹, Wei-Jia Kong¹

¹ Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.

Purpose: The aim of this study was to investigate the cost-benefit of intratympanic dexamethasone injection (ITD) in patients with medically intractable Ménière’s Disease (MD).

Methods: Fifty-five patients with MD receiving the ITD were reviewed. All participants were followed-up for 24 to 40 months. The vertigo control, functional level scale (FLS), visual analog scale (VAS), cost before and after ITD were recorded.

Results: For the Meniere’s patients involved, vertigo was effectively controlled in 87.3% after one or repeated ITD courses. Our results showed that, compared with the healthcare cost before ITD, the cost after ITD (including the cost of related examinations and treatments) decreased, except for patients with bilateral MD. In addition, compared with results before ITD, the FLS decreased and self-assessed satisfaction, assessed by VAS, increased significantly. Two parameters related to the cost-effectiveness, cost/(6-FLS) and cost/VAS, decreased significantly after ITD treatment.

Conclusions: For the patients with medically intractable MD, ITD is an economic and effective treatment for controlling vertigo. Various natural courses, delayed diagnoses and lacking objective diagnostic test may result in substantial healthcare burden for MD patients.

OP13-3 - Follow-up of a randomised, double-blind, trial of methylprednisolone vs gentamicin in unilateral MD

14. Meniere’s Disease and Related Disorders

Jonny Harcourt¹

Aileen Lambert¹, Phui Yee Wong¹, Kiran Agarwal², Mitesh Patel², John Golding³,

Adolfo Bronstein²

¹ Charing Cross Hospital, Imperial College NHS Trust, London, UK

² Imperial College London, Neuro-otology unit, London, UK

³ University of Westminster, Department of Psychology, London, UK

Purpose: Our recent randomised, double-blind trial in The Lancet showed that the effectiveness of intratympanic methylprednisolone is comparable to gentamicin in managing refractory unilateral MD with 24 months follow-up. We now aim to assess the long-term outcome of the interventions as MD is a chronic relapsing disease.

Methods: A questionnaire package was sent to all participants of the original trial followed by a telephone follow-up if necessary. Of the 60 participants, one dropped out, one was lost to follow-up and two had died of unrelated causes. We had 46 responses (82%) of which 22 had methylprednisolone and 24 had gentamicin.

Results: All patients for both treatments had excellent vertigo control at an average of 70 months follow-up. In the gentamicin group the mean number of vertigo attacks in the previous 6 months were 1.0 (SD 2.4) and for the steroid group 0.8 (SD 2.6). Eight participants (five methylprednisolone and three gentamicin) had had further injection treatment due to recurrent symptoms following the original study period.

Conclusions: Long-term outcomes for intratympanic methylprednisolone are comparable to gentamicin with satisfactory vertigo control at 70 months follow-up.

OP13-4 - Exploring Fluctuating Sensorineural Hearing Loss In Meniere’s Disease Using iPad-Based Audiometry

14. Meniere’s Disease and Related Disorders

Darren Tse¹

Danny Lelli²

¹ University of Ottawa, Department of Otolaryngology - Head & Neck Surgery, Ottawa, Canada.

² University of Ottawa, Division of Neurology, Department of Medicine, Ottawa, Canada

Purpose: Fluctuating sensorineural hearing loss (FSNHL) is a diagnostic symptom of Meniere’s Disease (MD). Little is known about how hearing fluctuates, the relationship between FSNHL and vertigo, whether FSNHL should be targeted for treatment, or if treatments alter permanent hearing loss. Patients normally have infrequent audiologic testing. iPad-based audiometry is validated, portable, and extremely easy to use. We aim to explore FSNHL by having patients test their own hearing daily.

Methods: 5 patients were recruited with MD. Patients who had migraines or intratympanic injections within one year were excluded. Patients were trained to use the iPad-based audiometer. They kept a diary of attacks and performed daily and post-attack audiograms for 3 months. Patients had conventional audiometry monthly. Pure tone averages were plotted over time for both ears. Data analysis looked for trends and variability.

Results: All patients completed at least 50 audiograms. iPad-based audiometry was easy to use with no side effects or technical issues. 2 of 5 patients showed marked daily PTA variability in the diseased ear. All normal ears, and diseased ears where the patient experienced no attacks, showed limited PTA variability. All patients felt that without testing sequence randomization, responses could be predicted.

Conclusions: This is proof of principle that iPad-based audiometry can be used to track FSNHL in MD. This technology allow improved understanding of the cochlear manifestations of MD, with the potential to fine-tune diagnostic criteria for FSNHL in MD and allow improved diagnosis and treatment of hearing loss. Future larger studies are planned.

OP13-5 - Endolymphatic hydrops diagnosis at 3T MRI: Reproducibility and correlation with Meniere’s disease.

14. Meniere’s Disease and Related Disorders

François Voruz¹

Nils Guinand¹, Vincent Lenoir², Angelica Perez Fornos¹, Minerva Becker²

¹ Université de Genève/HUG, Neurosciences Cliniques - ORL, Switzerland

² Université de Genève/HUG, Département d’imagerie et des sciences de l’information médicale, Switzerland

Purpose: Evaluate the reproducibility of magnetic resonance imaging (MRI) for the diagnosis of endolymphatic hydrops in patients with Meniere’s disease (MD) symptoms and assesse its correlation with clinical diagnosis of MD.

Methods: This retrospective analysis included 3T MRI examinations of 50 patients with MD symptoms (21 men, 29 women, mean age = 53+/-12). 3DT2 and 3D FLAIR were performed 4 hours after iv. injection of gadolinium and a « hydrops sequence » was obtained by subtracting the first two sequences. Two experienced readers assessed blindly and independently the presence and location of hydrops. Inter-observer agreement was evaluated per patient, per ear and whether the hydrops was vestibular, cochlear or vestibulo-cochlear. According to the 2013 Barany Society’s criteria for MD, 16 patients had definite MD, 6 probable MD and 28 didn’t match criteria. Correlation between clinical and MRI findings was based on the most experienced reader’s findings.

Results: Inter-observer agreement was substantial for the MRI diagnosis of hydrops per patient (=0.82) and moderate for hydrops diagnosis per ear (=0.76), moderate for vestibular hydrops per ear (=0.78) and fair for cochlear hydrops per ear (=0.40). MRI hydrops was found in 93% of definite MD, in 83% of probable MD and in 75% of non-MD patients. 76% of MRI hydrops were bilateral.

Conclusions: Although overall MRI diagnosis of hydrops is well reproducible, the diagnosis of cochlear hydrops should be made with caution due to substantial interobserver variability. Despite strong correlation between clinical MD and MRI-hydrops, MRI-hydrops is also found in many patients not matching the strict MD criteria.

OP13-6 - Endogenous Ouabain in Meniere’s Disease

14. Meniere’s Disease and Related Disorders

Roberto Teggi¹

Laura Zagato¹, Chiara Lanzani¹

¹ San Raffaele Scientific Institute

Purpose: Endogenous Ouabain (EO) has been demonstrated to modulate the activity of ionic exchangers, and genetically determined activity of them has been studied as a predisposing factor to develop Menière’s Disease (MD). We recently published data on gene polymorphism of SLC8A1 and SIK1 in MD subjects. Our purpose was to assess EO plasma levels in MD subjects and assess a possible correlation with these gene polimorphism.

Methods: EO plasma levels have been assessed in 127 MD subjects and 129 normal Caucasian subjects; clinical history for migraine, hypertension, autoimmune disorders and SLC8A1 / SIK1 gene polimorphism have been saved.

Results: EO plasma levels in MD subjects was 195 pmol/L (range 59-540, median 194) , while in controls was 137 pmol/L (range 39-341, median 124). A significance has been detected between groups by a non parametric analysis (p=0.005). No correlation has been found in MD subjects with hypertension (p=0.1), migraine (p=0.07) and autoimmune disorders (p=0.59). Moreover, no correlation has been found with SLC8A1 and SIK1 mutation (p=0.3 and 0.5 respectively)

Conclusions: Since EO has been demonstrated to be a regulator of ionic and water balance in the inner ear, we propose that altered plasma levels of EO may act as a predisposing level to develop MD. Our data support the hypothesis that EO and SLC8A1 / SIK1 gene polimorphism act as independent predisposing factors.

OP13-7 - Acoustic absorbance in wideband tympanometry of Meniere’s Disease is greater in affected side

14. Meniere’s Disease and Related Disorders

Shuna Li¹

Guiliang Zheng¹, Jingchun He¹, Jun Yang¹

¹ Department of Otolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine

Purpose: To compare acoustic absorbance of wideband tympanometry in patients with Meniere’s disease with control group without inner ear and middle ear disorders.

Methods: Acoustic absorbance were detected using wideband tympanometry in 60 patients with unilateral Meniere’s disease and 30 control subjects excluding inner ear and middle ear disease. All patients with Meniere’s disease underwent electrocochleography and Sp/Ap was recorded. Meniere’s disease was diagnosed and graded according to diagnostic criteria for Meniere’s disease (published in Journal of Vestibular Research,2015) and graded. The integral area formed by the absorbance curve on peak pressure and x-axis (frequency) was calculated. Student’s t-test was used to compare integral areas difference of 2 ears in Meniere’s disease patients and control group.

Results: The integral area of absorbance was greater in affected side than unaffected side in Meniere’s disease patients. The average integral area difference in Meniere’s disease patients was 5.69%±2.20%, in control group was 2.09%±1.25% (P<0.01). But there was no significant difference between Meniere’s disease in different grade(P>0.05). Only 45% Meniere’s disease patients showed Sp/Ap >0.4 in affected side.

Conclusions: Affected side in Meniere’s disease showed higher absorbance than other side. Whereas, in control group, the difference between 2 ears is not significance. Wideband tympanometry is more sensitive than electrocochleaography in Meniere’s disease.

OP14-1 - Video-Head-Impulse testing in infants younger than 24 months

7. Clinical Testing for Vestibular Function

Angela Wenzel¹

Roland Huelse¹, Karl Hoermann¹, Manfred Huelse¹, Nicole Rotter¹

¹ University Hospital Mannheim, Department of Otorhinolaryngology

Purpose: Earlier work revealed that Video-Head-Impulse testing (vHIT) is often difficult to perform on infants younger than 24 months. In particular, calibration of the system can be challenging, as active cooperation of the child is required. The aim of our study was to evaluate horizontal semicircular vestibular function in infants using a newly developed software that simplifies vHIT examination.

Methods: 18 patients (10 boys, 8 girls) aged 4-24 months were included. The newly developed software enabled calibration of the eye position signal with the infants fixating on animated graphics projected on a screen. After calibration, a vHIT goggle (EyeSeeCam ©) was used to perform head impulses in the horizontal plane while the infant was watching a movie sitting on their parent’s lap or in a baby chair. At least 15 impulses to each side were obtained and the occurrence of refixation saccades was analyzed.

Results: The new calibration method and modified test setup provided reproducible results in all infants tested (n=18). An increased incidence of artifacts was not observed. In 4 patients, more than one test was needed to obtain reproducible resuts. Median gain for impulses to the right side was 0.87 (+/– 0.23) and 0.86 (+/-0.19) for impulses to the left. Refixation saccades could not be identified.

Conclusions: The study emphasizes that vHIT with an optimized calibration is an easy and sensitive screening tool to evaluate vestibular function in infants younger than 24 months and should be used as the gold standard in pediatric vestibular assessment.

OP14-2 - Video head impulse test data in subjects with and without vascular risk factors and vertigo

7. Clinical Testing for Vestibular Function

Anders Hansson¹

Jonatan Salzer¹

¹ Department of Pharmacology and clinical Neuroscience, Umeå University, Sweden

Purpose: To compare video head impulse test (VHIT) vestibulo-ocular reflex (VOR) gain values and proportion of subjects with saccades among healthy subjects, subjects with cerebrovascular disease (CVD), and subjects with an acute vestibular syndrome (AVS).

Methods: We recruited at Umeå university hospital between 2016-06-14 and 2017-11-17: i) healthy adults without vascular risk factors, a history of neurological disease, vestibular disease or head injury, n=70, median age 43 (SD) 16.6; ii) subjects with anterior circulation TIA/stroke admitted to the stroke ward, n=51, median (IQR) age 74 (SD) 12.5; and iii) subjects presenting at the emergency department with an AVS, n=46, median (IQR) age 64 (SD) 17.

All subjects provided informed consent. The head impulse test battery was conducted using the Synapsys VHIT Ulmer II system. We used one-way ANOVA to compare means, and the chi-square test to compare proportions, across subject categories.

Results: The mean gain for all horizontal canal impulses were higher among healthy subjects vs subjects with CVD and subjects with an AVS (0.97 vs 0.92 vs 0.74, p<0.001). All three categories of subjects displayed saccades on horizontal canal testing, however the proportion was lower among healthy subjects vs subjects with CVD and subjects with an AVS (11.6% vs 22.2% vs 29.1%, p=0.025).

Conclusions: Low VOR gain and occurrence of saccades on VHIT testing among subjects without known vestibular dysfunction, especially among subjects with vascular risk factors, may affect the interpretation of the HINTS algorithm in acute vertigo presentations.

OP14-3 - Viewing-target distance influences the VOR gain when assessed using the vHIT

7. Clinical Testing for Vestibular Function

Patricia Castro¹

Sara Sena Esteves², Florencia Lerchundi³, David Buckwell⁴, Michael Gresty⁴, Adolfo Bronstein⁴, Qadeer Arshad⁴

¹ (1) Neuro-otology Unit, Division of Brain Sciences, Charing Cross Hospital Campus, Imperial College London, London, UK. (2) Escuela de Fonoaudiología, Facultad de Medicina, Clínica Alemana Universidad del Desarrollo, Santiago, Chile.

² Centro Hospitalar do Porto. Porto, Portugal.

³ Fundación para la lucha contra las enfermedades Neurológicas de la infancia (FLENI). Buenos Aires, Argentina

⁴ Neuro-otology Unit, Division of Brain Sciences, Charing Cross Hospital Campus, Imperial College London, London, UK.

Purpose: Gaze stabilisation during head movements is provided by the vestibular ocular reflex (VOR). Clinical assessment of this reflex is performed using the video head impulse test (vHIT). To-date the influence of different fixation distances in VOR gain using the vHIT remains unknown.

Methods: We assessed the horizontal VOR using the vHIT, in 18 healthy subjects. Firstly, we assessed the VOR gain with viewing targets at 150cm, 40 cm, 30 cm, 20 cm, and 10cm.

Results: The gain increased significantly as viewing target distance decreased. Pearson’s correlation showed a significant relationship between VOR gain and target distance. We performed a second experiment in 10 subjects in complete darkness whilst subjects imagined targets at different distances. There was a significant negative correlation between gain and distance. There was a statistically significant difference between light and dark 20 and 40cm distances, but not for 150cm.

Conclusions: Theoretical VOR gains at different target distances were calculated and compared with those found in light and dark. The gain increase observed was less than predicted by the formulae, implying a physiological ceiling-effect of the VOR. The VOR gain increase in the dark represents a convergence-mediated VOR gain enhancement. The physiological VOR modulation with distance/convergence can be replicated using vHIT.

OP14-4 - Dissociation between caloric test and video head impulse test: device factor vs stimulus factor

7. Clinical Testing for Vestibular Function

Joo Hyun Park¹

Jae Jun Han², Jae-Jin Song², Ji Soo Kim²,

Ja-Won Koo²

¹ Department of Otorhinolaryngology, Dongguk University Ilsan Hospital, Korea

² Dizziness Center, Seoul National University Bundang Hospital, Korea

Purpose: The caloric test and the video head impulse test (vHIT) can lateralize vestibulopathy by measuring vestibulo-ocular reflex (VOR) of each horizontal canal separately. However, they are frequently dissociated. The aim of study is to test if the discrepancy between vHIT and caloric test is related to the device-specific gain calculation algorithm (device factor) or different characteristics of vestibular stimuli (stimulus factor).

Methods: Among the patients who received caloric test and vHIT, 27 subjects (12 males, mean age=48) showed ipsilateral canal paresis (CP, >25%) and normal VOR gain on vHIT-device A (vHIT-A) (0.86-1.22). For those subjects, vHIT was subsequently repeated using vHIT device-B (vHIT-B). All the tests were performed on the same day. The gain of vHIT-A was compared with that of vHIT-B at 40, 60, and 80 msec.

Results: The average of CP was 50.8%. The average gain of vHIT-A was 1.0±0.08, and the gain of the vHIT-B was 1.07±0.32, 1.06±0.23, and 0.97±0.17. The gain of vHIT-B did not show any correlation with CP (40, 60, 80ms; P=0.08, P=0.15, P=0.95). Twenty-four among 27 subjects showed normal gain in both vHIT-A and vHIT-B. In the remaining 3 patients, the gains with vHIT-A and vHIT-B at 60 ms were 0.95 and 0.75, 0.93 and 0.79, 0.95 and 1.47, respectively.

Conclusions: Device factors do not seem to be associated with dissociation between the caloric test and vHIT in dizzy patients. Considering the dissociation between two tests is mostly originated from stimulus factor, caloric test and vHIT should be complementary tools for the lateralization of vestibular dysfunction.

OP14-5 - Changes in vestibulo-ocular reflex during video Head Impulse Test in patients with cerebellar ataxia

7. Clinical Testing for Vestibular Function

Michaela Dankova¹

Rudolf Cerny¹, Martin Vyhnalek¹, Jaroslav Jerabek¹

¹ Department of Neurology, 2nd Faculty of Medicine, Charles University and Motol University Hospital

Purpose: Vestibulo-ocular reflex (VOR) is a reflex that stabilizes the visual image on the retina during brief head movements, information from semicircular canals. Head impulse test detects disorders of vestibulo-ocular reflex and thus peripheral vestibular dysfunction; however, cerebellar impairment can cause changes in corrective saccadic eye movements. The aim of the study was to analyze corrective saccades during head impulse test in patients with cerebellar ataxia and to compare these findings with a group of patients with peripheral vestibulopathy and with healthy controls.

Methods: 45 patients with cerebellar ataxia were examined (11 genetically determined, 34 idiopathic cerebellar ataxia), results were compared with 15 patients with peripheral vestibulopathy and 25 healthy persons. The video Head Impulse Test was administered in all subjects; we evaluated gain of VOR and distribution of the corrective saccades. Vestibular reactivity was examined by means of electronystagmography with rotational and caloric testing. Range of impairment in patients with cerebellar ataxia was assessed by the Scale for the assessment and rating of ataxia.

Results: The video Head Impulse Test, especially the distribution of the corrective saccades helps to distinguish patients with cerebellar impairment from the patients with vestibular impairment and healthy controls. Scattered corrective saccades prevail in patients with cerebellar ataxia (64%), gathered saccades in peripheral vestibulopathy.

Conclusions: The video Head Impulse Test allows to identify and quantify combined vestibular and cerebellar pathology. VOR gain and character of distribution of corrective saccades could serve as a neurophysiological biomarker of the disease and thus help in the diagnostic algorithm.

OP14-6 - vHIT VOR-gain is not yet a reliable measure for bilateral vestibulopathy

7. Clinical Testing for Vestibular Function

Tessa van Dooren¹

Florence Lucieer¹, Tinka Hoogterp², Angelica Perez-Fornos³, Nils Guinand³, Jean-Philippe Guyot³, Herman Kingma¹, Raymond van de Berg¹

¹ Department of Otorhinolaryngology and Head & Neck Surgery, Maastricht University Medical Center, Maastricht, Netherlands

² Faculty of Health, Medicine and life Sciences, University of Maastricht, Maastricht, Netherlands

³ Service of Otorhinolaryngology and Head and Neck Surgery, Department of Clinical Neurosciences, Geneva University Hospitals, Geneva, Switzerland

Purpose: To evaluate the vestibulo-ocular reflex (VOR) gain of three different video head impulse test systems (vHIT).

Methods: vHITs were performed in 50 patients with bilateral vestibulopathy (BV) and a control group of 37 healthy volunteers. All BV patients had a reduced caloric response of summated slow phase mean peak velocity of less than 20°/s. In the BV patients, a lateral vHIT was performed with the EyeSeeCam, Otometrics and Synapsys systems and the vertical vHIT was performed with the Eyeseecam and Otometrics systems. These results were compared with the group of healthy volunteers. VOR-gains obtained by the different systems were compared. The order of the tests was randomized. All tests were performed under standardized circumstances.

Results: As expected, VOR-gain of the lateral vHIT was mainly reduced in BV patients. Most importantly, VOR-gains between systems differed significantly for BV patients as well as for healthy volunteers. When only relying on vHIT-results, some BV-patients did match the criteria for BV with one system, but not with the other.

Conclusions: VOR-gains remarkably differed between systems within the same subjects. This could lead to misdiagnoses regarding vestibular function. The differences could most likely be attributed to different types of gain calculation. It is therefore of utmost importance to have a uniform way of gain calculation for all VHIT-systems.

OP14-7 - Problems with vertical Video Head Impulse Test (vHIT)

7. Clinical Testing for Vestibular Function

Fredrik Tjernström¹

Per-Anders Fransson¹, Mikael Karlberg¹, Måns Magnusson¹

¹ Dept. Otorhinolaryngology, Head and Neck Surgery, Lund University, Sweden

Purpose: To highlight some inherent problems with vertical HIT

Methods: Retrospective review on vertical HIT on patients deemed as having normal vestibular function a considerable number with both Otometrics and Interacoustics systems reveal large differences between the RALP and LARP plane. On 12 healthy volunteers vertical HIT was simultaneously recorded with the cameras over both eyes, with gaze directed straight ahead and 20 degrees to either side in the direction of the stimulated SCC.

Results: Statistical difference in gain values were obtained regardless of the examined SCC when comparing the recordings of left vs. right eye. Gain values increased when gazing in the direction of the stimulated SCC but there were still significant differences between gain-values between recordings of the different eyes. We also demonstrate the movement of goggles in 3D and its implications of the obtained values.

Conclusions: The algorithms when calculating vertical HIT gain do not seem to be sufficient to reliably reflect actual vestibular function and the question is whether goggles (especially if the camera is fixed over one eye) will survive to the future vestibular test-battery. Transparency is urgently needed both for interpreting clinical findings as well as research.

OP15-1 - Meniere’s disease affected inner ears are distinct from healthy controls with MRI and Radiomics

13. Imaging of the Inner Ear & Vestibular System

M. Van Hoof¹

M.C.J. de Wit¹, E.L. van den Burg¹, H. Kingma¹, A.A. Postma², A.M.L. Janssen³, M. Bilderbeek-Beckers⁴, A. Laurent⁴, E. Theunissen⁵, P. Dammeijer⁵, V. Van Rompaey⁶, Tj. D. Bruintjes⁷,

Raymond van de Berg¹

¹ Dept. Otorhinolaryngology and Head and Neck Surgery, Maastricht University Medical Center

² Dept. Radiology, Maastricht University Medical Center

³ Dept. Methodology and Statistics, School for Public Health and Primary Care (CAPHRI), Maastricht University

⁴ Dept. Radiology, VieCuri Medical Center, Venlo

⁵ Dept. Otorhinolaryngology, VieCuri Medical Center, Venlo

⁶ Dept. Otorhinolaryngology and Head & Neck Surgery, Antwerp University Hospital

⁷ Apeldoorns Duizeligheidscentrum, Apeldoorn

Purpose: Ménière’s disease (MD) is characterized by non-exclusive symptoms, relying on diagnostic criteria instead of imaging. Recently it has been shown (Aerts et al. 2014) that intensities in conventional medical imaging can be processed using data-characterization algorithms (radiomics) to enable feature quantification beyond the human eye. The purpose of this project was to investigate if conventional MRI scans of the inner ear contains radiomics features that can specifically be attributed to MD and if machine learning would be able to discriminate subjects with and without definite MD.

Methods: A retrospective study was performed in Maastricht University Medical Center, VieCuri hospital, the Antwerp University Hospital and the Apeldoorn Dizziness center. Patients with definite MD according to the American Academy of Otolaryngology-Head and Neck Surgery criteria were included. The control group consisted of patients with idiopathic asymmetrical sensorineural hearing loss, i.e. the unaffected inner ear as control. The T2-weighted MRI scans were characterized by a set of primary and secondary radiomics features which were analyzed by the machine learning package of Wolfram Mathematica 11.2 (Wolfram Research Inc., USA).

Results: The prevalence of MD in the 288 included patients was 44%. The randomly mixed training set consisted of 213 scans. The separate randomly mixed validation set consisted of 50 scans in which a statistically significant accuracy of 80±6% was achieved (p = 0.005).

Conclusions: Machine learning can distinguish inner ears affected by definite MD accurately from healthy controls by using semiautomatic volumetric segmentation and radiomics features of conventional MRIs obtained in different centers.

OP15-2 - MRI in Meniere patients: reliability of standard and additional diagnostic imaging criteria.

13. Imaging of the Inner Ear & Vestibular System

Robby Vanspauwen¹

Anja Bernaerts², Cathérine Blaivie¹, Jan Casselman³, Bert De Foer²

¹ ENT Department, Sint-Augustinus Hospital, European Institute for ORL-HNS

² Department of Radiology, GZA Hospital Sint-Augustinus, Antwerp, Belgium

³ Department of Radiology, GZA Hospital Sint-Augustinus, Antwerp, Belgium; Department of Radiology, AZ St-Jan AV, Brugge, Belgium

Purpose: In this retrospective study we determined: 1) intra- and interrater variability of our MRI technique, 2) sensitivity and specificity of hydrops imaging in definite Ménière’s disease (MD) patients, 3) value of additional diagnostic imaging criteria.

Methods: Patients were scanned (3T MRI, 3D-FLAIR) 4 hours after intravenous gadolinium (double dose). 148 patients (296 ears) were graded twice by 3 experienced radiologists: cochlear endolymphatic hydrops (CEH) was classified as either none, grade I or grade II. For vestibular endolymphatic hydrops (VEH), a third grade was added. Three additional diagnostic imaging criteria were evaluated: enhancement of: 1) cochlea, 2) vestibule and 3) vestibular aqueduct (VA). We determined the intraclass correlation coefficient (ICC) for inter-reader variability (inter-RV) and intra-reader variability (intra-RV).

Results: For all patients (296 ears), inter-RV values were: 0.90 (CEH); 0.93 (VEH); 0.84 (cochlear enhancement); 0.73 (vestibular enhancement) and 0.65 (enhancement VA). The intra-RV values were: 0.93 (CEH); 0.96 (VEH); 0.91 (cochlear enhancement); 0.80 (vestibular enhancement) and 0.80 (enhancement VA). The sensitivity, determined in 79 unilateral definite MD patients, was 84.8% when only the grading of CEH and VEH was taken into account and increased to 91.1% when making use of the additional diagnostic imaging criteria. The specificity, determined on 105 healthy ears of unilateral MD patients, was 90.4%.

Conclusions: Endolymphatic hydrops imaging is a robust and reliable MR technique, able to detect and grade hydrops with a very high sensitivity and specificity. Adding extra diagnostic imaging criteria might augment the sensitivity, but should be further investigated.

OP15-3 - The human vestibular cortex

13. Imaging of the Inner Ear & Vestibular System

Peter zu Eulenburg¹

Thomas Stephan², Marianne Dieterich³,

Ria Maxine Rühl²

¹ University Hospital, LMU Munich, Department of Neurology, Germany; German Center for Vertigo and Balance Disorders – IFB LMU

² University Hospital, LMU Munich, Department of Neurology, Germany;German Center for Vertigo and Balance Disorders – IFB LMU

³ University Hospital, LMU Munich, Department of Neurology, Germany;German Center for Vertigo and Balance Disorders – IFB LMU; Munich Cluster for Systems Neurology (SyNergy), Munich, Germany

Purpose: A cortical vestibular network of at least seven regions has been established in non-human primates 20 years ago. The complete delineation of a human vestibular cortex has been impeded by several confounders and technical limitations so far. Aim was to localize all cortical vestibular regions in humans.

Methods: We examined 60 healthy subjects with galvanic vestibular stimulation (GVS) after local postauricular anaesthesia in 3T fMRI (64-channel coil). Data analysis was performed using SPM12. Results were considered significant at FDR p<0.01.

Results: We were able to identify the cortical homologues to known non-human primate vestibular representations. Beside the cerebellar nodule and uvula, we found area OP2 in the parietal operculum to be the human core equivalent to PIVC. Monkey VPS could be mapped to area PFcm, whereas area 7 is probably located in area PF. Area VIP, areas 2v and 3aV were identified in the human IPS, and area 6 in the human lateral premotor region. Human area CSv was found to be the VC region. Strong vestibular responses were shown in area MST. Responses in monkey periarcuate cortex may be homologous to activations in the human SMA. All findings could be replicated internally in an independent cohort.

Conclusions: We were able to robustly map the human vestibular cortex and to identify all established cortical vestibular regions. The confounder-minimised GVS response patterns show that the core of the cortical vestibular network in humans is represented by areas OP2 (PIVC), MST, PFcm (VPS), PF (area 7) and CSv (VC).

OP15-4 - Head tap stimulus to image the vestibular cortex on fMRI– a pilot study

13. Imaging of the Inner Ear & Vestibular System

Jeremy Hornibrook¹

Edward Flook², Tracy Melzer³, Melissa Babbage⁴, Gurjuot Vraich², Philip Bird²

¹ Christchurch Hopsital, Christchurch, New Zealand

² Department of Otolaryngology-Head and Neck Surgery, Christchurch Hospital, Christhcurch, New Zealand

³ New Zealand Brain Research Institute, Christchurch, New Zealand

⁴ Department of Communication Disorders, University of Canterbury, Christchurch, New Zealand

Purpose: Very different areas of the cerebral cortex have been labelled vestibular. More recently PET and fMRI scans have confimed it is the parietoinsular cortex. Delivery of the vestibular stimulus (optokinetic, caloric for canals, tone bursts for otoliths) in the scanner has been challenging. Vestibular evoked myogenic responses (VEMPs) are an inhibitory response elicited from the saccule (cVEMP) detected in the neck and utricle (oVEMP) detected in the contralateral inferior oblique. oVEMPs can be ilicited from a simple forehead tap. It was decided to investigate whether a head tap in the fMRI sanner could produce reliable vestibular responses.

Methods: Six “normal” adults were tested who had normal hearing for age, normal vHIT test, and present oVEMPS. There were three controls: (1) a woman who had had a right acoustic neuroma removed with no right hearing, reduced vHIT and absent oVEMP (2) a profoundly deaf male with absent vHIT and absent oVEMP (3) a profoundly deaf male with normal VOR and present oVEMP. In a 3Tesla fMRI scanner a series of forehead taps were delivered.

Results: In all the normal adults there was bilateral vestibular activity. A correlation with handedness could not be established. Controls: (1) There was absence of vestibular activity on the right side (2) There was no vestibular activity (3) Bilateral vestibular activity was present.

Conclusions: Simple head taps in the fMRI scanner elicit vestibular cortex activity. The two profoundly deaf controls imply that the stimulus is not activating a hearing response. The technique could easily be automated.

OP15-5 - MR volumetric measurement of endolymphatic space in patients without vertigo or hearing loss

13. Imaging of the Inner Ear & Vestibular System

Hiroshi Inui¹

Yuka Katsube¹, Taeko Ito², Tsuyoshi Sakamoto³, Toshiaki Yamanaka², Tadashi Kitahara²

¹ Inui ENT Clinic, Japan

² Nara Medical University, Department of Otolaryngology-Head and Neck Surgery, Japan

³ PixSpace Ltd. Japan

Purpose: The presence of endolymphatic hydrops (ELH) in patients with Meniere’s disease (MD) is generally accepted as a hallmark of this disease. The purpose of this study was to quantitatively measure the volume of inner ear endolymphatic space (ELS) in patients without vertiginous or cochlear symptoms and to determine the normal value for the ELS using three-dimensional inner ear MR imaging.

Methods: Forty-seven patients with chronic rhinosinusitis were enrolled. Inner ear fluid space images and positive perilymph/positive endolymph images were acquired using a 3.0-tesla unit. Three-dimensional (3-D) images were constructed semi-automatically using both anatomical and tissue information by fusing the 3-D images of the TFS and the ELS (KIIS technique).

Results: The ELS/the total fluid space (TFS) ratio in the cochlea was 10.2 ± 1.7% and that in the vestibule was 17.7 ± 10.2%. Age-related differences were found in the TFS, ELS, and ELS/TFS ratio in the inner ear and the ELS and ELS/TFS ratio in the vestibule.

Conclusions: The existence of the ELS in patients without vertiginous or cochlear symptoms was shown. These findings could be useful as a standard reference for further research for the relationship between ELH and clinical and functional aspects of MD and other disease.

OP15-6 - PET visualized stimulation of the vestibular organ

13. Imaging of the Inner Ear & Vestibular System

Louise Devantier¹

Jens-Jacob Mølby-Henriksen², Michael Pedersen³, Therese Ovesen¹, Måns Magnusson⁴, Per Borghammer⁵

¹ Dep. of Clinical Medicine, Aarhus University, Dep. of Oto-Rhino-Laryngology, Regional Hospital West Jutland, Comparative Medicine Lab, Aarhus University, Denmark

² Dep. of Oto-Rhino-Laryngology, Regional Hospital West Jutland, Denmark

³ Comparative Medicine Lab, Aarhus University, Denmark

⁴ Dep. of Oto-Rhino-Laryngology, Lund University Hospital, Sweden

⁵ Dep. of Nuclear Medicine & PET centre, Denmark

Purpose: Our knowledge of the vestibular cortical network in humans is variegated. The current knowledge of vestibular cortical processing in humans is mostly based on studies where PET or fMRI were performed during a non-physiological stimulation either with caloric testing, galvanic stimulation, or vestibular evoked myogenic potentials (VEMP). However, the use of non-physiological stimulation may always be discussed and interpreted carefully. For instance, a caloric test not only stimulates the vestibular organ but also vagal, thermal, nociceptive and tactile sensory receptors leading to a potential misguiding cortical activation.

This study aims to visualize cortical activity during physiologic stimulation of the human vestibular organ.

Methods: 12 healthy right-handed healthy volunteers underwent three FDG-PET scans. In our self-propelled chair the volunteers were injected with an FDG-tracer. After the injection the chair was set in motion for 35 minutes. Subsequently a brain PET-scan was obtained. To obtain a comparable baseline, participants were injected with FDG while seated in the chair without movement.

Results: Linear acceleration

A significant increase in activity is seen in the left posterior insula. The increase is seen in all 12 participants. In addition a significant increase is seen in the right posterior insula and the thalamus.

Rotation

A significant increase is seen in the left posterior insula. A smaller but significant increase is seen in the right posterior insula and the thalamus.

Conclusions: The left posterior insula showed a significant increase in brain activity during both types of vestibular stimulation suggesting that this may represent a main part of the human vestibular cortex.

OP15-7 - The Ups and Downs of Endolymphatic Hydrops Imaging

13. Imaging of the Inner Ear & Vestibular System

Robert Gürkov¹

Wilhelm Flatz², Maximilian Patzig³, Rebecca Maxwell⁴, Aram Keywan⁴, Claudia Jerin⁴

¹ University of Munich, Otorhinolaryngology, Germany

² University of Munich, Radiology, Munich

³ University of Munich, Neuroradiology, Germany

⁴ University of Munich, Otorhinolaryngology & German Vertigo Centre, Germany

Purpose: In the last decade, MR imaging of the inner ear with the aim of visualizing endolymphatic hydrops has seen a fast and worldwide distribution. This method has an unprecedented diagnostic value since it can unequivocally confirm the presence of endolymphatic hydrops. Nevertheless, unawareness of some pitfalls can lead to frustrating results.

Methods: The complex and variable MRI anatomy of the inner ear is revisited, since its knowledge is essential for the interpretation of endolymphatic hydrops imaging data. The implications of the complex geometry of endolymph fluid spaces for the interpretation of the data are explained. The multitude of parameters that can influence the image quality are reviewed and examples are presented. The problems associated with a very weak endolymph/perilymph contrast and the advantages and disadvantages of intratympanic vs intravenous contrast application are discussed. Multiplanar reconstructions for the visualization of the inner ear structures including sacculus and utriculus are demonstrated.

Results: The clear visualization of endolymphatic hydrops is of great value for the diagnosis of Hydropic Ear Disease. However, especially early in the disease course, the hydrops may be too faint to be recognized with certainty on MRI. Utriculus distension may be overestimated if only axial images are analyzed. For the evaluation of vestibular hydrops, multiplanar reconstructions are helpful tools. For the evaluation of cochlear hydrops, a sufficiently strong signal intensity is necessary.

Conclusions: A detailed knowledge of the complex anatomy of the inner ear and recognition of many confounding technical parameters are necessary for a reliable interpretation of endolymphatic hydrops imaging.

OP15-8 - Neuroinflammation along the vestibular nerve and nucleus in acute unilateral vestibulopathy

13. Imaging of the Inner Ear & Vestibular System

Andreas Zwergal¹

Sandra Becker-Bense¹, Marcus Unterrainer², Simon Lindner², Matthias Brendel², Peter Bartenstein³, Nathalie Albert², Thomas Brandt⁴, Marianne Dieterich¹

¹ Ludwig-Maximilians-University Munich, Department of Neurology, German Center for Vertigo and Balance Disorders (DSGZ)

² Ludwig-Maximilians-University Munich, Department of Nuclear Medicine

³ Ludwig-Maximilians-University Munich, Department of Nuclear Medicine, German Center for Vertigo and Balance Disorders (DSGZ)

⁴ Ludwig-Maximilians-University Munich, Clinical Neurosciences, German Center for Vertigo and Balance Disorders (DSGZ)

Purpose: The aetiology of acute unilateral vestibulopathy is unknown. Some histological findings suggest that it may originate from inflammation of the vestibular afferents. In the present study a novel PET-based approach was used to show neuroinflammation along the vestibular nerve and brainstem entry zone in patients with acute unilateral vestibulopathy in vivo.

Methods: Six patients with an acute unilateral vestibulopathy were included in the study. All patients underwent detailed neuro-ophthalmological and vestibular testing to confirm the clinical diagnosis. MRI was done to exclude a central aetiology. Glial activation as a marker of neuroinflammation was visualized by [¹⁸F]GE180-PET within the first 7 days after symptom onset.

Results: All patients showed signs of an acute unilateral peripheral vestibulopathy including spontaneous nystagmus, pathological video-head impulse test and caloric asymmetry towards the affected side, ipsilesional SVV deviation and falling tendency. Central ocular motor and vestibular signs were absent. MRI was unremarkable in all patients. [¹⁸F]GE180-PET depicted glial activation in the ipsilesional vestibular nerve in 4 of 6 patients and in the ipsilesional vestibular nucleus in 5 of 6 patients at 3 to 7 days after symptom onset. The one patient without [¹⁸F]GE180 uptake developed additional clinical signs indicate for Meniére’s disease (i.e. hearing loss, tinnitus, recurrent vertigo attacks) in the longer-term follow-up, challenging the initial diagnosis of an acute unilateral vestibulopathy.

Conclusions: In patients with acute unilateral vestibulopathy the majority of cases show in vivo evidence for neuroinflammation in the ipsilesional vestibular nerve and nucleus during the acute and subacute stage of symptoms.

OP16-1 - DIZZYNET - a European network initiative for vertigo and balance research: visions and aims

27. Others

Andreas Zwergal¹

Eva Grill², Erna Kentala³, Hans Straka⁴, Neşe Çelebisoy⁵, Doreen Huppert¹, Antonio Lopez-Escamez⁶, Marianne Dieterich¹, Alexandre Bisdorff⁷, Thomas Brandt⁸, for all DIZZYNET members⁹

¹ Ludwig-Maximilians-University Munich, Department of Neurology, German Center for Vertigo and Balance Disorders (DSGZ)

² Ludwig-Maximilians-University Munich, German Center for Vertigo and Balance Disorders (DSGZ)

³ Helsinki University Central Hospital, Department of Otorhinolaryngology

⁴ Ludwig-Maximilians-University Munich, Division of Neurobiology, German Center for Vertigo and Balance Disorders

⁵ Ege University Medical School, Department of Neurology

⁶ Centre for Genomics and Oncological Research (GENYO), University of Granada

⁷ Centre Hospitalier Emile Mayrisch, Esch-sur-Alzette, Luxembourg, Department of Neurology

⁸ Ludwig-Maximilians-University Munich, Clinical Neurosciences, German Center for Vertigo and Balance Disorders (DSGZ)

⁹ DIZZYNET

Purpose: Patients with vertigo often receive inappropriate treatment. The most important reasons are insufficient interdisciplinary cooperation, nonexistent standards in diagnostics and therapy, missing translations of basic science findings to clinical applications, and the scarcity of prospective multicenter clinical trials.

Methods: To overcome these problems, 20 European expert centers started an initiative to establish a European Network for Vertigo and Balance Research called DIZZYNET. The central aim was to create a platform for collaboration and exchange among scientists, physicians, technicians, and physiotherapists in the fields of basic, translational, and clinical research.

Results: DIZZYNET members defined the following objectives as regards structure and content: to focus on multidisciplinary translational research in vertigo and balance disorders, to develop interdisciplinary networks for patient care, to increase methodological competence by implementing common SOPs, to internationalize the infrastructure for RCTs, to create a common database for patients with vertigo and balance disorders, to offer and promote attractive educational and career paths in a network of cooperating institutions. As first results of networking activity (1) a pilot databank was implemented, (2) a European UEMS initiative for a common curriculum in vestibular medicine was supported, (3) common fundraising activities were prompted, (4) a European guideline process for driving licence in vestibular patients was initiated and (5) annual joint teaching and training events were offered.

Conclusions: DIZZYNET will function as an additional structure that addresses some of the practical problems in vestibular and balance research and does not compete with the traditional national or international societies active in the field.

OP16-2 - Cochlear cooling for neuroprotection: The Cool-cochlea Project

17. Pharmacotherapy

Charles Anzalone¹

Yening Feng¹, Kent Carlson², M. Dan Dragomir Daescu², Shuai Leng³, John Lane³, David Kallmes³, Gayla Poling⁴, Devin McCaslin⁴, Neil Shephard⁴, Matt Carlson¹

¹ Department of Otorhinolaryngology, Mayo Clinic, Rochester, MN

² Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN

³ Department of Radiology, Mayo Clinic, Rochester, MN

⁴ Department of Audiology, Mayo Clinic, Rochester, MN

Purpose: Hypothermia is an effective neuroprotective strategy for a variety of injuries. Cooling the cochlea offers the capability to selectively protect inner ear neural structures. This study investigated the efficiency of inner ear cooling in a cadaveric head with thermocoupling electrodes providing real time temperature monitoring.

Methods: Two fresh cadaveric heads were imaged using a 192 slice computed tomography (CT) scanner to evaluate for standardized anatomy. Thermocoupling electrodes were placed in the ear canal, middle ear, lateral semicircular canal, and basal turn of the cochlea and electrode localization was verified with CT. System input temperature served as an independent variable. Air and water, at controlled temperature levels, were introduced into the ear canal and directly into the middle ear and the efficiency of thermal transfer was measured.

Results: Temperature curves were recorded and graphed as a continuous function of time. Results showed a brief response delay to each caloric modulation with a subsequent linear temperature response in the inner ear. Time to reach near steady state was determined in each experiment. Temperature change effects were noted to be greater with liquid medium than air. Direct modulation of the middle ear temperature showed greater temperature changes in the cochlea; however, significant change was also noted with ear canal delivery.

Conclusions: Cochlear cooling via a caloric irrigation system can effectively lower the temperature of the inner ear. Applications of therapeutic hypothermia for inner ear neuroprotection range broadly and include treatment of labyrinthitis, sudden sensorineural hearing loss, hearing preservation cochlear implantation, among others.

OP16-3 - Vestibular dysfunction in mitochondrial disease: a common, treatable cause of dizziness or imbalance

12. Genetics, Development, and Regeneration

Amanda Male¹

Sarah Holmes², Enrico Bugiardini², Olivia Poole², Natalie James², Gita Ramdharry², Ros Quinlivan², Diego Kaski³, Michael Hanna², Robert Pitceathly²

¹ Therapy Services, National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, United Kingdom

² MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital of Neurology and Neurosurgery, Queen Square London, WC1N 3BG, United Kingdom

³ Department of Neuro-Otology, The Royal National, Throat, Nose and Ear Hospital, 330 Gray’s Inn Road, London, WC1X 8DA, United Kingdom

Purpose: Mitochondrial diseases are a clinically heterogeneous group of genetic disorders with limited treatment options. Despite the known rehabilitation benefits for vestibular disorders, there is limited data concerning the incidence of vestibular dysfunction in mitochondrial disease. Thus, advancing understanding could potentially inform therapy and outcome development for those affected.

