Journal of Vestibular Research - Volume 27, issue 5-6

Authors: Reschke, Millard F. | Wood, Scott J. | Clément, Gilles

Article Type: Research Article

Abstract: BACKGROUND: Ground-based studies have reported shifts of the vestibulo-ocular reflex (VOR) slow phase velocity (SPV) axis toward the resultant gravito-inertial force vector. The VOR was examined during eccentric roll rotation before, during and after an 8-day orbital mission. On orbit this vector is aligned with the head z-axis. Our hypothesis was that eccentric roll rotation on orbit would generate horizontal eye movements. METHODS: Two subjects were rotated in a semi-supine position with the head nasal-occipital axis parallel to the axis of rotation and 0.5 m off-