Methods: People attending a specialist mitochondrial disease clinic between May 2016 and August 2017 were included. They were asked about dizziness and imbalance using pre-determined criteria. Referral for neuro-otological investigation was arranged when symptoms could not be explained by neuropathy or cerebellar ataxia.

Results: Forty-two people with a clinic pathological, biomechanical or genetic diagnosis of mitochondrial disease were included in the study; age range 24-84 years; females: male 2:1. Of the 34 (81%) individuals who reported dizziness, a neuro-otological diagnosis was confirmed in 91% (31/34; OR 3.69, CI 0982 to 16.66, p=0.08). Eight people were not referred for neuro-otological investigations; six had cerebellar ataxia; one had biomechanical falls; and one with presynsope.

Peripheral (unilateral or bilateral) vestibulopathy was confirmed in 77% (24/31), vestibular migraine in 6% (2/31), central vestibular dysfunction in 10% (3/31) and BPPV in 6% (2/31). Seven people had dual neuro-otological diagnoses.

Of those with peripheral vestibulopathy, 88% (21/24) had coexistent hearing loss. Two individuals with previously documented unilateral vestibular deficit progressed to develop bilateral vestibulopathy.

Conclusions: This review demonstrates a high occurrence of vestibular dysfunction in people with mitochondrial disease reporting dizziness and/or imbalance. Neuro-otological investigation may help guide therapeutic intervention and may serve as a possible clinical biomarker of disease progression.

OP16-4 - Otoconial loss a new important diagnosis - explanation for residual dizziness and chronic imbalance

27. Others

Stefan C. A. Hegemann¹

Arneborg Ernst², Dietmar Basta², Christopher Bockisch³

¹ BALANCE-clinic

² Unfallkrankenhaus Berlin, Berlin

³ University Hospital Zurich, Zurich

Purpose: We will again describe the new diagnosis of otoconial loss, first described on the Barany meeting in 2012 but with a different etiolgy. A patient slipped on ice, fell on the back of her head with consequent MTBI and massive bilateral BPPV in the horizontal and posterior SCCs. After several canalith repositioning maneuvers, she was free of BPPV but is suffering since then (2010) from chronic imbalance, often described as “Residual Dizziness” (RD)

Methods: Case report: Audiogram, calorics, vHIT, cVEMP, oVEMP, subjective visual vertical during whole body tilt and eccentric rotation, linear VOR (search-coil)

Results: Traumatic hearing loss on the left, Normal calorics, HIT, c- and oVEMP, tested twice.

Significantly increased variability of (SVV) during whole body tilt. Low lVOR gains horizontally and vertically. Pathologic SVV during eccentric rotation.

Conclusions: From normal oVEMP we conclude that her urtricular haircells were intact, but because she had massive BPPV, we believe that she lost too many otoconia or maybe all of the left urticle. Since we know that animals with intact haircells but missing otoconia have lifelong balance problems. We belive that otoconial loss is a major factor to explain persisting dizziness after MTBI, RD after successful CRM and is also most likely involved in imbalance associated with aging, because we know that otoconia are progressively degenerating with age above at least 60 years. Otoconial loss has never been considered as an explanation for the symptom of imbalance although this seems quite logical for us, even if there is still missing absolute proof.

OP16-5 - Amelioration of hyperacusis impacts vestibular symptoms and binocular vision dysfunction symptoms

27. Others

Debby Feinberg¹

Arthur Rosner², Mark Rosner³

¹ Vision Specialists Institute, Dept of Clinical Care, USA

² Oakland University, Dept of Otolaryngology, USA

³ Vision Specialists Institute, Dept of Education and Research, USA

Purpose: Patients with binocular vision dysfunction (BVD) have vestibular symptoms (dizziness, nausea, gait abnormalities) as well as headache/head pressure, neck pain, anxiety and unclear vision. Treatment of BVD with micro-prism lenses usually significantly reduces these symptoms. One cohort did not improve as expected, and all admitted to hyperacusis. This study’s purpose is to demonstrate reduction of residual symptoms with noise cancelling devices.

Methods: This retrospective study includes 23 patients presenting for annual vision examination previously diagnosed with BVD and treated with microprism lenses for >1 year who had residual vestibular and BVD symptoms and who admitted to hyperacusis. Baseline data included completion of the modified Khalfa questionnaire, and subjective 0-10 scoring of headache, neck pain, dizziness, unsteadiness walking, nausea, anxiety and light sensitivity. Bose QC 30 earbuds or QC 25 headphones were placed upon the patient and subjective symptom scoring was repeated. Then the vision examination was performed with the patient wearing the sound cancelling device. Post-examination, subjective symptom scoring was repeated with both the updated vision prescription and sound cancelling device in place.

Results: 65% of patients had moderate to severe hyperacusis. All subjective symptom scores decreased markedly including dizziness (58.4%), nausea (63.3%), and unsteady walking (76.6%). Over 90% of symptom reduction was due to sound cancellation, with <10% due to micro-prism lenses.

Conclusions: In patients previously diagnosed with BVD and treated with micro-prism lenses, who had residual vestibular and BVD symptoms and who admitted to hyperacusis, amelioration of the hyperacusis using sound cancelling devices resulted in marked reduction of the residual symptoms.

OP16-6 - Correlations with hearing recovery and vestibular testing in sudden sensorineural hearing loss

3. Autonomic Function and Vestibular Disorders

Liu Xiaowei¹

Sun Jinhwu²

¹ Anhui provincal hospital

² Anguish provincal hospital

Purpose: The vestibular testing has been applied to the vetigo disease,but the relationship between vestibular testing and the hearing revovery has been unclear in patients with sudden sensorineural hearing loss(SSNHL).We therefore conducted a retrospective study in order to identify parameters that influence hearing recovery

Methods: The data base contains results of basic vestibular testing of 154 patients with SSHL , diagnosed and treated at the Anhui Provincal Hospital,China between 2016 and 2017. Hearing recovery was measured by pure tone audiometry.

Results: Multivariate linear and logistic regression analysis indicated that the chance of hearing recovery is lower for the patients with vertigo, age>=60 years and abnormal vestibular testing, including vestibular evoked myogenic potentia(VEMP) , caloric testing and horizontal semicircular canal(HC) of video head pulse Test(v-HIT).The risk factors of hearing recovery chance include vertigo,C-VEMP,HC of v-HIT,anterior semicircular cana(AC) of v-HIT.The magnitude of hearing recovery is lower for the patients with vertigo, age>=60 years and abnormal vestibular testing,including VEMP caloric testing. The risk factors of hearing recovery magnitude include vertigo,C-VEMP,o-VEMP and HC of v-HIT.

Conclusions: We conclude that associated with disorders of the vestibular system represent special sub- entitles of SSHL that may be caused by unique pathophysiological mechanisms and are associates with worse outcome. The vestibular testing is very important to the patients with SSHL.Vestibular rehabilitation and psychological intervention should be carried out as early as possible for patients with abnormal vestibular testing.

OP16-7 - A reappraisal supported by functional and morphological assessments of delayed endolymphatic hydrops

3. Autonomic Function and Vestibular Disorders

Jing Yu¹

Jing wang¹, Yujuan Zhou¹

¹ Eye & ENT hospital of Fudan University, Department of otorhinolaryngology-head and neck surgery, China

Purpose: To investigate the morphological and functional characteristics in patients with delayed endolymphatic hydrops(DEH), by observing the involvements of endolymphatic hydrops imaging(EHI) and the impairments of vestibular function. Meanwhile, to speculate the feasible pathological process by analyzing the correlation between morphological and functional features.

Methods: 30 patients who visited Department of Otology and Skull Base Surgery of EENT Hospital of Fudan University were enrolled in this study. All were diagnosed with DEH and medical history was collected, including the onset age of precedent deafness, onset age of vertigo and the time delay. Workup included caloric tests, cervical and ocular vestibular evoked myogenic potentials(c-VEMP and o-VEMP),and magnetic resonance imaging(MRI) of inner ear after intratympanic gadolinium injection.

Results: Vestibular hydrops could be definitely observed as its function declined, dysfunction of both saccule and utricle was not essential when vestibular hydrops were detected from imagings. In the LSCC, there was not necessarily morphological abnormality as its function decreased. However dysfunction was bound to exist as LSCC hydrops were observed from imagings.The results of hydrops localization consisted of three status: vestibular hydrops (13.04%)vestibular-cochlear co-hydrops (69.57%), vestibular-cochlear-LSCC co-hydrops (17.39%). There were no cochlear hydrops or canal hydrops alone.

Conclusions: In patients with DEH, the vestibule is most likely to be involved in hydrops, followed by cochlear, and the semicircular system tend to to be the latest; functional and morphological changes in the vestibule was inconsistent with that in the canal system.

OP17-1 - Detecting Perilymphatic Fistula by Variation of 3D Reconstruction Thresholds on CT scan

16. Perilymphatic Fistula

Alexis Bozorg Grayeli¹

Jean-Loup Bensimon², Maxime Guyon¹, Serge Aho-Glele³, Michel Toupet¹

¹ Dijon University Hospital, Otolaryngology depatment, France

² Clinique Turin, Imaging Center, Paris, France

³ Dijon University Hospital, Epidemiology depatment, France

Purpose: We hypothesized that a perilymphatic fistula (PLF) decreases the radiological density of the labyrinthine windows. Our objective was to evaluate this parameter by virtual endoscopy of the labyrinthine windows on CT scan combined to the variation of density threshold and its diagnostic performance.

Methods: This prospective study included 47 adult patients with a PLF and 98 control patients. Diagnosis of PLF was based on a composite radio clinical score > 7 (Portmann et al, 2005) and/or intra operative visualization of the fistula and/or resolution of the symptoms after surgery. Labyrinthine windows were examined by virtual endoscopy and the reconstruction threshold was gradually increased until a virtual opening appeared corresponding to the region with lowest density in the field (opening threshold, OT). The OT difference between the suspected and contra lateral side was calculated for each window in the same patient. The highest (maximal) OT difference among round and oval windows in the same patient was chosen as the diagnostic criteria. The side of the fistula was indicated by the lowest OT value.

Results: The maximal OT difference was higher in patients than in controls (60.2 ± 10.36 (SEM), n=47 versus 28.0 ± 2.29 Hounsfield units, n=98, p<0.01 unpaired t-test). A non parametric ROC analysis showed that at an OT difference of 31.5 UH had a sensitivity of 75 % and a specificity of 75% for the PLF diagnosis.

Conclusions: CT-scan virtual endoscopy and threshold variation provided high specificity and sensitivity in the PLF diagnosis.

OP17-2 - Postoperative recurrence of perilymphatic fistula

16. Perilymphatic Fistula

Taisuke Kobayashi¹

Tetsuo Ikezono², Han Matsuda², Hiroaki Ito¹, Masamitsu Hyodo¹

¹ Kochi Medical School, Department of Otolaryngology, Japan

² Saitama School of Medicine, Department of Otolaryngology, Japan

Purpose: Patients with perilymphatic fistula (PLF) usually undergo operations if their symptoms persist after conservative therapy. If the operation is performed with appropriate timing, hearing loss and vertigo or dizziness can be eliminated. Many previous reports support the effect of the operation; however, few studies have addressed postoperative course or recurrence. In this retrospective study, the postoperative course in patients with PLF was investigated.

Methods: Between January 2010 and January 2017, 22 ears in 22 cases were operated on in our department. Four patients were excluded because they were diagnosed with other diseases postoperatively. The age of the 18 remaining cases ranged from 16 to 78 years old (median 48.5), and the patients included 15 males and 3 females. Diagnosis was based on the criteria of the Intractable Hearing Loss and Research Committee of the Ministry of Health and Welfare, Japan.

Results: The follow-up period was 3 to 73 months (mean 15 months). Ten cases were probable PLF and eight cases were definite PLF. Of the eight definite PLF cases, three had recurrence of vertigo and two of the three underwent re-operation. In probable PLF, two cases had recurrence of vertigo and one underwent re-operation. The recurrence rate was 28%. These cases are presented with the results of the Cochlin tomo-protein detection test, which detects a perilymph-specific protein.

Conclusions: In conclusion, long-term follow-up is necessary in PLF patients who undergo surgery because postoperative recurrence is not rare.

OP17-3 - The change of hearing and positional nystagmus after surgery in barotraumatic perilymph fistula(PLF)

16. Perilymphatic Fistula

Won-Ho Chung¹

Jungmin Ahn¹, Se Eun Son¹

¹ Department of Otorhinolaryngology and Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University, School of Medicine

Purpose: The purpose of this study was to evaluate the changes in hearing and nystagmus after surgery of the PLF.

Results: Hearing was improved in 20 out of 27 when hearing improvement defined as postoperative 4-frequency PTA of bone conduction ≤ 25dB or hearing gain ≥ 15dB. Twenty-five out of 27 had nystagmus, of which 36% had spontaneous nystagmus(SN), and 100% had positional nystagmus(PN). Within a week after surgery, SN was persistent in four patients, and it was resolved in three of them at one month postoperatively. In addition, PN was observed in 10 patients one week after surgery and persisted in 7 patients one month later. Vertigo and nystagmus were completely improved in 22 patients. However, three subjects who had recurred dizziness with PN underwent revision surgery. The pattern of PN was multi-directional, and sustained longer in duration with slower velocity without reversibility. Also, there was a tendency of no improvement by the otolith repositioning maneuver.

Methods: Twenty-seven patients who underwent the surgery on suspicion of barotraumatic PLF were enrolled. The change in hearing and nystagmus were analyzed preoperatively and at 1week and 1month postoperatively.

Conclusions: Patients suspicious on barotraumatic PLF showed improvement in hearing and vertigo by surgical repair. However, the PN can continue for a while after surgical repair. It could also recur after complete remission. Therefore, it might conclude that the hearing loss was related directly to perilymph leak, but the PN was probably related to positional effects of perilymph volume or other microstructure rather than simple perilymph leak.

OP17-4 - The results of a nationwide study of PLF using a novel ELISA for human CTP detection test.

16. Perilymphatic Fistula

Tetsuo Ikezono¹

Han Matsuda², Tomohiro Matsumura³, Akira Sasaki⁴, Yasuhiro Kase¹, Members of PLF study group of Japan⁵

¹ Department of Otorhinolaryngology, Saitama Medical University Faculty of Medicine, Otorhinolaryngology

² Department of Otorhinolaryngology,Saitama Medical University Faculty of Medicine, Otorhinolaryngology

³ Department of Biochemistry and Molecular Biology, Nippon Medical School, Graduate School of Medicine

⁴ Department of Otorhinolaryngology, Hirosaki University Graduate School of Medicine

⁵ the consortium for Multicenter investigator-initiated trial of the CTP detection test

Purpose: The manifestations of perilymphatic fistula include a broad spectrum of neuro-otological symptoms such as hearing loss, vertigo/dizziness, disequilibrium, and tinnitus. The difficulty in making a definitive diagnosis due to the lack of an appropriate biomarker to detect perilymph leakage has caused a long-standing debate regarding its management. We have reported an ELISA-based human Cochlin-tomoprotein(CTP) detection test and its high diagnostic accuracy in clinical subjects (sensitivity and specificity were 86.4% and 100%) (1).

Methods: We have performed a multicenter investigator-initiated trial of the CTP detection test (2).

Results: We have tested 497 cases in total. Eight to 50% of patients in category 1 (trauma, middle and inner ear disease cases), and about 20% of those in categories 2, 3 and 4 (external origin antecedent events; internal origin antecedent events; without antecedent event, respectively) were positive for CTP. The characteristic clinical features of CTP positive cases will be presented.

Conclusions: The present study clarified that CTP detection test-positive patients exist at considerable rates among patients with inner ear-related manifestations. Appropriate recognition and treatment of perilymphatic fistula can improve a patient’s condition and hence the quality of life. 1) Ikezono T et al., The diagnostic performance of a novel ELISA for human CTP (Cochlin-tomoprotein) to detect perilymph leakage.PLOS ONE 2018. 2) Matsuda H et al., A nationwide multicenter study of the Cochlin tomo-protein detection test: clinical characteristics of perilymphatic fistula cases. Acta Otolaryngol 2017.

OP17-5 - What are the serious symptoms of chronic perilymph fistula (PLF)?

16. Perilymphatic Fistula

Jeremy Hornibrook¹

¹ Department of Otolaryngology-Head and Neck Surgery, Christchurch Hospital, Christchurch, New Zealand

Purpose: Perilymph fistula is a leak of perilymph at the oval or round window, initially recognized after stapedectomy surgery. It easily comes to mind for a patient presentng with aural barotrauma or direct blow to the ear, but usually not considered in a patient presenting months or years after mild head trauma where mild brain injury is assmumed. That various traumas could cause a PLF was recognized early but then claims of “spontaneous” PLF and two decades of unjustified ear explorations with misdiagnosis resulted its becoming a confused and emotional topic amongst Otolaryngolgists and non-recognition by Neurologists. Early work by Grimm and Black in regards to the vestibular and congitive symptoms and Robert Kohut’s unique temporal bone studies for predisposing cause have been largely ignored.

Methods: Twenty-two patients (most with mild head trauma or whiplash months or years prior) presented with chronic unilateral postural instability, nausea, motion intolarance and mild congnitive symtpoms. The postural instabilty is easily demonstable.

All had total resolution of symptoms after PLF repair. These features are illustrated by a video-documented case history of a 53 year-old professional rugby coach with disabling right postural instability and congitive symptoms for months after hitting his head on a table.

Results: Video-documented PLF repair at the right oval window fissula antefenestram resuted in immediate cessation of all symptoms and an increasingly successful career.

Conclusions: Although chronic PLF symptoms have been assumed to be due to inner ear endolymphatic hydrops, they are almost certainly from fluctuating otolith organ dysfunction, first stated by Brandt in 2001.

OP17-6 - Specificity and sensitivity of two video Head Impulse Test systems in Vestibular Schwannoma patients

27. Others

Mathilde Aalling¹

Emil Riis Abrahamsen¹, Regitze Kuhr Skals²,

Dan Dupont Hougaard¹

¹ Department of Otolaryngology, Head & Neck Surgery and Audiology, Aalborg University Hospital, Aalborg, Denmark

² Unit of Clinical Biostatistics and Bioinformatics, Aalborg University Hospital, Aalborg, Denmark

Purpose: To determine both the specificity and the sensitivity of two different video Head Impulse Test systems (v-HIT) in a Danish cohort of Vestibular Schwannoma patients. Secondary endpoint examined if inter examiner variability significantly affected the test results.

Methods: 46 patients diagnosed with a vestibular schwannoma all underwent audio-vestibular testing with standard tone- and speech audiometry. All patients also filled out the Dizziness Handicap Inventory (DHI). Complete v-HIT testing of all six semicircular canals (SCCs) with two separate v-HIT systems was carried out randomly by an experienced and an unexperienced examiner. A pathological test included concomitant low gain values (lateral<0.8, vertical<0.7) AND pathological saccades.

Results: Specificity of both v-HIT systems for five SCCs was close to 100%; only exemption was the left posterior SCC with around 90% for both v-HIT systems. Sensitivity in general was 44.4% with system 1 and 48.9% with system 2. Sensitivities of the right SCCs, in general, were higher than the left SCCs with both v-HIT systems, and system 2 produced the highest sensitivities of all six SCCs independently. The experienced examiner had a sensitivity of 56.5% with both v-HIT systems whereas the unexperienced examiner had a sensitivity of 31.8% and 40.9% respectively with system 1 and system 2. Higher than normal gain values were seen with all six SCCs when testing patients with system 1.

Conclusions: Close to 100% specificity with both v-HIT systems regardless of examiners experience. The experienced examiner produced the highest sensitivities with both v-HIT systems. The sensitivity of system 2, in general, was the highest.

OP17-7 - Preoperative determination of nerve of origin in patients with vestibular schwannoma

27. Others

Stefan Plontke¹

Christian Strauss², Torsten Rahne¹

¹ Department of Otorhinolaryngology, Head & Neck Surgery, Martin Luther University Halle-Wittenberg, Germany

² Department of Neurosurgery, Martin Luther University Halle-Wittenberg, Germany

Purpose: Most Vestibular schwannomas (VS) arise from one of two vestibular branches: the superior or inferior vestibular nerve. Determining the specific nerve of origin may improve patient management in terms of preoperative counseling, treatment selection, and operative decision-making and planning. The aim of this study was to introduce a novel scoring system that was designed to preoperatively determine the nerve of origin.

Methods: The nerve of origin was predicted based on video head-impulse assessments (vHIT) of all semicircular channels, together with cervical/ocular vestibular-evoked myogenic potential tests (cVEMPs, oVEMPs). The acquired data were entered into a scoring system developed to allocate the tumor origin. Finally, the nerve of origin was definitively determined intraoperatively. The blinded results were then compared.

Results: The novel scoring system was used in 30 consecutive patients undergoing surgery for VS treatment. Three decisions were indifferent. In 27 cases, the preoperatively predicted tumor origin was the same as the nerve origin determined during surgery.

Conclusions: The scoring system can predict the origin of schwannomas of the 8th cranial nerve with high accuracy. The scoring system is now applied in an ongoing larger cohort study.

OP18-1 - Apogeotropic Central Positional Nystagmus: Characteristics and Mechanism

6. Central Vestibular Disorders

Jeong-Yoon Choi¹

Stefan Glasauer², Ji Hyun Kim³, David Zee⁴, Ji-Soo Kim¹

¹ Seoul National University Bundang Hospital/Dizziness Center/Korea

² Ludwig-Maximilian University Munich/German Center for Vertigo and Balance Disorders/Germany

³ Korea University Guro Hospital/Neurology/Korea

⁴ The Johns Hopkins University School of Medicine/Neurology, Ophthalmology, Otolaryngology–Head and Neck Surgery/USA

Purpose: To determine the underlying mechanism of apogeotropic type of central positional nystagmus (CPN), we analyzed the characteristics of nystagmus and responsible lesions, and simulated apogeotropic CPN using a velocity storage model that is involved in resolution of ambiguity between tilt and translation.

Methods: In twenty-seven patients with apogeotropic CPN and 20 patients with apogeotropic benign paroxysmal positional vertigo (BPPV), we recorded spontaneous nystagmus while sitting, supine, and ear-down positions. To identify the possible lesions of apogeotropic CPN, demarcated lesions of twenty-two patients with apogeotropic CPN were overlapped.

Results: The spontaneous nystagmus was similar between sitting and supine positions in apogeotropic CPN, but stronger while supine in apogeotropic BPPV. In CPN, the lesions mostly involved the nodulus, uvula, and tonsil. Persistent apogeotropic CPN was successfully generated by implementing the gain of lesion in the connection between the cerebellum and brainstem that conveys the information for estimated gravity.

Conclusions: Apogeotropic CPN shows positional modulation that is different from that observed in apogeotropic BPPV. Apogeotropic CPN can be explained by lesions involving the central graviceptive pathway involving the cerebellum and brainstem.

OP18-2 - Combined Central & Peripheral Vestibular Disorders: CANVAS, iCABV & Other Differential Diagnoses

6. Central Vestibular Disorders

David Szmulewicz¹

Hamish MacDougall², Catriona McLean³, Leslie Roberts⁴, Michael Halmagyi⁵

¹ Balance Disorders and Ataxia Service, Royal Victorian Eye and Ear Hospital, Melbourne, Australia; Cerebellar Ataxia Clinic, Neuroscience Department, AlfredHealth, Melbourne, Australia Florey; Institute of Neuroscience and Mental Health, Melbourne, Australia

² Psychology departmEnt, University of Sydney, Australia

³ Pathology department,Alfred Hospital, Monash University, Australia

⁴ St. Vincent’s Hosital, University of Melbourne, Australia

⁵ Royal Prince Alfred Hospital, University of Sydney, Australia

Purpose: The traditional dichotomy of central versus peripheral causes of imbalance may be viewed as an obstacle, rather than an aid to diagnosis. This paper aims to review the clinical assessment of conditions with combined central and peripheral vestibular impairment and the more common conditions which may manifest this joint pathology.

Methods: Detailed clinical, neuro-otological, neurophysiological, pathological and imaging data has been gathered on 182 patients with the Cerebellar Ataxia with Bilateral Vestibulopathy (CABV) phenotype, in an effort to further our undersatnding of the pathophyiology as well as the nosology of these disorders.

Results: CABV was initially believed to be a distinct syndrome but has more recently been recognised as a phenotype which may be found in a number of disorders including CANVAS, Friedreich’s ataxia, spinocerebellar ataxia types 3 and 6 and multiple system atrophy. Oculomotor assessment provides a valuable means of identifying such patients and centres around the identification of an abnormal visually enhanced vestibulo-ocular reflex.

Conclusions: The growing number of conditions which express the CABV phenotype raises important questions around the utility of conceptually separating central and peripheral vestibular pathology, and how ths may hamper the progress of taxonomy within the field of balance disorders. In the clinical context, identification of the CABV phenotype limits the number of potential differential diagnoses and provides a directed investigation pathway in order to facilitate an accurate diagnosis.

OP18-3 - Mal de Debarquement Syndrome: motion-triggered versus spontaneous/other onsets.

6. Central Vestibular Disorders

Viviana Mucci¹

Josephine J.M Canceri², Rachel Brown³, Mingjia Dai⁴, Sergei Yakushin⁴, Angelique Van Ombergen⁵, Vedat Topsakal⁶, Paul H. Van de Heyning⁶, Floris Wuyts⁷, Cherylea J. Browne⁸

¹ University Department of Otorhinolaryngology and Head and Neck Surgery, Antwerp University Hospital / Antwerp University Research Centre for Equilibrium and Aerospace (AUREA) Antwerp, University of Antwerp, Belgium

² School of Science and Health, Western Sydney University, NSW, Australia

³ School of Medicine, Western Sydney University, NSW, Australia

⁴ Icahn School of Medicine, Mount Sinai Hospital, NY, United States of America

⁵ University Department of Otorhinolaryngology and Head and Neck Surgery, Antwerp University Hospital / Antwerp University Research Centre for Equilibrium and Aerospace (AUREA) Antwerp, University of An

⁶ University Department of Otorhinolaryngology and Head and Neck Surgery, Antwerp University Hospital, Antwerp, Belgium

⁷ Antwerp University Research Centre for Equilibrium and Aerospace (AUREA) Antwerp, University of Antwerp, Belgium

⁸ Translational Neuroscience Facility, School of Medical Sciences, UNSW Sydney, NSW, Australia / School of Science and Health, Western Sydney University, NSW, Australia

Purpose: Mal de Debarquement Syndrome (MdDS) is a neurological condition characterised by a sensation of motion. The most common form of MdDS is motion triggered (MT) and it occurs after disembarking from a vehicle. However, it has been acknowledged that some patients develop it spontaneously, those are here named as spontaneous or other onset (SO) MdDS subtype. Our studies aimed to address similarities and differences between the two MdDS subtypes involving diagnostic procedure and comorbidities. Secondly, we replicated for the first time a potential treatment for MdDS patients based on the previously proposed protocol of Dr.Dai involving optokinetic stimulation.

Methods: Part of the study was based on a retrospective online survey involving 370 MT and SO MdDS participants. Participants were required to respond to a set of comprehensive questions regarding epidemiological details, onset and diagnostic procedures. The second part of the study was a clinical trial involving 25 MdDS patients the same protocol of Dr.Dai was reproduced.

Results: MdDS is often misdiagnosed, more so for the SO subtype. In addition levels of stress, anxiety and depression were present in both subtypes. A higher percentage of MT MdDS better reacted to the VOR treatment protocol compared to the SO subtype.

Conclusions: It appears at present that both MdDS subtypes are still poorly recognised, thus we proposed new comprehensive diagnostic guidelines. In addition,we addressed that stress, anxiety, depression should be closely considered when treating patients. In our study, the optokinetic protocol previously proposed by Dai resulted to be a successful treatment for MT MdDS patients.

OP18-4 - The mystery of conversion of upbeat to downbeat nystagmus in thiamine deficiency

6. Central Vestibular Disorders

Jorge Kattah¹

Ali Saber-Therani², Sascha Du Loc³, David E Newman-Toker²,

David S Zee²

¹ University of Illinois College of Medicine, Peoria, IL

² University of Illinoi College of Medicine . Peoria,IL

³ The Johns Hopkins University. Baltimore, MD

Purpose: To study the mechanism of conversion of acute upbeat nystagmus (UBN), to chronic downbeat nystagmus DBN in patients with Wernicke’s encephalopathy (WE)

Methods: Serial clinical oculomotor and vestibular examination in two WE patients; they presented with acute UBN, and converted to chronic DBN which is unchanged for the last six and seven years respectively.

Results: The initial evaluation revealed a primary gaze UBN in both patients, UBN suppression occurred with convergence in both cases, and vertex vibration in patient one and by head shaking in patient two. A low amplitude DBN developed during these suppressive stimuli. Treatment with thiamine and return to a normal diet improved the WE, Overtime, however an enduring DBN replaced UBN. The MRI in case one showed FLAIR MRI hyperintensity in periventricular areas of the midbrain, pons and medulla.

Conclusions: Here we develop a hypothesis to explain how this pattern of nystagmus in WE patients relates to the normal anatomical substrate for holding the eyes still; why there is UBN in the first place; in addition, why UBN disappears leaving DBN? Our overriding hypothesis is that there is a selective vulnerability and selective recovery from thiamine deficiency of neurons within the brainstem and cerebellar circuits that hold vertical gaze steady (nucleus of Staderini, superior vestibular nucleus, interstitial nucleus of Cajal and the paramedian tract neurons). Furthermore, since these structures are paraventricular, we suggest a local BBB breakdown in WE. We conclude that UBN to DBN transition points to thiamine deficiency preceding a chronic, non-progressive DBN/truncal ataxia syndrome.

OP18-5 - Uncommon causes of episodic vertigo and imbalance: Ictal characteristics

6. Central Vestibular Disorders

Allison Young¹

Nicole Reid¹, Benjamin Jonker¹, Kaitlyn Parratt¹, G Michael Halmagyi¹, Miriam Welgampola¹

¹ University of Sydney, Central Clinical School, Institute of Clinical Neurosciences, Royal Prince Alfred Hospital, Sydney, Australia

Purpose: Episodic vertigo is associated with ictal nystagmus, facilitating diagnosis of the underlying disorder. Ictal characteristics of common disorders such as Benign Positional Vertigo, Vestibular Migraine and Meniere’s Disease have been described. Here we describe eye-movement characteristics arising from uncommon aetiologies.

Methods: Ictal-nystagmus was recorded from seven subjects with vertigo and imbalance.

Results: A patient with paroxysmia due to a large right petroclival meningioma demonstrated six-second flurries of spontaneous right-beating nystagmus with a slow-phase velocity (SPV) of 15 degrees/sec (°/s). Two patients with Episodic Ataxia Type-II presented with oscillopsia and imbalance, and demonstrated spontaneous vertical nystagmus; The first showed up-beating nystagmus with an SPV of 79.5°/s, and the second had down-beating nystagmus with an SPV of 34.5°/s. Of three patients diagnosed with Paraneoplastic syndrome, the first presented with cerebellar ataxia and oscillopsia with spontaneous right-beating nystagmus (46.3°/s SPV), the second presented with imbalance and bi-directional nystagmus flurries lasting four seconds each with an SPV of 10.9°/s, and the third presented with brainstem encephalitis with ocular flutter, each flurry lasting 3-11 seconds. The final patient was found to have a stable, calcified, medullary lesion and presented with spontaneous, torsional down-beating nystagmus with an SPV of 16.3°/s.

Conclusions: Vestibular event monitoring in the form of video-oculography, both in the outpatient and home setting is a useful technique that contributes to the accurate diagnosis of common and uncommon causes of vertigo and imbalance.

OP18-6 - Vestibular Paroxysmia: Not Always As Simple As It Seems

6. Central Vestibular Disorders

Jeremy Hornibrook¹

Martin MacFarlane²

¹ Department of Otolaryngology-Head and Neck Surgery, Christchurch Hospital, Christchurch, New Zealand

² Department of Neurosurgery, Christchurch Hospital, Christchurch, New Zealand

Purpose: Compression of a cranial nerve by a blood vessel has long been recognized as the cause of trigeminal neuralga, glossopharyngeal neuralgia and hemifacial spasm. Acceptance that the same mechanism for the 8th cranial nerve can cause tinnitus, vertigo attacks and other symptoms has been extremely slow. Early evidence came from pioneering otoneurosurgeons in the pre-MRI era. The Barany Society has now recognized the phenomenon as vestibular paroxysmia with published diagnostic criteria which require that the vertigo attacks last only seconds or minutes. However, they can be much longer.

Methods: Three patients with vestibular paroxysmia treated by surgical 8th nerve IACA decompression are presented, with operative videos. (1) a 68 year-old female with as many as 12 attacks in a month lasting hours, occasionally twice a day, with no auditory symptoms. (2) a 51 year-old female who for 5 years experienced motion sickness, visual vertigo, and then vertigo attacks lasting at least 2 hours with a hissing and pulsating noise in her left ear, followed by an occipital headache. (3) a 70 year-old male with tinnitus and

Results: All had immediate cessation of vertigo and other symptoms, with long-term followup.

Conclusions: While many patients with vestibular paroxysmia experience only very brief vertigo atttacks, in some cases the presence of a progressive hearing loss and tinnitus and headache accompanying the attacks can cause confusion with vestibular migraine in particular and with Meniere’s disease.

OP18-7 - How to diagnose ataxia

6. Central Vestibular Disorders

Laura Power¹

Pubudu Pathirana², N Dang Nguyen², T My Dung Phan², B Kashyap², Malcolm Horne¹,

David Szmulewicz³

¹ Florey Institute of Neuroscience and Mental Health, Melbourne, Australia

² Faculty of Science Engineering and Built Environment, Deakin University, Melbourne, Australia

³ Balance Disorders and Ataxia Service, Royal Victorian Eye and Ear Hospital, Melbourne, Australia; Cerebellar Ataxia Clinic, Neuroscience Department, Alfred Hospital, Melbourne, Australia; Florey Institute of Neuroscience and Mental Health, Melbourne, Australia

Purpose: One of the most common and medically concerning manifestations of ataxia is gait imbalance. In contrast to periheral vestibular pathology, there are a lack of ‘tools’ for readily describing and measuring dysfunction in the central vestibular systems. This program of work aims to instrument key aspects of the clinical examination that are utilized in the assessment of the ataxic patient, with the aims of: 1. Being able to reccommend which bedside components of the ataxia examination are most clinically valuable. 2. Creating a device to add objective, quantifiable, in-office assessment of ataxia for clinicians & researchers 3. Aiding accurate diagnosis based on objective metrics 4. Advancing the classification of the central and peripheral ataxias

Methods: Customized inertial measurement units, speech recognition and visual-kinematic systems have been applied to a set of functional clinical domains in 127 patients with diagnoses of combined central and peripheral vestibular conditions as well as pure central vestibular disorders.

Results: We have been able to instrument the bedside examination of ataxia, and thus quantify the relative utility of the various traditional clinical measurements. By employing these objective metrics, we are able to rank the clinical utility of clincial tests within a functional domain. This has formed the foundations for the development of a portable device which is capable of both diagnostics and scalable measurements of ataxia severity, within each of the functionalataxia domains.

Conclusions: We envisage that this work will aid not only accurate diagnosis but also advances in the classification of central and peripheral vestibular disease.

OP19-1 - Can Sensory Condition affect the Modified CTSIB relative to the SOT?

11. Gait, Posture, and Locomotion

Bo LIU¹

Su-Lin Zhang ¹, Renhong Zhou¹, Yangming Leng¹, Jingjing Liu¹, Dongdong Liu¹, Wei-Jia Kong¹

¹ Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.

Purpose: Aim of this study is to investigate the relationship between two balance test, modified clinical test of sensory interaction and balance (mCTSIB) and sensory organization test (SOT) of computerized dynamic posturography (CDP).

Methods: Seventy patients with unilateral vestibular hypofunction (vertigo group) and 37 healthy subjects (control group) were enrolled in tests of SOT and mCTSIB. The correlations of equilibrium scores (ES) between the SOT and mCTSIB were analyzed for both groups individually, and the sensitivity and specificity of mCTSIB for the vertigo group were evaluated.

Results: Our findings demonstrated that the strongest correlation between the sensory conditions on the mCTSIB and the equivalent condition on the SOTs existed between the mCTSIB4 versus the SOT5 in both groups respectively. Each 95% confidence interval of the correlation coefficient has a coincidence part, and the differences of correlation coefficient were not statistically significant. Fifty-one patients had abnormal SOT results (72.9%) and 47 had abnormal mCTSIB results (67.1%). The sensitivity and specificity of mCTSIB versus SOT was 74.5% and 52.6% respectively.

Conclusions: The significant correlations between the mCTSIB and SOT are more likely occur in the conditions of visual and/or somatosensory cues interrupted. However, the levels of these correlations may not be affected by the degree of sensory conflicting.

OP19-2 - Visual priming inducing expectational mismatch distorts sense of instability during postural control

11. Gait, Posture, and Locomotion

Sami Mahmoud¹

Patricia Castro², Efstratia Papoutselou³, Constanza Fuentealba Bassaletti⁴, Adolfo Bronstein³, Qadeer Arshad³

¹ Fakultät für Medizin, Technische Universität München, München, Germany,

² 1) Neuro-otology unit, Brain sciences division, Imperial College London, London, UK. 2) Escuela de Fonoaudiologia, Facultad de Medicina, Clinica Alemana Universidad del Desarrollo. Santiago, Chile.

³ Neuro-otology unit, Brain sciences division, Imperial College London, London, UK.

⁴ Escuela de Fonoaudiologia, Facultad de Medicina, Universidad San Sebastian. Concepcion, Chile.

Purpose: Several studies have suggested a link between anxiety and postural control. Previously we have shown that subjective instability during a postural task is correlated with anxiety as well as the amount of sway in healthy individuals. Here, we investigated whether it is possible to modulate these correlations by changing expectations via visual priming.

Methods: 30 healthy participants (19-36yr) performed a postural task standing as steady as possible on a linearly oscillating sled for 30sec whilst blindfolded. Before performing the task, participants were split into two groups randomly and watched either a video of an actor being stable (Group 1) or the same actor being unstable (Group 2) whilst performing the task. Task-related anxiety was assessed before and after the task using two different scales. Participants rated their subjective instability on a numerical scale. Upper trunk sway, angular hip velocity and steps were recorded as objective measures of instability.

Results: We observed a strong correlation (r=.531; p=.042) between upper trunk sway and subjective instability ratings in Group 1. This relationship was abolished in Group 2 (r=.213; p=.447). No significant between-group differences were found in measures of sway, subjective instability or anxiety. However, in Group 1 anxiety was significantly higher after the task (p<.05).

Conclusions: We showed that it is possible to distort the perception of instability, which usually correlates with objective instability measures, by changing expectations using visual priming. This finding highlights the prominent influence that expectation and anxiety can have on the perception of self-stability.

OP19-3 - Sensitivity and specificity of 3 Hz tremor in patients with cerebellar ataxia

7. Clinical Testing for Vestibular Function

Michaela Dankova¹

Martin Vyhnalek¹, Tomas Funda², Jaroslav Jerabek¹, Ondrej Cakrt³

¹ Department of Neurology, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Czech Republic

² Department of Information and Communication Technologies in Medicine, Faculty of Biomedical Engineering, Czech Technical University in Prague, Czech Republic

³ Department of Rehabilitation and Sports Medicine, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Czech Republic

Purpose: 3 Hz postural tremor was described in patients with anterior cerebellar lobe atrophy, however sensitivity and specificity of this sign in degenerative cerebellar diseases has not yet been evaluated. The aim of the study was to analyze posturography findings – to assess sensitivity and specificity of 3 Hz postural tremor in patients with cerebellar ataxia and to compare these findings with a group of patients with balance problems of non-cerebellar etiology (peripheral vestibulopathy) and with healthy controls.

Methods: 30 patients with cerebellar ataxia were examined, results were compared with 30 patients with peripheral vestibulopathy and 30 healthy persons. Static posturography was performed in all subjects, 3 Hz tremor was assessed both qualitatively and quantitatively, its sensitivity and specificity was compared with other standard posturography parameters. Vestibular reactivity was examined by means of electronystagmography with rotational and caloric testing. Range of impairment in patients with cerebellar ataxia was assessed by the Scale of the assessment and rating of ataxia.

Results: Posturography is able to distinguish patients with cerebellar and vestibular impairment from healthy controls. Finding of 3 Hz postural tremor can differentiate patient groups among themselves. Prevalence of 3Hz tremor in patients with cerebellar ataxia was 90%, including those with mild impairment, with 100% specificity.

Conclusions: 3Hz tremor can serve as an objective correlative of cerebellar impairment. The evaluation of 3 Hz postural tremor should be a standard part of posturography examination when considering a cerebellar impairment.

OP19-4 - Validity & kinematic outcomes of New Balance Test

7. Clinical Testing for Vestibular Function

Oz Zur¹

Hadas Ben Rubi Shimron¹, Itai Dattner², Eli Carmeli³

¹ The Israeli Center for Dizziness and Balance Disorders, Physical Therapy Department, Israel

² University of Haifa, Statistics Department, Israel

³ University of Haifa, Physical Therapy Department, Israel

Purpose: Background: There are many balance tests, but all have significant disadvantages, including ceiling effects, long administration, or limited to people with mild-to-moderate balance disorders. In addition, a balance test that can specifically examine the visual, vestibular and somatosensory systems in standing position is lacking.

Objective: 1) To assess the reliability of the Zur Balance Scale (ZBS) and to determine normal range scores for different age groups, and 2) To differentiate healthy vs. retrospective vestibular subjects (positive vHIT with low VOR gain) using the modified ZBS on the AMTI force plate.

Methods: In this cross-sectional, double-blind study, 88 subjects, ages 29-70 years old, recruited from a high-tech company in Petah-Tikva, were evaluated using the ZBS compared to the Modified Clinical Test Sensory Integration for Balance (mCTSIB). Inter-tester and intra-tester reliability were evaluated, and normal age results were checked. As well we added an additional 27 subjects with a diagnosis of vestibulopathy were compared to 44 of 88 healthy subjects to characterize four common kinematics parameters: Velocity Avg, ML sway, AP sway and Area95.

Results: ZBS had high inter-tester reliability (0.945 Cronbach Alpha, and 0.945 ICC), and high intra-tester reliability (0.938 Cronbach’s Alpha). ZBS scores decreased with increasing age. T-tests for all four kinematic parameters were significant (p<0.05) in both mCTSIB and mZBS.

Conclusions: ZBS is a sensitive test to detect balance disorders. It is reliable, simple and easy to administer. The kinematic parameters of the mZBS can differentiate vestibular subjects.

OP19-5 - DHI score variation in vestibular rehabilitation patients, regardless of pathology

7. Clinical Testing for Vestibular Function

Javier Martin Previgliano¹

Rafael Suarez¹, Nerina Coria¹, Valerio Hinojosa¹, Christiane Ponteville¹, Myrian Nuñez¹

¹ Centro Martin Previgliano

Purpose: The dizzines handicap inventory is a tool used to quantify the affect of heself-perceived disability in patients with vertigo, dizziness or inestability in relation to its impact on daily life, indentifying among the imbalance problems that the patient presents the reasons for funtional, physical and emotional character and as their self perception. Vestibular kinesthetic rehabilitation is a therapy that has shown its importance in the treatment of patients wits vertigo, dizziness and balance disorders, significantly improving the quality of life of these.

Methods: Chid cards were collected from 1057 patients, of both sexes with vestibular pathology, argentineas, with ages between 5 and 98 years, possibility of understanding spanish. these patients were approached through vestibular rehabilitation, performed a the beginning and end of the treatment of the questionnaire D.H.I, for the power of the changes produced in the automatic perception of disability after its first 10 sessions.

Results: The mean of the D.H.I at the time of pre-treatment measurement was 20.16 points, while the average of the subsequent treatment was 10.56 which is equivalent to a 47,6% general improvement. In this way, when we observed the articles separately, a functional level of 31.92% was obtained, emotionally 36.32% and physical level of 33.87% evidencing improvements in all aspects evaluated.

Conclusions: The data obtained in this study demonstrate the efficacy of the kinesthetic rehabilitation protocols applied in the private practice of Martin Previgliano being able to observe a significant improvement in the same, in all the aspects evaluated after the treatment.

OP19-6 - Balanci: Improving balance in children with bilateral cochleovestibular loss using cochlear implants

8. Cochlear Implant and Vestibular Function

Sharon Cushing¹

Nikolaus Wolter¹, Karen Gordon², Jennifer Campos³, Luis Vilchez Madrigal¹, David Pothier⁴, Cian Hughes⁴, Blake Papsin¹

¹ Department of Otolaryngology, Head and Neck Surgery, Hospital for Sick Children, University of Toronto

² Archie’s Cochlear Implant Laboratory, Hospital for Sick Children, University of Toronto

³ Toronto Rehabilitation Institute (TRI), Department of Psychology, University of Toronto

⁴ Department of Otolaryngology, Head and Neck Surgery, Toronto General Hospital, University Health Network

Purpose: We set out to determine the impact of a head referenced cochlear implant stimulation system “BalanCI” on balance in children with bilateral cochleovestibular loss (BCV’;/.2) as well as using the Wii Balance Board, a validated clinical measure postural control.

Methods: This prospective, blinded case-control study of balance was perfomed in 2 settings: a quiet clinical and an immersive virtual environment at the Challenging Environmental Assessment Laboratory in the Toronto Rehabilitation Institute’s iDAPT Centre. Balance was assessed in 16 patients with bilateral cochlear implants and total bilateral vestibular loss. Children wore the BalanCI system which is a head mounted device to restore head-referenced spatial information. Postural control measured by center of pressure (COP) and balance measured by the BOT2.

Results: In the virtual environment, children demonstrated better balance when using BalanCI as measured by an improvement in BOT-2 scores. Similarly, in a quiet clinical setting, the use of BalanCI led to better postural control as demonstrated by a significant reductions in COP root mean square (RMS) and velocity. The number of falls was significantly reduced with the use of BalanCI.

Conclusions: BalanCI is a simple and effective means of improving postural control and balance in children with congenital bilateral vestibular loss and bilateral cochlear implants. This device could potentially improve the safety of these children and allow them to take part in more complex balance tasks where sensory information may be limited.

OP19-7 - Balance, Gait and Dizziness in Adult Patients post Cochlear Implant

8. Cochlear Implant and Vestibular Function

Deirdre Murray¹

Dara Meldrum², James Garvan³, Alexandra Murphy⁴, Roisin Vance⁴, Cristina Simoes-Franklin⁴, Jacyln Smith⁴, Laura Viani⁴

¹ School of Medicine, Trinity College Dublin. Beaumont Hospital, Dublin

² School of Medicine, Trinity College Dublin

³ Royal College of Surgeons, School of Physiotherapy

⁴ Beaumont Hospital, Dublin

Purpose: Cochlear implantation may affect the vestibular apparatus due to the proximity to the surgical site but this has not been comprehensively investigated. The aim of the study was to evaluate the prevalence and severity of dizziness, balance and walking problems in cochlear implant users.

Methods: An observational, cross-sectional, clinical study of a cohort of cochlear implant users. Outcomes included; subjective dizziness and balance confidence (Vestibular Rehabilitation Benefit Questionnaire (VRBQ) and Activities Specific Balance Questionnaire (ABC) respectively), gait (Functional Gait Assessment and 10m walk test), balance (Equitest Sensory Organisation Test: SOT), and computerised Dynamic Visual Acuity (DVA). The Dix Hallpike test was also performed.

Results: 20 participants (n=10F), mean age 59.3 years (SD15.8) were assessed. Mean time post implantation was 3.8 years (SD4.6). Mean VRBQ score was low at 6.4% (SD18.1) and mean ABC score was high at 83.5% (SD14.2). FGA scores were minimally below expected range (mean 25.1, SD 4.4) and gait speed was 1.8m/sec (SD 0.41). Dix Hallpike was positive in 3 (15%) participants. Mean DVA loss was -3.2 LogMAR (SD1.9). Mean SOT score was 59.5% (SD14.2), with 70% (n=14) of participants demonstrating vestibular dysfunction by falling on balance conditions 5 and 6.

Conclusions: Physical measures indicated vestibular dysfunction post cochlear implantation in this sample, with a high frequency of falls in SOT conditions 5 and 6. A higher than expected frequency of BPPV was found and DVA was often impaired. Further longitudinal studies are required but the findings suggest an unmet need for vestibular rehabilitation in this population.

OP20-1 - Endolymphatic fluid absorption in the developing inner ear

22. Vestibular and Inner Ear Physiology

Sung Huhn Kim¹

Daniel Marcus², Philine Wangemann²

¹ Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Republic of Korea

² Department of Anatomy & Physiology, Kansas State University, Manhattan, KS, USA

Purpose: Mutations of SLC26A4 are a common cause of hearing loss associated with enlargement of the endolymphatic sac and duct and vestibular aqueduct (EVA). The purpose of our present study was to gain insight into the functional, molecular and cellular architecture of the developing endolymphatic sac and to identify the components of the physiologic-developmental pathway that is disrupted in EVA.

Methods: Endolymphatic sacs were isolated from E14.5 Slc26a4^Δ/+ and Slc26a4^Δ/Δ 129S6 mice, filled with a solution containing a fluorescent dye, and maintained in organ culture in the absence and presence of inhibitors of channels and transporters. The rate of fluid absorption was quantified by volume measurements with 3D confocal microscopy. Gene array analysis was performed on embryonic endolymphatic sacs from E13.5, E14.5, E16.5, and E17.5 Slc26a4^Δ/+ and Slc26a4^Δ/Δ mice to determine temporal gene expression profiles and differences between genotypes.

Results: Endolymphatic sacs from E14.5 Slc26a4+/- mice engaged in fluid absorption. The rate of fluid absorption at E14.5 was higher in endolymphatic sacs from Slc26a4^Δ/+ than from Slc26a4-/- mice, sensitive to ouabain and gadolinium and insensitive to benzamil, bafilomycin and S3226. Microarray analysis demonstrates expressed genes encoding transporters, ion channels and pumps and four genes (Slc26a4, Foxi1, Atp6v0a4, Atp6v1b1) known to cause EVA, suggesting that MRCs mediate vectorial ion transport.

Conclusions: Based on functional and pharmacological data and expression profiles, we propose a molecular mechanism for fluid absorption in the endolymphatic sac during development based on the absorption of NaCl. We conclude that disruption of this mechanism is the root cause of endolymphatic hydrops.

OP20-2 - Application of Gene Therapy to a Mouse Model of Vestibular Dysfunction

2. Animal Models and Molecular Approach

Kevin Isgrig¹

WIll Shteamer¹, Inna Belyantseva¹, Meghan Drummond¹, Tracy Fitzgerald¹, Sherri Jones², Andrew Griffith¹, Thomas Friedman¹, Lisa Cunningham¹,

Wade Chien³

¹ NIDCD/NIH, Bethesda, USA

² University of Nebraska-Lincoln, Lincoln, Nebraska, USA

³ Johns Hopkins School of Medicine, Baltimore, USA

Purpose: Vestibular dysfunction is a common and debilitating medical condition. The whirler mouse, a model of Usher syndrome, has a mutation in the whirlin gene which results in short and abnormal stereocilia in cochlear and vestibular hair cells. Consequently, these mice are deaf and have significant vestibular dysfunction. In this study, we assess whether gene therapy with wild type whirlin cDNA can be used as a treatment for vestibular dysfunction in the whirler mouse.

Methods: Adeno-associated virus serotype 2/8 containing whirlin cDNA (AAV8-whirlin) was delivered to the inner ears of neonatal whirler mice (P0-P5) via the posterior semicircular canal approach in vivo. Vestibular function was assessed by behavioral testing (circling, swim test, rotarod), as well as vestibular evoked potential (VsEP) measurements. Stereocilia morphology and whirlin expression were examined using immunohistochemistry.

Results: Treatment with AAV8-whirlin gene therapy resulted in whirlin expression at the stereocilia tips of vestibular hair cells in whirler mutant mice. Infected whirler vestibular hair cells have normalized stereocilia lengths compared to non-injected controls. Whirler mice treated with AAV8-whirlin gene therapy had improved vestibular function, as measured by circling behavior, swim test, rotarod, as well as VsEP peak latencies.

Conclusions: AAV8-whirlin gene therapy was effective at restoring whirlin expression and stereocilia lengths in vestibular hair cells of whirler mutant mice. In addition, AAV8-whirlin gene therapy was able to significantly improve vestibular function in whirler mutant mice. These results suggest inner ear gene therapy holds potential as a viable treatment for vestibular dysfunction.

OP20-3 - Assessment of D-methionine Protecting Gentamicin-induced Otolith Toxicity

2. Animal Models and Molecular Approach

Wu-Chia Lo¹

Chih-Ming Chang¹, YI-HO YOUNG², Po-Wen Cheng¹

¹ Far Eastern Memorial Hospital, Department of otolaryngology, Taiwan

² National Taiwan University Hospital, Department of Otolaryngology, Taiwan

Purpose: to determine whether gentamicin wound induce otolith toxicity and vestibular-evoked myogenic potentials (VEMPs) are practical electrophysiological methods of testing and to examine if D-methionine (D-met) pre-injection would protect the otolith organs against gentamicin-induced changes in enzyme activities and/or oxidative status.

Methods: Guinea pigs were intraperitoneally treated once daily with the following injections for 14 days: sterile 0.9% saline control, gentamicin (120 mg/kg) only, D-met (300 mg/kg) only, or a combination of D-met (300 mg/kg) and gentamicin (120 mg/kg). Each animal underwent the oVEMP and cVEMP tests before and after treatment. The changes in the biochemistry of the otolith organs, including membranous Na⁺, K⁺-ATPase and Ca²⁺-ATPase, lipid peroxidation (LPO) levels and nitric oxide (NO) levels, were also evaluated.

Results: In the gentamicin-only treated group, the mean amplitudes of the cVEMP and oVEMP tests were significantly (p < 0.05) decreased when compared to the other three groups. In guinea pigs receiving both D-met and cisplatin, the amplitudes of their cVEMP and oVEMP tests were significantly larger (p < 0.05) than those of the gentamicin-only group, but smaller (p < 0.05) than those of the saline control or D-met-only group. In comparison with the other three groups, the gentamicin-only group had the lowest (ps < 0.05) mean Na⁺, K⁺-ATPase and Ca²⁺-ATPase, and the highest (ps < 0.05) LPO and NO levels.

Conclusions: The VEMP tests were feasible for the evaluation of gentamicin-related otolith dysfunction. D-met attenuated the reduced ATPase activities and increased oxidative stress induced by gentamicin toxicity in the otolith organs.

OP20-4 - What is the insulin signaling system doing in the inner ear? implications for diabetes

2. Animal Models and Molecular Approach

Eva Degerman¹

Ann-Ki Pålbrink¹, Rene In’t Zandt², Måns Magnusson³

¹ Lund University Diabetes Centre, Department of Experimental Medical Science, Lund, Sweden

² Lund University Bioimaging Center, Lund University, Lund, Sweden

³ Lund University & Skåne University Hospital,Department of Otorhinolaryngology, Clinical Sciences, Lund, Sweden

Purpose: A number of studies indicate that diabetes is associated with inner ear dysfunction, however, basically nothing is known about mechanisms involved. We have demonstrated that the insulin receptor and related signaling components are expressed in the human inner ear sensory epithelium, however, the functionality and targets of the signaling system remain to be established in vitro and in vivo.

Methods: To study the impact of insulin signaling and action in the inner ear, human saccules and HEI-OC1 cells, a cell-line originating from auditory sensory epithelium established by Dr. Kalinec, are used in combination with immunohistochemistry and cell signaling strategies. The impact of insulin resistance on inner ear fluid homeostasis is studied in mice using MR imaging. The Andis (All new Diabetes patients in Skåne) study will be expanded to include also an inner ear perspective initially using diagnosis codes.

Results: Preliminary results show that the HEI-OC1 cells are highly sensitive to insulin (protein kinase B phosphorylation) as well as the beta adrenergic agonist isoproterenol (PKA substrate phosphorylation). A PI3kinase inhibitor blocked the insulin effect and the isoproterenol effect was enhanced by a phosphodiesterase 4-inhibitor. Identification of targets for insulin and cAMP-signaling such as ion channels, aquaporins and metabolic enzymes and MR-imaging on mouse models are on-going.

Conclusions: The inner ear appears to be a target for insulin signaling and action with implications for insulin resistance and diabetes. It is tempting to speculate that the known association between diabetes and inner ear dysfunction could be related to insulin resistance in the inner ear.

OP20-5 - Biocompatibility and therapeutic effect of three intra-tympanic drug-delivery vehicles

17. Pharmacotherapy

Myung-Whan Suh¹

Yu-Jung Hwang¹, Mina Park¹, Tae-Soo Noh¹

¹ Department of Otorhinolaryngology, Seoul National University Hospital

Purpose: We assessed the biocompatibility of several intra-tympanic (IT) drug-delivery vehicles and compared hearing outcomes.

Methods: After acute acoustic trauma, rats were treated with IT 5 mg/mL dexamethasone (D) and divided into the following groups for drug delivery: saline+D (n = 15), HA+D (hyaluronic acid, n = 17), and MP+D (methoxy polyethylene glycol ɛ-polycaprolactone block copolymer, n = 24).

Results: No inflammation was found in the saline+D or HA+D groups. The duration of vehicle/drug persistence in the bulla was significantly longer for the MP+D (47.5 d) and HA+D groups (1.8 d) than the saline+D group (<1 day). The tympanic membrane was significantly thicker in the MP+D group than in the saline+D and HA+D groups. The proportion of ears with good hearing outcome was significantly higher (63.6%) in the HA+D group than the MP+D group. The number of hair cells in the hearing loss (HL) control group was significantly fewer than in the MP+D group.

Conclusions: Thus, HA shows great potential as a biocompatible vehicle for dexamethasone delivery via the IT route, without an inflammatory reaction and with better hearing outcomes. Considering inflammation and hearing, MP may not be a good candidate for IT drug delivery.

OP20-6 - The effects of electrical vestibular stimulation on neurochemical release in the rat striatum.

1. Anatomy and Morphology

Paul Smith¹

Lucy Stiles¹, Yiwen Zheng¹

¹ Dept. of Pharmacology and Toxicology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand

Purpose: For over a century, it has has been speculated that the vestibular system, as a result of its role in sensing angular and linear acceleration of the head, transmits information about self-motion to the basal ganglia, and the striatum in particular. Nonetheless, there are virtually no data available on the effects of stimulating the vestibular system on neurochemical release in the striatum.

Methods: In this study we used in vivo microdialysis to analyse changes in the levels of a number of amino acids and monoamines in the rat striatum, following electrical stimulation of the peripheral vestibular system.

Results: We found that only serine and threonine showed significant changes in the stimulated animals, compared to the sham controls (P < 0.005 and P < 0.01, respectively); these were decreases that were independent of side and/or current intensity. Dopamine (DA) also exhibited a small but significant decrease in release on the ipsilateral side of stimulated animals (P < 0.05); the ratio of DOPAC:DA, also decreased on the ipsilateral side (P < 0.005). Taurine levels exhibited a significant treatment x side x intensity interaction (P < 0.002), which appeared to be due to a small but consistent decrease on the contralateral side in stimulated animals, which varied as a function of current.

Conclusions: These results are consistent with the view that activaton of the vestibular system exerts effects on the function of the striatum.

OP20-7 - Is it time for optical coherence tomography to be part of our vestibular workup?

7. Clinical Testing for Vestibular Function

Marcello Cherchi¹

¹ Northwestern University Feinberg School of Medicine, Department of Neurology, Chicago, Illinois, United States

Purpose: Complete lesions of the vestibular nerve (as in vestibular neurectomy) result in ipsiversive ocular cyclodeviation (torsion of the retinae towards the side of the lesion) that diminishes over months. Incomplete lesions (as in vestibular neuritis) cause less pronounced, but still detectable, ocular cyclodeviation. The torsional position of the retinae is partly influenced by utricular afferents, so one would expect for there to be some correlation between diminished ocular vestibular evoked myogenic potentials (oVEMPs) and ipsiversive ocular cyclodeviation. We report here a pilot study of patients diagnosed with superior division vestibular neuritis who were also assessed with oVEMPs and retinal imaging by optical coherence tomography (OCT).

Methods: We studied a series of patients with a clinical history compatible with vestibular neuritis, whose workup showed a unilateral superior division vestibular weakness (based on caloric testing and video head impulse testing), who also had oVEMPs and OCT performed.

Results: Patients with superior division vestibular neuritis studied within 6 months of symptom onset exhibited cyclodeviation ipsiversive to the side of reduced or absent oVEMPs. One patient studied at 11 months after symptom onset exhibited no cyclodeviation depite persistently reduced oVEMPs.

Conclusions: OCT may be a useful tool in the acute/subacute evaluation of patients with superior division vestibular neuritis. Since OCT is non-invasive, rapid, easy to perform and to interpret, it could play a more prominent role in vestibular workups, or be deployed in acute settings (such as emergency rooms) where more detailed vestibular testing is unavailable.

OP21-1 - Pain a common finding in patients with persistent dizziness

23. Vestibular Compensation and Rehabilitation

Eva-Maj Malmström¹

Måns Magnusson², Johan Holmberg², Mikael Karlberg², Per-Anders Fransson²

¹ Lund University, Skane University Hospital, Department of Clinical Sciences Lund, Otorhinolaryngology AND Skåne University Hospital Lund, Department of Pain Rehabilitation, Sweden

² Lund University, Skane University Hospital, Department of Clinical Sciences Lund, Otorhinolaryngology, Sweden

Purpose: Persisting dizziness causes suffering and interferes with daily activities. Impaired sensory processing with multi-sensory interference, such as vestibular and nociceptive inputs, has been suggested as a maintenance factor.

Methods: Patients referred to a tertiary center for balance disorders (n=49, 34, 15; 14 peripheral vestibular, 8 central vestibular and 27 with no vestibular diagnosis) were asked for the presence of pain and filled out Dizziness Handicap Inventory (DHI, 0-100 points) and intensity ‘as most common’ of perceived dizziness and pain (if applicable) on Visual Analog Scales (0=no, 10=worst possible). If pain was present its location was reported and any interference with daily activities was stated on a Visual Analog Scale. Duration of symptoms was estimated.

Results: Dizziness intensity was stated to 6.0±2.5 (mean±SD) and DHI to 42.0±23.2 (e 15.3±9.4, f 14.5±9.6, p 11.6±6.7). 61% of the patients reported pain, most commonly in neck/shoulders, head and back. Pain intensity was reported to 3.4±3.2 with a pain interference of 3.0+3.5. 88% reported dizziness with a duration of more than 6 months and 85% of the patients with pain reported a pain duration of more than 6 months. 30% of the patients indicated that dizziness came first, 35 % that pain came first and 35% that dizziness and pain started simultaneously.

Conclusions: Patients with persistent dizziness often report concomitant pain. We suggest a multi-sensory interaction with possible interference with pain syndromes when dizziness persist. This might be important for the choice of therapy and rehabilitation.

OP21-2 - Individualized vibrotactile neurofeedback training in bilateral vestibular loss patients

23. Vestibular Compensation and Rehabilitation

Dietmar Basta¹

Roseli Bittar², Marcos Rossi-Izquierdo³, Andres Soto-Varela⁴, Kai Wonneberger⁵, Arne Ernst¹

¹ Department of ENT at ukb, University of Berlin, Germany

² Department of ENT, University of Sao Paulo, Brazil

³ Department of ENT, University Hospital Lucus Augusti, Spain

⁴ Department of ENT, Complexo Hospitalario University of Santiago de Compostela, Spain

⁵ ENT-center, Krefeld, Germany

Purpose: Bilateral vestibular loss (BVL) patients suffer extremely from postural instability during daily life conditions which in turn lead to a high frequency of falls. Unfortunately, conservative vestibular rehabilitation techniques are successful in only 50 % of all patients. The individualized vibrotactile neurofeedback training (iVNT) with the Vertiguard-system has a proven high efficacy for the vestibular rehabilitation in many different balance disorders. The present study investigates therefore the effect of this modern approach on the postural control in BVL-patients.

Methods: All patients without a bilateral caloric response (n=19) performed the iVNT in stance and gait tasks daily for 10 days. Before and after the training period stance stability was tested by the Sensory Organisation Test (SOT). The risk to fall was estimated by the Standard Balance Deficit Test (SBDT) which contains stance and gait tasks under different sensory conditions. Subjective complaints in daily life performance were determined by the Dizziness Handicap Inventory (DHI).

Results: The iVNT reduced the DHI-score and the risk to fall (SBDT-score) significantly (39.7 % and 19.2 %, respectively). The stance stability (SOT-score) was significantly enhanced (22.9 %). In total, the rehabilitation was successful in approximately 90 % of all patients (DHI-score).

Conclusions: The hard to treat BVL-patients benefit significantly from an iVNT training. Nearly all treated patients showed and reported an improved postural stability. The long-term effect should be further investigated.

OP21-3 - Multi-sensory training and wrist fractures. A randomized controlled trial

23. Vestibular Compensation and Rehabilitation

Bergthora Baldursdottir¹

Susan L Whitney², Alfons Ramel³, Hannes Petersen⁴, Palmi V Jonsson⁴, Brynjolfur Mogensen⁴, Ella K Kristinsdottir⁴

¹ University of Iceland; Faculty of Medicine. Landspitali-University Hospital, Iceland, Department of Physical Therapy

² University of Pittsburgh; Department of Physical Therapy, USA

³ The Icelandic Gerontological Research Centre, Reykjavik, Iceland

⁴ University of Iceland; Faculty of Medicine

Purpose: To investigate whether multi-sensory balance training improves postural control, vestibular function, foot sensation and functional ability among people with fall-related wrist fractures compared to those receiving wrist stabilisation training.

Methods: Ninety-eight people (mean age: 61.9 ± 7.1 yrs; range 50-75) who had sustained a fall-related wrist fracture participated in the study. They were randomized to either multi-sensory (MST) or wrist stabilization training (WT). Measurements pre- and post-training included the Head-Shake test (HST), Video-head impulse test (vHIT), Semmes-Weinstein monofilaments (SWF), Biothesiometer (BT), Sensory Organization Test (SOT), 10-meter walk-test (10mw), and the Five-times sit-to-stand test (FTSTS).

Results: There was a 16% non-significant (p=0.058) reduction in asymmetric vestibular function (HST) in the MST group but no change in the WT group. According to linear models correcting for baseline values, age and gender, there were significant endpoint differences in the SOT (p=0.01) between the two groups, in favor of the MST group,but not in other outcome variables. Subgroup analysis using participants with below normal baseline SOT scores indicated that the MST was more effective in improving 10mw fast (p=0.04), FTSTS (p=0.04), SWF (p=0.04) and SOT scores (p=0.04) than the WT.

Conclusions: Multi-sensory training improves postural control among people who have sustained a fall-related wrist fracture. The results of the study further suggest that the program is more effective for those with balance scores below age related norms on the SOT. These findings need to be confirmed in subsequent studies.

OP21-4 - Vestibular rehabilitation exercises as a form of neural priming to regain motor control of the arm

23. Vestibular Compensation and Rehabilitation

Igor Dijkers¹

¹ Chiropractie Harderwijk, private practice, the Netherlands

Purpose: To describe the effects of vestibular rehabilitation exercises to address idiopathic lost motor control of the right arm in a 56-year-old female. Motor control loss was complete for the right arm for 4 months duration and for which traditional rehabilitation was unsuccessful.

Methods: The hypothesis was to use vestibular and oculomotor exercises to prime the motor cortex to regain control over the right arm. Vestibular stimuli were induced by passive and active gaze stability exercises. These were combined with hemisphere specific oculomotor exercises i.e. leftward pursuit combined with rightward saccades. When minor movements were feasible, therapy was extended to include mirror box therapy, timing and coordination training using Interactive Metronome®. Training was performed daily for 4 consecutive days.

Results: Within two hours of vestibular and oculomotor applications mild movement of the shoulder and elbow occurred. Coupling these mild movements with hemisphere specific eye exercises by simultaneously timing led to further progression after which functional aspects could be addressed. On the fourth day she was able to perform all regular daily activities e.g. typing, lifting a cup, using scissors, and using knife and fork whilst eating.

Conclusions: In this case, vestibular and hemisphere specific motor exercises were successful in priming the left motor cortex to regain control over the paralytic and dysfunctional right arm.

OP21-5 - The reliability and validity of the Life Space Assessment in persons with vestibular disorders

23. Vestibular Compensation and Rehabilitation

Pamela Dunlap¹

Kefah Alshebber¹, Gregory Marchetti², Susan Whitney¹

¹ University of Pittsburgh, Department of Physical Therapy, USA

² Duquesne University, Department of Physical Therapy, USA

Purpose: The objective of this study was to determine the reliability and external structure validity of the Life Space Assessment (LSA), a self-reported measure of mobility, in persons with balance and vestibular disorders.

Methods: This prospective cohort study conducted in a balance disorders clinic included a convenience sample of patients experiencing dizziness or imbalance. Subjects completed the LSA, Dizziness Handicap Inventory (DHI), and Short Form 12-Item Health Survey (SF-12) at the start of care and the LSA, Global Rating of Change (GROC), and disability questions at 3 months.

Results: Seventy-two subjects (mean age 53 ± 16 years) completed the outcome measures at baseline and 42 subjects at 3 months. Test-retest reliability of the total LSA (n=37) was excellent (ICC [3,1] = 0.92) and internal consistency was good (Cronbach’s alpha=0.77) measured at the start of care. The LSA showed moderate correlations with the DHI (r=-0.402), with the SF-12 physical (r=0.602) and mental (r=0.405) component summary scores (n=37). Patients who reported improvement at 3 months (n=19) based on GROC >= 4 had significantly better LSA scores (88.3±27) at 3 months than those who did not improve (n=23) (67.9±30.2), p=.023. An improvement in LSA over 3 months was moderately correlated with less activity limitations at work, home, and in the community over 3 months (n=42) (r=-.322, -.341, -.442).

Conclusions: Measurements of mobility using the LSA appear to be valid and reliable in persons with vestibular disorders. The LSA may be a potential measure of mobility in vestibular rehabilitation clinics.

OP21-6 - Histamine H1 receptor contributes to vestibular compensation

23. Vestibular Compensation and Rehabilitation

Zhang-Peng Chen¹

Xiao-Yang Zhang¹, Shi-Yu Peng¹, Yan-Bo Wang¹, Yang-Xun Zhang¹, Xi Chen¹, Jian-Jun Wang¹,

Jing-Ning Zhu¹

¹ State Key Laboratory of Pharmaceutical Biotechnology and School of Life Sciences, Nanjing University, China

Purpose: Vestibular compensation is critical for facilitating recovery from vestibular disorders and is of great importance in understanding the post-lesion neural plasticity. However, the underlying neural mechanism is still far from clear. Intriguingly, betahistine, a widely used clinical drug for treatment of vestibular disorders, exerts not only antagonistic action on the presynaptic H3 receptor, but also agonistic effect on postsynaptic H1 receptor, indicating a possible involvement of H1 receptor in betahistine’s pharmacological effect. Therefore, we assess the exact role of postsynaptic H1 receptor in vestibular compensation.

Methods: Unilateral labyrinthectomy (UL) was performed on adult male Sprague-Dawley rats to establish a model for vestibular compensation. Behavioral assessment, western blotting, immunostaining, retrograde tracing, and whole-cell patch-clamp recording were combined to investigate the pathophysiological function of histamine H1 receptor in the medial vestibular nucleus (MVN) in vestibular compensation and the underlying mechanisms.

Results: Selective blockage of H1 receptor in the MVN retards the recovery of both static symptoms, including postural asymmetry and nystagmus, and dynamic dysfunction in locomotion and motor coordination following UL. The expression of H1 receptor is significantly and restrictedly increased in the ipsilesional rather than contralesional GABAergic MVN commissural neurons. Furthermore, the histamine-induced excitation mediated by postsynaptic H1 receptor is selectively increased in the ipsilesional MVN commissural inhibitory but not excitatory neurons.

Conclusions: Histamine H1 receptor mediates the asymmetric activation of MVN commissural inhibitory system and actively promotes vestibular compensation. The findings reveal a previously unknown functional role for H1 receptor in vestibular compensation and provide new insight into the post-lesion neural circuit plasticity.

OP22-1 - Balance control impairments in Fabry disease

11. Gait, Posture, and Locomotion

Philippe Perrin¹

Laetitia Peultier-Celli², Joëlle Deibener-Kaminsky³, Pierre Kaminsky³, François Feillet⁴, Roland Jaussaud³

¹ Development, Adaptation and Handicap, University of Lorraine, and Pediatric ENT Dpt, University Hospital of Nancy, Nancy, France

² Development, Adaptation and Handicap, University of Lorraine, Nancy, France

³ Dpt of Internal Medicine and Clinical Immunology, University Hospital of Nancy, France

⁴ Reference Centre for Inborn Errors of Metabolism, University Hospital of Nancy, Children Hospital, France

Purpose: Fabry disease (FD) is an X-linked recessive inborn error glycosphingolipid metabolism due to the deficient activity of the lysosomal enzyme alpha-galactosidase A. The deficiency of this enzyme leads to an accumulation of glycosphingolipids throughout the body. Impairments include renal, cardiac and neurological damages. FD may also have neurootological and visual impairments, which can generate postural control alterations, inner ear and vision being involved in this function. This study aimed to evaluate the impact of FD on postural control.

Methods: Fourteen adult patients (mean age = 37.62 +/- 11.43 years) and two children (mean age = 11.01 +/- 2.54 years) with FD and 19 healthy adults (mean age = 36.51 +/- 16.99 years) and two children (mean age = 10.49 +/- 0.79) took part in this study. Postural control was evaluated by a sensory organisation test combining three visual situations (eyes open, eyes closed, sway referenced visual surround motion) with two platform situations (stable platform, sway referenced platform motion), aiming to calculate a composite equilibrium score (CES). Somatosensory contribution to postural control (R-SOM), visual contribution (R-VIS) and vestibular contribution (R-VEST) were calculated.

Results: The CES was lower in patients with FD compared to healthy subjects (p < 0.001). R-VIS (p = 0.001) and R-VEST (p = 0.003) were lower in FD patients compared to the control group.

Conclusions: Inner ear and visual pathologies associated to central nervous system impairments are factors of a postural control impairments. Physical activities, which can also be rehabilitative, by maintaining or increasing the weight of proprioception, may help diminish dependency to altered sensorial inputs.

OP22-2 - Body sway is mediated by vestibular cortical dominance

11. Gait, Posture, and Locomotion

Qadeer Arshad¹

¹ Imperial College

Purpose: The posterior parietal cortex is heavily implicated in vestibulo-cortical processing. Recent behavioural data and meta-analysis of imaging data suggests a right-hemispheric dominance for vestibular processing. Functionally, the vestibular cortex is implicated for maintaining spatial orientation and postural control, However, to-date whether the degree of an individual’s hemispheric dominance influences postural control remains unknown.

Methods: 24 right-handed healthy individuals underwent either cathodal or anodal transcranial Direct Current Stimulation (tDCS) for 15min over the left Posterior Parietal Cortex (PPC). Vestibulo-cortical hemispheric dominance was quantified using the, “nystagmus suppression index” calculated as the change (i.e. before/after tDCS) in the peak Slow Phase Velocity in response to cold-water caloric irrigations. To assess postural control, subjects performed a postural task before and after tDCS which required them to maintain balance whilst they stood on a linear sled and were exposed to random left-right perturbation. Objective measures of body sway were recorded.

Results: Increased right vestibulo-cortical dominance (i.e. larger nystagmus suppression index) was negatively correlated with the sway path change (r:0.7, p<0.05) in the cathodal group. Sway velocity was also positively correlated with the degree of nystagmus suppression index in the cathodal group (r:0.65 p<0.05). No relationship was observed following anodal stimulation (control group).

Conclusions: The degree of right hemispheric vestibulo-cortical dominance influences postural control.

OP22-3 - Changes in Cortical Activity during Dual-task Walking in Individuals with and without Visual Vertigo

11. Gait, Posture, and Locomotion

Carrie Hoppes¹

Theodore Huppert², Susan Whitney³, Pamela Dunlap³, Kefah Alshebber³, Nikki DiSalvio³, Joseph Furman⁴, Yong Kwon⁵, Andrea Rosso⁶

¹ Army-Baylor University, Physical Therapy, USA

² University of Pittsburgh, Radiology, USA

³ University of Pittsburgh, Physical Therapy, USA

⁴ University of Pittsburgh, Otolaryngology, USA

⁵ Yeungnam University College, Physical Therapy, South Korea

⁶ University of Pittsburgh, Epidemiology, USA

Purpose: Under dual-task conditions, cognitive resources are divided between a cognitive task and a dynamic balance task. The aim of this study was to determine differences in cortical activity in the frontal cortex between individuals with and without visual vertigo (VV).

Methods: Fourteen individuals with VV and 14 age- and gender-matched healthy controls (mean 39 ± 11 years old) were monitored with functional near-infrared spectroscopy (fNIRS) over the frontal cortex. Subjects performed a cognitive task (every other letter of the alphabet) while walking over an even or uneven surface and fNIRS signals were compared to quiet standing.

Results: Individuals with VV had greater increases in deoxy-hemoglobin over the left frontal cortex while standing with a cognitive task (T = 4.35, p < .001), walking over an even surface with (T = 4.34, p < .001) and without (T = 4.20, p < .001) a cognitive task, and walking over an uneven surface (T = 5.81, p < .001) compared to quiet standing relative to healthy individuals. During dual-task walking over an uneven surface, individuals with VV had decreases in deoxy-hemoglobin over the left frontal cortex compared to quiet standing relative to healthy individuals (T = -22.93, p < .001).

Conclusions: During complex walking tasks, individuals with VV display greater activity in the frontal cortex, indicating that they may be devoting greater cognitive resources to performing dual-tasks than healthy individuals. During the most challenging task, individuals with VV may have shifted attention away from the cognitive task or may have been utilizing regions of the brain other than the frontal cortex.

OP22-4 - Influence of hearing on postural control and stability in healthy subjects

11. Gait, Posture, and Locomotion

Ingmar Seiwerth¹

Johannes Jonen¹, René Schwesig², Andreas Lauenroth², Torsten Rahne¹, Timothy Hullar³, Stefan Plontke¹

¹ Martin Luther University Halle-Wittenberg, Department of Otorhinolaryngology, Head and Neck Surgery, Halle (Saale), Germany

² Martin Luther University Halle-Wittenberg, Department of Orthopedic and Trauma Surgery, Halle (Saale), Germany

³ Oregon Health & Science University, School of Medicine, Department of Otolaryngology - Head and Neck Surgery, Portland, Oregon, USA

Purpose: In postural control, auditory input seems to interact with vestibular, somatosensory and visual information. However, various, sometimes conflicting, assessments of this process have been reported during both static and mobile posturography experiments. We hypothesize a beneficial effect of sound, and that there are differences in audiovestibular regulation mechanisms depending on the type of experiment.

Methods: 30 normal hearing, healthy subjects were tested in a sound-insulated hypoechoic auditory booth in two conditions, with and without 0°-presentation of sound. Stability was measured using a force plate system (Interactive Balance System, IBS) with 8 standardized stance conditions. Postural control was measured with the Vertiguard trunk sway device using the Standard Balance Deficit Test (SBDT, 14 tasks).

Results: Trunk sway measurement showed a significant reduction of angular sway velocity with auditory input in two tasks of the SBDT: walking over four barriers (pitch plane, p < 0.0001) and standing on one leg with eyes closed (roll plane, p = 0.0055). In the condition with sound, IBS showed a relevant decrease of the level of postural regulation in the frequency bands F1 (eta² = 0.122) and F2-4 (eta² = 0.125), representing the visual and the peripheral-vestibular system, as well as in the Weight Distribution Index (eta² = 0.159).

Conclusions: We could show a significant benefit of auditory input on postural control. Force plate based stability analysis indicates a shift of multisensory regulation weighting due to auditory input. Audiovestibular regulation mechanism seems to influence the postural performance, particularly visual and vestibular subsystems.

OP22-5 - The auditory influence on postural control in stance and gait conditions

11. Gait, Posture, and Locomotion

Dietmar Basta¹

Kristina Anton¹, Arne Ernst¹

¹ Department of ENT at ukb, University of Berlin, Germany

Purpose: The influence of visual, vestibular and proprioceptive sensory information on postural control has already been well investigated. However, little is known about the impact of auditory information on balance in stance and gait conditions. In the present study, body sway was therefore evaluated in young, healthy volunteers under different auditory and motor condition.

Methods: All volunteers (n=30, age 16-40 y) showed normal hearing, normal visual acuity and normal peripheral vestibular receptor function.

Body sway was measured with the Vertiguard mobile posturography system at the hip close to the center of body mass in eleven stance and gait tasks under the following acoustic conditions: o quiet (reference condition) o continuous white noise (frontal) o pulsed with noise (frontal) o plugged ears o amplified walking sound

Results: Continuous noise and ear plugging increased the body sway during most stance tasks, while pulsed noise was able to enhance the postural control. The sway during walking was significantly decreased by all kind of applied noise if the head was not turned in rhythm. Amplified walking sound did not influence postural control during walking.

Conclusions: Postural control in stance tasks could be impaired by masking the auditory input with continuous noise or earplugs and enhanced with the application of additional, exactly timed acoustic reflections. The sway during walking could be reduced by the permanent localization of a sound source.

The results indicate that specific auditory information seem to have a significant influence on postural control during specific stance or gait tasks.

OP22-6 - Vestibular loss effects on standing balance during postural threat

11. Gait, Posture, and Locomotion

Taylor W. Cleworth¹

John H.J. Allum², M. John Luu¹, Jane Lea³, Brian D. Westerberg³, Mark G. Carpenter¹

¹ School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada

² Department of Otolaryngology, University Hospital, Basel, Switzerland

³ BC Rotary Hearing and Balance Centre at St. Paul’s Hospital, Vancouver, British Columbia, Canada

Purpose: Vestibular deficit patients have an increased fall risk and presumably an increased fear of falling. Postural threat, known to increase balance-related fear and anxiety, has been shown to influence vestibular gains during quiet standing in young healthy adults. Threat-related balance changes were found to be unaffected by unilateral vestibular loss (Young et al., 2012). However, short duration standing trials, with a mild postural threat (standing on a 62cm high platform) limited previous work. The current study was designed to examine the relationship between vestibular loss and strong threat effects on standing balance control.

Methods: Eight patients with complete unilateral vestibular loss (UVL) due to operated vestibular nerve tumors and six healthy controls stood for two minutes on a force-plate mounted to a hydraulic lift placed at two heights: low (0.8m, away from edge) and high (3.2m, at edge). Amplitude (root mean square, 90% range), mean power frequency, (MPF), and mean position were analyzed for center of pressure (COP; AMTI, USA) and trunk sway (SwayStar, CH).

Results: UVL patients had larger COP amplitudes, larger 90% ranges for trunk sway and velocity, but smaller 90% ranges for COP velocity than controls. Independent of group, height significantly increased COP MPF and the 90% ranges for COP and trunk velocity, and lean away from the edge.

Conclusions: Independent of height, balance in UVL patients differs from controls, presumably due to reduced vestibular gain. However, increased sway velocity with height and the balance strategy used by UVL patients under fearful conditions is not different.

OP22-7 - Virtual Reality for Vestibular and Balance Rehabilitation A Preliminary report

11. Gait, Posture, and Locomotion

Elodie Chiarovano¹

Hamish MacDougall¹

¹ The University of Sydney, School of Psychology, Australia

Purpose: We report here five patients complaining for chronic dizziness and five healthy subjects (controls) who performed balance rehabilitation using Virtual Reality (VR).

Methods: We used a Wii Balance Board and our ‘BalanceRite’ App on an iPhone to assess balance on a stable surface and a compliant surface (Wii board+foam). Several visual conditions were used: eyes open, eyes closed, and using Virtual Reality goggles (Samsung Gear VR). The VR scene generated by our ‘Tuscan Villa’ App was an immersive garden that can be perturbed (by a sum-of-sines) at various amplitudes (unpredictable visual distractor). The rehabilitation was done with a VR optokinetic cloud of dots or a drum of black and white stripes. Baseline balance performance was assessed at an initial stage before any intervention. After subjects had been exposed to 8-10 mins of the rehabilitation stimulus their balance was assessed again. This process was repeated once a week for four weeks.

Results: Patients showed an improvement of balance performance measures. Balance of healthy subjects was not affected by the VR stimulus. For those subjects tested again one month later, balance performance improvements were still maintained.

Conclusions: Balance rehabilitation using virtual reality could be a very efficient way to improve balance in patients.

OP23-1 - Exposure to an extreme environment comes at a sensorimotor cost

27. Others

Kyoung Jae Kim¹

Yoav Gimmon², Kara Beaton³, Sharmeen Sorathia²,

Michael Schubert²

¹ Department of Physical Therapy, University of Miami, USA

² Laboratory of Vestibular NeuroAdaptation, OHNS, Johns Hopkins University, USA

³ National Aeronautics and Space Administration, USA

Purpose: Long duration space flight disrupts sensorimotor function. In prepararation for future exploration, NASA employs research analogs that mimic some of the physical, psychological, and emotional challenges that crewmembers will experience. NASA’s Extreme Environment Mission Operations (NEEMO) is one such research analog; individuals live for up to three weeks at saturated atmospheric pressure (~2.5 ATM) in a habitat located 19 m undersea in the Florida Keys National Marine Sanctuary.

Methods: We have developed the Portable Sensorimotor Assessment Platform (PSAP) to measure different aspects of sensorimotor function. PSAP uses a Microsoft Surface Pro 3 tablet computer (Microsoft Corporation, USA) and five small MTw inertial sensors with a sampling frequency of 100 Hz (Xsens Technologies BV, Netherlands). Ten crewmembers (six from NEEMO 21 and four from NEEMO 22) were recruited to perform tandem walking in two conditions: eyes open (EO) and eyes closed (EC).

Results: We found significant changes in performance while tandem walking in both EO and EC conditions. During the EC tandem walk condition, significant correlations between the mission duration and gait regularity and trunk displacement worsened over the duration of the mission. Trunk displacement did not return to baseline upon return to land (1 ATM).

Conclusions: The results of our study reveal that the PSAP instrumented version of tandem walking test can be useful for identifying crewmembers with transient sensorimotor deficits. Our data suggest crewmembers exposed to the long duration NEEMO mission suffer a postural control cost. This cost may be avoidable, or treatable given the plasticity existent in sensorimotor function.

OP23-2 - Sensation and functional balance in elderly - low efficacy using the 256 Hz tuning fork

27. Others

Anna Hafström¹

¹ Department of Otorhinolaryngology, Head and Neck Surgery, Clinical Sciences, Lund University, Sweden.

Purpose: In elderly, diminished foot somatosensation contributes to balance deficits and increased fall risk. However, it remains unclear how to adequately measure somatosensation in the outpatient clinical setting.

Methods: Discrimination between vibration sensation and pressure perception was tested bilaterally with a 256 Hz tuning fork at the base of the first metatarsal bone (MTP-I), the medial malleolus (Mall), and proximal Tibia in 36 relatively healthy elderly (mean 69.4±5.3 years). Subject were allocated into 4 four different tuning fork sensation groups (TFSG) according to their ability to detect vibration from pressure on at least one leg: TFSG 3 (three sites), TFSG 2 (Mall, Tibia), TFSG 1 (Tibia) and TFSG 0 (no sites). Vibration perception thresholds (VPTs) were measured with a 120 Hz biothesiometer and tactile pressure sensation thresholds (TPSTs) with a 20-piece monofilament kit. Balance was assessed with one-leg standing time (OLST) on firm and compliant surfaces with eyes open or closed, walking speed, Figure-8, Timed Up & Go (TUG), Berg Balance Scale (BBS), and posturography.

Results: Four subjects were included in TFSG 3, nine in TFSG 2, 14 in TFSG 1 and nine in TFSG 0. There were no significant differences in age, BMI, VPTs, or TPSTs between the four groups, nor in the outcome of OLST (any condition), walking speed, Figure-8, TUG, BBS, or posturography results.

Conclusions: Vibration perception measured with a 256 Hz tuning fork seems to be a very minor determinant for functional balance and thus a superfluous test when evaluating the importance of vibration perception for balance control in elderly.

OP23-3 - Paroxysmal positional ocular flutter associated with middle cerebellar peduncle demyelination

15. Ocular Motility: Physiology and Pathology

Ana Inês Martins¹

Maria Carmo Macário¹, César Nunes², João Lemos³

¹ Coimbra University Hospital Centre, Neurology Department, Coimbra, Portugal

² Coimbra University Hospital Centre, Neuroradiology Department, Coimbra, Portugal

³ Coimbra University Hospital Centre, Neurology Department, Coimbra, Portugal; Coimbra University, Faculty of Medicine, Coimbra, Portugal

Purpose: Positional ocular flutter is a rare disorder, with two cases described in the literature, both lacking an underlying focal lesion (ie, in one patient with degenerative ataxia and in another with Krabbe’s disease). Given its strictly positional nature, a dysfunction of the cerebellar saccadic-otolithic network has been hypothesized. We describe a patient with a right middle cerebellar peduncle demyelinating lesion associated with symptomatic positional ocular flutter, in whom the use of dalfampridine (4-AP) was not effective.

Methods: History taking; Clinical exam; Video-oculography; Head MRI

Results: A 24 year-old woman presented with a 3-year history of paroxysmal oscillopsia and nausea when moving to supine position. Brain MRI revealed several lesions in the supratentorial region and one located at the anterior and medial aspect of the right middle cerebellar peduncle, consistent with demyelinating disease. Video-oculography in upright position showed occasional single saccadic pulses and square-wave jerks on fixation. When moving to head hanging position, a ~2 second positional ocular flutter followed by ~30 second square-wave oscillations was consistently precipitated, along with intense nausea. She was started on 4-AP, 10mg bid. 180 minutes after the first intake, positional ocular flutter was unchanged. Five days later, minor side effects led to 4-AP interruption.

Conclusions: Positional ocular flutter in our case may reflect transverse ephatic spread of excitation from a lesion involving tracts that subserve otolithic input, to contiguous cerebellar tracts modulating saccadic burst neuron activity in the brainstem. Dalfampridine does not seem to be effective in positional ocular flutter.

OP23-4 - Main sequence of torsional saccade under videooculography recordings.

15. Ocular Motility: Physiology and Pathology

Takeshi Tsutsumi¹

Takamori Takeda¹, Takuo Ikeda², Yutaka Fukuoka³

¹ Department of Otorhinolaryngology, Tokyo Medical and Dental University

² Department of Otorhinolaryngology, Tsudumigaura medical center for children with disabilities

³ Faculty of Engineering, Kogakuin University

Purpose: 3-dimensional eye movement description can recently be obtained using video-oculography. We’ve been quantifying video of eye movement into horizontal, vertical and torsional dimensions, and integrating them into rotational vector. During this procedure, pattern matching of subject’s iris is employed to quantify torsional eye movement, which tends to cause the error and reduce the accuracy of recordings. We are seeking for a procedure to set the upper limit on the angular value per frame, to restrict the recordings of torsional movement under reasonable numeric, which enables us to exclude false measurements. However, it may also exclude actual torsional saccade, and rather decrease the accuracy. To settle appropriate value of limitation, angular velocity characteristics of torsional saccade should be clarified.

Methods: Relationship between torsional amplitude and angular velocity (torsional “Main Sequence”) of healthy subjects’ saccade was evaluated under videooculography recordings. Torsional saccade cannot be delivered intentionally. So, we employed intermittent saccade during torsional vestibulo-ocular reflex.

Results: Amplitude of torsional saccades distributed up to about 10 degrees, and did the velocity up to around 100 deg/sec. Angular velocity increases proportionately to the torsional amplitude, and its averaged coefficient was around 10.

Conclusions: Main sequence of torsional saccade demonstrates linear characteristics mimicking horizontal and vertical saccade. It can enable us to set upper limit of torsional angular change per each sampling frame under video-oculography recordings, to improve the accuracy of 3D eye movement analysis.

OP23-5 - Structural connectome of the human vestibular cortex

1. Anatomy and Morphology

Iole Indovina¹

Roberta Riccelli², Luca Passamonti³, Gianfranco Bosco², Francesco Lacquaniti², Nicola Toschi⁴

¹ Santa Lucia Foundation, Laboratory of Neuromotor Physiology, Rome, Italy

² University of Rome Tor Vergata, Department of Systems Medicine, Rome, Italy; University of Rome Tor Vergata, Centre of Space BioMedicine, Rome, Italy.

³ University of Cambridge, Department of Clinical Neurosciences, Cambridge, UK

⁴ University of Rome Tor Vergata, Department of Biomedicine and Prevention, Rome, Italy; Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Boston, MA, USA

Purpose: The aim of this study is to characterize modules and hubs within the multimodal vestibular system and in particular to test centrality of posterior peri-sylvian regions.

Methods: Structural connectivity matrices from 100 unrelated healthy right-handed subjects from the Human Connectome Project (HCP) database were analyzed using multishell diffusion-weighted data, probabilistic tractography (constrained spherical-deconvolution informed filtering of tractograms) in combination with subject-specific grey matter parcellations. Network nodes included parcellated regions within posterior thalamus (Fan 2016 atlas), insula, opercula, superior temporal, parietal, frontal and cingulate cortex, hippocampus and parahippocampal cortex (Glasser 2016 atlas). A group matrix was then calculated by averaging weights across the most consistent tracks. Modularity calculation maximized the number of within-module links and minimized the number of between-module links. Hub-regions were identified according to aggregate ranking of multiple metrics (average range across node strength, nodal efficiency and betweenness centrality).

Results: Areas in both hemispheres were grouped in three modules: the first comprised the posterior thalamus, insula and opercula, superior parietal and peri-insular frontal regions; the second module was constituted by high order visual areas (MT, MST), inferior parietal and temporal peri-sylvian regions; the third module included the cingular, hippocampal, and parahippocampal areas. Hubs were mainly located in the parietal opercula and peri-sylvian inferior parietal cortex.

Conclusions: This analysis revealed three paths within the multi-modal vestibular system, seemingly related to vestibular / somaesthetic processing, vestibular / visual processing and spatial orientation / navigation. Posterior peri-sylvian regions may represent the main hubs of this modular network.

OP24-1 - Abnormal Visuo-vestibular Interactions in Vestibular Migraine

24. Vestibular Migraine

Qadeer Arshad¹

¹ Imperial College

Purpose: Vestibular migraine (VM) is amongst the commonest causes of episodic vertigo. Chronically, VM patients develop both an abnormal responsivity to vestibular and visual stimuli, as characterised by heightened self-motion sensitivity and visually-induced dizziness. However, to-date the neural mechanism mediating such symptoms in VM remains unknown. We postulate that impaired visuo-vestibular cortical interactions in VM disrupt normal vestibular behaviour and in-turn mediate the evolution of symptoms.

Methods: To assess this, we investigated whether full-field, prolonged (5 minute) visual motion exposure, which has previously been shown to modulate visual cortical excitability, could modulate vestibular ocular reflex (VOR) and vestibular-perceptual thresholds of self-motion during horizontal yaw rotations in VM patients.

Results: Our findings reveal that VM patients exhibit abnormally elevated VOR and vestibular-perceptual self-motion detection thresholds at baseline. Following visual motion adaptation both reflex and perceptual vestibular thresholds were further increased in comparison to healthy controls and migraineurs without vestibular symptoms.

Conclusions: We provide a novel demonstration of abnormal baseline vestibular thresholds in VM. Additionally, we observed altered visuo-vestibular cortical interactions following visual motion adaptation, as reflected by modulation of vestibular thresholds, in VM patients only, thereby elucidating a potential neurophysiological bio-marker.

OP24-2 - Errors of Upright Perception in Patients with Vestibular Migraine

24. Vestibular Migraine

Ariel Winnick¹

Jorge Otero-Millan¹, Shirin Sadeghpour¹, Tau-Pu Chang²,

Amir Kheradmand³

¹ Johns Hopkins, Department of Neurology, USA

² Department of Neurology, Neuro-medical Scientific Center, Taiwan

³ Johns Hopkins, Departments of Neurology and Otolaryngology & Head and Neck Surgery, USA

Purpose: Patients with vestibular migraine (VM) suffer from disturbances in perception of spatial orientation with symptoms triggered or worsened by changes in the head or body positions. Here we studied the impact of static head tilt on spatial perception by measuring subjective visual vertical (SVV) at different lateral head tilt positions in 27 VM patients and 27 healthy volunteers matched for age and handedness.

Methods: SVV responses were collected using a forced choice SVV paradigm in three head tilt conditions (upright, +/- 20°) with the head immobilized using a bitebar in a dark room.

Results: In the upright head position, SVV accuracy was within the normal range for VM patients and healthy controls (two degrees from true vertical). During the static head tilts of 20° to the right, VM patients showed errors consistent with overestimation of the tilt magnitude (i.e. greater E-effect than controls) (-3.21° ± 0.93 vs. 0.52° ± 0.70; p=0.002). During the head tilts to the left, SVV errors in VM patients did not differ significantly from controls (0.77° ± 1.05 vs. -0.04° ± 0.68; p=0.52). There was no significant difference in SVV precision between the VM patients and healthy controls for any head tilt position. Consistent with the SVV errors, the majority of VM patients reported symptoms toward the right side with daily activities.

Conclusions: The larger errors of upright perception during head tilt suggests abnormal sensory integration for spatial perception in vestibular migraine. This finding could be related to symptoms induced by changes in the head position in these patients.

OP24-3 - Living with Vestibular Migraine; A qualitative investigation of patients perspectives

24. Vestibular Migraine

Mahsa Bakhit¹

Jessica Jane Vitkovic¹, Caitlin Barr², David Szmulewicz³

¹ The University of Melbourne, Department of Audiology and Speech Pathology, Melbourne, Australia.

² The University of Melbourne, HEARing CRC, Department of Audiology and Speech Pathology, Melbourne, Australia.

³ The University of Melbourne, The Royal Victorian Eye & Ear Hospital, Department of Neuroscience (LR), St Vincent’s Hospital, Melbourne, Australia.

Purpose: This study investigated the patients’ perspectives on living with Vestibular Migraine (VM) to help Healthcare Professionals (HCPs) gain a more comprehensive understanding of needs and wants of the patients. This information will be used to inform recommendations to help practitioners optimize their practice.

Methods: A qualitative descriptive method was implemented in this study. Eleven adults with a confirmed diagnosis of VM by their physicians were interviewed for an average of 35 minutes. Interviews were audio-recorded, transcribed and analyzed using thematic coding.

Results: Four major themes emerged through categorization and abstraction of the concepts; 1) VM resembles a restrictive wall, 2) Life within the wall is dramatically different than life outside, 3) Isolation and 4) Hopelessness. Within the theme two, six subthemes were identified where participants described variable impacts on their lifestyle, occupation, personal life, self-sufficiency, social network and self-image. This finding specifically highlights VM as a debilitating illness with pervasive functional restriction and extensive psychologically repercussions.

Conclusions: Disregarding the VM impacts on patients’ quality of life downgrades the therapy outcome. To Optimize VM clinical management, practitioners must implement a holistic collaborative approach comprising of not only the medical treatment but also the development of goal-oriented interventions that address the patients’ unique functional/psychological restriction.

OP24-4 - Severe motion sickness - a possible rare presentation of vestibular migraine

24. Vestibular Migraine

John Waterston¹

¹ Alfred Hospital, Melbourne, Australia

Purpose: To describe a rare presentation of severe motion sickness due to possible vestibular migraine.

Methods: A retrospective review of patients presenting with severe motion sickness who responded to migraine prophyaxis was conducted. These cases were collected over a 20 year period and were analysed according to the medications prescribed, duration of symptoms, history of migraine and presence of migrainous features during bouts of motion sickness.

Results: A total of 16 patients with severe motion sickness were identified who responded dramatically to the use of migraine prophylaxis, with a greater than 50% reduction in symptoms of motion sickness, though most had a substantial or near total improvement in their symptoms. Medications used included pizotifen, topiramate, amitriptyline and propanolol. This collection was from a total cohort which inclued over 600 patients with a diagnosis of suspected vestibular migraine. Of the 16 cases, 7 had a history of motion sickness dating back to early childhood. Only 5 cases (31%) had a history of migraine according to IHS criteria. Nine cases (56%) had a history of headache or photophobia during bouts of motion sickness. No cases fulfilled the IHS criteria for the diagnosis of vestibular migraine.

Conclusions: Severe motion sickness may be a presenting feature of vestibular migraine. These cases responded dramatically to trials of migraine prophylaxis and this treatment should be considered in patients presenting with severe motion sickness. A trial of therapy may be indicated even when there is no other history to suggest a diagnosis of migraine.

OP24-5 - Vertigo in Pediatric population. Migraine prevalence

24. Vestibular Migraine

Sergio Carmona¹

Patricia Sommerfleck², Romina Weinschelbaum¹

¹ Neurotology. INEBA. Buenos Aires. Argentina

² Neurotology. Garrahan Hospital. Buenos Aires. Argentina

Purpose: To establish the prevalence of Vestibular Migraine (VM) in our series of pediatric patients.

Methods: A retrospective, observational, descriptive, and cross-sectional study was conducted.

Patients aged 1-18 years who consulted because of balance disorders at the Otolaryngology Department of a Pediatric Tertiary-Care Hospital between June 2014 - June 2017.

Results: 247 patients ages 1-18 were included in the study; 123/247 (49%) girls y 124/247 (51%) boys. The age median was 9 years.

Within this group of studied patients 76/247 (30%) referred vestibular symptoms and headaches. Fifteen of them (20% - 15/76) met the diagnostic criteria for defined VM and 6/76 (8%) met the criteria for probable VM, i.e. 21/76 (28%) patients are included in this condition. This represents 8.5% (21/247) of the total sample considered in this work. Fifty five patients 55/76 (76%) do not meet the VM criteria.

A family history of migraine is relevant data to be considered in this group of patients. 100% (15/15) of the patients with defined vestibular migraine had a family history of migraine.

BPVC is a migraine equivalent: 21/247 (8.5%) patients present this pathology in our series.

Thus, we have 21 patients with a VM diagnosis and 21 patients with BPVC. (total: 42/247-17%- patients)

Conclusions: It can be established that, out of all children who consult due to “headache” associated to balance disorders, only a percentaje below 10% meet the criteria for VM. The simple association of both symptoms does not define this pathology.

OP24-6 - Vestibular migraine: reference to International Classification of Headache Disorders 3rd edition.

24. Vestibular Migraine

Grażyna Tacikowska¹

Maciej Rzeski¹, Katarzyna Pietrasik¹, Magdalena Sosna¹, Henryk Skarżyński¹

¹ Institute of Physiology and Pathology of Hearing, Otoneurology Department, Poland

Purpose: Clinical characteristics of vestibular migraine in reference to actual diagnostic criteria of International Classification of Headache Disorders -3: verification.

Methods: A cross-sectional historical cohort study was conducted. Clinical records of all patients attended to the tertiary referral neurootological outpatient clinic in the period from January 2014 to May 2017 and diagnosed as having vestibular migraine were evaluated. Diagnosis was based on criteria of International Classification of Headache Disorders 3: main points extended by the notes which are enclosed to the criteria, especially concerning the duration of attacks (not only attacks between 5min to 72h but also lasting seconds up to five minutes and longer than 72 hours).

Results: A total of 156 records of patients (141 female, 15 male, 47 ± 13.0 years old) were enrolled in the study. The mean age of onset of vertigo was 38,1±13,2 years. The duriation of attacks less than 5 minutes or more than 72 hours was present in 24% of patients. Temporal relationship between headaches and vestibular symptoms occurred in 65% of patients, but the remaining part (35%) have never had headache during attacks of vertigo. 26% of patients did not reported any migrainous symptoms (photo and phonophobia) during vestibular migraine. Absence of concomitant occurrence of dizziness and headache and migraneous symptoms was observed in 15% of individuals.

Conclusions: Part of patients due to criterion of time attacks and the criterion of the presence of migraine symptoms do not fulfilled main points of ICHD-3 criteria for VM without concerning the notes added to main points.

OP24-7 - Benign Recurrent Spontaneous Vertigo with Interictal Head-Shaking Nystagmus

6. Central Vestibular Disorders

Sun-Uk Lee¹

Jeong-Yoon Choi¹, Hyo-Jung Kim¹, Ji-Soo Kim¹

¹ Dizziness center, Seoul National University Bundang Hospital

Purpose: To define a disorder characterized by recurrent spontaneous vertigo and interictal head-shaking nystagmus (HSN).

Methods: We had recruited 35 patients with recurrent spontaneous vertigo of unknown causes (also known as benign recurrent vertigo; BRV) and interictal HSN. We characterized the HSN in comparison to that recorded in randomly selected patients with compensated vestibular neuritis (VN), vestibular migraine (VM), and Meniere’s disease (MD).

Results: The estimated time constants (TCs) of the primary phase of HSN was 12 seconds (95% CI=12–13 seconds) in patients with BRV, which were larger than that from VN (5 seconds, 95% CI=4–5 seconds), VM (5 seconds, 95% CI=5–6 seconds) or MD (6 seconds, 95% CI=5–6 seconds). The TCs of the horizontal vestibulo-ocular reflex were also larger during rotatory chair test in patients with BRV. Among the 35 patients with BRV and HSN, seven showed vigorous long-lasting HSN with a peak slow phase velocity 50.0°/s. In five patients (5/7, 71%) with vigorous HSN, HSN could have been induced even with head shaking only for two to five seconds. Long-term prognosis was favorable with a resolution or improvement of the symptoms in more than half of the patients during the median follow-up of 12 years (range=2-58) from symptom onset. None developed VM or MD during the follow-up.

Conclusions: The clinical features and characteristics of HSN in our patients indicate hyperactive and asymmetric velocity-storage mechanism that gives rise to intermittent attacks of spontaneous vertigo

OP25-1 - Video-head impulse test results in Meniere’s disease related to duration and stage of disease

14. Meniere’s Disease and Related Disorders

Babette Van Esch¹

Kasra Abolhosseini², Hester van der Zaag-Loonen³, Peter Paul van Benthem¹, Tjasse Bruintjes³

¹ University Medical Centre Leiden, Department of Otorhinolaryngology and Head and Neck Surgery, The Netherlands

² Pacific University, Department of Audiology, Hillsboro, United States

³ Gelre Hospital, Apeldoorn Dizziness Centre, Apeldoorn, The Netherlands

Purpose: The video-head impulse test employs the vestibulo-ocular reflex (VOR) to assess vestibular function. To this day, no consensus has been reached among scientists in terms of whether or not vHIT results change in MD patients as the disease progresses. To assess whether the vHIT is more often abnormal during later stages of MD compared to earlier stages.

Methods: We retrospectively analyzed patients with ‘definite’ MD who had undergone the vHIT and caloric test between 2012 and 2015. Patients were evaluated based on duration of disease in years (≤1, >1≤5, >5≤10, >10) and stage of disease (stage I and II versus III and IV). For the vHIT, an abnormal vestibulo-ocular reflex was defined as a gain cut-off value of ≤0.8 and presence of correction saccades.

Results: In 89 definite MD patients (42 (47%) male, mean age 55±5 (SD)), data on both the caloric test and the vHIT was available. The risk at an abnormal vHIT was 25% in patients with a duration of disease over 10 years compared to 22% in the patients with a disease duration of 10 years or less (risk difference 3%, 95% CI:-28% to 35%), p=0.82). The risk for an abnormal vHIT in the Stage I and Stage II was 17% compared to 26% in Stage III and IV (risk difference 9%, 95% CI:-30% to 11%).

Conclusions: Using the criteria of either duration or stage of disease, no relationship could be demonstrated between the proportion of abnormal vHIT test results in patients with MD.

OP25-2 - Acute video-oculography for vertigo in emergency rooms for rapid triage (avert) Trial: pilot results

7. Clinical Testing for Vestibular Function

Adriana S. Batazzi¹

Tzu-Pu Chang², Vahid Eslami¹, Mehdi Fanai³, Jorge C. Kattah⁴, Kevin A. Kerber⁵, Daniel F. Hanley¹, John P. Carey⁶, David S. Zee¹, David E. Newman-Toker¹

¹ Johns Hopkins University School of Medicine, Department of Neurology, Baltimore, MD, USA

² Taichung Tzu Chi Hospital, Tzu Chi University, Buddhist Tzu Chi Medical Foundation, Department of Neurology, Taiwan

³ Johns Hopkins University School of Medicine, Armstrong Institute Center for Diagnostic Excellence, Baltimore, MD, USA

⁴ University of Illinois College of Medicine, Department of Neurology, Peoria, IL, USA

⁵ University of Michigan Health System, Department of Neurology, Ann Arbor, MI, USA

⁶ Johns Hopkins University School of Medicine, Department of Otolaryngology-Head and Neck Surgery, Baltimore, MD, USA

Purpose: Report preliminary results from a two-year logistical pilot phase of the AVERT trial. AVERT is a multicenter, patient-level randomized phase II trial comparing the impact of video-oculography (VOG)-guided rapid triage to standard Emergency Department (ED) diagnostic care (NCT02483429).

Methods: From November 2015 to November 2017, we screened 291 patients with acute vertigo at three EDs during the AVERT pilot trial. We performed a standardized screening battery of VOG tests using the ICS Impulse device (GNOtometrics, Taastrup, Denmark). Tests included Head Impulse, Nystagmus, and Test of Skew (HINTS) as well as gaze and positional testing. Of 131 VOG recordings, neuro-otology experts reviewed 101 to determine the presence of pathologic nystagmus (>10deg/sec), and, if present, render a final diagnosis, masked to the ED diagnosis. Expert diagnoses were compared to recorded ED diagnoses. Barriers to automated VOG interpretation were identified and addressed.

Results: Among 101 patients, 31% (n=31) had pathologic nystagmus (15 BPPV, 7 vestibular neuritis, 6 central, 3 unknown). Of these, 26% (n=8) were diagnosed correctly by ED providers. The principal barrier to automated VOG interpretation was false positive software readings suggesting nystagmus slow phase velocity >10deg/sec when no nystagmus was present. Measurement issues were addressed by implementing software updates allowing real-time review of VOG results before randomization, and review of VOG results for patients randomized to the intervention arm by an on-call neuro-otology fellow.

Conclusions: ED diagnosis of vestibular patients is highly inaccurate. We will further evaluate accuracy, efficiency, and safety of VOG-guided rapid triage in the main AVERT trial.

OP25-3 - Different vHIT results of sudden deafness with vertigo and vestibular neuritis

7. Clinical Testing for Vestibular Function

Shankai Yin¹

Dongzhen Yu¹

¹ Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Department of Otolaryngology, Shanghai, China

Purpose: The present study investigated whether sudden sensorineural hearing loss (SSHL) with vertigo (SHLV) and vestibular neuritis (VN) share the same etiology using the video head impulse test (vHIT).

Methods: The vHIT was conducted in 30 patients with SHLV and 22 patients with VN to quantitatively determine the vestibulo-ocular reflex (VOR) gains (vHIT-G). Next, vHIT-G and other parameters, including audiology variables and bedside examinations, were assessed and analyzed in the SHLV and VN patients.

Results: The SHLV and VN groups differed significantly in terms of vHIT-G in the anterior semicircular canal (AC) and horizontal semicircular canal (HC, P < 0.05) but not in terms of vHIT-G in the posterior semicircular canal (PC). The severity and extent of change in the affected canals differed between the two groups, as did vestibular nerve and vascular involvement.

Conclusions: The different vHIT results of the two patient groups suggest that VN and SHLV have different etiologies.

OP25-4 - Enhanced VOR suppression in dancers during passive high velocity head impulses

7. Clinical Testing for Vestibular Function

Maxime Maheu¹

Lydia Behtani¹, Audrey Delcenserie², François Champoux¹

¹ School of speech-language and audiology, University of Montreal

² Psychology, University of Montreal

Purpose: The vestibulo-occular reflex (VOR) is responsible for stabilizing images on the fovea during head movements. However, in some situations, one needs to suppress the VOR in order to be able to follow a target moving along with the head. This ability is either made possible by a central modulation of the sensitivity to head movements or by the generation of a signal counteracting the VOR. Evidence suggests that the visual mechanism underlying VOR suppression can be modulated by experience. Unfortunately, the non-visual mechanism underlying VOR suppression has never been examined in dancers and, consequently, it is still unsure whether dance training can enhance eye-head tracking accuracy. The goal of the present study was to look at the influence of dance training on the VOR suppression during passive head impulses.

Methods: Twenty-four individuals participated, 12 controls and 12 dancers. VOR and VOR suppression were assessed using a head impulse paradigm (HIMP) as well as a suppression head impulse test paradigm (SHIMP) with video head impulse test, respectively.

Results: The results suggest that dancers display a significantly reduced VOR gain during the SHIMP at 60ms in comparison to controls. Moreover, dancers with more than 10 years of dance training exhibited a significantly reduced VOR gain during the SHIMP at 60 ms.

Conclusions: Overall, the results suggest that dance training not only improves VOR suppression, but also modulates VOR suppression abilities by increasing the efficiency of the vestibular efferent system.

OP25-5 - Investigating Mechanisms of Overt and Covert Saccades Using a Computer Model of Head Impulse Test

7. Clinical Testing for Vestibular Function

Kamran Barin¹

¹ The Ohio State University, Dept. of Otolaryngology-Head & Neck Surgery (Emeritus), Columbus, OH, USA

Purpose: Overt and covert saccades during the head impulse test are cardinal signs of a peripheral vestibular lesion. The difference between the eye and target positions after the impulse is assumed to be the mechanism that triggers overt saccades. Yet very little is known about the possible mechanisms underlying covert saccades. The purpose of this study is to investigate the mechanisms for generating overt and covert saccades.

Methods: A fully-customizable model of the head impulse test was developed. The vestibulo-ocular reflex parameters include the cupula and velocity storage mechanism time constants as well as non- linearities of the vestibular nerve. Two different mechanisms, one based on head and eye position differences and one based on velocity differences, were implemented for generating catch-up saccades. Either or both mechanisms could be activated or deactivated selectively.

Results: Simulation results match findings in normal subjects for both standard vHIT and SHIMP protocols. Simulation results also match findings in patients with varying degree of unilateral and bilateral vestibular loss. Simulations included various clinical conditions such as different levels of static compensation and cerebellar clamping. Activation and deactivation of different saccade mechanisms enabled selective initiation of overt or covert saccades.

Conclusions: A mechanism that triggers covert saccades based on the difference between head and eye velocities matches pattern of findings in normal subjects and patients with different levels of unilateral and bilateral loss. Knowledge of mechanisms underlying overt and covert saccades may assist in developing more effective therapy protocols as patients with covert saccades demonstrate improved functional impairment.

OP25-6 - Bedside examinations distinguish central from peripheral causes of vertigo

7. Clinical Testing for Vestibular Function

Hui Wang¹

shujian huang¹, Bin Chen¹, Yanmei Feng¹, Huiqun Zhou¹, shankai yin¹

¹ Department of Otolaryngology head and neck surgery, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital

Purpose: To explore the accuracy of bedside examinations used to distinguish central from peripheral causes of vertigo and to determine the best strategy for vertigo management in otorhinolaryngology practice.

Methods: We recruited 1,335 patients presenting with vertigo to our otorhinolaryngology department. All patients underwent bedside evaluation, including history-taking, eye movement examination, otological and neurological examinations. Based on these examinations, we decided whether to perform further evaluation or institute treatment. Patients with BPPV underwent canalith reposition maneuvers (CRPs) and were instructed to engage in self-treatment at home.

Results: Bedside examinations yielded clear diagnoses for 53.03% of patients (708/1,335). In detail, two older patients (0.15%) had cerebral infarctions, in which bilateral sudden sensorineural hearing loss presented before the infarctions. A total of 579 patients (43.37%) presented with BPPV, of whom 91 (6.82%) had atypical BPPV without nystagmus, but in whom vertigo was relieved after the first repositioning maneuver. Of the typical BPPV cases, 85.86% of patients had posterior semicircular canal BPPV and 67 (13.73%) horizontal semicircular canal BPPV. The initial CRP was effective in 86.1% of patients, and 96.5% of patients reported relief after one further week of self-treatment. We used the bedside head- impulse test to evaluate vestibular function; this measure was associated with a sensitivity of 63.6% (95%CI=41.0%~86.3%) and a specificity of 95.5% (95%CI =91.4%~99.7%).

Conclusions: The bedside examinations provided a valuable contributor to differentiate central from peripheral vertigo. The combination of history-taking with bedside examination prior to further evaluation or treatment is the best strategy for vertigo management in the otorhinolaryngology department.

OP25-7 - Oral glycerol reduces the enhanced eye velocity in vHIT testing of patients with probable hydrops

14. Meniere’s Disease and Related Disorders

Ian S. Curthoys¹

Ann M. Burgess¹,

Leonardo Manzari²

¹ Vestibular Research Laboratory, School of Psychology, the University of Sydney, NSW, Australia

² MSA ENT Academy Center – Cassino, Italy

Purpose: The reduction in auditory thresholds after oral intake of glycerol is a subjective test for identifying hydrops. Our modelling has shown that hydrops can cause enhanced eye velocity in head impulse testing (Grieser et al., 2014). Here we report the effect of glycerol dehydration on objective measures of semicircular canal function using the video head impulse test (vHIT) (MacDougall et al., 2009). On vHIT some patients with probable hydrops show an enhanced eye velocity response, so that eye velocity exceeds head velocity and we tested if glycerol reduced that enhanced eye velocity in such patients.

Methods: All the subjects were given orally 86 % glycerol in 1.5 ml/kg of body weight, dissolved 1:1 in physiological saline. Horizontal vHIT testing was performed at the initial examination before glycerol intake (time 0), then at intervals of 1 (time 1), 2 (time 2) and 3 (time 3) hours after the oral glycerol intake. The testing was conducted with the patient’s approval as part of the standard clinical assessment of their vestibular function. We used a new measure of the enhanced eye velocity – peak VOR gain – defined as the peak eye velocity/ head velocity measured at peak eye velocity

Results: We found that glycerol caused a temporary but significant reduction in the enhanced eye velocity. Control testing over the same time intervals with water instead of glycerol had no effect on the eye velocity response.

Conclusions: This reduction appears to be an objective indicator of endolymphatic hydrops.

OP26-1 - A retrospective cross-sectional study in an emergency department of a tertiary referral centre

9. Epidemiology

Georgios Mantokoudis¹

Martina Goeldlin², Janika Gaschen², Lukas Comolli¹, Christoph Kammer², Corrado Bernasconi², Claudio Bassetti², Aristomenis Exadaktylos³, Urs Fischer², Roger Kalla²

¹ Department of Otorhinolaryngology, Head and Neck Surgery, Inselspital, University Hospital Bern and University of Bern

² Department of Neurology, Inselspital, University Hospital Bern and University of Bern

³ Emergency Department, Inselspital, University Hospital Bern and University of Bern

Purpose: Vestibular symptoms are common complaints in the general population with prevalences of up to 60%. In emergency departments (ED) dizziness has been reported in 3.3% of all patients. We assessed frequency and aetiology of vestibular symptoms in a large interdisciplinary tertiary ED.

Methods: We screened all 23.608 patients admitted to the ED in 2013 and included patients with vestibular symptoms either as a chief or accompanying complaint. Clinical, radiological and laboratory findings as well as presumed aetiologies from ED medical records were manually extracted. Symptoms were classified according to the Classification of Vestibular Disorders of the Bárány Society.

Results: 2473 patients (11%; mean age/SD 51.9/20.2 years; 50.7% females) complained about any vestibular symptom with 64.5% as a chief complaint. Vestibular symptoms were classified as vertigo (44.8%), dizziness (55%), postural symptoms (15.8%) and unknown vestibular symptoms (0.6%). Most frequent aetiologies were strokes (12.4%), orthostatic (12.1%), infections (10.3%), cardiovascular (9.8%), other central vestibular disorders (9.3%), peripheral vestibular disorders (8.8%). All other causes including trauma and somatoform dizziness were <5% each. In 13.8%, no diagnosis was assigned. 23% of underlying causes were potentially life threatening.

Conclusions: Reported one-year prevalence of vestibular symptoms was 11% in a tertiary ED setting, which is higher than previously described. Every 4th patient with vestibular symptoms suffers from a stroke and/or any other potentially life threatening condition. Every 7th patient was sent home with a diagnosis of dizziness “not further specified”. Improvement of diagnostic accuracy should be pursued to reduce the risk of missing severe pathologies.

OP26-2 - Health Burden of Balance Problems and Falling: 2016 United States Health Survey of 33,028 Adults

9. Epidemiology

Howard J. Hoffman¹

Christa L. Themann², Anne E. Hogan³, Katalin G. Losonczy¹, Chuan-Ming Li¹, Helen S. Cohen⁴, Bryan K. Ward⁵, Charles C. Della Santina⁶

¹ Epidemiology & Statistics Program, Division of Scientific Programs, National Institute on Deafness and Other Communication Disorders (NIDCD), National Institutes of Health (NIH), Bethesda, Maryland, USA

² Biomedical and Behavioral Sciences Division, National Institute for Occupational Safety and Health (NIOSH), Centers for Disease Control and Prevention (CDC), Cincinnati, Ohio, USA

³ School of Audiology, College of Health Professions, Pacific University, Hillsboro, Oregon, USA

⁴ Bobby R. Alford Department of Otolaryngology–Head and Neck Surgery, Baylor College of Medicine, Houston, Texas, USA

⁵ Clinical Neurotology, Department of Otolaryngology–Head and Neck Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland, USA

⁶ Vestibular NeuroEngineering & Clinical Testing Laboratories, Department of Biomedical Engineering and Otolaryngology–Head and Neck Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland, USA

Purpose: This study examined falling risk last 1 (and 5) years due to self-reported balance and dizziness problems (BDP) in a nationally-representative health survey. The objective was to estimate prevalence, risk factors, and sequelae.

Methods: Data from the 2016 National Health Interview Survey (NHIS) Balance and Dizziness Supplement were analyzed. NHIS was administered to 33,028 randomly-sampled adults aged 18+ years. BDP was classified based on questions about dizziness and unsteadiness. Follow-up questions about specific symptoms during the past 12 months included vertigo and blurred vision with head movement. Subjects were asked which symptoms were most bothersome. Outcome variables were falling, injuries, and resulting days of interrupted activities. Prevalence estimates and adjusted risk ratios (RR) were calculated using post-stratification national weights with 95% confidence intervals (CIs).

Results: Lifetime BDP prevalence for adults was 23.9% (58.5 million); during the past 12 months, BDP prevalence was 15.1% (37.1 million). The 12-month BDP prevalence was strongly associated with age, rising from 11.7% to 25.8% for adults aged 18-44 to 85+ years, respectively. Nearly 12 million adults (4.8%) could not perform their usual activities, more than 7 million (2.9%) were injured owing to falls, and 5.6 million (2.3%) missed work or school days because of BDP in the past 12 months. Approximately half, 49.6% (95%CI: 45.6%-53.6%), with BDP had seen a healthcare provider. More than 50% had fallen in the last 5 years while experiencing BDP.

Conclusions: BDP prevalence is substantial for young as well as older U.S. adults. Sequelae include increase risk of falls, injuries, and healthcare burden.

OP26-3 - Prevalence of Dizziness and Balance Problems and Significant Head Injuries in United States Children

9. Epidemiology

Chuan-Ming Li¹

Howard J. Hoffman¹, Christa L. Themann², Devin L. McCaslin³, Rose Marie Rine⁴, Keiko Hirose⁵, Anne E. Hogan⁶, Helen S. Cohen⁷, Charles C. Della Santina⁸

¹ Epidemiology & Statistics Program, Division of Scientific Programs, National Institute on Deafness and Other Communication Disorders (NIDCD), National Institutes of Health (NIH), Bethesda, Maryland, USA

² Biomedical and Behavioral Sciences Division, National Institute for Occupational Safety and Health (NIOSH), Centers for Disease Control and Prevention (CDC), Cincinnati, Ohio, USA

³ Vestibular and Balance Laboratory, Otorhinolaryngology Department, Mayo Clinic College of Medicine, Rochester, Minnesota, USA

⁴ School of Physical Therapy, Marshall University, Huntington, West Virginia, USA, and Specialty Therapy Source, LLC, Jacksonville, Florida, USA

⁵ Departments of Otolaryngology and Pediatrics, Washington University School of Medicine, St. Louis, Missouri, USA

⁶ School of Audiology, Pacific University, Hillsboro, Oregon, USA

⁷ Bobby R. Alford Department of Otolaryngology–Head and Neck Surgery, Baylor College of Medicine, Houston, Texas, USA

⁸ Vestibular NeuroEngineering & Clinical Testing Laboratories, Departments of Biomedical Engineering and Otolaryngology–Head and Neck Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland, USA

Purpose: To study balance and dizziness problems (BDP) in children and examine the potential association with significant head injuries or concussions.

Methods: A multistage, nationally representative sample of children (n=9,247; aged 3-17 years) was selected for the 2016 National Health Interview Survey. Parents reported if during the past 12 months their child had BDP (i.e., vertigo/motion sensation, light-headedness/fainting, clumsiness/poor coordination, poor balance/unsteadiness when standing-up or walking, frequent falls, or other BDP) and if their child ever had significant head injuries or concussions. Logistic regression was used to examine associations after adjusting for socio-demographic variables and accounting for the complex survey design.

Results: BDP prevalence was 5.5% (3.4 million U.S. children); females, 5.6%, males, 5.4%. Prevalence increased with age from 3.4% (3-5 years) to 9.1% (15-17 years), p<0.001. Significant head injury/concussion prevalence was 7.0% (4.3 million); females, 5.8%, males, 8.1%, p<0.001. Head injuries of non-Hispanic (NH) white (8.7%) were increased compared to Hispanic (5.9%) and NH black (4.5%) children, p<0.001. Head injuries increased with age, from 4.0% (3-5 years) to 11.8% (15-17 years), p<0.001. Among children with head injury, 13.7% had BDP, while among children with BDP, 17.5% had head injury. During the past year, 39.4% with BDP were seen by healthcare providers and 33.8% received treatment. If BDP was a moderate/big/very bid problem, 79.3% had seen healthcare providers and 62% received treatment. Head injuries were associated with BDP, adjusted odds ratio=2.7 (95% confidence interval: 2.0-3.7).

Conclusions: BDP (>5% of children) is common and significant head injuries and concussions in childhood are associated with BDP.

OP26-4 - Sensory impairments and wrist fractures. A case-control study.

9. Epidemiology

Bergthora Baldursdottir¹

Hannes Petersen², Palmi V Jonsson², Brynjolfur Mogensen², Susan L Whitney³, Alfons Ramel⁴, Ella K Kristinsdottir²

¹ University of Iceland; Faculty of Medicine. Landspitali-University Hospital, Iceland, Department of Physical Therapy

² University of Iceland; Faculty of Medicine

³ University of Pittsburgh, Department of Physical Therapy, USA

⁴ The Icelandic Gerontological Recearch Center, Reykjavik, Iceland

Purpose: To investigate vestibular function, foot sensation, postural control and functional abilities and to evaluate whether these variables are associated a with fall-related wrist fracture.

Methods: A case control study was conducted with 98 subjects, age range 50-75 years, who had sustained a fall-related wrist fracture. Forty-eight sex-, age- and physical activity-matched individuals, with no previous history of wrist fracture, served as controls. Measurements included: the head-shake test (HST), a tuning fork, the biothesiometer, Semmes-Weinstein monofilaments (MF), the Sensory Organization Test (SOT), the Five-Times-Sit-to-Stand Test (FTSTS), the 10-m-walk test (10MWT), the Activities-specific Balance Confidence (ABC) scale and the Dizziness Handicap Inventory (DHI). Logistic regression models were used to determine associations of variables with a fall-related wrist fracture.

Results: Vestibular asymmetry was apparent in 82% of wrist fracture subjects and 63% of controls (p=0.012). Plantar pressure sensation (p<0.001), SOT composite scores (p<0.001), 10MWT (p<0.001), FTSTS (p<0.001), ABC (p<0.001) and DHI (p<0.005) were significantly poorer among cases than controls. A positive HST (odds ratio (OR) 5.424; p=0.008) and monofilament sensation (OR 3.886; p=0.014) showed the strongest associations with having a fall-related wrist fracture.

Conclusions: Asymmetric vestibular function and reduced plantar pressure sensation appear to be associated with fall related wrist fractures among the ageing population. Vestibular function and plantar sensation are potential targets for future interventions.

OP26-5 - Stroke Risk after Diagnosis of Benign Vertigo is Lower in Specialty Care than General Practice

9. Epidemiology

Tzu-Pu Chang¹

Anand Bery², Hsun-Yang Chuang³, Zheyu Wang⁴, David Newman-Toker⁵

¹ Department of Neurology, Taichung Tzu Chi Hospital, Taiwan

² Department of Medicine, University of Toronto, Canada

³ Department of Research, Taichung Tzu Chi Hospital, Taiwan

⁴ Department of Biostatistics, Johns Hopkins University School of Public Health, USA

⁵ Department of Neurology, Johns Hopkins University School of Medicine, USA

Purpose: To compare stroke risk among patients discharged with “benign vertigo” across medical specialties.

Methods: Patients with first incident vertigo (ICD-9-CM 386.x, 780.4) in outpatient departments from the National Health Insurance Research Database of Taiwan (2002-2009). We excluded patients with emergency department referral or hospitalization at the index visit and index diagnoses that were stroke-related or “vertigo of central origin”. We analyzed short- (1-month) and long-term (~3-year) stroke incidence. We compared stroke risk across general practice and specialty disciplines using a Cox proportional hazards model and incidence rate ratios (1-month rate divided by average 12-36-month rate).

Results: We studied 178,981 patients. One-month/3-year stroke incidence was 0.35%/1.81% in internal medicine, 0.22%/1.61% in family medicine, 0.20%/1.29% in neurology, 0.09%/0.86% in otolaryngology, and 0.07%/0.73% in other specialties. After adjusting for demographic and cardiovascular risk factors, long-term stroke risk in specialty practice (neurology & otolaryngology) was lower than in general practice (internal & family medicine) (aHR=0.78). Stroke incidence in the first month was significantly higher than in later months across all disciplines with incidence rate ratios (misdiagnosis rate) ranging from 4.2 (otolaryngology/other specialties) to 8.8 (internal medicine).

Conclusions: Across disciplines, risk of stroke following a diagnosis of “benign vertigo” is highest in the first month, suggesting misdiagnosis in all ambulatory settings. Both short- and long-term risk vary by discipline of the diagnosing physician, suggesting there are both diagnostic accuracy and patient population differences. Stroke misdiagnosis risk was highest in internal medicine and lowest in otolaryngology. Future research should seek to address root causes.

OP27-1 - Symptom severity and fluctuations in 192 patients with Hydropic Ear Disease

14. Meniere’s Disease and Related Disorders

Sonja Floerke¹

Claudia Jerin², Rebecca Maxwell²,

Robert Gürkov¹

¹ University of Munich, Otorhinolaryngology, Germany

² University of Munich, Otorhinolaryngology & German Vertigo Centre, Germany

Purpose: Changes in the relative distributions of endolymphatic fluid volumes within the inner ear are assumed to cause paroxysmal symptoms in Hydropic Ear Disease (Menière’s Disease). Here, we investigate for the first time the relationship between the severity of endolymphatic hydrops (ELH) and the severity and fluctuations of audiovestibular symptoms in a large population of patients with Hydropic Ear Disease.

Methods: 192 patients with clinically definite MD according to the AAOHNS criteria who underwent locally enhanced inner ear MRI (LEIM) were included. Caloric canal paresis, pure tone audiometry and standardized symptom diaries recording vertigo attacks, hearing loss, tinnitus and aural fullness were evaluated. The severity of endolymphatic hydrops (ELH) was graded on a nominal scale (0-3). Spearman rank correlations were calculated.

Results: The disease duration correlated highly significantly with severity of cochlear and vestibular ELH (p<0.01). Moreover, the ELH severity is highly significantly correlated with audiometric hearing loss (p<0.01). The severity of ELH did however not correlate with audiovestibular symptom severity and fluctuations in the short or middle term. Furthermore, the vertigo attack frequency did not decrease with disease duration.

Conclusions: The correlation between hearing loss and ELH severity was confirmed in this large population of patients with Hydropic Ear Disease. The assumed rapid or short-term dynamics of endolymphatic fluid volume changes in Hydropic Ear Disease, however, may be too small to be detected by clinical inner ear imaging, despite being present in animal models. Furthermore, these data are challenging the concept of “burning out” in Hydropic Ear Disease.

OP27-2 - Outcomes after Surgical Treatment of Meniere’s Disease: Experience from Shanghai Xinhua Hospital

14. Meniere’s Disease and Related Disorders

Jun YANG¹

¹ Department of Otorhinolaryngology-Head and Neck Surgery of Shanghai Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine, China

Purpose: To report functional outcomes after different surgical treatments of Ménière’s disease in ENT Department of Shanghai Xinhua Hospital from October 2003 to January 2016.

Methods: Patients with Ménière’s disease were categorized into groups based on hearing staging. Individualized surgical procedure was provided including endolymphatic sac shunt or decompression(ESS), vestibular neurectomy(VN), labyrinthectomy(LC), semicircular canals plugging(SCP) and endolymphatic duct blockage(EDB). The functional outcomes after different surgeries in terms of vertigo control, hearing level and quality of life (QOL score of Meniere’s Disease Outcomes Questionnaire) were evaluated.

Results: 374 patients were diagnosed as definite Ménière’s disease according to the AAO-HNS criteria. Four patients had bilateral Ménière’s disease and four received surgery on the same side for twice. Thus, a total of 382 surgeries were carried out such as ESS(n=111), VN(n=206), LC(n=20), SCP(n=23) and EDB(n=22). Vertigo control rate of Grade A and B was 78.4% for patients in ESS, 100% in VN, 100% in LC, 85.7% in SCP and 86.4% in EDB. Hearing was preserved in ESS, VN and EDB with no significant difference between the preoperative and the postoperative levels (P>0.05). There is a significant hearing loss after surgery in SCP (P<0.05). Postoperatively, the QOL score improved significantly in each group (P<0.001).

Conclusions: The functional outcomes after different surgical treatments are generally satisfying. VN is always the last line of defense for eradicate vertigo with residual hearing. Besides, as for VN, compared with retrosigmoid sinus approach, retrolabyrinthine approach could provide a shorter distance between posterior fossa dura and vestibulocochlear nerve, enough exposure and consume less time.

OP27-3 - Prediction of unilateral Meniere’s disease attack using inner ear test battery

14. Meniere’s Disease and Related Disorders

Pohsuan Wu¹

Powen Cheng¹

¹ Far Eastern Memorial Hospital, Taipei, Taiwan

Purpose: The pure tone audiometry, caloric test, VEMP tests via different stimulation modes were recorded in patients with unilateral meniere’s disease. Furthermore, clinical symptoms were collected via chart review. The results were statistically analyzed to evaluate retrolabyrinthine involvement and to predict vertigo attack.

Methods: We retrospectively enrolled 50 patients with unilateral Meniere’s disease. In addition to clinical symptoms, all results of pure tone audiometry, caloric test, ACS-cVEMPs, GVS-cVEMPs, BCV-oVEMPs, and GVS-oVEMPs were collected via chart review. The frequency score is defined as 0: no attack; 1: one to four times per year; 2: four to twelve times per year; 3: more than twelve times per years. The multiple linear regression method was used to examine which independent variables have a statistically significant influence on vertigo attacks.

Results: In affected ears, the abnormal rate of caloric test, acoustic cVEMPs, galvanic cVEMPs, vibratory oVEMPs and galvanic oVEMPs was 80%, 52%, 30%, 28% and 18%, respectively. According to the regression model, the abnormal GVS-cVEMP response and abnormal GVS-oVEMP response had significant negatively correlations with the frequency of disease attacks. A predictive model for disease attack frequency using significant parameters and their regression coefficients in combination was proposed as: predicted attack frequency score = 2.679 + (-0.829)*(GVS-cVEMP) + (-0.922)*(GVS-oVMEP).

Conclusions: The disease attack frequency is significantly negatively correlated to GVS-cVEMPs and GVS-oVEMPs, in contrast to caloric test, acoustic cVEMPs and vibratory oVEMPs. Using the model proposed by these significant parameters, clinicians can easily predict unilateral Meniere’s disease attack frequency by galvanic VEMPs.

OP27-4 - Shift of the frequency tuning on Ocular Vestibular-Evoked Myogenic Potentials in Meniere’s disease

14. Meniere’s Disease and Related Disorders

Yongsheng Tian¹

¹ Aerospace Center Hospital, Department of Otolaryngology, Beijing,China

Purpose: To study the change of frequency tuning of Ocular Vestibular-Evoked Myogenic Potentials (oVEMP) in patients with unilateral Meniere’s disease, by air-conducted tone bursts stimulus in various frequencies.

Methods: 32 cases of patients with unilateral Meniere’s were tested for oVEMP in 500Hz and 1000Hz air-conducted tone bursts respectively, and 20 healthy subjects(40 ears) matched for age and sex were used as healthy control. The amplitudes of the N1-P1 wave and the frequency amplitude ratios of 500/1000Hz in affected ears, unaffected ears and normal ears were compared; and receiver operating characteristic curve was analyzed for frequency amplitude ratios of 500/1000Hz.

Results: Amplitudes of N1-P1 waveforms in 500Hz air-conducted tone bursts in affected ears with unilateral Meniere’s patients are smaller than in the normal control and contralateral ears. There was significant difference between affected ears and healthy control ears (t=3.942, p=0.000).There was no significant difference (t=-0.087, p=0.899, t=-0.879, p=0.175) in amplitude between affected, contralateral and normal ears in 1000Hz tone bursts. Frequency amplitude ratios of 500/1000Hz in affected ears were significantly under the contralateral and control ears (t=-0.449, p=0.017; t=-0.98, p=0.000). The frequency amplitude ratio critical value of frequency tuning is 1.19, the rate of frequency tuning in the affected ear was 55%, and the frequency change was 19% in the contralateral ears, significantly higher than normal control ears (5%χ²= 22.423, p=0.000).

Conclusions: Compared with healthy people, frequency tuning oVEMP with Meniere’s disease was changed and shift from low frequency region to high frequency region. Frequency amplitude ratio is useful for the diagnosis of Meniere’s disease.

OP27-5 - Simultaneous triple semicircular canal plugging and cochlear implantation in Meniere’s disease

14. Meniere’s Disease and Related Disorders

Zhaomin Fan¹

Daogong Zhang¹, Lei Xu¹, Yuechen Han¹, Yafeng Lv¹, Yawei Li¹, Xiaofei Li¹, Jing Wang¹, Haibo Wang¹

¹ Department of Otorhinolaryngology-Head and Neck Surgery, Shandong Provincial Hospital affiliated to Shandong University, Jinan, China

Purpose: To evaluate the feasibility of combining simultaneous triple semicircular canal plugging (TSCP) and cochlear implantation (CI) to treat vertigo and hearing loss in advanced MD patients.

Methods: Data from 10 patients, who were referred to our hospital and diagnosed with unilateral MD from Jan. 2015 to Jan. 2016, were retrospectively analyzed in this work. All patients had bilateral severe sensorineural hearing loss. One side hearing loss was due to MD and another side was due to other reasons. Ten patients underwent simultaneous TSCP and CI. Postoperative follow-up time was all more than one year. Vertigo control and auditory function were measured. Pure tone audiometry, speech perception scores, caloric test, vestibular evoked myogenic potential (VEMP) were performed for evaluation of audiological and vestibular function.

Results: The total control rate of vertigo was 100.0% in one-year follow-up, with complete control rate of 90.0% and substantial control rate of 10.0%. Improved in hearing threshold and speech perception scores were observed in all study participants. Postoperative average aided hearing threshold was 30.4 dB HL, the average monosyllabic word score was 54.2% and speech perception scores of sentences tested in quiet was 63.4%. Tinnitus improved in 7 cases (70.0%). One year after treatment, loss of semicircular canal function by caloric test was found in the operation side of all patients and no change in cVEMP or oVEMP test was noted.

Conclusions: A combined approach of TSCP and CI which could control vertigo effectively and improve hearing loss and tinnitus represents an effective therapy for some advanced MD patients.

OP27-6 - Slow-phase velocity of thermally-induced nystagmus is early reduced in Meniere’s Disease

14. Meniere’s Disease and Related Disorders

Augusto Pietro Casani¹

Niccolò Cerchiai¹, Navari Elena¹, Chiara Re¹

¹ Pisa University Hospital, Italy

Purpose: to assess whether Menière’s Disease (MD) determines any alteration on caloric vestibular test parameters according with an increased severity of cochlear involvement.

Methods: the study retrospectively analyzed the caloric vestibular test results of 72 patients affected by unilateral “definite MD” according with the Barany Society Diagnostic Criteria. The statistical analysis put in relationship both the frequency and the slow phase velocity of the thermally-induced nystagmus with an increasing severity of the cochlear involvement (American Academy of Otolaryngology-Head & Neck Surgery staging system).

Results: there were 7 patients in stage 1 (9.72%), 27 in stage 2 (37.50%), 35 in stage 3 (48.61%), and 3 in stage 4 (4.16%). No patients had undergone any ablative treatment. The frequency of the thermally-induced nystagmus showed greater values in more severe stages (p= .033). Conversely, the slow-phase velocity did not show significant differences among the stages and showed abnormal values even in lower stages of the disease (71% in stage 1, 81% in stage 2, 91% in stage 3, and 100% in stage 4), exclusively on the affected side.

Conclusions: abnormal values of slow-phase velocity on caloric vestibular test can be found in most of patients affected by Menière’s Disease, regardless of the cochlear involvement. A dissociation between frequency and slow-phase velocity values characterizes the early stages of Menière’s Disease.

OP28-1 - Isolated positional vertigo of vascular origin

6. Central Vestibular Disorders

Gabor Michael Halmagyi¹

¹ Royal Prince Alfred Hospital, Neurology Department, Sydney, Australia

Purpose: Review 2 cases of isolated positional vertigo of vascular origin

Methods: Clinical and imaging.

Results: (1) A male 62 without vascular risk factors, tying his kayak to the roof of his car experienced brief isolated vertigo. That night he awoke with vertigo and vomiting. In the emergency room no abnormalities were found; the diagnosis was BPV. Two days later he had more vertigo, now spontaneous, with vomiting and headache. He now had total horizontal ophthalmoplegia. CT angiogram showed total occlusion of the left intracranial vertebral artery. He then developed hemiplegia and apnea. MRI showed bilateral medial medullary and dorsal pontine infarcts. After a month in ICU and 3 months in rehabilitation he went home. (2) A male 61 with pulmonary fibrosis developed vertigo while drinking beer from a can. In our emergency room he had, sitting upright, right-beating spontaneous nystagmus. Three hours later the vestibular examination was normal. CT angiogram showed stenoses in both distal vertebral arteries and the proximal basilar. LDL cholesterol was high. With atorvastatin + clopigrel + aspirin and has had no further cerebrovascular symptoms after 18 months.

Conclusions: Isolated vascular vertigo, positional or spontaneous is rare but dangerous. Patients are rarely seen by a neuro-otologist during the attack so the diagnosis is based on history. They are difficult to distinguish from common benign aural causes isolated vertigo attacks. Once the attacks start there is a stroke is likely within a week; the patient who has had many attacks and is only seen weeks later is unlikely to have this problem

OP28-2 - Positional Downbeating Nystagmus due to BPPV variants: our experience

4. Benign Paroxysmal Position Vertigo

Sergio Carmona¹

Giacinto Asprella Libonati²,

Rudi Pecci³

¹ Department of Neuro-Otology, Fundación San Lucas para la Neurociencia, Rosario, Argentina

² Unit of Vestibology and Otorhinolaryngology “Giovanni Paolo II” Hospital Policoro MT Italy

³ Azienda Ospedaliero-Universitaria Careggi, Neuromusculoskeletal and Sensory Organs Department, Unit of Audiology, Florence, Italy

Purpose: Patients suffering from positional vertigo often show positional downbeating nystagmus. This latter is usually thought to be due to BPPV of the Anterior Canal (AC-BPPV), when any central cause has been excluded.

Recently, the existence of AC-BPPV has been questioned and more specifically by the possible existence of apogeotropic variant of Posterior Canal BPPV (aPC-BPPV).

The explanation to justify the presence of downbeat nystagmus in BPPV of the posterior canal is that the otoconia would be in the non-ampullary distal arm of the posterior canal, near the common crus. In such a condition, the Dix-Hallpike test causes the otoconia to move towards the dome, thus producing an inhibitory downward vertical nystagmus with a torsional component.

Methods: We included 20 patients observed in 4 balance centers between January 2016 and April 2017, presenting symptoms and vestibular signs consistent with AC-BPPV and that did not resolve with maneuvers specific for anterior canal.

Results: These patients, subsequently, were diagnosed as having aPC-BPPV, taking as a criterion the lack of response to the replacement maneuvers for AC-BPPV and the resolution of symptoms/signs with maneuvers for PC-BPPV (Semont, Epley).

Conclusions: While it cannot be stated that all BPPV with AC compromise characteristics are an apogeotropic variant of PC-BPPV, the latter being more frequent than the previous one, it is expected that many positional down beating nystagmus are due to apogeotropic variant of the posterior semicircular canal. This last variant should be kept in mind when the patients did not respond to the typical replacement maneuvers for the AC-BPPV.

OP28-3 - Probable benign paroxysmal positional vertigo, spontaneously resolved: incidence and natural course.

4. Benign Paroxysmal Position Vertigo

Gloria Guerra-Jiménez¹

María Guadalupe Álvarez-Morujo de Sande², González Aguado Rocío³, Esther Domènech-Vadillo⁴, Hugo Galera-Ruiz⁵, Enric Figuerola-Massana⁴, Ángel Ramos-Macías⁶, Carmelo Morales-Angulo³, AJ Martín-Mateos², Emilio Domínguez-Durán⁵

¹ Complejo Hospitalario Universitario Insular Materno-Infantil, Dept ENT Las Palmas de Gran Canaria, Spain

² Hospital Universitario Puerta del Mar, Dept ENT, Cádiz, Spain

³ Hospital Universitario Marqués de Valdecilla, Santander, Dept ENT Spain

⁴ Hospital Universitari Joan XXIII, Dept ENT, Tarragona, Spain

⁵ Hospital Infanta Luisa, Dept ENT, Sevilla, Spain

⁶ Complejo Hospitalario Universitario Insular Materno-Infantil, Las Palmas de Gran Canaria, Spain

Purpose: Probable benign paroxysmal positional vertigo, spontaneously resolved (pBPPVsr) could be a controvensial disgnosis since positional testing is negative. However, it is frequent in the population and there are few studies in this regard. Objectives: To calculate the incidence of pBPPVsr in our medical practice, compare its characteristics with BPPV not spontaneously resolved and describe the role of spontaneous resolution in BPPV natural course.

Methods: Prospective multicentric descriptive over BPPV consultant patients during one-year period. The incidence of pBPPVsr over the total of patients with BPPV was calculated. Prevalences of several variables related with the development of BPPV were compared between both groups. The timing of spontaneous resolution was estimated through Kaplan Meier curves.

Results: 457 patients met the inclusion criteria. Incidence of pBPPVsr was 33.5%. Incidence was statistically significant higher in men, normal bone mass and not-taking-sulpiride patients. Kaplan-Meier curve showed a hyperbolic shape with values of 18% of spontaneous resolution after the first month and 51% after the first year. No relevant or significant increase of this percentage happened after this moment. Curves of male, patients under 50 and patients with normal blood pressure decreased significantly faster.

Conclusions: Spontaneous resolution of BPPV happens in the half of the patient with BPPV during the first year after the onset of the disease, being rare from this point. This phenomenon seems more common in male and could be hindered by sulpiride intake, osteoporosis, advanced age and high blood pressure.

OP28-4 - Significance of repeated positional maneuver in the diagnosis of benign positional vertigo

4. Benign Paroxysmal Position Vertigo

Dae Bo Shim¹

Mee Hyun Song¹

¹ Myongji Hospital, Department of Otorhinolaryngology, Republic of Korea

Purpose: Although the Dix-Hallpike and supine head roll test are considered the gold standard tests for benign paroxysmal positional vertigo (BPPV) diagnosis, accuracy rate of the diagnostic tests is not 100 percent. Aim of this study is to identify diagnostic value of repeated positional maneuver in probable BPPV (Diagnostic criterion of BPPV presented by Barany Society).

Methods: This study was prospectively performed from July 2013 to May 2017. The repeated positional test was performed in patients suspected of having BPPV in their medical history but with negative initial positional test. Repeated test was performed on the same day of the initial diagnosis in Group 1 and 3 days after in Group 2. This grouping was designed to determine whether the same-day repeated positional test is more effective in increasing diagnostic rate of BPPV.

Results: 82 patients were enrolled (42 in Group 1, 40 in Group 2) and 78 were analyzed. 28 (35.9%) patients were identified as BPPV by repeated positional test. Of these, 19 patients (67.9%) with posterior canal, 7 patients (25.0%) (4 patients; canalolithiasis and 3 patients; cupulolithiasis) with horizontal canal and 2 patients (7.1%) were anterior canal BPPV. The diagnostic rate of BPPV in Group 1 (42.9%) was significantly higher than in Group 2 (27.8%).

Conclusions: The repeated positional maneuver may improve the diagnostic rate of BPPV in patients suspected of having BPPV but with negative initial positional test. In addition, performing repeated positional maneuvers on the same day as the initial diagnosis is recommended.

OP28-5 - Supplementation of Vitamin D and Calcium May Prevent Recurrences of BPPV

4. Benign Paroxysmal Position Vertigo

Seong-Hae Jeong¹

Ji-Soo Kim (corresponding author)², Hyo-Jung Kim², Kwang-Dong Choi³, Ji-Yun Park⁴, Seung-Han Lee⁵, Seo Young Choi⁶, Sun-Young Oh⁷, Jeong-Yoon Choi⁸, Jae Han Park⁹, Sung-Hee Kim¹⁰, Ileok Jung¹¹

¹ Department of Neurology, Chungnam National University Hospital, Daejeon, Korea.

² Department of Neurology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.

³ Department of Neurology, Pusan National University Hospital, Pusan National University School of Medicine, Pusan, Korea.

⁴ Department of Neurology, Ulsan University College of Medicine, Ulsan University Hospital, Ulsan, Korea.

⁵ Department of Neurology, Chonnam National University Medical School, Gwangju, Korea.

⁶ 6Department of Neurology, Chungbuk National University Hospital, Cheongju, Korea.

⁷ Department of Neurology, Chonbuk National University School of Medicine, Jeonju, Korea.

⁸ Department of Neurology, Korea University Ansan Hospital, Korea University College of Medicine, Ansan, Korea.

⁹ Department of Neurology, Catholic University of Daegu, School of medicine, Daegu, Korea.

¹⁰ Department of Neurology, School of Medicine, Kyungpook National University Chilgok Hospital, Daegu, Korea.

¹¹ Department of Neurology, Korea University College of Medicine, Korea University Ansan, Korea.

Purpose: Since vitamin D deficiency and osteoporosis are more common in patients with benign paroxysmal positional vertigo (BPPV) than in normal controls, supplementation of vitamin D and calcium may prevent further attacks of BPPV.

Methods: We performed a multicenter, randomized controlled trial in 8 teaching hospitals in Korea between December, 2013 and May, 2017. After treatment of BPPV with canalith repositioning maneuvers, patients were randomly assigned to either the intervention (n=518) or the observation (n=532) group. The annual recurrence rate was the primary outcome . The patients in the intervention group were instructed to take 800 IU of vitamin D and 1000 mg of calcium as calcium carbonate per day for one year when the serum vitamin D level was < 20 ng/ml. The patients in the observation group were followed up without the evaluation and medication.

Results: The intervention group showed a significant reduction in the annual recurrence rate [0.83 (95% CI: 0.74-0.92) vs. 1.10 (95% CI: 1.00-1.99) with an incident rate ratio of 0.76 (95% CI: 0.66-0.87, p<0.001) and an absolute rate ratio of -0.27 (-0.40 to -0.14)]. The intervention group showed lower proportion of patients with recurrences than the observation group (37.8% vs. 46.7%, p=0.005).

Conclusions: Patients with frequent attacks of BPPV and subnormal serum vitamin D may have a benefit from supplementation of vitamin D and calcium.

OP28-6 - Upright Head Pitch Test to diagnose Posterior Canal Benign Paroxysmal Positional Vertigo.

4. Benign Paroxysmal Position Vertigo

Giacinto Asprella Libonati¹

Rudi Pecci²

¹ Giovanni Paolo II Hospital, Unit of Vestibology and Otorhinolaryngology, Policoro (MT), Italy Viale Salerno, 75025 Policoro (MT) Italy

² Azienda Ospedaliero-Universitaria Careggi, Neuromusculoskeletal and Sensory Organs Department, Unit of Audiology, Florence, Italy

Purpose: The aim of this work is to evaluate the utility of the Head-Pitch Test in upright position (uHPT), as first step of the bedside examination of patients with history suggestive of Posterior Canal (PC) BPPV

Methods: This study was conducted from January 2015 to January 2017. We evaluated 688 patients (402 women and 286 men, average age 51.8 years) observed for acute positional vertigo and with history suggestive of PC-BPPV. The patients have been divided into 4 groups according to the delay between positional vertigo onset and our clinical observation: short delay (12-24 hours), medium delay (24-72 hours), medium-long delay (4-7 days) and long delay (over 1 week). The uHPT is performed by changing the head bending angle in the pitch plane while sitting. uHPT is considered positive when keeping extended head, it elicits a nystagmus with a double component, torsional and vertical up-beating, both suggesting a PC-BPPV diagnosis. Such a diagnosis is subsequently confirmed bringing the patient down to the Dix-Hallpike position, on the same side the torsional nystagmus was beating to.

Results: The uHPT was positive in 64.2% (442 patients) of the total sample, with a greater frequency as shorter was the delay: first group 42.3% (187 patients), second group 38.9% (172 patients), third group 13.6% (60 patients), fourth group 5.2% (23 patients).

Conclusions: The uHPT allows to early diagnose PC-BPPV in many patients thus enabling us to avoid many diagnostic manoeuvres and stimuli to the patient according to a “Minimum Stimulus approaching Strategy”.

OP28-7 - Vestibular evoked myogenic potentials in posterior canal benign paroxysmal positional vertigo

4. Benign Paroxysmal Position Vertigo

Natalia Kunel’skaya¹

Elena Baybakova²,

Alexandra Guseva³, Maria Chugunova², Elena Manaenkova²

¹ Sverzhevsky Research Institute of Clinical Otorhinolaryngology, Russia; Pirogov Russian National Research Medical University, Department of Otorhinolaryngology, Russia

² Sverzhevsky Research Institute of Clinical Otorhinolaryngology, Russia

³ Pirogov Russian National Research Medical University, Department of Otorhinolaryngology, Russia

Purpose: to evaluate the otolith function using vestibular evoked myogenic potentials (VEMP) in patients with idiopathic posterior benign paroxysmal positional vertigo (pBPPV).

Methods: Cervical (cVEMP) and ocular VEMP (cVEMP) in 34 patients 45 to 65 years with idiopathic pBPPV were measured before and 7 days after liberatory maneuver. Repeated Dix-Hallpike test 7 days after liberatory maneuver was negative in 27 patients and positive in 7 patients.

Results: There was no statistically significant difference in the amplitude of cVEMP between healthy and affected ear, either before or after repositioning treatment. Measurement of oVEMP showed decreased amplitude response on the affected side. The average values of the p1n1 on the healthy side were 12.84±1.09 and those on the affected side 4.62±0.69 (p<0,05). The successful repositioning treatment resulted in a significant increase of the oVEMP amplitude on the affected side (p<0,05). In the patients presenting with the persistent symptoms of pBPPV, the repositioning maneuvers didn’t cause sugnificant increase in the amplitude of oVEMP on the affected side (p<0.05).

Conclusions: The study reveals that in pBPPV utriculus is impaired, while the function of succulus stays preserved, as abnormal oVEMP on the affected side, and normal cVEMP on both sides were registered. In case of successful pBPPV treatment with liberatory maneuver the amplitude of oVEMP on affected side increases, asymmetry between both sides decreases, indicating the utriculus’ otolith function repair.

OP29-1 - Effects of Selective Electrical Vestibular Stimulation on the Rat Hippocampus

18. Spatial Orientation

Paul Smith¹

Martin Hitier², Yanfeng Zhang³, Go Sato⁴, Stephane Besnard⁵, Yiwen Zheng¹

¹ Dept. of Pharmacology and Toxicology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand

² Dept. of Otolaryngology Head and Neck Surgery, CHU, Caen, France

³ Dept. of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK

⁴ Dept. of Otolaryngology, University of Tokushima, Tokushima, Japan

⁵ UNICAEN, COMETE, INSERM, U1075, Normandie University, Caen, France

Purpose: Vestibular dysfunction leads to impairments in learning and memory as well as a disruption of head direction, place and grid cells. Therefore, it is clear that vestibular input is necessary for the normal function of the hippocampus. Less clear is how vestibular sensory information is used by the hippocampus. In these studies we attempted to selectively electrically stimulate the horizontal, anterior and posterior semi-circular canals as well as the utricle and saccule and record field potentials in the hippocampus.

Methods: Rats (n = 53) were anesthetized and a 16 electrode microarray was implanted into the bilateral hippocampi. Field potentials were recorded while electrically stimulating specific receptors within the vestibular labyrinth using bipolar electrodes and currents ranging from 50 to 400 mA. c-Fos expression was also analysed following electrical stimulation of the vestibular system.

Results: c-Fos expression was also analysed following electrical stimulation of the vestibular system. Field potentials were evoked throughout the hippocampus by stimulation of the different receptors, with significant differences in amplitude between the anterior, horizontal and posterior canals as well as the utricle and saccule, depending on the current used. Responses were obtained bilaterally from unilateral stimulation and the latencies were usually at least 20 ms; amplitudes were usually greater in dorsal regions compared to ventral regions. c-Fos expression was evoked by stimulation of the vestibular system, especially in the dorsal hippocampus. Double immunolabelling suggested that the neurons involved were adult neurons.

Conclusions: These results demonstrate that vestibular input to the hippocampus is complex and that all sensory receptors are represented.

OP29-2 - Biomechanical Origins of Tullio Phenomena

22. Vestibular and Inner Ear Physiology

M Iversen¹

H Zhu², W Zhou², C Della Santina³, J Carey³,

R Rabbitt⁴

¹ Dept. of Bioengineering, Univ. Utah, Salt Lake City, UT, USA

² Dept. Otolaryngology, Univ. Mississippi, Jackson, MS, USA

³ Dept. Otolaryngology-Head and Neck Surgery, Johns Hopkins School of Medicine, Baltimore, MD, USA

⁴ Dept. of Bioengineering, Otolaryngology, Neuroscience Program, Univ. Utah, Salt Lake City, UT, USA

Purpose: Nearly a century ago Pietro Tullio reported that generation of a fistula in the bony labyrinth can lead to pathological vestibular responses to audio frequency sounds. Lloyd Minor and colleagues demonstrated this condition occurs in patients with a dehiscence of the bone overlying the superior semicircular canal. Recordings from semicircular canal afferent neurons in animal models demonstrate phase-locked action potentials that synchronize to audio frequency stimuli up to several kHz, as well as slowly developing sustained changes in action potential discharge rate that build up during the audio frequency sound. The present study examined origins of these responses.

Methods: Neural responses and endolymph flow were measured in response to audio frequency stimuli using an animal model. Endolymph displacement was measured by introducing fluorescent micro-particles into the endolymph and using particle imaging velocimetry (PIV). A biomechanical model was developed to further examine origins of fluid pumping.

Results: Afferent neurons with irregularly spaced inter-spike intervals (ISIs) synchronized firing with the auditory frequency sound, while afferents with regularly spaced ISIs responded with sustained increases or decreases in discharge rate. PIV revealed continuous endolymph pumping, ampullofugal or ampullopetal dependent on stimulus frequency. Pumping was consistent with predictions of a nonlinear mathematical model.

Conclusions: Results demonstrate that synchronization of action potentials occurs due to vibration of hair bundles at the audio frequency, and that the slowly developing change in discharge rate occurs due to endolymph pumping in the membranous labyrinth arising from nonlinear interaction between mechanical waves traveling along the membranous duct and the endolymph inside the canal.

OP29-3 - How does 500Hz sound or vibration cause VEMPs

22. Vestibular and Inner Ear Physiology

Ian Curthoys¹

Wally Grant², Christopher Pastras³, Daniel Brown³

¹ University of Sydney, School of Psychology, Sydney, Australia

² VA Tech, Department of Biomedical Engineering and Mechanics, Blacksburg, VA. USA

³ University of Sydney, Meniere’s Laboratory, Brain and Mind Centre, Sydney, Australia

Purpose: To understand how the otolithic sensors, usually regarded as low frequency accelerometers, can respond to stimulus frequencies as high as 3000Hz. Premise; otolithic receptors are activated by deflection of the receptor cilia re the cell body.

Methods: Extracellular recordings from single primary afferent neurons from the utricular and saccular macula in response to air conducted sound and bone conducted vibration in anaesthetized guinea pigs. These data were combined with mathematical modelling of the neural results. Laser Doppler Vibrometry measures of the movement of the utricular macula during sound and vibration stimulation with simultaneous utricular microphonic recording from adjacent macula regions.

Results: Vibrometry shows that during high frequency stimulation the utricular macula moves up and down even to 3000Hz and the adjacent utricular microphonic shows that utricular receptors are activated at these frequencies. Irregular primary afferent neurons originate predominantly from receptors at the striola where the receptor cilia are short and stiff and have poor attachment to the otoconial membrane.

Conclusions: Modelling of the neural results indicates otoliths have two modes of operation: at maintained tilts and low frequencies, the otoliths function as accelerometers but at high frequencies they function as seismometers. We suggest that could happen if in the first case the cilia are deflected re the cell-body, in the second case the cell body is deflected re the cilia. Other modelling shows the stiff striolar cilia respond to the small displacements predicted by the simulation and Vibrometer measurement, while extrastriolar hair bundles respond to larger displacements.

OP29-4 - Development of a non-human primate model for the cervical vestibular evoked myogenic potential

2. Animal Models and Molecular Approach

Brian Corneil¹

Chao Gu², Katherine Faubert³, Blake Butler², Sharon Cushing⁴, Aaron Camp⁵

¹ University of Western Ontario, Department of Physiology & Pharmacology, Canada

² University of Western Ontario, Department of Psychology, Canada

³ University of Western Ontario, Robarts Research Institute, Canada

⁴ Hospital for Sick Children, Department of Otolaryngology-Head and Neck Surgery, Canada

⁵ University of Syndey, Bosch Institute, Australia

Purpose: cVEMPs provide a simple and cost-effective means to assess the patency of vestibulospinal reflexes. Research in gerbils and cats have revealed the mechanisms of excitation in the vestibular apparatus and the processing of such information in the vestibular nuclei. However, there are major differences in the anatomy of the head-neck system of gerbils, cats, and humans. We are developing a non-human primate (NHP) model for cVEMPs, as a more suitable model for human cephalomotor control.

Methods: cVEMPs were recorded in awake, head-restrained NHPs in response to tone bursts (4 ms of a 500 Hz tone delivered at 7.4 Hz for between 30-150s; variable intensity ranging from 95 to 130 dB) in 3 animals, implanted with either acute or chronically-indwelling EMG electrodes in SCM, splenius capitis (SPL), and the dorsal suboccipital muscles obliquus capitis inferior (OCI) and rectus capitis posterior major (RCP maj). Background neck EMG was elicited by exploiting the known coupling between horizontal eye position and neck EMG.

Results: Robust cVEMPs evolved bilaterally on both superficial and deep neck muscles within 10-15 ms. As in humans, cVEMPs on ipsilateral SCM were associated with a temporary decrease in recruitment. Inhibition was also seen on contralateral OCI, RCP maj and SPL. Inhibition was accompanied by excitation of the muscles on the other side (e.g., contralateral SCM, and ipsilateral OCI, RCP maj and SPL).

Conclusions: The NHP is a suitable animal model for the cVEMP. cVEMPs distribute widely to many neck muscles, with a recruitment profile resembling that used for horizontal head turns.

OP29-5 - Probing the role of the efferent vestibular system using direct monosynaptic viral tracing

1. Anatomy and Morphology

Aaron Camp¹

Andrew Murray², Miranda Mathews¹

¹ University of Sydney, Sydney Medical School, Australia

² University College London

Purpose: Unlike other sensory modalities, the functional role of the efferent vestibular system (EVS) remains elusive. Previous work has focused on the morphology, physiology, and peripheral responses to EVS neuron activation, with few studies investigating EVS neurons directly. Moreover, a lack of understanding regarding EVS neuron circuit dynamics makes it impossible to link vestibular efferent activity to behaviour. Here, we sought to determine the central context within which EVS neurons are activated by tracing the monosynaptic inputs to this group of neurons, and expand on the work presented at the previous Neuroscience meeting.

Methods: We used monosynaptic rabies tracing to determine the direct inputs to EVS neurons. In mice (n =7) expressing Cre under the control of the choline acetyl transferase (ChAT) promotor we expressed the rabies glycoprotein (G) selectively in EVS neurons. Following G expression, we injected glycoprotein-deficient rabies (RABVG) virus expressing a fluorescent protein into the horizontal and posterior semicircular canals in the inner ear of the same animal. Histological analysis was performed to identify the direct inputs to EVS neurons.

Results: We observed >50 direct inputs from diverse regions throughout the brainstem, cerebellum, and forebrain including from structures in the telencephalon and diencephalon.

Conclusions: Identification of direct monosynaptic inputs to mouse EVN neurons with rabies virus will allow us to expand hypothesis regarding EVS function. In addition, this method will allow manipulation of EVS neurons, or their inputs, via electrical, chemical or optogenetic methods providing a means to explore the context-dependent central modulation of peripheral vestibular function.

OP29-6 - Visual Suppression has Minimal Effect on Adaptation to Magnetic Vestibular Stimulation

22. Vestibular and Inner Ear Physiology

Bryan K Ward¹

Dale C Roberts¹, Michael C Schubert¹, Nicolas Perez-Fernandez², David S Zee³, Jorge Otero-Millan³

¹ Johns Hopkins University, Department of Otolaryngology, Baltimore, USA

² University of Navarra, Department of Otolaryngology, Pamplona, Spain

³ Johns Hopkins University, Department of Neurology, Baltimore, USA

Purpose: A Lorentz force resulting from interactions between strong static magnetic fields and ionic currents in the inner ear endolymph is thought to displace the semicircular canal cupulae in an MRI machine, producing nystagmus. The nystagmus partially adapts; after leaving the magnetic field an aftereffect occurs where the nystagmus reverses direction, reflecting set-point adaptation inside the MRI (rebalancing tonic activity between both vestibular nuclei to prevent unwanted nystagmus when the head is still). The influences of visual fixation and head movements on this vestibular adaptation are unknown.

Methods: Three-dimensional video-oculography was performed in darkness with infrared illumination on in 6 individuals before, during (5 minutes) and after (4 minutes) entering a 7T MRI scanner supine. Trials were repeated entering the magnetic field in darkness, followed by either light with visual fixation or yaw head rotations (2 Hz) in darkness inside the MRI, beginning 60 seconds after entering the MRI. Subjects were placed in darkness again 30 seconds before exiting the bore.

Results: All subjects developed horizontal nystagmus inside the magnetic field, with slow-phase velocity partially decreasing over time, and an aftereffect upon exiting the magnet, developing nystagmus in the opposite direction. Nystagmus was suppressed during fixation; however, after resuming darkness before exiting the magnet, nystagmus returned with velocity close to the control condition and with the same aftereffect. Similar effects occurred with yaw head rotations.

Conclusions: Although vision and retinal slip are critical signals for adaptation of the dynamic components of the VOR, they have minimal impact upon VOR set-point adaptation.

OP29-7 - Sound-evoked vestibular projections to the trapezius muscles in humans

1. Anatomy and Morphology

Sally Rosengren¹

Konrad Weber², Sendhil Govender³, Miriam Welgampola⁴, James Colebatch³

¹ Royal Prince Alfred Hospital, Neurology Department, Australia

² University Hospital Zurich, Department of Neurology, Switzerland

³ University of New South Wales, Prince of Wales Clinical School and Neuroscience Research Australia, Australia

⁴ University of Sydney, Central Clinical School, Australia

Purpose: Vestibular-dependent reflexes have been recorded in trapezius muscles in human subjects, however the nature of the projection (polarity, lateralization and strength) is unknown. Prior studies used varying surface electrode montages and found small reflexes with differing polarity. We therefore used single motor unit to unequivocally demonstrate the nature of projections to trapezius in normal volunteers.

Methods: We recorded single motor unit (N=5 subjects) and surface (N=10) responses following vestibular stimulation with 2ms, 500Hz tone bursts. Concentric needle electrodes and active surface electrodes were placed into or over the upper portion of trapezius, approx. midway between the shoulder and the neck, with reference surface electrodes on the wrist. Trapezius was activated by shoulder elevation and responses were compared to those in sternocleidomastoid (SCM) during head elevation and rotation.

Results: In ipsilateral trapezius we found significant short-latency changes in single motor unit activity in 68% (21/31) of units at approx. 15ms and these were mostly excitatory (67%, 14/21) with median duration 1ms. In contralateral trapezius there were responses in only 52% (13/25) of units (62% excitatory, at 20ms, 1ms duration). Short-latency biphasic surface responses with initial negativity were present only in ipsilateral trapezius (right ear: 7/10 subjects, left ear: 5/10), with mean amplitude 17.7±15.2mV at initial peak latency 15.8±2.0ms, significantly smaller than those recorded in SCM (146.0±76.9mV, P<0.001).

Conclusions: The vestibular projection to trapezius in humans is ipsilateral and predominantly excitatory, but much weaker than that found in SCM, suggesting a minor role for trapezius in the vestibulo-collic reflex.

OP30-1 - Discussion on the significance of nystagmus detection for continuous variable positional nystagmus

22. Vestibular and Inner Ear Physiology

Xiaowu Tang¹

Yongkang Ou¹, Tianci Feng¹

¹ SUN YAT-SEN MEMORITAL HOSPITAL Otolaryngology head and neck surgery, China

Purpose: To explore the clinical application value of the neutral point detection of the persistent lateral geotropic direction-changing positional nystagmus (DCPN)

Methods: In July 2016 - May 2017 in our department outpatient examined positional of vertigo patients with Supine Roll test, 25 patients appeared a double side of persistent DCPN tested neutral point further. The horizontal persistent nystagmus occured in the supine position. Direction changing positional nystagmus canceled at the head rotation to right or left from the supine position is neutral point, recorded the yaw side and the angel.

Results: The 25 patients all occured neutral point, there were 9 patients with persistent lateral geotropic DCPN were confimed light cupula, other 16 patients with persistent lateral ageotropic DCPN were confimed heavy cupula, the angel of neutral point occured were 25.67±9.31°and 27.06±6.29°. End angel were 28.78±10.00°and 30.25±6.53°. No statistical significance between the two. The nystagmus direction in the supine position was opposite to the direction of neutral point was considered light cupula, On the contrary, it was considered heavy cupula.The light cupula and heavy cupula with neutral point were both appeared in the affected side

Conclusions: Neutral point detection method is a kind of confirmation in patients with light cupula or heavy cupula of a very effective method

OP30-2 - Gaze Stability in Elite Athletes

7. Clinical Testing for Vestibular Function

Shelly Massingale¹

Amy Alexander¹, Richard Allred¹, Elizabeth McQueary¹, Charles Leddon², Jamie Pardini¹

¹ Banner University Sports Medicine and Concussion Center

² Sports Science Initiatives Cincinnati Reds

Purpose: Of the variety of symptoms produced in sport-related concussion (SRC), dizziness and balance problems are among the most frequently reported. Gaze stability is part of balance function and is an important aspect of sport performance, contributing to both speed and accuracy. There are a few studies that directly address gaze stability in athletes; however, the sample sizes are fairly small. The purpose of this study was to establish gaze stability ranges of head velocity for elite athletes.

Methods: Subjects were 100 male professional baseball players aged 17 to 31 years (mean age = 23.08) who were assessed during Spring Training as part of a multi-modal preseason baseline assessment. Bertec® Vision Advantage equipment was used to complete the Static Visual Acuity Test, Perception Time Test, and Gaze Stability Test (GST) in high performance range in the yaw plane with the athlete positioned 5 feet from the laptop monitor.

Results: The mean head velocity was 208.15 d/sec (SD= 36.99) with leftward directional movement and 222.79 d/sec (SD = 45.34) with rightward directional movement. The median velocity was 210 d/sec to the left and 215 d/sec to the right. The range for leftward directional movements was 130-335 d/sec and for rightward directional movements was 130-365 d/sec.

Conclusions: Performance of elite athletes on GST measures was observed to be much higher than previously published normative data using non-athlete samples. Thus, it is important to utilize separate norms for elite athletes to ensure optimal clinical management following SRC.

OP30-3 - Comorbid inner ear disorders in patients with congenital nystagmus

7. Clinical Testing for Vestibular Function

Yun-Chen Huang¹

Shuo-Yen Hsu², Yi-Ho Young²

¹ Department of Otolaryngology, Taipei Tzu Chi Hospital, Taipei, Taiwan; School of Medicine, Tzu Chi University, Hualien, Taiwan

² Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan

Purpose: This study adopted an inner ear test battery and oculomotor function test by electronystagmography (ENG) in patients with congenital nystagmus. The aim of this study was to investigate how congenital nystagmus confounds the oculomotor function test, and suggest an inner ear test battery to overcome the potential pitfalls.

Methods: Fifty patients with congenital nystagmus underwent audiometry and caloric test with ENG recordings. The cervical vestibulo-evoked myogenic potential (cVEMP) and ocular VEMP (oVEMP) tests were added to the test battery after 2000 and 2008, respectively. MR imaging was performed in some patients.

Results: All congenital nystagmus patients had abnormal oculomotor function, probably because the ongoing nystagmus superimposed on the traces causing a diagnostic pitfall. In contrast, inner ear deficits ran from abnormal mean hearing level (34%) to abnormal oVEMP test (31%), cVEMP test (31%) and caloric test (25%), exhibiting non-significant differences among abnormality rates. Restated, approximately one-third of congenital nystagmus patients had comorbid inner ear disorders, while two-thirds of congenital nystagmus patients were devoid of inner ear disorders but just sought for evaluation at a neurotological clinic.

Conclusions: The ENG provides a diagnostic tool for differentiating congenital nystagmus from other potentially, hazardous acquired nystagmus, which can be confirmed by MR imaging. In contrast, an inner ear test battery helps investigate a comorbid inner ear disorders in a congenital nystagmus patient.

OP30-4 - Utility Of Positional Testing In Acute Vestibular Syndrome: A Transversal And Longitudinal Study

7. Clinical Testing for Vestibular Function

Joao Lemos¹

Ana Inês Martins², Cristina Duque², Sara Pimentel³, Luís Pimenta³, César Nunes⁴, António Freire Gonçalves¹

¹ Coimbra University Hospital Centre, Neurology Department, Portugal; Coimbra University, Faculty of Medicine, Portugal

² Coimbra University Hospital Centre, Neurology Department, Portugal

³ Coimbra University, Faculty of Medicine, Portugal

⁴ Coimbra University Hospital Centre, Neuroradiology Department, Portugal

Purpose: Positional testing is not usually indicated either in the acute stage or follow up of acute vestibular syndrome (AVS). We sought to evaluate its clinical utility in AVS.

Methods: Consecutive patients with acute vertigo and spontaneous nystagmus underwent ocular motor and positional testing at presentation (<14 days from onset), 3-month and 1-year follow-up, and head MRI.

Results: 31 patients were included, 16 with peripheral AVS (pAVS; 16, vestibular neuritis) and 15 with central AVS (cAVS; 10, stroke/5, demyelination). 23 (74,1%) completed the study. Median age (IQR) was 53 (21) and 58 (22.5) (P=0.429) and there were 13 (86.7%) and 10 (62.5%) (p=0.22) males in pAVS and cAVS groups, respectively. At visit 1, all pAVS patients showed abnormal head impulse test (HIT), absence of gaze-evoked nystagmus (GEN), and 2 (12.5%) showed skew deviation. 13 (86%) cAVS patients showed either skew deviation, GEN or normal HIT. During head hanging positions, 5 (33%) cAVS patients showed paroxysmal vertical nystagmus (3, downbeat). The downbeat form was still present at visit 3. During lateral supine, all pAVS patients showed greater intensity of spontaneous nystagmus when rotating towards the slow phase side (ie, the lesioned side), while half of (53%) cAVS patients showed the opposite pattern. Lateral supine findings at follow-up were highly variable, with both geotropic and ageotropic forms commonly appearing in both groups.

Conclusions: Up to 50% of patients with central acute vestibular syndrome seem to develop either positional paroxysmal vertical nystagmus during head hanging and/or signs of putative earlier vestibular compensation during lateral supine.

OP30-5 - Video ocular counter-roll (vOCR): A new clinical test of otolith-ocular function

7. Clinical Testing for Vestibular Function

Francesco Fornasari¹

Shirin Sadeghpour², Jorge Otero-Millan², David S Zee³, John P Carey⁴,

Amir Kheradmand⁵

¹ San Raffaele University, Italy

² Johns Hopkins, Department of Neurology, USA

³ Johns Hopkins, Departments of Neurology, Neuroscience, Ophthalmology, and Otolaryngology & Head and Neck Surgery, USA

⁴ Johns Hopkins, Department of Otolaryngology & Head and Neck Surgery, USA

⁵ Johns Hopkins, Departments of Neurology and Otolaryngology & Head and Neck Surgery, USA

Purpose: Video-oculography (VOG) is being integrated into the bedside quantification of vestibular function mainly as video head impulse testing (vHIT). Lacking, however, has been a comparable VOG method for evaluation of otolith-ocular function. During a static head tilt, there is a change in torsional position of the eyes in the opposite direction of the head tilt, which is known as the ocular counter-roll (OCR). We have previously shown that VOG quantification of OCR (vOCR) could detect loss of otolith function with an accuracy comparable to vestibular evoked myogenic potentials (VEMPs).

Methods: Here we examined feasibility of vOCR testing at the bedside using simple lateral head-on-body and whole-body tilts of 30 degrees. We recruited patients following CN VIII resection of vestibular schwannoma with acute, subacute, and chronic unilateral vestibular loss. The vOCR results from the patients were compared to a group of healthy controls.

Results: The average vOCR values from the patients were significantly lower compared with the healthy controls during both head-on-body and whole-body tilts (p values<0.05). In the acute group, vOCR was reduced on the side of vestibular loss compared to the healthy side (p values <0.05).

Conclusions: These results show that vOCR can be easily applied at the bedside to detect loss of otolith-ocular function.

OP30-6 - The clinical utility of vibration-induced nystagmus and its role in the vestibular examination

7. Clinical Testing for Vestibular Function

Devin McCaslin¹

Neil Shepard², Scott Eggers¹, Jim McPherson¹, Jamie Soper¹

¹ Mayo Clinic-Rochester, Otorhinolaryngology, United States

² Educational & Clinical Consulting-Missoula, United States

Purpose: The caloric test, rotational testing, ocular & cervical vestibular evoked myogenic potentials identify peripheral pathology. The purpose of this investigation was to describe the characteristics of ipsilesional mastoid vibration-induced nystagmus (VIN) in patients with varying levels of canal paresis. Secondary objectives were; 1) to determine if a relationship existed between these four tests and VIN; and 2) determine sensitivity/specificity of VIN for detecting horizontal canal impairment.

Methods: 580 adults presenting with symptoms of dizziness underwent caloric, rotational testing, ocular & cervical VEMP and VIN. Patients were stratified by caloric asymmetry (CA) into: 0–25%, 26–50%, 51–75%, & 76–100%. Slow component eye velocity (SCEV) was recorded 10 seconds before, during & after the application of vibration. Correlation coefficients were calculated for CA and VIN SCEV. ANOVA was used to determine significant differences in the amplitude of SCEV & CA groups; ROC analysis was used for sensitivity/specificity.

Results: Significant main effects for ipsilesional VIN SCEV noted (p ≤ 0.000). Bonferroni-adjusted t tests showed significant differences in ipsilesional VIN SCEV between all of the groups except 26-50% & 51-75%. CA showed a positive correlation with ipsilesional VIN SCEV (p < 0.000). The ROC for CA groups & identification of peripheral pathology as a function of the VIN SCEV gave ROC curve areas of .78-.95 & .59 respectively.

Conclusions: The study demonstrates that VIN and caloric data are correlated, yet each provides unique information regarding the functional integrity of the horizontal semicircular canal at different points on the frequency spectrum.

OP30-7 - Accuracy of Automated Nystagmus Velocity Calculation by Video-oculographyImplications for Eye ECG

7. Clinical Testing for Vestibular Function

Tzu-Pu Chang¹

Adriana Batazzi², Jorge Otero-Millan², Kevin Kerber³, Jorge Kattah⁴, Daniel Hanley², John Carey⁵, David Zee², David Newman-Toker²

¹ Department of Neurology, Taichung Tzu Chi Hospital, Tzu Chi University, Buddhist Tzu Chi Medical Foundation, Taiwan

² Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA

³ Department of Neurology, University of Michigan Health System, Ann Arbor, MI, USA

⁴ Department of Neurology, University of Illinois College of Medicine, Peoria, IL, USA

⁵ Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA

Purpose: Misdiagnosis of acute vertigo in the emergency department (ED) is frequent. Pairing onsite quantitative video-oculography (VOG) with computer-based decision support is one possible solution. The accuracy of automated nystagmus detection by VOG is unknown.

Methods: As part of the AVERT (Acute Video-oculography for Vertigo in Emergency Rooms for Rapid Triage) trial (ClinicalTrials.gov #NCT02483429), we prospectively recruited consecutive patients with acute vertigo from three hospital EDs (2016-2017). Patients underwent multiple ocular motor tests (~28 per battery) using a portable, lightweight VOG device (ICS Impulse, Otometrics, Taastrup, Denmark). We compared automated nystagmus detection based on peak slow-phase velocity ≥ 10 deg/sec (Otosuite software v4.0) to human expert assessment of pathologic nystagmus by video review. We calculated test accuracy and classified artifacts.

Results: We reviewed 2,656 individual VOG tests in 101 patients (31 with nystagmus). Pathologic nystagmus was present per expert review in 4.1% of tests with automated detection sensitivity 95.2%, specificity 95.3%, positive predictive value 52.1%, negative predictive value 99.7%. Among 91 false-positive tests, 34% had physiologic “artifacts” (normal slow eye movements or end-gaze nystagmus); 49% had pupil-tracking artifacts (blinking, ptosis, pupil out-of-frame, eyelash/long-hair in frame); and 16% had non-classifiable artifacts. At the patient level, there were 1 false negatives and 24 false positives.

Conclusions: Automated nystagmus detection by VOG is both sensitive and specific. However, when used in ED patients with a low likelihood of nystagmus undergoing multi-test batteries, patients without any nystagmus are frequently misclassified as having nystagmus (36.4%). Human review of positive results may be necessary pending improved computer algorithms.

OP31-1 - Impaired spatial orientation in 30 patients with bilateral vestibulopathy

18. Spatial Orientation

Bieke Dobbels¹

Julie Moyaert², Griet Mertens¹, Paul Van de Heyning¹, Vincent Van Rompaey¹

¹ Dept. Otorhinolaryngology & Head and Neck Surgery, Antwerp University Hospital, Belgium. Faculty of Medicine and Health Sciences, University of Antwerp, Belgium

² Dept. Otorhinolaryngology & Head and Neck Surgery, Antwerp University Hospital, Belgium.

Purpose: Our aim is to evaluate spatial cognition in patients suffering from bilateral vestibulopathy.

Methods: We examined thirty-seven patients with a previous diagnosis of bilateral vestibulopathy (BVP) at our center. All patients underwent vestibular testing by means of caloric irrigation, rotation swing and video-head-impulse-testing. Only patients who met the diagnostic criteria for BVP, as recently proposed by the Bárány Society, were included. The control group consisted of twenty healthy male and female subjects, without vestibular complaints and a zero score on the Dizziness Handicap Inventory. Spatial orientation was measured by performing a virtual version of the Morris Water Maze task with 20 hidden trials, 1 probe trial and 10 visible trials.

Results: Eighteen male (mean age 52 y ± 12) and twelve female (mean age 57 y ± 16) patients met the diagnostic criteria for BVP as proposed by the Bárány Society. Overall, patients with BVP took longer paths and more time to find a hidden platform (mean path length/pool diameter in BVP 1.42 ± 0.6, in controls: 1.32 ± 0.4, p = 0.47; mean latency in BVP 38 s ± 16, in controls: 32s ± 10, p=0.15). The difference in performance between BVP patients and the control group was more pronounced in male subjects (e.g. heading error in probe trial: male BVP patients 38° ± 32 versus healthy males 11° ± 11, p=0.05).

Conclusions: Our current findings demonstrate that patients with BVP suffer from an impaired spatial cognition. This effect seem to be more pronounced in male patients than in female patients with BVP.

OP31-2 - Etiology and hearing status of 129 patients with bilateral vestibulopathy

5. Bilateral Vestibulopathy

Bieke Dobbels¹

Olivier Peetermans², Bram Boon², Jonas De Belder², Stijn Matthysen², Paul Van de Heyning¹, Griet Mertens¹, Vincent Van Rompaey¹

¹ Faculty of Medicine and Health Sciences, University of Antwerp, Belgium, Dept. Otorhinolaryngology & Head and Neck Surgery, Antwerp University Hospital, Belgium.

² Faculty of Medicine and Health Sciences, University of Antwerp, Belgium.

Purpose: Our primary aim was to determine the definite and probable etiology in patients with bilateral vestibulopathy (BVP) at our center. Our secondary aim was to evaluate the hearing status in these patients.

Methods: A retrospective study was performed on BVP patients diagnosed and followed in a tertiary referral center (University hospital of Antwerp) between 2004 and 2018. Only patients who met the diagnostic criteria proposed by the Bárány Society, were included.

Results: We identified 129 BVP patients, 59% male. The mean age at diagnosis was 57 ± 15,6 years (range 10-84 years). The definite cause was determined in 40% of patients and the probable cause in 23% of patients. No cause was identified in 37% of BV patients. In op to 20% of patients, a different etiology was identified on each inner ear. The largest subgroup included patients with a genetic etiology, most frequently DFNA9. Of all patients, 22% had bilateral normal hearing to mild sensorineural hearing loss (SNHL) impairment, 12% had bilateral moderate to severe SNHL and 32% had bilateral profound SNHL. Furthermore, 22% of patients presented unilateral deafness and 7% unilateral moderate to severe SNHL.

Conclusions: Bilateral vestibulopathy is a heterogeneous condition, with over 1/3 of cases remaining idiopathic, and more than 3/4 affected by hearing loss. DFNA9 is the most common cause of BV in our population.

OP31-3 - Cognitive impairment in patients with bilateral vestibulopathy with and without hearing loss

5. Bilateral Vestibulopathy

Bieke Dobbels¹

Julie Moyaert², Griet Mertens¹, Paul Van de Heyning¹, Vincent Van Rompaey¹

¹ Dept. Otorhinolaryngology & Head and Neck Surgery, Antwerp University Hospital, Belgium. Faculty of Medicine and Health Sciences, University of Antwerp, Belgium

² Dept. Otorhinolaryngology & Head and Neck Surgery, Antwerp University Hospital, Belgium.

Purpose: Recent studies demonstrated cognitive impairment in small groups of patients with bilateral vestibulopathy (BVP). Our aim is to evaluate cognitive performance of 30 BVP patients with and without hearing loss, as this is an independent risk factor for cognitive decline.

Methods: Thirty patients (53y±12) with an established diagnosis of bilateral vestibulopathy (BVP) according to the Barany criteria, were included. Eighty-two healthy, normal hearing, controls (63y ± 11) were selected. They had no vestibular complaints and presented a zero score on the Dizziness Handicap Inventory. All subjects underwent audiometric evaluation. Cognition was assessed by means of the Repeatable Battery for the Assessment of Neuropsychological Status, for hearing impaired persons (RBANS-H). This is an adaptation of the original RBANS specifically designed for hearing impaired patients. The RBANS measures 5 domains of cognition: immediate memory, delayed memory, visuospatial abilities, attention and language.

Results: Overall patients with BVP had a worse total score on the RBANS-H comparing to healthy controls, although this was not statistically significant. Interestingly, patients with BVP and hearing loss performed worse than patients with BVP and normal hearing (p<0.05). Mainly, delayed memory and immediate memory seem to be affected in BV patients with hearing loss compared to BV patients without hearing loss (p=0.097 and p = 0.065, respectively).

Conclusions: Our results confirm the previous findings of impaired cognition in BVP patients. Further research is needed to evaluate the relative impact of either vestibular or hearing loss on cognition in these patients.

OP31-4 - Extensive exploration of symptoms of bilateral vestibulopathy

5. Bilateral Vestibulopathy

Florence Lucieer¹

Ruth van Hecke², Stijn Duijn³, Angelica Perez-Fornos⁴, Nils Guinand⁴, Jean-Philippe Guyot⁴, Herman Kingma¹, Manuela Joore⁵, Raymond van de Berg¹

¹ Department of Otorhinolaryngology and Head & Neck Surgery, Maastricht University Medical Center, Maastricht, Netherlands

² Department of Speech, Language and Hearing Sciences, University of Gent, Gent, Belgium

³ Faculty of Health, Medicine and life Sciences, University of Maastricht, Maastricht, Netherlands

⁴ Service of Otorhinolaryngology and Head and Neck Surgery, Department of Clinical Neurosciences, Geneva University Hospitals, Geneva, Switzerland

⁵ Department of Clinical Epidemiology and Medical Technology Assessment (KEMTA), Maastricht University Medical Centre, Maastricht, The Netherlands

Purpose: To obtain a clear inside in the full spectrum of symptoms of bilateral vestibulopathy (BV).

Methods: Qualitative research was performed in 18 BV patients. All subjects had a reduced caloric response of summated slow phase mean peak velocity of less than 20°/s. An extensive individual interview was performed with open-ended questions. The interviews were transcribed, coded and analyzed by the first two authors. The symptoms were organized in a mindmap and labeled by category. The symptoms were divided in physical symptoms, functional symptoms and emotions.

Results: Inner ear symptoms were reported such as oscillopsia, imbalance, vertigo, unsteadiness when walking or standing, and worsening of unsteadiness in darkness and/or on uneven ground. Moreover, symptoms beyond the inner ear were described by the BV patients, for example negative emotions (fear, agitation, etc), cognitive/memory problems, reduced quality of life, and reduced spatial orientation.

Conclusions: BV symptomatology has a broader spectrum of symptoms than most literature currently focuses on. It reaches beyond symptoms of the inner ear. It is therefore important to take this into consideration during the development of outcome measures for therapeutic interventions such as the vestibular implant.

OP31-5 - Hierarchical cluster analysis of semicircular canal and otolith deficits in bilateral vestibulopathy

5. Bilateral Vestibulopathy

Alexander A Tarnutzer¹

Christopher J Bockisch², Elena Buffone¹, Konrad P Weber³

¹ University Hospital Zurich, Department of Neurology

² University Hospital Zurich, Departments of Neurology, Ophthalmology and Otorhinolaryngology

³ University Hospital Zurich, Departments of Neurology and Ophthalmology

Purpose: Gait imbalance and oscillopsia are characteristic for bilateral-vestibular loss (BLV). Video-head-impulse testing (vHIT) of all six semicircular canals (SCCs) has demonstrated varying involvement of the canals. Sparing of anterior-canal function has been linked to aminoglycoside-related vestibulopathy and Menière’s disease. We hypothesized that utricular/saccular impairment may be disease-specific also.

Methods: We searched our vHIT-database for patients with bilaterally impaired SCC-function who also received ocular vestibular-evoked myogenic-potentials (oVEMPs) and cervical vestibular-evoked myogenic-potentials (cVEMPs) and identified 101 patients. oVEMP/cVEMP-latencies above the 95^th-percentile and peak-to-peak amplitudes below the 5^th-percentile of normal were considered abnormal. Frequency of impairment of vestibular end-organs (horizontal/anterior/posterior SCC, utriculus/sacculus) was analyzed with hierarchical cluster-analysis and correlated with the underlying etiology.

Results: Rates of utricular/saccular loss-of-function were similar (87.1% vs. 78.2%, p=0.136). oVEMP-abnormalities were found more frequently in aminoglycoside-related BVL compared to Menière’s disease (91.7% vs. 54.6%, p=0.039). Cluster-analysis indicated distinct patterns of vestibular end-organ impairment: Individual end-organs on both sides merged early. Sparing of anterior-canal function was reflected in late merging with the other end-organs, emphasizing their distinct state. Average (±1SD) number of damaged sensors was 6.8±2.2/10. Significantly (p<0.001) more sensors were impaired in patients with aminoglycoside-related BVL (8.1±1.2) or inner-ear infections (8.7±1.8) compared to Menière-related BVL (5.5±1.5).

Conclusions: Hierarchical cluster-analysis may help differentiate characteristic BVL-patterns. With a prevalence of ≈80%, utricular/saccular impairment was frequent. The extent of SCC and otolith impairment was disease-dependent, showing most extensive damage for inner-ear infection and aminoglycoside-exposure. Furthermore, assessing utricular function may help in the distinction between aminoglycoside-related BVL and bilateral Menière’s disease.

OP31-6 - On the effect of noisy galvanic vestibular stimulation on dynamic visual acuity.

5. Bilateral Vestibulopathy

Nolan Herssens¹

Wim Saeys¹, Luc Vereeck¹, Bieke Dobbels², Vincent Van Rompaey², Ann Hallemans¹

¹ University of Antwerp, Department of Rehabilitation Sciences and Physiotherapy, Belgium

² Antwerp University Hospital, Department of Otorhinolaryngology & Head and Neck Surgery, Belgium

Purpose: Recent studies have evaluated the potential of noisy galvanic vestibular stimulation (nGVS) to upregulate primary vestibular afferent and hair cell activity in bilateral vestibulopathy (BV) patients by means of stochastic resonance. Improvement in vestibular balance control and postural stability has been observed, however, the impact of nGVS on gaze stabilization has not been investigated. Therefore, the primary aim was to study the effect of nGVS on dynamic visual acuity (DVA) in BV-patients.

Methods: Nine BV-patients were included according to the diagnostic criteria suggested by the Bárány Society. Gaze stabilization was tested with the DVA-test during treadmill locomotion, both with and without nGVS in a randomized order and patients were blinded to the stimulation protocol. Additionally, health-related quality of life was evaluated through the Dizziness Handicap Inventory (DHI). The correlation between DHI (sub)scores and change in DVA-performance was studied.

Results: Age ranged from 28.13 to 73.27 years (5:4 male-female ratio). Etiologies included idiopathic BV (n=2), gentamicin toxicity (n=2), auto-immune inner ear disorder (n=2), meningitis (n=2) and bilateral vestibular neuritis (n=1). Total DHI scores ranged from 0 (no self-perceived disability) to 84 (severe self-perceived disability). DVA-performance remained stable in 5/9 patients, three patients performed better with nGVS and one patient performed worse. The “Physical” subscore of the DHI demonstrated a strong correlation (r=-0.684, p=0,042) with an improvement in DVA scores during nGVS.

Conclusions: This pilot study provides preliminary data suggesting that noisy galvanic vestibular stimulation could be effective in improving gaze stabilization in a subset of patients suffering from bilateral vestibulopathy.

OP31-7 - Vestibular perception in patients with bilateral vestibulopathy

5. Bilateral Vestibulopathy

Florence Lucieer¹

Bart Dupuits², Nils Guinand³, Angelica Perez-Fornos³, Herman Kingma¹, Raymond van de Berg¹

¹ Department of Otorhinolaryngology and Head & Neck Surgery, Maastricht University Medical Center, Maastricht, Netherlands

² Faculty of Health, Medicine and life Sciences, University of Maastricht, Maastricht, Netherlands

³ Service of Otorhinolaryngology and Head and Neck Surgery, Department of Clinical Neurosciences, Geneva University Hospitals, Geneva, Switzerland

Purpose: At this moment clinical vestibular testing mainly focuses on testing reflexes such as the vestibulo-ocular reflex (VOR) and the vestibulo-collic reflex (VCR). The objective of this study was to evaluate the perceptual thresholds in patients with bilateral vestibular loss using a recently proposed clinically useful test for vestibular perception

Methods: Fifty patients with bilateral vestibular loss and a control group of 55 healthy volunteers were tested on a MOTEK perception platform in dark. All BV patients had a reduced caloric response of summated slow phase mean peak velocity of less than 20°/s and a reduced VOR gain on the rotatory chair (0.1Hz). The platform delivered 12 different movements: 6 translations (forward, backward, right, left, up and down) and 6 rotations/tilt (yaw left, yaw right, pitch forward, pitch backward, roll left and roll right). Thresholds were determined by a staircase paradigm

Results: Perceptual thresholds of translation showed a wide distribution in both groups. Thresholds above 0,4m/s² were more prominent among BV patients. Perceptual thresholds for rotation/tilt movements in BV patients were significantly higher compared to those in healthy volunteers.

Conclusions: BV patients show generally higher perceptual thresholds than healthy volunteers. The spread of perceptual thresholds in BV patients is probably due to the use of other pathways than the regularly evaluated reflexes. Therefore, perception could be used as an additional treatment outcome measurement in the future.

PP1-1 - 3D Visualization and Position of Human Inner Ear Graviceptors A Synchrotron Imaging Study

1. Anatomy and Morphology

Sumit Agrawal¹

Hanif M. Ladak², Helge Rask-Andersen³,

Hao Li³

¹ Western University, Department of Otolaryngology-Head and Neck Surgery, Canada

² Western University, Department of Otolaryngology-Head and Neck Surgery, Department of Medical Biophysics and Department of Electrical and Computer Engineering, Canada

³ Uppsala University Hospital, Department of Surgical Sciences, Head and Neck Surgery Section of Otolaryngology, Department of Otolaryngology, Sweden

Purpose: Receptors located in the inner ear, muscles tendons and joints provide sensory information of body position, static equilibrium and gravitational forces. The saccule and utricle maculae in the labyrinth is a body “gyroscope” that delivers information to the brain of head orientation, gravity and linear acceleration. Their exact position and shape of the sensory tissues within the human skull are still somewhat poorly defined.

Methods: We used synchrotron-phase contrast imaging (SR-PCI) to study the 3D micro-anatomy and position of the gravireceptors in the human skull. This was accomplished by reconstructing human soft inner ear tissues including the sensorineural epithelial outline with juxtaposing CT skull images.

Results: The geometric position and outline of the maculae were also assessed relative to the location of the round and oval windows, stapes foot plate, cochlear lateral wall tissue and spiral lamina. Besides this information the 3D outline of the membranous endolymph duct system could be defined.

Conclusions: The exact position and shape of the inner ear graviceptors were mapped in the human skull using synchrotron-phase contrast imaging.

PP1-2 - A multifaceted tailored randomised-controlled trial to reduce the burden of dizziness in middle aged and older people

1. Anatomy and Morphology

J Menant¹

J Close², A Migliaccio¹, N Titov³, K Delbaere¹, D Sturnieks¹, C Mc Veigh², S Lord¹

¹ NeuRA, UNSW, Sydney, NSW, 2031, Australia

² NeuRA, UNSW, Sydney, NSW, 2031, Australia; Prince of Wales Clinical School, UNSW, Sydney, NSW, 2031, Australia

³ Department of Psychology, Macquarie University, Sydney, NSW, 2109, Australia

Purpose: Dizziness is common among middle-aged and older people. Its multifactorial etiology makes it difficult to investigate and if untreated, dizziness can lead to reduced quality of life, functional disability, depression, restricted participation in social activities and falls. Only a few multidisciplinary interventions of dizziness have been conducted to date, all of a pilot nature and none tailoring the intervention to the specific causes of dizziness.

The study aimed to test the hypothesis that a multidisciplinary dizziness assessment followed by a tailored multifaceted intervention would reduce dizziness handicap and self-reported dizziness, and enhance balance and gait in people aged 50 years and over with dizziness.

Methods: 305 community-dwelling people (mean (SD) age 68 (8) years, 62% women) who reported dizziness in the 12months prior and were not receiving treatment for it, completed the dizziness handicap inventory (DHI) and questionnaires regarding medical history, anxiety and depression. They also underwent assessments of vestibular function, sensorimotor function, balance, stepping and gait. Our multidisciplinary team of scientists and clinicians held case conferences fortnightly to discuss and recommend appropriate therapy(ies) for each participant, based on their baseline assessments. Participants were then randomised to intervention or control groups, and based on their test performances, intervention participants were allocated to one or more interventions: vestibular rehabilitation, cognitive behavioural therapy, medical/medication management by a general practitioner or at a falls clinic and strength and balance exercises using the Otago exercise program. Primary outcome measures comprised the DHI, frequency of dizziness episodes recorded with monthly calendars over the six-month follow-up, choice stepping reaction time and gait variability.

Results: At trial completion, the DHI scores in the intervention group (pre and post mean (SD): 25.9 (19.2) and 20.4 (17.7), respectively) were significantly reduced when compared to the control group (pre and post mean (SD): 23.0 (15.8) and 21.8 (16.4)), when controlling for baseline scores (mean (95% CI) difference between groups (baseline adjusted): -3.7 (-6.2 to -1.2); p=0.003).There were no other significant between-group differences in the primary outcomes. However, there were intervention-specific improvements in those allocated to the four intervention types.

Conclusions: The findings indicate that a multifactorial tailored approach for treating dizziness is effective in reducing dizziness handicap in community-living people aged 50 years and older. Individualised multifaceted evidence-based therapies should be implemented to improve the quality of life of middle-aged and older people with dizziness.

PP1-3 - Developing a Model for Quantification of Heat Transfer to the Vestibular System

1. Anatomy and Morphology

Charles Anzalone¹

Yening Feng¹, Matthew Carlson¹, Devin McCaslin², Gayla Poling², David Kallmes³, John Lane³, Shuai Leng³, Kent Carlson⁴, M. Dan Dragomir-Daescu⁴

¹ Department of Otorhinolaryngology, Mayo Clinic, Rochester, MN

² Department of Audiology, Mayo Clinic, Rochester, MN

³ Department of Radiology, Mayo Clinic, Rochester, MN

⁴ Department of Engineering, Mayo Clinic, Rochester, MN

Purpose: Caloric modulation of the vestibular system is an established technique to determine inner ear function. We aim to develop a cadaveric model to determine the role specific anatomic variables play in temperature change at the level of the lateral semicircular canal (LSC)

Methods: Two fresh frozen cadaveric heads were evaluated using a 192 slice computed tomography (CT) scanner to evaluate for standardized anatomy as well as tissue thickness and density. A continuous caloric irrigation system was placed at either the level of the external auditory canal or direct irrigation into the middle ear space; thermocoupling electrodes at the external auditory canal (EAC), middle ear, and LSC provided real time temperature monitoring.

Results: Radiographic analysis of each cadaveric model was performed to quantify anatomic variables: surface area and volume of the EAC, surface area of the tympanic membrane, volume and surface area of the middle ear space, LSC bony thickness, volume, surface area and distance to the tympanic membrane. Specific temperature coefficients were determined based off of contributions of air, bone, and soft tissue densities. Temperature transfer models were constructed from these variables.

Conclusions: Determining the variables affecting the delivery of heat to the LSC are paramount to determining the degree of vestibular stimulation from a given input temperature. Our model provides a reliable method of quantifying temperature transfer across the external, middle and inner ear anatomy. Further study is required to correlate these data to the general population.

PP1-4 - Distribution of extracellular matrix in vestibular nuclei of developing mouse brain stem

1. Anatomy and Morphology

András Birinyi¹

Ildikó Wéber¹, Klara Matesz¹

¹ Department of Anatomy, Histology and Embryology, Debrecen, Hungary

Purpose: The molecular and structural composition of the extracellular matrix (ECM) in the central nervous system undergoes profound transformation during embryonic and early postnatal development. The aim of this study was to detect the changes of staining pattern of different ECM molecules in the developing mouse brainstem.

Methods: We used using histochemical (Wisteria floribunda agglutinin (WFA), hyaluronic acid probe (HA)) and immunohistochemical (aggrecan, neurocan, versican (GAG beta), TN-R and HAPLN1) methods.

Results: We found that HA, neurocan and versican reactions showed diffuse neuropil staining at very early embryonic stage (E13.5), but perineuronal net (PNN) composed of these molecules were observed only postnatally (P7). We could not find any aggrecan, WFA or HAPLN1 staining before birth. Postnatally WFA and aggrecan established PNN in the reticular formation and in the vestibular and other brainstem nuclei. HAPLN1 were restricted to the neuropil of some brainstem nuclei, in contrast to HA, neurocan and TN-R which were found throughout the brainstem.

Conclusions: Our results show that at early stages of development only a diffuse staining of ECM molecules is present in the neuropil of the brainstem and the formation of a definitive PNN is recognizable postnatally. We found well developed PNNs in the vestibular nuclei of the brainstem in two weeks old animals. It is expected that the pattern of ECM expression appears to be related to the functional maturation of brainstem neural circuits, which is also evident in other developmental processes such as neurogenesis, synaptogenesis or synaptic plasticity. Supported by OTKA K 115471, and MTA TKI 355.

PP1-5 - Ion Transport Proteins and Claudin 11 Barrier in the Lateral Wall of the Human Cochlea

1. Anatomy and Morphology

Wei Liu¹

Rudolf Glueckert², Annelies Schrott-Fischer², Heval Benav³, Charlotta Kämpfe¹, Göran Laurell¹, Helge Rask-Andersen¹

¹ Uppsala university, ENT dept., Uppsala, Sweden

² University of Innsbruck, ENT dept., Innsbruck, Austria

³ MED-EL GmbH, Fuerstenweg 77a, A- 6020 Innsbruck, Austria

Purpose: The cochlea produces an electric field potential essential for hair cell transduction and hearing. This biological “battery” is situated in the lateral wall of the cochlea and contains highly organized molecular/cellular arrangement that secretes and recycles K+ ions. Its functioning depends on ion-transporting machinery and junctional proteins that guarantee a unidirectional delivery of K+ and restrict the para-cellular escape of the ion. Claudin 11 protein has been found to be one of the major constituents at tight junction that maintains ion gradients (Gow et al., 2004; Kitajirietal., 2004). We are the first to elucidate the human Claudin 11 framework and the associated ion transporters (channels/pumps/carriers) using super-resolution structured illumination microscopy (SR-SIM).

Methods: Archived human cochleae obtained during meningioma surgery were used for SR-SIM, together with confocal laser scanning microscopy and transmission electron microscopy after ethical permission as well as patients’ consent.

Results: Claudin 11-expressing cells formed parallel tight junction lamellae that insulated the epithelial layers of the stria vascularis and extended to the suprastrial region. Intercellular gap junctions were found between the barrier cells and fibrocytes.

Conclusions: EM, CLSM and SR-SIM revealed exclusive cell specialization in the various subdomains of the lateral wall of the human cochlea. The Claudin 11-expressing cells exhibited both conductor and isolator characteristics, and these microporous separators may selectively mediate the movement of charged units (mainly K+) to the intrastrial space in a manner that is analogous to a conventional electrochemical “battery.” The function and relevance of this “battery” for the development of inner ear diseases are discussed.

PP1-6 - Is there a Neuroimmunoaxis in the Human Inner Ear - Role in Disease and Repair?

1. Anatomy and Morphology

Wei Liu¹

Helge Rask-Andersen¹

¹ Uppsala university, surgical sciences department

Purpose: The human inner ear is segregated by a blood/labyrinth barrier but contains resident macrophages/microglia (CD163, IBA1-, and CD68-positive cells) within almost all the tissues including neurons and organ of Corti. In the lateral wall of the cochlea, these cells lie close to blood vessels as perivascular macrophages. Macrophages are also shown to be recruited from blood-borne monocytes to damaged and dying hair cells induced by noise, ototoxic drugs, aging and diphtheria toxin-induced hair cell degeneration. Precise monitoring may be crucial to avoid self-targeting. Macrophage biology has recently shown that populations of resident tissue macrophages may be fundamentally different from circulating macrophages. Macrophage migration inhibitory factor protein (MIF) signaling is a potential route to develop new therapeutic strategies to repair adult spiral ganglion neurons, hair cell synapses and even form new neurons from stem cells.

Methods: Human cochleae were removed during surgery for treating petro-clival meningioma compressing the brain stem, after ethical consent. Molecular and cellular characterization using immunohistochemistry with antibodies against IBA1, TUJ1, CX3CL1 and type IV collagen, and super-resolution structured illumination microscopy (SR-SIM) were made together with transmission electron microscopy.

Results: High resolution microscopy disclosed remarkable phenotypic variants of IBA1 cells closely associated with the spiral ganglion cells. Monitoring cells adhered to neurons with “synapse-like” specializations and protrusions. Active macrophages migrated occasionally nearby damaged hair cells.

Conclusions: In the human cochlea, the labyrinthine nerves are under the influence of a neurotrophic cytokine/chemokine cross-talk with the immune system. The interaction has possible roles in human inner ear disease, sensorineural injury, and repair processes.

PP1-7 - Microcomputed Tomography Analysis of the the Fundus of the Human Internal Acoustic Canal

1. Anatomy and Morphology

Nadine Schart-Morén¹

Sune Larsson², Hao Li¹, Helge Rask-Andersen¹

¹ Department of Surgical Sciences, Otorhinolaryngology, Head and Neck Surgery, Uppsala University, Uppsala, Sweden

² Department of Surgical Sciences, Orthopedics, Uppsala University, Uppsala, Sweden.

Purpose: The purpose of the study was to better understand and visualize tha anatomy of the human fundus with microcomputed tomography. Identification of the cochleovestibular nerve in the internal acoustic canal is crucial before cochlear implantation and other surgical interventions, such as tumor removal, vestibular nerve section, and decompression procedures. They all require a thorough knowledge of the gross and topographical anatomy in humans.

Methods: Using microcomputed tomography, we analyzed the fundus bone channels in an archival collection of 113 macerated human temporal bones and 325 plastic inner molds. Data were subsequently processed by volume-rendering software using a bony tissue algorithm. Three-dimensional reconstructions were made, and through orthogonal sections, the topographic anatomy was established.

Results: The technique provided additional information regarding the anatomy of the nerve foramina/channels of the human fundus region, including variations and destinations. Channel anastomosis were found beyond the level of the fundus. A foramen of the transverse crest was identified.

Conclusions: Three-dimensional reconstructions and cropping outlined the bone canals and demonstrated the highly variable VIIIth nerve anatomy at the fundus of the human inner acoustic canal. Myriad channel interconnections suggested an intricate system of neural interactive pathways in humans. Particularly striking was the variable anatomy of the saccule nerve channels. The results may assist in the preoperative interpretation of the VIIIth nerve anatomy.

PP1-8 - A new procedure of labyrinthectomy in mice by means of transtympanic injection of p-arsanilic acid

2. Animal Models and Molecular Approach

Kazuki Nakahara¹

Taeko Ito², Kouko Tatsumi¹, Tadashi Kitahara², Akio Wanaka¹

¹ Nara Medical University, Department of Anatomy and Neuroscience, Japan

² Nara Medical University, Department of Otolaryngology-Head and Neck Surgery, Japan

Purpose: Unilateral labyrinthectomy (UL) is usually adapted to make an animal model of vestibular dysfunction. However, there are few papers about UL in mice. For further understanding of vestibular compensation, a new method of UL in mice is required. In the present study, we devised a new accessible and reliable method to damage mice inner ear.

Methods: We used 8 weeks old male C57BL/6N mice. A retroauricular incision was made to expose the external ear canal. It was opened just anterior to the exit point of facial nerve and the tympanic membrane was perforated caudally to handle of malleus. After paracentesis, 50 µl of 0.4M p-arsanilic acid sodium salt solution was instilled into the tympanic cavity and after 5 min, the solution was aspirated. As behavior markers, we recorded head deviation and spontaneous nystagmus using a digital camera. Head deviation was measured once a day, defined as the angle between the horizontal plane and a line passing through the center of the animal’s head in the coronal plane. To understand the neurological activities in vestibular nucleus (VN), we counted immunoreactive cells of immediately early genes (IEGs): c-fos, Arc, and Zif268.

Results: The angle of head deviation became the least at 48 hrs and gradually recovered by 168 hrs after UL. The spontaneous nystagmus appeared at 24 hrs and disappeared by 48 hrs after UL. IEGs-immunoreactivities in VN were higher in the injured side than the intact side.

Conclusions: The present UL procedure is simple and reliable for making a mice model of vestibular dysfunction.

PP1-9 - Altered circadian locomotor activity after acute otovestibular failure in rodents.

2. Animal Models and Molecular Approach

Vincent Van Rompaey¹

Stephan Missault¹, Krystyna Szewczyk¹, Paul Van de Heyning¹, Peter De Deyn², Debby Van Dam²

¹ University of Antwerp, Faculty of Medicine and Health Sciences, Dept. Translational Neurosciences, Belgium

² University of Antwerp, Laboratory of Neurochemistry and Behaviour, Institute Born-Bunge, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, Belgium

Purpose: Similar to Alzheimer’s disease, diurnal rhythm disturbances and cognitive dysfunction have been observed in rodent models of bilateral vestibulopathy (BV). Sleep and circadian disruption can impair hippocampal neurogenesis and subsequently impair hippocampus-dependent learning and memory. Recent insights have explored the connection between the vestibular system and hypothalamic regulation of circadian rhythms. The aim of this study was to evaluate circadian patterns of locomotor activity before and after acute otovestibular failure in mice.

Methods: We evaluated adult 129S1/SvImJ mice, purchased from Charles River - Jackson Laboratories (JAX), 1 week before and 1 week after allylnitrile exposure (p.o. in 6 ml/kg of corn oil). Vestibular function was evaluated with the validated score reported by Jordi Llorens. Cage activity was evaluated continuously over a period of 47 hours, including a 12-hour dark phase (active) and a 12-hour light phase (less active). Ambulatory movements (e.g. walking through cage) included multiple infrared beams crossed sequentially. Fine movements (e.g. grooming) included one infrared beam disrupted multiple times. Statistical analysis was performed using a mixed model with random and fixed effects.

Results: Allylnitrile exposure resulted in acute-onset and permanent vestibular failure and profound sensorineural hearing loss. A statistically significant interaction was observed on ambulatory (p<0.05) and fine movements (p<0.0001) when comparing measurements before versus after allylnitrile exposure and comparing with the control group.

Conclusions: Our findings support the hypothesis that the vestibular system has a short-term influence on daily rhythm homeostasis in rodents. This circadian rhythm disturbance might play a role in decreased adult hippocampal neurogenesis and spatial cognitive decline.

PP1-10 - Effect of thioperamide on vestibular compensation in rats with immunohistochemistry

2. Animal Models and Molecular Approach

Kazunori Matsuda¹

Tadashi Kitahara², Taeko Ito², Munehisa Fukushima³, Go Sato¹, Noriaki Takeda¹

¹ Department of Otolaryngology, University of Tokushima School of Medicine,Japan

² Department of Otolaryngology- Head and Neck Surgery, Nara Medical University,Japan

³ Department of Otolaryngology and Head and Neck Surgery, Osaka University Graduate School of Medicine, Japan

Purpose: Unilateral labyrinthectomy (UL) causes ocular and postural asymmetries, which disappear over time in the processes of equilibrium recovery known as vestibular compensation.

Vestibular compensation consists of two stages: the inhibition of the contralesional medial vestibular nucleus (contra-MVe) activities at the acute stage after unilateral labyrinthectomy (UL) and the recovery and maintenance of the ipsilesional MVe (ipsi-MVe) spontaneous activities at the chronic stage after UL.

Methods: In rats, the inhibitory N-methyl-D-aspartate (NMDA) receptor systems related to central vestibular system may play an important role for central processes of the vestibular compensation. Therefore, the expression of MK801(a specific antagonist of NMDA receptors )-induced Fos-like immunoreactive (-LIR) neurons in the contra-MVe after UL demonstrated the time course of vestibular compensation.

We evaluated the progression of vestibular compensation at two stages. The acute stage of vestibular compensation was evalutated with changes of spontaneous nystagmus frequency, the chronic stage of vestibular compensation was evalutated with temporal changes of MK801-induced Fos-LIR neurons in the contra-MVe after UL.

There have been no study directly demonstrating the influence of thioperamide, a pure antagonist of the H3 receptor, on vestibular compensation with immunohistochemistry.

Results: Neither SN frequency nor its rate of compensation were significantly different between Thioperamide-treated group and the control untreated group. In contrast, Thioperamide-treated group significantly decreased earlier the temporal changes of MK801-induced Fos-LIR neurons in the contra-MVe after UL compared with the control group.

Conclusions: In conclusion, Thioperamide improve the chronic stage of vestibular compensation in rats, not the acute stage.

PP1-11 - Evaluating an kinase inhibitor library for effects on hair cells using the zebrafish lateral line

2. Animal Models and Molecular Approach

Yoshinobu Hirose¹

Yousuke Takemoto¹, Kazuma Sugahara¹, Makoto Hashimoto¹, Hiroshi Yamashita¹

¹ Department of Otolaryngology, Yamaguchi University Graduate School of Medicine, Japan

Purpose: Zebrafish lateral line hair cells are physiologically and morphologically similar to inner ear hair cells. As the zebrafish lateral line is located on the body surface, damage to the hair cells can be rapidly assessed. Therefore, the zebrafish lateral line is an effective system for the evaluation of drugs that damage or protect hair cells. In this study, we examined the role of kinase in hair cells. A kinase phosphorylates a protein, have an important role for hair cell alive or death. We have screened a library of 18 kinase inhibitor-drugs that protected or damaged hair cells of the zebrafish lateral line.

Methods: 5 days post-fertilization zebrafish were used in this study. Larvae were exposed to kinase inhibitor (0.1-10 ug/ml) with or without neomycin (100 uM) to investigate hair cell protection and toxicity . Anti-parvalbumin was used as a primary antibody, hair cells were immunostained. Hair cells from the SO1, SO2, O1, and OC1 neuromasts were counted with a fluorescent microscope.

Results: One kinase inhibitor drug show toxity in hair cells. On the other hand, the screen successfully identified four protecting drugs against neomycin.

Conclusions: We examined the relevant of kinase and hair-cell death using the larvae of a zebrafish. Our date suggested that kinase were work as toxic and protective effect in hair cells.

PP1-12 - Extracellular matrix in vestibular compensation

2. Animal Models and Molecular Approach

Botond Gaál¹

Ágnes Magyar², Klára Matesz¹, Éva Rácz¹

¹ University of Debrecen, Dept. of Anatomy

² University of Debrecen, Dept. of Pediatric Surgery

Purpose: Impaired balance function evokes postural, oculomotor and autonomic deficits, which symptoms partly restore by vestibular compensation. The role of extracellular matrix (ECM) has been long suggested in such plastic modifications of a neural network. Our laboratory investigates the ECM environment in the brainstem vestibular nuclei (VN) of rats, mice and frogs both in physiological conditions, and during compensation after unilateral labyrinth lesion. We perform the damage of balance receptors mechanically, by microsurgical exposure of the labyrinth.

Methods: ECM in the mammalian CNS is composed of hyaluronan (HA), chondroitin sulfate proteoglycans (CSPG) and glycoproteins. This ternary complex accumulates as perineuronal net (PNN) surrounding perikaryons and neuronal processes, or is distributed diffusely. The PNNs stabilize synaptic contacts on the perikaryon and neuronal processes, but also influences restoration capacity of the vestibular system. In contrast with mammals, our results confirmed a HA based ECM in the amphibian VN.

Results: In frogs transection and reunion of the vestibular nerve was followed by an in-growth of nerves into VN and re-establishment of synaptic contacts, parallel with restoration of vestibular functions. In normal rats and mice unilateral damage of the inner ear initiated a radical but dynamic alteration of PNNs in the VN, which is temporally parallel with functional recovery, although no evidence proves considerable axonal re-growth.

Conclusions: These experiences suggest that a HA-rich but CSPG-free perineuronal environment facilitates a high degree of plasticity and regenerative potential in frogs, whereas in rodents the strong presence of CSPGs presumably is against plastic modifications of the vestibular network.

PP1-13 - Locomotor hyperactivity in bilateral vestibulopathic rats: a consequence of spatial disorientation?

2. Animal Models and Molecular Approach

Andreas Zwergal¹

Eva Eilles², Lisa Günther², Roswitha Beck², Magdalena Lindner², Marianne Dieterich¹, Thomas Brandt³

¹ Ludwig-Maximilians-University Munich, Department of Neurology, German Center for Vertigo and Balance Disorders (DSGZ)

² Ludwig-Maximilians-University Munich, German Center for Vertigo and Balance Disorders (DSGZ)

³ Ludwig-Maximilians-University Munich, Clinical Neurosciences, German Center for Vertigo and Balance Disorders (DSGZ)

Purpose: Comparative investigation of the locomotor behaviour in open and restricted space after bilateral labyrinthectomy in the rat.

Methods: Ten Sprague-Dawley rats underwent a bilateral labyrinthectomy (BL) by transtympanic injection of bupivacaine and arsenilate, 10 rats received a bilateral middle-ear injection of saline (sham) as a control group. Behavioural testing was performed 1 day before and at days 1, 2, 3, 7, 15, 30 and 60 after BL/sham injection as follows: 1) quantitative analysis of locomotor and spatial exploration behaviour in a square open field by the Noldus EthoVision System; 2) quantitative analysis of locomotion pattern in a straight corridor by the Noldus CatWalk System.

Results: In the open field, mean locomotor velocity was significantly higher in the BL than in the sham group until day 60. This was mostly due to different movement strategies in open space: rats of the sham group showed a strategically distributed exploration pattern with a preferred movement along the lateral edges at all time points. In contrast, rats of the BL group presented with a omnidirectional exploration strategy and stayed in the central parts of the open field significantly longer. A completely different locomotor behaviour was seen in restricted space: mean locomotor velocity during CatWalk measurement was lower at the initial time points and adapted consecutively between groups after day 15 post BL/sham injection.

Conclusions: Locomotor hyperactivity following a bilateral vestibular lesion seems to be a consequence of disorientation in open space. Locomotor velocity in restricted space adjusts completely to the level of controls indicating central compensation mechanisms.

PP1-14 - Macrophages in the Human Endolymphatic Sac - Molecular Expression and Interaction

2. Animal Models and Molecular Approach

Charlotta Kämpfe Nordström¹

Niklas Danckwardt-Lillieström¹, Wei Liu¹, Helge Rask-Andersen¹

¹ Uppsala University Hospital, Department of Surgical Sciences, Uppsala

Purpose: Several otologic disorders are thought to have an immunologic component. The endolymphatic sac (ES) is endowed with a multitude of white blood cells and may serve as an immunologic defense organ for the inner ear. Recently, the human ES, as well as the rest of the inner ear, were found to contain resident macrophages. To gain more information about their roles, we examined these cells using super resolution structured fluorescence microscopy (SR-SIM).

Methods: Human vestibular aqueducts were removed during trans-labyrinthine surgery for removal of acoustic neuroma. Tissues were placed in fixative, decalcified, and rapidly frozen and cryostat sectioned. Antibodies against IBA-1, fractalkine (CX3CL1) and the major histocompatibility type II (MHCII) were used.

Results: A larger number of IBA1-positive cells than expected were found to reside in the ES populating both the surrounding connective tissue and the epithelial lining. Several epithelial cells expressed IBA1 as well as the major histocompatibility complex II (MHCII). Evidence of macrophage diapedesis into the ES lumen was obtained. The chemokine CX3CL1 was richly expressed in the ES.

Conclusions: Macrophages constitute a large, interactive population of locomotive sub-epithelial, intra-luminal and fixed epithelial cells in the human ES. Molecular expression includes that of antigen-presenting cells important for initiating immune responses.

PP1-15 - Neural Correlates of Galvanic Vestibular Stimulation in the Alert and Behaving Macaque

2. Animal Models and Molecular Approach

Kathleen Cullen¹

Annie Kwan², Jean-Sébastien Blouin³, Patrick Forbes⁴

¹ Johns Hopkins University, Baltimore, USA

² McGill University, Montreal, Canada

³ University of British Columbia, Vancouver, Canada

⁴ Erasmus Medical Centre, Rotterdam, the Netherlands

Purpose: The vestibular influence on motor and perceptual responses can be manipulated in isolation by delivering electrical currents over the mastoid processes. This galvanic vestibular stimulation (GVS) evokes stereotypical ocular and postural responses as well as virtual sensations of motion that have been well described in humans. Exactly how this non-invasive tool activates the vestibular system, however, remains an open question.

Methods: To link neuronal and behavioural responses, we recorded eye movements and individual vestibular afferent activity while applying transmastoid GVS in alert macaques.

Results: We found that GVS predominately evoked torsional eye movements, similar to those reported in humans. Our single unit recordings revealed that canal and otolith afferents were similarly activated by GVS. Notably, afferents from both types of sensors displayed high-pass tuning, with irregular afferents showing greater response modulation. This differs markedly from their response to natural motion and overturns previous expectations that afferent response dynamics to GVS are invariant across stimulation frequency.

Conclusions: Taken together, these results reveal the neural correlates underlying GVS-evoked perceptual, ocular and postural responses – a fundamental step into understanding the representation and use of such information in the brain that is critical to advance the applicability of GVS for biomedical uses in humans.

PP1-16 - Photobiomodulation for peripheral vestibular dysfunction induced by aminoglycoside in animal model

2. Animal Models and Molecular Approach

Jung Hyun Ahn¹

Jae Yun Jung¹, Ji Eun Choi¹, Min Young Lee¹

¹ Department of Otorhinolaryngology, Hean and Neck Surgery, Dankook University Hospital

Purpose: Vertigo is related to the dysfunction of peripheral vestibular system and no specific medical treatment is available to cure the symptom. Gentamicin is known vestibular toxic agent, various degree of balance problem is observed after exposure to this pharmacologic agent. Photobiomodulation using low level laser is widely adopted in medical field, and due to its ability to reach deeply locating organs inner ear is one of the candidate target. But not much studies have shown the effect of photobiomodulation on balance function.

Methods: We used rat model to resemble the human vestibulopathy condition using Gentamicin and evaluated the effect of photobiomodulation on this vestibular toxicity. Both functional and histologic evaluation were aimed to assess the cupula of lateral semicircular canal. Slow Harmonic Acceleration (SHA) rotating chair testing was used for functional evaluation and both qualitative and quantitative epifluorescence analysis of cupula histology was performed. Animals were divided into laser group and Gentamicin only group. Laser was applied in unilateral ear, and function and histology was evaluated in both ear.

Results: After Gentamicin treatment, decrease of function of both ear was observed, showing low gain and no asymmetry. With laser treatment to unilateral ear, this reduction was minimized showing increased gain in laser treated ear and showing asymmetry of right and left ear function. Histological results corresponded to the functional results showing increased density of hair cell and epifluorescence intensity in laser applied cupula.

Conclusions: Promising outcome was observed showing increased vestibular function after photobiomodulation and this could be alternative approach for vestibulopathy.

PP1-17 - Tissue optical clearing of the mouse temporal bone for downstream applications

2. Animal Models and Molecular Approach

Tomoko Makishima¹

Rebecca Cook¹, Lorenzo Ochoa², Gracie Vargas²

¹ University of Texas Medical Branch, Department of Otolaryngology, U.S.A.

² University of Texas Medical Branch, Department of Neuroscience, Cell Biology and Anatomy, U.S.A.

Purpose: The mouse inner ear histological analysis is challenging due to its membranous structures encapsulated within a small, hard, boney shell, the temporal bone. Tissue optical clearing techniques enable whole organs to be studied without tedious fine dissection. While different organs have been successfully cleared, the temporal bone is one of the more difficult organs to manipulate. Tissue optical clearing needs to be combined with suitable labeling methods in order to be used in downstream studies. Our goal was to establish methods suitable for mouse temporal bone 3D reconstruction using tissue optical clearing methods suitable for single-cell histological analysis.

Methods: Whole temporal bones of C57BL6J, Casp3 knockout and transgenic Cib2 mice were fixed, decalcified, labeled and optically cleared. We modified clearing protocols/reagents, SeeDB and Sca/eS, to be suitable for the mouse temporal bone. Imaging was obtained using Zeiss Lightsheet Z.1 lightsheet microscope, two-photon microscope, or light microscope, and 3D reconstruction was obtained using Imaris, Arivis or Fiji software. We used the 3D reconstructed images to determine the spatial planar orientation of the utricle and saccule as an example of a downstream application.

Results: We successfully cleared and 3D reconstructed the mouse temporal bone. We determined the planar orientation of the utricle and the saccule to be approximately 53 ± 8 degrees.

Conclusions: Many labeling methods can be successfully used in combination with tissue clearing, imaging and 3D reconstruction in the mouse temporal bone. We hope to use the whole temporal bone optical clearing in combination with vestibular functional studies.

PP1-18 - Selective otolith organ dysfunction in patients with non-spinning vertigo

3. Autonomic Function and Vestibular Disorders

Bin Luo¹

Jingwu Sun¹, Zhu Zhao¹, Ruirui Guan¹

¹ Anhui Provincial Hospital, The First Affiliated Hospital of University of Science and Technology of China, Department of Otolaryngology Head and Neck Surgery, China

Purpose: To elucidate the correlation of non-spinning vertigo symptom with the otolith organ dysfunction in patients with sudden deafness.

Methods: We reviewed the clinical records of 86 patients with sudden deafness and divided them into three groups according to the symptom of vertigo: sudden deafness without vertigo group (n = 36), sudden deafness with non-spinning vertigo group (n = 18) and sudden deafness with spinning vertigo group (n = 32). All the patients underwent testing of cervical and ocular vestibular evoked myogenic potentials (cVEMPs and oVEMPs), caloric testing and video head impulse testing (vHIT).

Results: The abnormal rates of VEMPs (either cVEMPs or oVEMPs or both), vHIT and caloric testing were 36.1%, 19.4%, 38.9% in the sudden deafness without vertigo group, 83.3%, 11.1%, 11.1% in the sudden deafness with non-spinning vertigo group and 75%, 68.8%, 78.1% in the sudden deafness with spinning vertigo group.

Conclusions: The symptom of non-spinning vertigo can be caused by selective otolith organ dysfunction.

PP1-19 - The effect of distraction on motion sickness

3. Autonomic Function and Vestibular Disorders

Art Mallinson¹

Gilles Bosser², Lillian Wong³, Gaelle Quarck⁴, Philippe Perrin⁵

¹ University of British Columbia, Department of Surgery; Vancouver General Hospital, Vancouver, CANADA

² University Hospital, Department of Pediatric Cardiology, Nancy FRANCE

³ University of British Columbia, Department of Surgery; Vancouver, CANADA

⁴ Normandie University, Department of Chronobiologie, Caen, FRANCE

⁵ University Hospital of Nancy, Department of Pediatric Otolaryngology, -Nancy, FRANCE.

Purpose: Motion sickness (MS) can affects children, sailors, rally car drivers, fishermen and astronauts. Motion sickness is of vestibular origin, likely otolithic and newly developed symptoms suggest an abnormality in the structures.

Traditional theories about motion sickness have suggested a “sensory conflict”. Reading a book or an electronic reader in a car will increase the conflict and invoke the related symptoms. However some anecdotal observations by us have revealed that engaging in interactive video games in a car can actually serve to reduce these symptoms.

Methods: We developed a questionnaire for children in English and in French for normal children and their parents to ask them about their habits in the car. This included activities in a car, and also the structure of the vehicle they are in, the type of travel undertaken and the length of trip.

Results: Our long term study has shown that there are many different aspects of vehicle travel that can affect motion sickness, there are certain controllable factors that can alleviate those symptoms.

Conclusions: Although this study was carried out in normal children engaged in daily vehicle travel, we feel the information can be translated into a further understanding of motion sickness in other activities, such as rally car driving or deep-sea fishing, as well as in the patient with vestibular pathology complaining of newly developed motion sickness. All of these situations are a set of symptoms arising from the balance system.

PP1-20 - Efficacy of the Gufoni maneuver for treating the horizontal canal BPPV

4. Benign Paroxysmal Position Vertigo

Yasuo Ogawa¹

Takashi Iwasawa¹, Koji Otsuka², Taro Inagaki², Noriko Nagai², Mamoru Suzuki²

¹ Tokyo Medical University Hachioji Medical Center, otorhinolaryngology, Japan

² Tokyo Medical University, otorhinolaryngology, Japan

Purpose: To investigate the therapeutic efficacies of Gufoni maneuver in geotropic and apogeotropic type of the horizontal canal variant of benign paroxysmal positional vertigo (HC-BPPV),

Methods: Twenty five patients (19 women and 6 men, age range: 14-88 years, mean age 66.9 years) with HC-BPPV were included in this study. All patients had bi-directional-changing positional nystagmus, 13 patients with geotropic type and 12 with apogeotropic type. We underwent Gufoni maneuver immediately after diagnosis. We evaluated the number of days to resolution of nystagmus and symptom.

Results: After the first session of Gufoni maneuver, 2 patients with geotropic type nystagmus switched to apogeotropic type and 7 patients with apogeotropic type switched to geotropic type. The number of resolution days of geotropic type were 4-42days (average 11.4days), on the other hand, the number of resolution days of apogeotropic type were 11-183 days (average 70.3 days).

Conclusions: In geotropic type, patients with no switch to apogeotropic type were easy to resolution. In apogeotropic type, the patients who switch to geotropic type were easy to resolution; on the other hand, patients with no switch to geotropic type took long time to resolution. Although there are intractable cases, Gufoni maneuver is worth to perform.

PP1-21 - 25 (OH) D3 levels, incidence and recurrence of different clinical forms of BPPV

4. Benign Paroxysmal Position Vertigo

Anamarija Sestak¹

Sinisa Maslovara²

¹ Department of Otolaryngology, County General and Veterans Hospital, Vukovar, Croatia

² Department of Otorhinolaryngology and Maxillofacial Surgery, Medical Faculty, University of Osijek, J. Huttlera 4, Osijek 31 000, Croatia

Purpose: The aim of this study was to measure the serum levels of 25-hydroxyvitamin D3 (25-OH D3) in patients with BPPV and determine whether there is a difference in the serum levels of vitamin D3 between patients with and without recurrence, as well as between the different clinical forms of BPPV.

Methods: The study included 40 patients diagnosed with PC-BPPV based on the positive Dix-Hallpike’s test. All patients underwent Epley manoeuvre after the diagnosis. Patients were classified according to current guidelines for levels of vitamin D3 in the serum in three groups: the deficiency, insufficiency and adequate level.

Results: The average serum level of 25-OH D3 among respondents was 20.78 ng/mL, indicating a lack or insufficiency of the aforementioned 25-OH D3. According to the levels of 25-OH D3, most patients suffer from deficiency (47.5%). 7 (17.5%) respondents had adequate blood level of 25-OH D3, and 14 (35%) respondents suffer from insufficiency. A significant difference was not found in the serum level of 25-OH D3 between patients with and without BPPV recurrence. There was a significant difference in the serum levels of 25-OH D3 in comparison to the clinical form of the disease. Lower 25-OH D3 values were found in patients with canalithiasis compared to those with cupulolithiasis.

Conclusions: Given that the largest number of patients has decreased values of 25-OH D3, it is recommended that all patients diagnosed with BPPV have 25-OH D3 levels measured and in the event of reduced values implemented adequate replacement therapy.

PP1-22 - Accuracy of Questionnaire-Based Diagnosis of Benign Paroxysmal Positional Vertigo

4. Benign Paroxysmal Position Vertigo

Hyo-Jung Kim¹

Jin-Ok Lee², Jeong-Mi Song², Seo Won Oh², Ji-Soo Kim²

¹ Research Administration Team, Seoul National University Bundang Hospital, Seongnam, Korea.

² Dizziness Center, Seoul National University Bundang Hospital, Seongnam, Korea

Purpose: To develop an algorithm for self-diagnosis of benign paroxysmal positional vertigo (BPPV) using a simple questionnaire that is feasible for self-administration of an appropriate canalith repositioning procedure (CRP) when BPPV recurs.

Methods: We developed a questionnaire that is consisted of six questions, the first three to diagnose BPPV and the following three to determine the involved canal and type of BPPV. From 2016 to 2017, 578 patients with dizziness completed the questionnaire before the positional tests using a video-oculography at the outpatient Dizziness Clinic of Seoul National University Bundang Hospital.

Results: Of the 578 patients, 200 were screened to have BPPV and 378 were decided to have dizziness/vertigo due to disorders other than BPPV based on the results of questionnaire. The sensitivity and specificity of the questionnaire for diagnosis of BPPV were 87% and 90% respectively. Of the 200 patients with a questionnaire-based diagnosis of BPPV, 30 failed to respond the Q4-6 to determine the involved canal and type of BPPV. The questionnaire and positional tests showed the same results on the subtype and affected side of BPPV in 121 patients (60.5%). Cohen’s Kappa indicates a substantial agreement (Kappa index =0.673) between the questionnaire and positional tests. Overall, the questionnaire could identify the affected canal and type accurately in 121 (65%) of the 185 patients with confirmed BPPV on positional tests.

Conclusions: The accuracy of questionnaire-based diagnosis of BPPV is acceptable, and self-treatment of BPPV may be first attempted by adopting an appropriate CRP based on the results of questionnaire.

PP1-23 - Apogeotropic variant of posterior semicircular canal benign paroxysmal positional vertigo

4. Benign Paroxysmal Position Vertigo

Giacinto Asprella Libonati¹

Rudi Pecci²

¹ Giovanni Paolo II Hospital, Unit of Vestibology and Otorhinolaryngology, Policoro (MT), Italy Viale Salerno, 75025 Policoro (MT) Italy

² Azienda Ospedaliero-Universitaria Careggi, Neuromusculoskeletal and Sensory Organs Department, Unit of Audiology, Florence, Italy

Purpose: The aim of this study is to verify that debris could sometimes localize into PSC close to the common crus, thus configuring the apogeotropic PSC-BPPV, characterized by torsional down beating-paroxysmal positional nystagmus (TDB-PPN) in Dix-Hallpike position, and to allow the differential diagnosis from Anterior Semicircular Canal (ASC) BPPV, characterized by the same nystagmus direction.

Methods: From January to August 2014 we selected 28 patients complaining of positional vertigo with TDB-PPN in Dix-Hallpike position. All of them were submitted to specific physical therapies aimed to cure apogeotropic PSC-BPPV: in 23 patients we used a liberatory manoeuvre, in 5 patients we used a forced prolonged position. All patients were checked within three days.

Results: The liberatory manoeuvre was effective in 20 out of 23 patients: 13 patients completely recovered and 7 showed a typical PSC-BPPV torsional up-beating paroxysmal positional nystagmus (TUB-PPN). The forced prolonged position had a positive outcome in 3 of 5 patients: one patient was symptoms and signs free and 2 had a typical TUB-PPN.

Conclusions: The described therapeutic techniques were successful in 82.1% of cases, either recovering the apogeotropic PSC-BPPV or transforming it in a typical PSC-BPPV form. Our study confirms both ASC BPPV and apogeotropic PSC-BPPV can manifest with identical TDB-PPN. The TDB-PPN recovery or its transformation into typical PSC-BPPV with TUB-PPN, allow us to distinguish ASC-BPPV from PSC-BPPV apogeotropic variant.

PP1-24 - Asking about dizziness when turning in bed predicts benign paroxysmal positional vertigo

4. Benign Paroxysmal Position Vertigo

Ellen Lindell¹

Caterina Finizia¹, Mia Johansson², Therese Karlsson¹, Jerker Nilson³, Måns Magnusson⁴

¹ Sahlgrenska University hospital, Department of Otolaryngology, Head and Neck Surgery, Gothenburg, Sweden

² Sahlgrenska University hospital, Department of oncology, Gothenburg, Sweden

³ Södra Älvsborgs Hospital, Borås, Sweden

⁴ Lunds University, Department of Otorhinolaryngology Head and Neck surgery, Clinical Sciences, Lund, Sweden

Purpose: This study aims to assess useful questions when suspecting benign paroxysmal positional vertigo (BPPV) caused dizziness as well as identifying if a single question can usefully identify or distinguish patients with BPPV from other dizziness aetiology.

Methods: A total of 149 patients were included in the study. Patients admitted to the Ear, Nose and Throat department due to complaints of dizziness or vertigo were included. The patients answered a study-specific questionnaire and were investigated with Dix-Hallpike manoeuvre and the supine roll test. The diagnosis of BPPV was set following a positive Dix-Hallpike manoeuvre or supine roll test including presence of canal specific nystagmus.

Results: Two of the 17 questions were of diagnostic importance. Dizziness when laying down or turning over in bed, increased the likelihood of a BPPV diagnosis by an odds ratio (95% CI) of 60 (7.47-481.70) and identified patients with a clinical diagnosis of BPPV at 98% sensitivity and 60% specificity. Continuous dizziness duration as opposed to lasting seconds decreased the likelihood of BPPV with an odds ratio of 0.06 (0.01-0.27).

Conclusions: Dizziness when turning in bed is highly correlated to BPPV. A negative response to the question of dizziness in bed was 98% accurate in ruling out BPPV in a sample with a 39% prevalence. Vertiginous attacks when turning or laying down in bed together with dizziness < 1 minute, are important questions when taking a medical history and may help to early identify BPPV, also for non-medical staff, as well as reduce the need of further investigations.

PP1-25 - Canalith jam of the horizontal canal masquerading as acute vestibular loss: role of the video-HIT

4. Benign Paroxysmal Position Vertigo

Andrea Castellucci 1,2¹

Pasquale Malara 3², Cristina Brandolini 1³, Valeria Del Vecchio 1³, Giovanni Carlo Modugno 1³, Angelo Ghidini⁴, Antonio Pirodda 1³

¹ 1. ENT & Audiology Unit, DIMES, Sant’Orsola – Malpighi University Hospital, Bologna, Italy. 2. ENT Unit, Department of Surgery, AUSL – IRCCS, Reggio Emilia, Italy.

² 3. ENT Unit, Audiology & Vestibology Service, Centromedico, Bellinzona, Switzerland.

³ 1. ENT & Audiology Unit, DIMES, Sant’Orsola – Malpighi University Hospital, Bologna, Italy.

⁴ 2. ENT Unit, Department of Surgery, AUSL – IRCCS, Reggio Emilia, Italy.

Purpose: The differential diagnosis in case of spontaneous horizontal nystagmus (SHN) can be challenging. Thanks to the introduction of the video head impulse test (vHIT), peripheral SHN can be easily differentiated from SHN of central origin. Moreover, diagnosis of selective, partial or total loss of vestibular sensors/afferents can be made by matching vHIT data with cervical- and ocular-VEMPs results. We present a case of SHN where vHIT allowed to hypothesize a spontaneous plug due to a canalith jam as possible underlying mechanism.

Methods: A 74-year old woman presented with a history of acute vertigo, left-beating SHN and a clinical picture consistent with right peripheral acute vestibular loss. Bithermal caloric test (BCT) revealed a severe right unilateral weakness (90%). Nevertheless, both cervical- and ocular-VEMPs were symmetrical and vHIT revealed an isolated hypofunction of the right horizontal canal (RHC).

Results: After repeated head-roll maneuvers, bilateral positional paroxysmal geotropic horizontal nystagmus was evoked by Pagnini-McClure maneuvers suggesting BPPV involving the non-ampullated arm of the RHC. Restitution of RHC function after repositioning maneuvers was confirmed by vHIT and BCT. A spontaneous canalith jam affecting the RHC, leading to an isolated and transitory canal pseudo-areflexia, could be likely responsible for the presenting signs.

Conclusions: An extensive assessment of vestibular sensors and afferents should always be given in case of SHN. A canalith jam should be considered in case of selective canal dysfunction on vHIT. Similarly, canalith jam of vertical canals could likely account for selective and transient canal dysfunctions leading to spontaneous torsional nystagmus, generally considered of central origin.

PP1-26 - Characteristics of the Recurrence of Idiopathic Benign Paroxysmal Positional Vertigo

4. Benign Paroxysmal Position Vertigo

Yongsheng Tian¹

¹ Department of Otolaryngology Head and Neck Surgery, Aerospace Center Hospital, Beijing, China

Purpose: To investigate the clinical features of the recurrence of idiopathic benign paroxysmal positional vertigo (IBPPV) patients. MethodsPatients with IBPPV were enrolled and were followed-up for 36 months after being well controlled. The data of the patients including age, gender, and co-morbidities (hypertension, diabetes, hyperlipidemia,) were analyzed. Characteristics of the recurrent BPPV were compared with those of the former onset.

Methods: Patients with IBPPV were enrolled and were followed-up for 36 months after being well controlled. The data of the patients including age, gender, and co-morbidities (hypertension, diabetes, hyperlipidemia,) were analyzed. Characteristics of the recurrent BPPV were compared with those of the former onset.

Results: Two hundred and one patients were enrolled in study and twenty two (10.5%) patients presented recurrent IBPPV within 36 months. Among them, about 16% showed changes in the involved semicircular canals. 50% recurrence occurred within 6 months after the first treatment. The recurrence rate of BPPV in 5060 years old patients(50%) is higher than other patients (P =0.018). Both the gender, and co-morbidities (hypertension, diabetes, hyperlipidemia) showed no significant difference between the two groups.

Conclusions: The incidence of recurrence in idiopathic BPPV patients was 10.5% in the present study. The mean period of 50% recurrence after a symptom-free interval was about 6 months. Furthermore, about 50% of patients suffered from recurrence of idiopathic BPPV at a different type of canal from the semicircular canal of the initial idiopathic BPPV attack. Age but not gender or co-morbiditie might be correlated with BPPV recurrence.

PP1-27 - Characteristics and recurrent risks of Benign Paroxysmal Positional Vertigo in young and elder group

4. Benign Paroxysmal Position Vertigo

Cuiting Zhu¹

Ju Yi¹, Xing quan zhao¹, Wang Yan², Meimei Chen², Cui Yu²

¹ Beijing Tian Tan Hospital, Capital Medical University, Vascular Neurology Center Department of Neurology, Beijing

² Beijing Tian Tan Hospital, Capital Medical University, Department of Neural Electrophysiology, Beijing

Purpose: To investigate the characteristics and recurrent risk of the Benign Paroxysmal Positional Vertigo (BPPV) in young and elder patients.

Methods: A total of 354 patients with BPPV treated and completed follow-up in our clinic between January 2010 to June 2015were enrolled,including 127 patients aging from 18 to 45 years old (young group) and 227 patients more than 60 years old (elder group). The characteristics and recurrent risks of BPPV in young and elder patients were evaluated.

Results: There were 58 males and 69 females in young group, and 81 males and 146 females in elder patients, with no significant difference in gender between two groups (P=0.065). There were no significant difference in the frequency of cases with Meniere’s disease, sudden hearing loss, migraine, head trauma, and history surgery (P0.05).But the prevalence of hypertension, hyperlipemia, diabetes, coronary heart disease, arterial plaque and cerebral infraction in elder group was higher than in young group (P0.05). The recurrent rate of BPPV one month after repositioning maneuvers was 16.5% in young group and 29.1% in elder group, with significant difference (P=0.0090.05). Meniere’s disease and hypertension are independent risk factors of the recurrence of BPPV in elder group.The recurrence of the elder than 60 year-old BPPV group combining with 0,1,≥2 cerebrovascular disease risk factors respectively is 7.5%,10.7%, 47.4%.

Conclusions: The prevalence of hypertension, hyperlipemia, diabetes, coronary heart disease, arterial plaque and cerebral infraction in elder group was higher than in young group. Meniere’s disease and hypertension are independent risk factors for the recurrence of BPPV in elder group.

PP1-28 - Characteristics of Benign Positional Vertigo Tested on the Epley Omniax Chair

4. Benign Paroxysmal Position Vertigo

Emma Argaet¹

Corinna Lechner¹, Andrew Bradshaw¹,

Benjamin Nham¹, G. Michael Halmagyi¹, Miriam S. Welgampola¹

¹ University of Sydney Australia

Purpose: To describe the spatiotemporal characteristics of BPV and its variants.

Methods: We studied 2559 consecutive patients referred to a neuro otology clinic dedicated to the management of BPV. Patients were tested on the Epley Omniax Rotator, a positioning device which allows alignment of the patient in the plane of any given canal and simultaneously display and records video oculography. Video data was extracted and analysed offline using a custom written LabVIEW programme. Nystagmus onset, duration and slow phase velocities were analysed.

Results: BPV was diagnosed in 1207 subjects: 814 had unilateral posterior-canalithiasis while 167 had bilateral posterior-canal involvement and 72 patients had more than 2 canals affected; 96 patients had horizontal-canal BPV. In 11 patients anterior-canal BPV was found. In PC BPV, nystagmus onset occurred before 1second in 73% subjects. Nystagmus duration was 13.4 sec (median). The median peak-SPV was 32.4/sec. In horizontal-canalithiasis with the affected ear down, nystagmus onset was <1s in nearly all subjects. Nystagmus lasted for 22.5 sec (median) and peaked at 56.8/sec(median). When the unaffected ear was lowermost the nystagmus duration was similar 25 s (median) and peak-SPV 18.1/sec. In all subjects with canalithiasis, the time taken for the peak-SPV to halve (T50) was <60s. In contrast, subjects diagnosed with vestibular migraine (n=334) had persistant vertical or horizontal positional nystagmus with a T50 that exceeded 60s.

Conclusions: Canalithiasis uniformly demonstrated a crescendo decrescendo SPV profile. Symptomatic horizontal or vertical positional nystagmus recorded in canalithiasis could be separated from horizontal positional nystagmus recorded in vestibular migraine.

PP1-29 - Clinical analysis of benign paroxysmal positional vertigo with multiple canal involvement

4. Benign Paroxysmal Position Vertigo

Bo Shen¹

Xu Yang¹

¹ Department of Neurology, Aerospace Center Hospital, Peking University Aerospace School of Clinical Medicine, Beijing, China.

Purpose: To investigate the clinical features, diagnosis and treatment of multi-canal benign paroxysmal positional vertigo (BPPV).

Methods: 41 patients with multi-canal BPPV who received treatment between January 2015 and December 2017 were included in this study. All included patients were diagnosed according to the nystagmus as confirmed by videonystagmograph during the Dix-Hallpike, straight head hanging and Roll tests and treated according to the involvement of canal (Epley’s maneuver for the posterior canal, Yacovino maneuver for the anterior canal, Barbecue or Gufoni maneuver for the lateral canal).

Results: Among 267 patients with BPPV, 41 (15.4%) developed multi-canal BPPV. These 41 patients consisted of 15 (36.6%) males and 26 (63.4%) females, with an average age of 64.24 ±13.93. Seventeen patients (41.5%) had up-beating nystagmus with torsional components and horizontal nystagmus, suggesting BPPV involving both posterior and lateral canals. Eleven patients (26.8%) had up-beating nystagmus with torsional components and down-beating nystagmus with or without torsional components, suggesting BPPV involving both posterior and anterior canals. Eleven patients (26.8%) had down-beating nystagmus with or without torsional components and horizontal nystagmus, suggesting BPPV involving both anterior and lateral canals. Two patients (4.9%) had bilateral up-beating nystagmus with torsional components, suggesting BPPV involving bilateral posterior canals. Thirty-one (75.6%) of the patients were cured after one or two maneuvers. Thirty-seven patients (90.2%) were cured with an average of 2.1 therapeutic sessions per patient.

Conclusions: Multi-canal BPPV is not so rare, and the posterior and horizontal canals are involved in most cases. Repositioning maneuver is effective for multi-canal BPPV.

PP1-30 - Clinical characteristic and risk factor of canal conversion in benign paroxysmal positional vertigo

4. Benign Paroxysmal Position Vertigo

Geonho Lee¹

Jin-woong Choi¹

¹ Chungnam national university hospital, department of otorhinolaryngology, South Korea

Purpose: The purposes of this study were to investigate the incidence of canal conversion in benign paroxysmal positional vertigo (BPPV) and to analyze the risk factors and clinical features of the canal conversion.

Methods: We retrospectively reviewed medical chart in 2450 patients diagnosed with BPPV from March 2012 to December 2017. The following parameters were analyzed in patients with (canal conversion group) and without canal conversion (non-canal conversion group) after canalith repositioning procedure (CRP) for treatment: demographics including age and sex, etiology, side and type of semicircular canal involved, and type and number of CRP.

Results: Canal conversion occurred in 56 of total 2450 patients (2.3%). Demographic, etiology, and side of semicircular canal involved did not differ between the two groups. However, canal conversion occurred more commonly in the lateral semicircular canal (LC) than in the posterior semicircular canal, (PC) which was statistically significant (P = 0.003). There were no significant differences in those parameters in patients with and without canal conversion in the PC. In the LC, the parameters did not differ according to the presence of canal conversion. Furthermore, there was no difference in those parameters when analyzed by type of conversion.

Conclusions: There is no difference in the outcome of treatment, such as the number of CRP in patients with or without canal conversion, but canal conversion can occur in approximately 2.3% of BPPV patients. Moreover, the canal conversion is more common in LC than in PC, so the possibility of canal conversion should be considered in treating BPPV in LC.

PP1-31 - Demographics of patients with BPPV and treatment efficacy in the Singapore population

4. Benign Paroxysmal Position Vertigo

Lee Huan Tee¹

Eu Chin Ho¹

¹ Tan Tock Seng Hospital

Purpose: BPPV is one the commonest vestibular conditions. This study aims to investigate the demographics of BPPV patients and treatment efficacy for patients with BPPV by physiotherapists in Singapore.

Methods: 536 patients with BPPV referred for vestibular rehabilitation from 2004 to 2015 were retrospectively analysed. Patients were assessed with Dix Hallpike Test and Supine Roll Test (Pagnini-McClure) for vertical and horizontal canals BPPV respectively, and treated with appropriate repositioning maneuvers by three vestibular rehab-trained physiotherapists. Maneuvers were repeated, if vertigo and nystagmus persisted upon re-evaluation of tests until patients were asymptomatic or unable to tolerate further maneuvers. Successful treatment was determined by resolution of symptoms following re-evaluation of tests 1-2 weeks post treatment. The Dizziness Handicap Inventory (DHI) was also administered to evaluate the self-perceived handicap effects of dizziness pre and post treatment.

Results: The mean age onset of BPPV is 57 years. Females:male ratio = 2:1. 97% of patients have Canalithiasis is the most common type of BPPV (97%). Canal type was posterior (71%), horizontal (12%), anterior (6.5%) and indeterminate (9.7%).

The success rate of the repositioning techniques is 71% within 2 maneuvers within a single treatment session. 98% of all patients are symptom free after repositioning within 3 physiotherapy sessions. Compared to pre-treatment, there was a significant improvement in self-reported DHI scores post-treatment. (p = 0.000, p <0.05).

Conclusions: The demographics and treatment effectiveness of patients with BPPV for the Singapore population is high and comparable with other populations.

PP1-32 - Diagnosis and Treatment of Anterior Canal Benign Paroxysmal Positional Vertigo

4. Benign Paroxysmal Position Vertigo

Xia Ling¹

Xu Yang¹

¹ Department of Neurology, Aerospace Center Hospital, Peking University Aerospace School of Clinical Medicine, Beijing, China.

Purpose: To investigate the diagnosis and treatment of anterior canal benign paroxysmal positional vertigo (AC-BPPV).

Methods: Forty patients (14 males and 26 female) diagnosed with AC-BPPV were enrolled. All patients were diagnosed based on the presence of nystagmus during the Dix-Hallpike (D-H), straight head hanging (SHH) and Roll tests and were treated by Yacovino maneuver.

Results: In the D-H test, down-beating nystagmus (DBN), and DBN with torsional components were observed in 22 and 18 patients, respectively. In the SHH, DBN, and DBN with torsional components were observed in 37 and 3 patients, respectively. The type of nystagmus evoked through D-H and SHH tests was statistically different (P<0.05).The right and left sides AC-BPPV were 17 (42.5%) and12 (30%), and 11 patients (27.5%) were not clear the affected side.11 patients had combined the posterior canal BPPV, and 11 patients had combined horizontal canal BPPV. 39 patients (1 patient were treated before and recovered) were treated by Yacovino maneuver. 34 patients (87.1%) were cured after treatment for an average 1.8 times. Diagnosis method: 17 patients were diagnosed by the effectiveness of treatment, 20 patients were diagnosed by the combination of other canal typical BPPV, and 3 patients were diagnosed by the canal conversion during follow-up.

Conclusions: D-H often evoke DBN with torsional component, and is more beneficial to identify the affected side of AC-BPPV compared with the SHH. The effectiveness of Yacovino maneuver, the presence of typical BPPV, canal conversion phenomenon and follow-up outcomes contribute to the diagnosis of AC-BPPV. Yacovino maneuver was effective in AC-BPPV patients.

PP1-33 - Effect of Intratympanic Steroid Injection in Light Cupula

4. Benign Paroxysmal Position Vertigo

Jin Su Park¹

Min-Beom Kim²

¹ Department of Otorhinolaryngology-Head and Neck Surgery, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine

² Department of Otorhinolaryngology-Head and Neck Surgery, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea

Purpose: To evaluate the effects of intratympanic steroid injection in light cupula.

Methods: 47 patients with persistent geotropic direction changing positional nystagmus with null point (light cupula) participated in this study. All study populations were randomly classified into three groups on initial visit day: the intratympanic steroid injection (ITS, n=15) group, Vestibular supressant (VS, n=16) group (treated with a vestibular suppressant [dimenhydrinate 50 mg per day for 1 week]) and canalith repositioning procedures (CRP, n=16) group. Positional nystagmus, dizziness handicap inventory (DHI) questionnaires and dizziness severity by visual analogue scale (VAS) were completed before and after each treatment.

Results: The DHI score before treatment in ITS, CRP and VS groups were 35.8, 34.06, and 34.75, respectively. At 1 week after the 1^st treatment, the score had statistically significantly decreased in all groups. But, there were no differences among three groups. At 1 week after the 1^st treatment, patients who showed resolution of persistent geotropic DCPN in ITS, CRP and VS groups were 7, 6 and 7, respectively. There were no significant differences between three groups. In ITS group only, however, reversal of stronger side on head roll test after each treatment was observed in 6 patients, and 2 out of 6 patients showed early resolution of DCPN at 3^rd day.

Conclusions: ITS was not significantly effective for the light cupula at 1 week follow up. But, some patients of ITS group showed reversal of stronger side in DCPN on head roll test and resolution of DCPN at earlier follow up.

PP1-34 - Efficacy of Gufoni maneuver and head-shaking for treating apogeotropic horizontal BPPV

4. Benign Paroxysmal Position Vertigo

Liying Chang¹

¹ Xiangyang Central Hospital, Affiliated Hospital Of Hubei University of Arts and Science. Xiangyang, Hubei province, China. 441021

Purpose: To evaluate the efficacy of Gufoni maneuver and Head-shaking for treating apogeotropic horizontal benign paroxysmal positional vertigoHC-BPPV, a randomized, prospective study was conducted.

Methods: A total of 84 patients from October 2014 to October 2017 with apogeotropic HC-BPPV in the Dizziness Clinic in Xiangyang Center Hospital were randomly assigned to group AGufoni maneuver,n=29), group B (Head-shaking, n=28 and group C(Brandt-Daroff exercisen=27). These manuevers were performed once a day until the treatment success. Successful treatment was defined as disappearance of positional nystagmus or as transition into geotropic horizontal nystagmus.The efficacy were evaluated at the 1st hour, 3rd day and 1st week after treatment.

Results: The 1st hour after treatment, the successful cases of group A, B and C were respectively 15/29,15/28 and 7/27. The efficacy in group AP=0.048and group BP=0.036is better than that in group C, but there was no difference between group A and group B (P=0.889) .On the 3rd day, the success rate of group A,B and C were respectively 82.76%, 85.71% and 62.96%, the therapeutic effect between group A and B P=0.760A and CP=0.095B and CP=0.053 had no significant difference.One week after treatment, the success rate of group A, B and C were respectively 93.10%, 92.86% and 77.78%, the therapeutic effect between group A and B (P=0.971)A and C(P=0.101), B and C(P=0.113) had no difference.

Conclusions: Both Gufoni maneuver and Head-shaking are effective treatment for apogeotropic HC-BPPV and they are better than B-D exercise at immediate (1 hour) effect. However, there is no difference between the three methods on the 3rd day and 1st week after treatment.

PP1-35 - Frequency tuning of ocular vestibular evoked myogenic potential in BPPV

4. Benign Paroxysmal Position Vertigo

Yongsheng Tian¹

Zufei Li¹, Rong Ma¹

¹ Department of Otolaryngology Head and Neck Surgery, Aerospace Center Hospital, Beijing 100049, China

Purpose: The aim of this study was to investigate changes in the frequency tuning of the ocular vestibular evoked myogenic potential (oVEMP) in patients with idiopathic benign paroxysmal positional vertigo (IBPPV).

Methods: A total of 103 consecutively consenting patients with IBPPV were included in the study: 42 patients with horizontal semicircular canal IBPPV and 61 patients with posterior semicircular canal IBPPV. As normal controls, 30 age-matched healthy patients were enrolled in the study. The oVEMP were recorded using air-conducted tone bursts at 500 Hz and 1000 Hz, and the 500/1000 Hz amplitude ratio of oVEMP was determined.

Results: The 500/1000 Hz amplitude ratio of the N1-P1 wave complex of the oVEMP in the affected ears was significantly lower than that of the unaffected ears and normal control ears. The unaffected ears of the IBPPV subjects also showed a lower amplitude ratio compared to that of the healthy controls, but the difference was not statistically significant. No significant differences in the 500/1000 Hz amplitude ratio of the oVEMP were found between the Horizontal Canal IBPPV and Posterior Canal IBPPV patients.

Conclusions: IBPPV can affect the frequency tuning of ocular vestibular evoked myogenic potential and decrease the sensitivity of low-frequency sound signals in the utricular otolith organs.

PP1-36 - Idiopathic benign paroxysmal positional vertigo in the elderly: A long-term follow-up study

4. Benign Paroxysmal Position Vertigo

Seong-Ki Ahn¹

Hyun Woo Park¹, Seong-Ghul Yeo¹, Jin Hyun Seo¹, Dae Hwan Kim¹

¹ Gyeongsang National University and Gyeongsang National University Hospital, Department of Otolaryngology, South Korea

Purpose: Benign paroxysmal positional vertigo (BPPV) is the most common cause of peripheral-type vertigo in the elderly. While some studies have investigated BPPV among the elderly, no study has focused on the isolated idiopathic BPPV (iBPPV) in the elderly.

Therefore, this study was to investigate the clinical features and recurrence rate in elderly patients diagnosed with iBPPV.

Methods: The authors prospectively reviewed the medical records of 627 patients diagnosed with BPPV, and a total of 370 patients fulfilled the inclusion criteria. The subjects were divided into two groups by age (experimental group ≥65 years and control group 17-64 years), and the gender, numbers of canalith reposition maneuver (CRM) for successful treatment, time elapsed from onset of symptoms to clinic visit, the affected semicircular canal, and the 1- and 5-year recurrence proportion were analyzed.

Results: The gender, numbers of CRM for successful treatment, affected semicircular canal, and the 1- and 5-year recurrence proportion showed no statistically significant difference between two groups (p > 0.05). The only exception was the experimental group which took a longer duration from manifestation of symptoms to hospital visit than control group (student’s t test, p = 0.021).

Conclusions: The elderly with iBPPV could be treated as effective as general population.

PP1-37 - Immediate efficacy of Gufoni maneuver for HC-BPPV: a meta-analysis

4. Benign Paroxysmal Position Vertigo

Wei Fu¹

Dong Wei²

¹ Fourth Military Medical University, Xijing Hospital, Department of Geriatrics, China

² Fourth Military Medical University, Xijing Hospital, Department of Neurology, China

Purpose: Gufoni maneuver is a very common and efficient treatment for horizontal canal benign paroxysmal positional vertigo (HC-BPPV), with which patients with either a canalolithiasis or a cupulolithiasis can be successfully treated. However, there is no evidence-based study to reveal the immediate efficacy of this maneuver for HC-BPPV. Therefore,This meta-analysis aims to systematically measure the immediate efficacy of the Gufoni maneuver for HC-BPPV.

Methods: A extensive search electronic databases,including PubMed, Embase, Web of Science, Cochrane and Chinese medical databases, were searched until to September 1, 2017 for relevant articles. we selected only randomized clinical trials studying with treatment of HC-BPPV employ by the Gufoni maneuver.

Results: Six randomized clinical trials were included in the current meta-analysis with a total of 696 HC-BPPV patients. The pooled odds ratio of efficacy (ORe) and odds ratio of otolith switch (ORos) were used to estimate overall therapeutic performance. The pooled ORes were 4.00 (95% CI, 2.05-7.78, p<0.01, Gufoni VS. Sham), 1.87(95% CI, 0.42-8.33, p=0.41, Gufoni VS. Barbecue maneuver), while the pooled ORos was 2.17(95% CI, 0.55-8.53, p=0.27). Subgroup analyses showed that the respective pooled ORes were 3.51(95% CI,2.09-5.89, p<0.01) and 3.23(95% CI, 1.24-8.39, p<0.05) in groups of geotropic nystagmus and geonegative nystagmus.

Conclusions: Gufoni maneuver has a satisfactory immediate efficacy for HC-BPPV and doesn’t increase otolith switch.

PP1-38 - Objective Characteristics of Nystagmus in Posterior Semicircular Canal BPPV

4. Benign Paroxysmal Position Vertigo

xu kaixu¹

chen taisheng¹, wang wei¹

¹ Tianjin first hospital, Otolaryngology head and neck surgery, China

Purpose: To analyze and discuss the clinical characteristics and mechanism of nystagmus direction, latency, duration time and intensity in posterior semicircular canal benign paroxysmal positional vertigo.

Methods: Subjects in the study were 564 patients with Posterior Semicircular Canal CanalithasisPSC-CanBPPV. The induced nystagmus in Dix-Hallpike test was recorded by video nystagmuo graph(VNG)and the direction, latency, duration time and intensity characteristics of nystagmus were compared in hanging and sitting

Results: Vertical torsional nystagmus were both induced by hanging and sitting in Dix-Hallpike test. The vertical direction of the induced nystagmus is upward and downward respectively. The latency, duration time and intensity turning to lesion side were L2.65±1.92; 1.44±1.24D14.90±10.46; 15.28± 8.06P29.75±21.26; 14.08± 9.48. The latency, and intensity in hanging were larger than sit. The intensity rate is about 2:1,the difference is statistically significant. The direction of the induced nystagmus is opposite to turning in HSC-Can BPPV. The intensity turning to normal side were larger than lesion side obviously. The intensity rate is about 2:1, the difference is statistically significant (t=17.296, P0.01)

Conclusions: a.The nystagmus intensity rate in Dix-Hallpike test of hanging to lesion side in PSC-Can was 2:1, following Ewald’s law; b. BPPV is either a disease, or a physical model to study the single semicircular-nystagmus effect; c.These nystagmus parameters of VNG in Dix-Hallpike test is an objective guideline for BPPV diagnose.

PP1-39 - Optimal reassessment timing after treatment in posterior canal benign paroxysmal positional vertigo

4. Benign Paroxysmal Position Vertigo

Dae Bo Shim¹

Junhui Jeong²

¹ Myongji Hospital, Department of Otorhinolaryngology, South Korea

² National Health Insurance Service Ilsan Hospital, Department of Otorhinolaryngology, South Korea

Purpose: The aim of this study is to evaluate the optimal reassessment time for treatment response in posterior canal benign paroxysmal positional vertigo (p-BPPV) following the initial Epley maneuver.

Methods: This is a prospective, single-blinded, randomized study that included 108 patients with p- BPPV who agreed to participate. All patients included in the study received a single modified Epley maneuver (recommended by the 2008 AAO guideline) daily until the positional nystagmus disappeared during the Dix-Hallpike maneuver 24 hours after the treatment. Repeated Dix-Hallpike testing to reassess the treatment response was performed at 1 hour (post-1 hr), every 24 hours (post-24 hr) until resolution of positional nystagmus, 1 week (post-1 wk), and 1 month (post-1 mo) following the therapeutic maneuver. The difference in the resolution rate at post-1 hr and post-24 hr reassessment was analyzed and the recurrence rates at post-1 wk and post-1 mo were evaluated.

Results: The resolution rate was 67.6% at post-1 hr which increased to 79.6% at post-24 hr reassessment. There was statistically significant difference in the results of the Dix-Hallpike test between post-1 hr and post-24 hr follow-up. After complete resolution, nine of 108 patients (8.3%) demonstrated recurrence within 1 month.

Conclusions: Reassessment after 24 hours following the initial Epley maneuver is more advantageous than 1-hour follow-up in patients with p-BPPV. This information may provide helpful guideline for clinicians in deciding the appropriate follow-up period after treatment in p-BPPV.

PP1-40 - Positional downbeat nystagmus in posterior canal benign paroxysmal positional vertigo

4. Benign Paroxysmal Position Vertigo

Eun Hye Oh¹

Jae-Hoon Lee¹, Hyo-Jung Kim², Seo-Young Choi³, Kwang-Dong Choi³, Jae-Hwan Choi¹

¹ Pusan National University Yangsan Hospital, Neurology, South Korea

² Seoul National University Bundang Hospital, Research Administration Team, South Korea

³ Pusan National University Hospital, Neurology, South Korea

Purpose: To assess the incidence and clinical significance of positional downbeat nystagmus (pDBN) after treatment of posterior canal benign paroxysmal positional vertigo (PC BPPV).

Methods: We have recruited 77 patients with a diagnosis of PC BPPV. After Epley manueuver, we assessed the presence of DBN during follow-up positional tests. We compared clinical characteristics between pDBN (+) and pDBN (-) group in patients with successful treatment.

Results: Of 57 patients with successful treatment, 22 (39%) showed pDBN during one hour follow-up tests. The mean latency and duration of pDBN were 3.2 ± 2.0 and 12 ± 10.0 s (mean ± SD), respectively. The maximal SPV of pDBN ranged from 2.0 to 12.2 degree (mean ± SD = 5.1 ± 2.5 degree). A torsional component was detectable in six patients. At one week follow-up, there was no difference in the questionnaires scores between pDBN (+) and pDBN (-) group, but a recurrence rate was significantly higher in pDBN (+) group (5/22, 23%) than pDBN (-) group (1/31, 3%, p=0.036). pDBN disappeared in all patients within 6 months.

Conclusions: Our study shows that transient pDBN can be observed in 40% of patients after a successful treatment of PC BPPV. The patients with pDBN showed a high tendency of recurrence within one week. The pDBN may be caused by the remaining debris in the distal portion of the PC, which can move towards the ampulla producing an ampullopetal endolymphatic flow during positioning.

PP1-41 - Relationship between clinical features and therapeutic approach in benign BPPV outcomes

4. Benign Paroxysmal Position Vertigo

Koji Otsuka¹

Yasuo Ogawa¹, Taro Inagaki¹, Shigetaka Shimizu¹, Ujimoto Konomi¹, Noriko Nagai¹, Eriko Sakurai¹, Shigeto Itani¹, Mamoru Suzuki¹

¹ Tokyo Medical University, Department of Otolaryngology, Japan

Purpose: To examine the age and gender distribution of patients, clinical features, treatment methods and outcomes of benign paroxysmal positional vertigo.

Methods: We reviewed 357 BPPV patients for 5 years. Posterior canal BPPV patients were divided into 2 groups, one underwent the Epley manoeuvre and the other received medication. Lateral canal canalolithiasis patients were divided into 2 groups, one underwent the Lempert manoeuvre and the other received medication.

Results: In the posterior canal BPPV group, the average resolution time was 9.6 days. The average resolution time was 7.7 days in the Epley manoeuvre group and 14.1 days in the medication group. In the lateral canal canalolithiasis group, the average resolution time was 11.1 days. The average resolution time was 8.3 days in the Lempert manoeuvre group and 13.4 days in the medication group. In the lateral canal cupulolithiasis group, the average resolution time was 36.7 days.The average age at recurrence was 61.3 years at the 1^st recurrence, 64.5 years at the 2^nd recurrence, and 68.0 years at the 3^rd recurrence. As the number of recurrences increased female gender predominance increased.

Conclusions: In posterior canal BPPV patients, the resolution time in the Epley manoeuvre group was significantly shorter than in the medication group. In lateral canal canalolithiasis patients, the resolution time in the Lempert manoeuvre group was significantly shorter than in the medication group. The resolution time was significantly longer in the lateral canal cupulolithiasis group than in other types of BPPV. As the number of recurrences increased, average age and female gender predominance increased.

PP1-42 - Residual dizziness after repositioning in BPPV with preexisting central neurologic disorders

4. Benign Paroxysmal Position Vertigo

Hsun-Hua Lee¹

Che-Hsuan Lin², Hsiao-Shan Cho¹, Chih-Chung Chen¹

¹ Taipei Medical University – Shuang Ho Hospital, Department of Neurology, Taiwan

² Taipei Medical University Hospital, Department of Otolaryngology, Taiwan

Purpose: Diagnosis and treatment of BPPV in patients with preexisting central neurologic disorders is not always straightforward. Except for migraine, the effectiveness of repositioning treatment in patients with preexisting central neurologic disorders is not described before. In addition, the incidence of residual dizziness after successful repositioning treatment in this group remains unclear.

Methods: Clinical information of consecutive BPPV cases over a duration of 18 months are collected from specialized neurologic clinics in an academic university hospital. After excluding secondary cases, the remaining cases are classified into BPPV with preexisting central neurologic disorders (CND+) group and BPPV without preexisting central neurologic disorders (CND-) group. Age, gender, side of BPPV, involved canal, number of trials for successful repositioning and residual dizziness are compared between both groups.

Results: Clinical data of consecutive 108 cases are collected. Fifteen secondary cases and 1 lost follow-up are excluded. CND+ group comprises 29 cases (13 migraine, 11 cerebrovascular disease, 3 Parkinson disease, 1 restless leg syndrome, 1 orthostatic hypotension) and CND- group comprises 63 cases. Group comparisons (CND+ vs. CND-) show mean age 64.6 vs. 62.7 (p>0.05), female 89.6% vs. 63.5 % (p<0.05), right side 75.9% vs. 52.4% (p<0.05), posterior canal 86.2% vs. 66.7% (p>0.05), success within 2 trials of repositioning 100% vs. 92.1% (p>0.05) and residual dizziness 41.4% vs. 31.7% (p>0.05).

Conclusions: Similar to CND- group, CND+ group shows female, right side and posterior canal predominance. Number of trials needed to treat patients and incidence of residual dizziness are not significantly higher in BPPV patients with preexisting central neurologic disorders.

PP1-43 - The discussing between premier solution of Roll Test and Dix-Hallpike Test inBPPV

4. Benign Paroxysmal Position Vertigo

chen taisheng¹

wang wei¹, xu kaixu¹, Li Shanshan¹, wen chao¹, liu qiang¹, lin peng¹

¹ Tianjin first center Hospital, Otolaryngology Head and Neck surgery, China

Purpose: To analyze the objective characteristics of Roll Test and Dix-Hallpike Test in benign paroxysmal positional vertigoBPPVpatientsdiscussing the premier solution of positional test.

Methods: A total of 230 patients with BPPVwhereas 170 PSC-Can BPPV and 60 HSC-Can BPPV were involved respectively. The induced nystagmus in Roll Test and Dix-Hallpike Test was recorded by video nystagmuo graph (VNG), and the direction, intensity and time characteristics of nystagmus were compared in various BPPV.

Results: Vertically upward nystagmus was induced by hanging in 170 PSC-Can Dix-Hallpike Test, and the nystagmus reversed and turned weaker when the subjects came to sit. The intensity of nystagmus at turning to lesion side by hanging and sit were (30.3±14.1)°/s and (12.6±7.5)°/s respectively. However, no nystagmus was induced in PSC-Can Roll Test. Horizontal nystagmus in the same direction with turning were induced in 60 HSC-Can Roll Test. The intensity of nystagmus at turning to lesion side and normal side were (42.0±18.0)°/s(20.3±8.7)°/s respectively. Furthermore, horizontal nystagmus in the same direction with turning were induced in 57 HSC-Can Dix-Hallpike. With the results of Roll Test for reference, the coherence is 95%.

Conclusions: Dix-Hallpike Test not only can be used to diagnose PSC-Can, but also induce nystagmus in HSC-Can effectively. Whereas the Roll Test only shown significance in diagnosing HSC-Can.

PP1-44 - Trial of a two-item questionnaire for identifying patients with Benign Paroxysmal Positional Vertigo

4. Benign Paroxysmal Position Vertigo

Jeremy Corcoran¹

Simon Michalski¹, Julian Ahmed¹, Louisa Murdin¹

¹ Guy’s and St Thomas’ NHS Foundation Trust, Multidisciplinary Balance Clinic, London

Purpose: Benign paroxysmal positional vertigo (BPPV) accounts for 19% attendances at our specialist Multidisciplinary Balance Clinic (MBC). Patients with BPPV can often be managed with particle repositioning manoeuvres without need for complex MBC assessments. The aim of the study was to assess effectiveness of a postal screening tool and targeted intervention to identify and treat patients with BPPV.

Methods: Patients on the MBC waiting list in June 2017 were posted a brief paper questionnaire: • Do you experience dizziness when rolling over in bed? • Does this dizziness last less than 2 minutes? Patients with negative responses proceeded to full MBC assessment. Those who responded affirmatively to both questions were triaged to a designated physiotherapy clinic for focussed assessment. Patients diagnosed with BPPV were treated with particle repositioning manoeuvres. Patients without BPPV, and those identified as having additional complex presentations, proceeded to the MBC.

Results: 360 patients were sent questionnaires. 64 responded affirmatively to both questions and were offered appointments; of which 52 patients attended. 19 of these had positive positioning tests. 13 had a suggestive history but negative tests (62% in total). Of those with positive positioning tests, 10 (19% of those seen) were discharged without further intervention; the other 9 had residual symptoms despite successful BPPV treatment. Therefore 42 (81%) required further intervention.

Conclusions: A simple postal screening tool can identify patients with BPPV with a positive predictive value of 62%, allowing appropriate triage to a targeted clinic. However many such patients have needs which cannot be managed with repositioning alone.

PP1-45 - TRV Chair For Diagnosis and Treatment of BPPV

4. Benign Paroxysmal Position Vertigo

Harry Akram¹

¹ Royal National Throat, Nose & Ear Hospital, London, UK.

Purpose: We investigate the diagnostic yield and treatment success rate of the TRV Chair for BPPV, which is thought to be the most common cause of vertigo in adults. Although the TRV Chair is not a recent innovation, it is not widely used in the UK and is under-studied.

Methods: We collected data from 150 patients reporting “positional vertigo” as a symptom by performing positional tests on the bedside directly followed by TRV Chair (and Video Frenzel) assessment. If indicated, subjects were treated with repositioning manoeuvres. Success was measured by complete resolution of symptoms and/or absence of nystagmus at follow up (2-4 weeks post-treatment). Treatment manouvres used were Epley, Semont and Lempert.

Results: Preliminary normative data suggests up to 5% of subjects who do not have vertigo will have some degree of positional nystagmus. 90% of patients reporting positional vertigo as a symptom were found to have positional nystagmus (and therefore BPPV). We report an 89% success rate for all subjects with positional nystagmus, 97% success for subjects who were identified without Video Frenzel technology and subsequently treated in the TRV Chair, and 100% success for those identified to have lateral canal BPPV.

Conclusions: The TRV Chair is a very effective method for treatment of BPPV, especially for the lateral canal form and recurrent, treatment resistant BPPV; further study requires comparison with Video Frenzel alone and comparison of long term recurrence rates compared to traditional methods. Preliminary data suggests BPPV may be even more common than previously documented.

PP1-46 - Use of the Brny Society criteria to diagnose benign paroxysmal positional vertigo

4. Benign Paroxysmal Position Vertigo

Qingxiu Yao¹

Qiang Song¹, Hui Wang¹, Haibo Shi¹, Dongzhen Yu¹

¹ Shanghai Jiao Tong University Affiliated Sixth People’s Hospital

Purpose: We reviewed the classifications of different subtypes of benign paroxysmal positional vertigo and the problems we encountered using the diagnostic criteria of the Bárány Society.

Methods: Both the Dix–Hallpike maneuver and supine roll test were performed on 568 patients, and diagnoses were made based on patient history and the type of provoked nystagmus (if any). Next, the numbers of patients with each subtype and other parameters, including age and sex, were analyzed.

Results: Posterior semicircular canal BPPV (pc-BPPV) accounted for the largest proportion, followed by horizontal semicircular canal BPPV (hc-BPPV). Both anterior canal BPPV and multiple canal lithiasis BPPV were rare, and no patient was diagnosed with cupulolithiasis of the posterior canal.

Conclusions: pc-BPPV, hc-BPPV, and hc-BPPV-cu were the three major subtypes that could be definitively diagnosed, whereas the diagnoses of pBPPV and pBPPVsr require further investigation, with special attention being paid to appropriate differentiation and repositioning maneuvers.

PP1-47 - Utility of Bow and Lean Test in Predicting Subtype of Benign Paroxysmal Positional Vertigo

4. Benign Paroxysmal Position Vertigo

Chang-Hee Kim¹

Seongjun Choi¹, Jung Eun Shin¹

¹ Department of Otorhinolaryngology-Head and Neck Surgery, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Republic of Korea

Purpose: To investigate the role of “bow and lean test” (BLT) in the diagnosis of benign paroxysmal positional vertigo (BPPV).

Methods: Between March 2015 and June 2017, we enrolled 113 patients with posterior semicircular canal (PSCC) BPPV, 74 patients with lateral semicircular canal (LSCC) canalolithiasis, 53 patients with LSCC cupulolithiasis, and 32 patients with light cupula. We retrospectively assessed bowing nystagmus (BN) and leaning nystagmus (LN).

Results: In PSCC BPPV, 75% of the patients showed at least one of BN and LN, and direction of nystagmus provoked by a Dix-Hallpike test on the affected side was consistent with that of LN and opposite to that of BN. In LSCC canalolithiasis, 65% (48 of 74) of the patients showed both BN and LN which were in the same direction in 38 patients (of 48) and in the opposite direction in 10 patients (of 48). The affected side can be determined according to the results of BLT in 74% (55 of 74) of LSCC canalolithiasis patients, and among them, the side determined according to the results of head-roll test was discordant with that according to BLT in 20 patients (of 55, 36%). In LSCC cupulopathy (n = 85), both BN and LN were persistent and observed in all cases, but we could not distinguish LSCC cupulolithiasis from light cupula according to nystagmus direction in BLT.

Conclusions: Although a BLT yields better lateralization in LSCC canalolithiasis, it may be more useful in predicting the diagnosis and lateralization of PSCC BPPV than LSCC canalolithiasis.

PP1-48 - Vitamin D deficiency and Benign Paroxysmal Positional Vertigo recurrence.

4. Benign Paroxysmal Position Vertigo

Giacinto Asprella Libonati¹

Rudi Pecci²

¹ Giovanni Paolo II Hospital, Unit of Vestibology and Otorhinolaryngology, Policoro (MT), Italy Viale Salerno, 75025 Policoro (MT) Italy

² Azienda Ospedaliero-Universitaria Careggi, Neuromusculoskeletal and Sensory Organs Department, Unit of Audiology, Florence, Italy

Purpose: The study was carried out to verify the effect of supplementation with Vitamin D (VD) or VD + alpha lipoic acid (ALA) on BPPV recurrence.

Methods: From January 2015 to July 2015 we enrolled 125 patients with recurrent BPPV (78 women and 47 men; average age 56 years). All patients underwent physical therapy and venous blood sampling with dosage of VD. Patients with VD deficiency or insufficiency were supplemented with oral VD or VD + ALA. All patients were checked after 3 (T1), 6 (T2) and 12 (T3) months.

Results: All the patients supplemented with only VD, completely compensated their VD deficiency, showing no BPPV recurrence or lower recurrence at T2. Patients showing longer time to recovery VD deficiency (4 patients were still insufficient at T1) had decreased BPPV recurrence at T3. Patients supplemented with VD + ALA, showed lower BPPV recurrence at T2, and no BPPV recurrence or its decrease at T3. All the patients with VD deficiency and still insufficient at T1 (6 patients) had lower BPPV recurrence. All the patients treated adding ALA had no BPPV recurrence at T3, included 6 patients deficient at T0 and insufficient at T1, 4 patients still insufficient at T1 treated with only VD, despite correcting the VD deficit at T2, showed a decreased BPPV recurrence at T3.

Conclusions: VD supplementation reduces the BPPV recurrence in all the treated patients. The addition of alpha lipoic acid, thanks to its antioxidant properties, further improves these results, especially in patients with higher initial deficit (deficiency) and longer recovery time.

PP1-49 - Cogans syndrome: An autoimmune inner ear disease

5. Bilateral Vestibulopathy

Qin Wang¹

¹ The Second Xiangya Hospital, Central South University, Department of Otolaryngology Head & Neck Surgery

Purpose: Cogan’s syndrome is a rare disease characterized by coexisting audiovestibular and ocular symptoms. We report a case of clinical manifestation, audiovestibular function, treatment and prognosis of Cogan’s syndrome to have a better understanding of it.

Methods: We describe a case of Cogan’s syndrome in patients with clinical manifestations. The Patient was assessed by Pure tone audiometer, the head impulse protocol and suppression head impulse protocol (HIMPs and SHIMPs), caloric test, vestibular-evoked myogenic potentials (VEMPs) at the initial visit and then then evaluated for symptomatic improvement after 6 months.

Results: The patient had recurrent ocular symptoms for more than ten years, and gradually appeared repeated right knee, right foot pain, accompanied by the collapse nose, ear cartilage bilateral integration, After the emergence of vestibular dysfunction, ears have developed into deafness. The audiovestibular function tests were all abnormal.

Conclusions: Cogan’s syndrome is a rare syndrome with multiple symptoms of ocular symptoms and ear symptoms. The symptoms are not specific and the early diagnosis is difficult. However, the auditory-vestibular system is often poorly predicted and needs to be diagnosed by early diagnosis and treatment.

PP1-50 - Etiology analysis and vestibular assessment of bilateral vestibulopathy

5. Bilateral Vestibulopathy

Ying Lin¹

¹ Xijing Hospital, Department of Otolaryngogology Head and Neck Surgery

Purpose: To define clinical and laboratory characteristics of bilateral vestibulopathy (BVP) and to propose diagnostic criteria of this disorder based on clinical and laboratory vestibular function test findings.

Methods: 42 case series with a clinical suspicion of BVP were retrospectively analyzed, in an attempt to determine etiology. Presenting auditory-vestibular symptoms, bedside dynamic visual acuity tests and laboratory test were reviewed, including bithermal caloric test, rotatory chair tests, video head impulse test(vHIT), vestibular-evoked myogenic potentials(VEMP).

Results: Among these 42 patiests, dizziness was seen in 42 case (100%) oscillopsia was seen in 21case (50%) Hearing loss was seen in 30 (71.4%). Eight cases(19%)had tinnitus25 cases showed vestibular loss in dynamic visual acuity test (69.4%). Definite diagnosis of complete BVP was made in 36 patients when the patients showed abnormal findings on caloric test, rotatory chair test and vHIT tests in addition to the symptoms. Whereas probable diagnosis of partial BVP was obtained in 6 patients with abnormal caloric test and rotatory chair test but no pathological vHIT. VEMP(ocular or cervical ) could be recorded in 20 patients. 14 cases were caused by ototoxic drugs while no causes could be determined in 6 cases among these 42 cases.

Conclusions: The diagnosis of BVP is challenging. Vestibular laboratory test battery which reflect full frequency function of VOR has great value to confirming the diagnosis and differentiate definite complete BVP to possible partial BVP. Diagnosis standard shall be made combining clinical history, characteristic symptoms and the results of auditory-vestibular function testing. Ototoxic drugs contribute most considering etiology.

PP1-51 - Frequency properties of postural sway in bilateral vestibulopathy and somatosensory disorder

5. Bilateral Vestibulopathy

Makoto Kinoshita¹

Chisato Fujimoto¹, Naoya Egami¹, Keiko Sugasawa¹, Tatsuya Yamasoba¹, Shinichi Iwasaki¹

¹ University of Tokyo, Department of Otolaryngology and Head and Neck Surgery, Japan

Purpose: To assess the frequency characteristics of postural instability in patients with idiopathic bilateral vestibulopathy (IBV) in comparison with those with somatosensory disorder.

Methods: 36 patients with IBV, 26 patients with somatosensory disorder, and 194 healthy controls were included. In posturography test, two-legged stance tasks were performed in 4 conditions: eyes open with and without foam rubber, and eyes closed with and without foam rubber. We normalized frequency distribution provided by maximum entropy method from 0.01 Hz to 10 Hz every 0.5 Hz about the anterior-posterior and the left-right direction. We defined the “eyes-open-closed difference” as the difference between the normalized values with the eyes closed and that with the eyes open. In addition, we defined the “rubber difference” as the difference between the normalized values with and without foam rubber. We regarded power beyond averages ± 2SD of healthy controls as abnormal.

Results: In IBV patients, postural abnormalities were observed in widespread frequencies in the conditions with eyes closed with and without foam rubber. On the other hand, in patients with somatosensory disorder, those were especially observed above 6Hz in the conditions with eyes closed with and without foam rubber. The abnormality of the rubber difference was characteristic of IBV patients, and the abnormality of the eyes-open-closed difference was characteristic of patients with somatosensory disorder.

Conclusions: The frequency power spectrum analysis of postural stability is useful for the differentiation between IBV and somatosensory disorder.

PP1-52 - Impact of Bilateral Vestibulopathy on Spatial and non-Spatial Cognition: a Systematic Review

5. Bilateral Vestibulopathy

Bieke Dobbels¹

Griet Mertens², Paul Van de Heyning², Vincent Van Rompaey²

¹ Dept. Otorhinolaryngology & Head and Neck Surgery, Antwerp University Hospital, Belgium. Faculty of Medicine and Health Sciences, University of Antwerp, Belgium

² 1Dept. Otorhinolaryngology & Head and Neck Surgery, Antwerp University Hospital, Belgium. 2Faculty of Medicine and Health Sciences, University of Antwerp, Belgium

Purpose: Growing evidence in animal and human studies suggest that not only hearing loss, but also vestibular loss might result in cognitive deficits. In this review our aim is to evaluate the presence of spatial and non-spatial cognitive deficits in patients with bilateral vestibulopathy (BVP), with and without hearing loss.

Methods: We performed a systematic review according to the PRISMA guidelines on studies considering cognitive performances in BVP patients. Three independent researchers explored Medline and the Cochrane Library. Studies reporting on cognition in BV patients were included according to a predefined eligibility assessment. Data of the patients’ characteristics and their cognitive outcomes were extracted.

Results: Seven studies reporting on 73 BVP patients matched the inclusion criteria. Overall, the methodology of the included papers was of good quality. Criteria for including BVP patients varied widely across studies. Cognitive domains evaluated in patients included visuospatial abilities, memory, language, attention and executive function. Only in one of the seven studies hearing performance of the included patients was briefly described. Nearly all studies demonstrated a significant impairment of spatial cognition in BVP patients. Only recent papers investigated other cognitive domains then spatial cognition. In these papers a negative impact of BVP on the other cognitive domains was also described.

Conclusions: Strong evidence exists that BVP patients suffer from impaired spatial cognition and possibly even general cognitive deficits. However, in all previous studies conclusions on the link between cognitive performance and BVP were drawn without taken hearing loss into consideration as a possible cause of the cognitive impairment.

PP1-53 - Progressive central and peripheral vestibulopathy in superficial siderosis

5. Bilateral Vestibulopathy

Sang Yun Lee¹

Dong Han Lee¹, Jae-Jin Song¹, Yun Jung Bae², Ji Soo Kim¹,

Ja-Won Koo¹

¹ Dizziness Center, Seoul National University Bundang Hospital, Korea

² Department of Radiology, Seoul National University Bundang Hospital, Korea

Purpose: Superficial siderosis (SS) is a rare condition in which hemosiderin, an iron-storage complex, is deposited in neuronal tissues due to recurrent subarachnoid bleeding. Since it is still not clear how the vestibule-cochlear dysfunction and cerebellar ataxia progress, we reviewed the clinical course, patterns of vestibulopathy and progression of cochleovestibular dysfunction over the long term follow-up period, and correlated with radiologic finding in MRI.

Methods: Six patients who diagnosed with SS by magnetic resonance imaging were enrolled. The medical records and radiologic findings of the case series were retrospectively reviewed, particularly, we described the progression of vestibulo-cochlear manifestations and radiologic charicteristics of each case.

Results: All patients showed SNHL. Five out of 6 showed progressive hearing deterioration over years and the progression was asymmetric between ears in 4 patients. Based on the most recent evaluations, four out of six patients showed CA and bilateral vestibulopathy, namely, bilateral combined central- and peripheral vestibulopathy. Remaining two patients demonstrated the bilateral peripheral vestibulopathy, isolated central vestibulopathy, respectively. Hypointensity lesions on T2 weighted images surrounding cerebellum were remarkable in all patients but such lesion surrounding brain stem was not remarkable 1 patients. Though cochlea-vestibular dysfunction was mostly asymmetrically progressed, there was no left-right asymmetry on MRI.

Conclusions: Typically, SS presents bilateral asymmetrically progressive cochleovestibular dysfunction with cerebellar ataxia. Pattern of vestibular dysfunction is most frequently bilateral combined central- and peripheral vestibulopathy. In this perspective, identification of the exact vestibular status and central signs through the regular comprehensive and neurotological evaluations is crucial for treatments and prognosis in SS.

PP1-54 - Are gonadal hormones involved in the pathophysiology of Mal de Debarquement Syndrome?

6. Central Vestibular Disorders

Viviana Mucci¹

Josephine M. Canceri², Rachael Brown³, Mingjia Dai⁴, Sergei Yakushin⁴, Watson Shaun⁵, Angelique Van Ombergen¹, Yves Jacquemyn⁶, Paul H. Van de Heyning⁷, Floris Wuyts⁸, Cherylea J. Browne⁹

¹ Antwerp University Research Centre for Equilibrium and Aerospace/ Department of Gynaecology, Antwerp University Hospital, University of Antwerp. Belgium.

² School of Science and Health, Western Sydney University, NSW, Australia Western Sydney University , Australia.

³ School of Medicine, Western Sydney University, NSW, Australia Western Sydney University, Australia.

⁴ Neurology Department, Icahn School of Medicine, Mount Sinai Hospital, NY, United States of America.

⁵ Department of Neurology, Prince of Wales Private Hospital, NSW, Australia.

⁶ Department of Gynaecology, Antwerp University Hospital, University of Antwerp, Belgium.

⁷ Department of Otorhinolaryngology and Head and Neck Surgery, Antwerp University Hospital, University of Antwerp, Belgium.

⁸ Faculty of Sciences – Lab of Biophysics and Biomedical Physics, University of Antwerp, Belgium.

⁹ School of Science and Health, Western Sydney University, NSW, Australia Western Sydney University / Translational Neuroscience Facility, School of Medical Sciences, UNSW Sydney, NSW, Australia.

Purpose: Mal de Debarquement Syndrome (MdDS) is a neurological condition which is characterised by a phantom sensation of motion, following exposure to passive motion (e.g. cruise, flight, etc.). This is defined as motion triggered (MT) MdDS. However, it is known that some patients develop typical MdDS symptoms without an apparent motion trigger. This is named spontaneous or other onset (SO) MdDS. For both subtypes, a female predominance has been previously described. The role of gonadal hormones in MdDS pathophysiology has never been investigated. Similarly to what observed in migraine, hormonally regulated mechanism is here hypothesised as a potential contributor to MdDS pathogenesis. Our study aimed to evaluate if MdDS patients report abnormal hormonal profiles and assess possible hormonal influences in the pathophysiology of MdDS.

Methods: This assessment was performed via a retrospective online questionnaire study for both subtypes (MT and SO MdDS).

Results: A total of 370 patients participated in the questionnaires; including 334 females, 25 males and 11 with unspecified gender. Naturally cycling female respondents (from the MT group) reported a significant aggravation of symptoms during ovulation and menstruation.

Conclusions: The results of this study clearly demonstrate a link between hormone fluctuation and symptom aggravation in the MdDS MT group. This provides a strong basis for further hormonal investigation. Our next step is to evaluate hormonal levels through blood sampling, to identify if abnormal hormonal fluctuations or profiles are present in reproductive female patients. We hope this study will help the medical community to broaden their awareness and hormonal knowledge of this condition.

PP1-55 - Central Positional Vertigo

6. Central Vestibular Disorders

Duilio De Schutter¹

Zacharias Adham², Jorge Kattah²

¹ Neurology, Hospital Del Carmen, Mendoza, Argentina

² University of Illinois College of Medicine at Peoria?, USA.

Purpose: To review the central positional vertigo etiology and diagnosis

Background: Benign paroxymal positional vertigo (BPPV) is the most frequent cause of episodic vertigo. Central positional vertigo and nystagmus (CPV) are also precipitated by positional testing; though infrequent it must be recognized for proper triaging, as it requires an expeditious neurologic work-up. CPV and nystagmus may account for 1% of all causes of vertigo

Methods: Retrospective 16–year analysis of patients with CPV. We excluded all cases with previous history of BPPV and included patients with positional paroxysmal and non-paroxysmal DBN or central horizontal apogeotropic nystagmus examined in two large medical centers in North and South America.

Results: 21 patients with CPV and nystagmus of different etiologies were found. Main diagnosis were: CNS tumor, post-surgical tumor resection and superior canal dehiscense, vascular, infectious, demielinating, familial ataxia, and episodic ataxia syndromes. In one cerebellar glioma positional vertigo was the first manifestation of disease. Positional DBN was largely the most common nystagmus found, followed by horizontal apogeotropic-nystagmus. Nystagmus pattern was decrescendo and no latency was found in the series. Most patients presented other neurological features associated.

Conclusions: Migraine may be a benign cause of CPV, however, a broad spectrum of diseases including tumors, stroke , infections and neurodegenerative disorders may be responsible. Earlier detection of posterior fossa lesions is critical to improve the outcome. Moreover, central positional vertigo could be the very first manifestation of the underlying disease.

PP1-56 - Dissociation between semicircular canals and saccular function in Machado-Joseph Disease

6. Central Vestibular Disorders

Dario Geisinger¹

Zohar Elyoseph², Roy Zaltzman³, Matti Mintz⁴,

Carlos Gordon⁵

¹ Tel Aviv University, Sackler Faculty of Medicine, Israel

² Tel Aviv University, School of Psychological Sciences, Israel

³ Tel Aviv University, Sackler Faculty of Medicine, Meir Medical Center, Department of Neurology, Israel

⁴ Tel Aviv University, School of Psychological Sciences and Sagol School of Neuroscience, Israel

⁵ Tel Aviv University, Sackler Faculty of Medicine, Meir Medical Center, Department of Neurology and Sagol School of Neuroscience, Israel

Purpose: Although ocular motor abnormalities are frequent in all forms of Spinocerebellar ataxias (SCAs), vestibulo-ocular reflex (VOR) deficit seems to be a characteristic of SCA-3 (Machado-Joseph disease -MJD). However, all previous studies were focused on lateral semicircular canals function without information regarding the anterior and posterior canal responses and the otolithic function. The aim of this study was to evaluate the three semicircular canals VOR responses and otolithic function in Jew Yemenite patients with MJD in a search for a better neurophysiologic biomarker of the disease.

Methods: Sixteen MJD patients underwent a detailed clinical and laboratory neuro-otological evaluation including horizontal and vertical VOR recordings with the video head impulse test (vHIT) system. Eight of them underwent also cervical vestibular evoked myogenic potentials (cVEMPs) by bilateral tone burst stimulation measuring otolithic saccular function

Results: All MJD patients had significant angular VOR gain decrease (about 50% of normal values) in both horizontal and vertical planes. cVEMPs responses (latency and amplitude of P13 and N23) were normal in all eight examined patients. Ataxia severity evaluated by the Scale for the Assessment and Rating of Ataxia (SARA) was mildly correlated with the degree of VOR impairment.

Conclusions: Angular VOR impairment in horizontal and vertical planes seems to be a distinctive feature of MJD and could be explained by selective rostral vestibular nuclei degeneration. We suggest that quantitative VOR measures could probably be a neurophysiologic biomarker for detecting the appearance and progression of neuro-degeneration in MJD.

PP1-57 - Evaluation of gravitational recognition in patients with spinocerebellar degeneration

6. Central Vestibular Disorders

Takamori Takeda¹

Akihisa Tasaki¹, Yuichiro Inaba¹, Yusuke Kiyokawa¹, Yasuhiro Suzuki¹, Takeshi Tsutsumi¹

¹ Department of Otolaryngology, Tokyo Medical and Dental University, Tokyo, Japan

Purpose: Spinocerebellar degeneration (SCD) is neurodegenerative disorder and demonstrates symptoms with progressive cerebellar ataxia resulting in instability of gravitational recognition. The gravitational recognition associated with SCD has hardly been evaluated and only a limited number of studies exist. We recently develop a method of calculating Listing’s plane obtained from video-oculograms (VOGs), which reflects gravitational recognition constructed through integration of visual, vestibular, and proprioceptive sensory inputs. The purpose of this study is to establish the methods of evaluating gravitational recognition in patients with SCD, using the thickness of the Listing’s plane as a parameter.

Methods: The subjects were wearing infrared CCD-mounted goggles in the sitting and supine position, leaving both eyes unobstructed. 50 cm in front, we placed a screen on which were 9 fixation points. The subjects were instructed to fixate for 1 s on each of the 9 fixation points consecutively. We digitized the video recording using a macro program for ImageJ and calculated thickness of the Listing’s plane on each SCD subjects and healthy controls. In this time, we succeeded to improve the accuracy of measurement, by setting the upper limit of rotational values per frame, to eliminate large rotational artifacts in analyzing data of VOGs.

Results: We identified thickening of Listing’s plane on sitting position in SCD patients than healthy controls, and on sitting position against supine position in SCD patients.

Conclusions: The thickness of Listing’s plane could serve as a parameter which reflects the instability of gravitational recognition in SCD patients.

PP1-58 - Long term observation of slow saccades and caloric response in a SCA2 patient

6. Central Vestibular Disorders

Masakatsu Taki¹

Tatsuhisa Hasegawa², Yuzuru Ninoyu¹, Hirofumi Sakaguchi¹, Shigeru Hirano¹

¹ Department of Otolaryngology - Head and Neck Surgery, Kyoto Prefectural University of Medicine, Japan

² Department of Otolaryngology, Akashi City Hospital, Japan

Purpose: To follow up long term of slow saccades and caloric responses in a patient with spinocerebellar ataxia type2 (SCA2)

Methods: The subject was a male patient with SCA2. At age of 32 years old, he was referred to the Department of Otolaryngology - Head and Neck Surgery, Kyoto Prefectural University of Medicine for the evaluation of eye movements and vestibular function. Saccadic, and smooth pursuit eye movements and caloric stimuation were examined. Saccadic eye movements were also examined at the angles of 10, 20, 30, 60 and 90 degrees. To calculate main sequence of saccadic eye movements, maximum velocities were plotted against amplitudes and were exponentially fitted as follows: Vmax = k x (1-exp(-amp/tau)). Eye movements were measured with electronystagmugraphy. We compared saccadic, and smooth pursuit eye movements and maximum slow phase velocity of caloric nsytagmus every year.

Results: Slow saccades were observed from one year later (first examination) to five years later. Six years later, tremor was superimposed. Eight years later, he could not pursuit target. Smooth pursuit eye movements were normal until five years later. However, maximum slow phase velocity of caloric nystagmus fluctuated depending on years. The coefficient k also increased and decreased as caloric responses changed by year. k was 93.6, 212.9, 249.3, 194.8 for three, four, five ,six years later, respectively. In normal subject, k was 824.9.

Conclusions: These results suggest that slow saccades may not monotonically be aggravated by year. In this case, rehabilitation probably improved the saccadic eye movements but only for several years.

PP1-59 - Metabolic and Visuospatial Memory Function Changes in Transient Mal de Debarquement Syndrome

6. Central Vestibular Disorders

Seung-ho Jeon¹

Ko woon Kim¹, Hyun-June Shin¹, YEON-HEE HAN², HWAN-JEONG JEONG², Sun-Young Oh¹

¹ Department of Neurology, Chonbuk National University Medical School and Hospital, Jeonju, Korea

² Department of Nuclear Medicine, Chonbuk National University Medical School and Hospital, Jeonju, Korea

Purpose: Mal de debarquement syndrome (MdDS) is a subjective perception of self-motion after a period of travel, classically by boat. It is not commonly encountered in clinical practice, but an enigmatic neurotological disorder with high morbidity. The pathogenesis of MdDS is not well-understood and therefore, treatment options are limited.

Methods: We studied 29 subjects who were fishermen at Buan, including 16 subjects (6 males) who had transient MdDS (t-MdDS) or land sickness (less than 12 hours of symptoms after boating) and 13 subjects who do not have symptoms. They were undertaken a neurotological examination, vestibular function tests and visuospatial function tests including Corsi block task. Brain MRI and ¹⁸F-FDG brain PET were also performed.

Results: Vestibular functions were within normal range and structural brain lesion was not detected in any subjects. However, the Corsi block test was scored as a mean of 6.40 in t-MdDS subjects and 5.31 in the control group (p=0.016). ¹⁸F-FDG brain PET imaging revealed increased glucose metabolism in the primary visual cortex, prefrontal and inferior parietal lobules bilaterally in the setting of decreased inferior cerebellum metabolism in subjects with transient MdDS.

Conclusions: Our results show that the patients of t-MdDS revealed better performance of visuospatial memory task and hypermetabolism in neural systems involving visual spatial working memory with hypometabolism in cerebellum. These findings indicate that MdDS maybe a disorder of over-synchronization of visuospatial memory networks caused by persistent background low-amplitude oscillating environments coupled with an inability to subsequently desynchronize the activity of these networks reflected by hypometabolism in the cerebellum.

PP1-60 - Nystgamus and vestibular loss in autoimmune and paraneoplastic ataxia syndromes

6. Central Vestibular Disorders

Jorge Kattah¹

Ali Saber Tehrani², Diana Londono³, Xiaojun Zhang⁴

¹ University of Illinois College of Medicine . Peoria, IL

² University of Illinois College of Medicne. Peoria, IL

³ University of Illinois College of Medicine. Peoria, Il

⁴ University of Illinois College of Medicine. Peoria,IL

Purpose: To investigate oculomotor and vestibular evaluation results and to correlate them with immuno-phenotypes in autoimmune ataxia (AA).

Methods: Retrospective neurotologic chart reviews of adult AA patients examined from 2001-2016. None of the patients had a history of familial ataxia (FA)

Results: 13 patients met the diagnostic criteria of AA, 12 had one specific antibody that was presumably the cause of the ataxia. The initial MRI of the brain was normal in all instances. Six patient had an anti-Gad antibody, two had ant-Yo, two anti-Hu and two had miscellaneous antibodies. Seven had the ataxia as the first symptom of cancer and two had previous cancer in remission. One had a previous thymoma resection. The remaining four cases were autoimmune. One had RA and other Chron’s disease. The most common primary gaze nystagmus was downbeat (DBN) in n= six, one had Opsoclonus and the remaining had gaze evoked nystagmus (GEN) and abnormal pursuit. Three patients had bilateral, symmetric vestibular paresis. Six patient had a lymphocytic meningitis, the CSF was normal in the anti-GAD antibody patients.

Conclusions: A syndrome characterized by acute or subacute ataxia and imbalance associated with a normal MRI and no history of FA, suggests AA. The ant-GAD antibody syndrome was less frequently associated with cancer than other autoantibodies; common findings included DBN, GEN, impaired pursuit, bilateral vestibular paresis and Opsoclonus. Rapid initiation of immunosuppression, plasma exchange and search for an occult cancer are the first step in management. The anti-Gad antibody syndrome has better prognosis even if cancer is present.

PP1-61 - Positional tests under Videonistagmography for Central Positional Vertigo Diagnosis

6. Central Vestibular Disorders

Fernanda Vidigal Vilela Lima¹

Claudia Marques Dias¹

¹ Hospital Madre Teresa

Purpose: Positional vertigo is vertigo triggered by and occuring after a change of head position in space realtive to gravity.

Central vestibular disorders are caused by lesions along the vestibular pathways in the brainstem. It can manifest the same symptoms than peripheral disorders. The clinical examination of eye movements and of nystagmus is important for differential diagnostics. The positional test under Videonistagmography can be very helpful, specially for the patients that didn’t present any abnormality in MRI.

Methods: This study selected patients that had positional vertigo and were evaluated under Videonistagmography. They didn’t fulfilled the diagnostic criteria for vestibular migraine, presented nystagmus that dind’t fulfilled the criteria for peripheral disorders and had normal MRI. Eye movements were recorded in darkness in the following positions: sitting with head upright, sitting with chin to chest position, lying, lying with the left and right ear down. Oculomotor test were also taken.

Results: Seventeen patients with positional vertigo were evaluated under VNG and presentes abnormal nystagmus with central characteristics during the exam. Two patients were male and fifteen were female. The mean age was sixty five years. Fourteen patients had their nystagmus inverted after head postion changes.

Conclusions: The Videonistagmography positional test allows an easily evaluation of nystagmus and play a decisive role in the diagnosis of Central Positional Vertigo. It can give an effective mesure for diagnose and follow-up in these patients.

PP1-62 - Subjective visual vertical in typical Alzheimer’s disease and posterior cortical atrophy

6. Central Vestibular Disorders

Dilek Ocal¹

Amy Peters², Matthew Bancroft²,

Diego Kaski², Chris Lane¹, Thomas Parker¹, Aida Suarez Gonzalez¹, Ivanna Pavisic¹, Jessica Collins¹, Natalie Ryan¹, John Schott¹, Nick Fox¹, Keir Yong¹, Brian Day², Sebastian Crutch¹

¹ Dementia Research Centre, Department of Neurodegeneration, UCL Institute of Neurology, University College London, London, UK

² Sobell Department of Motor Neuroscience and Movement Disorders, University College London, London, UK

Purpose: The parietal lobes, an area fundamental for integrating multimodal sensory input, have been implicated in the misperception of verticality, suggesting a possible link between damage in this area and inappropriate internal representation of verticality which has been associated with imbalance. The current project investigated perception of verticality in posterior cortical atrophy (PCA) and typical Alzheimer’s disease (tAD) under varying visual cue conditions using the Rod-and-Frame task.

Methods: Twenty PCA, 16 tAD and 13 healthy control participants performed the ‘rod and frame’ test, where they were asked to align an oblique white rod presented on a screen with the perceived vertical while seated (24 trials). The Rod was presented at 45° tilt with or without the presence of a visual cue (square frame) which was randomly presented under two tilt conditions (18° left/right). Task performance measures included orientation error between perceived and absolute vertical.

Results: In the absence of visual cues, orientation error was greater in PCA relative to tAD and control groups; there was no evidence of an overall difference between tAD and control groups. Visual cues exerted greater influence upon the perception of verticality in both PCA and tAD relative to control groups, with cue orientation inducing particular bias in patient responses. We observed lateralized effects of visual cues in PCA, but not tAD or control groups.

Conclusions: Findings support erroneous internal representation of verticality in both PCA and tAD, but also suggest differences between clinical phenotypes. Results are interpreted in the context of differences in structural imaging profiles.

PP1-63 - The Semicircular Canal Coordinate System and Its Relation to Neural Circuits for Saccades

6. Central Vestibular Disorders

Mayu Takahashi¹

Yuriko Sugiuchi¹, Yoshikazu Shinoda¹

¹ Tokyo Medical and Dental University, Dept. of Systems Neurophysiology, Japan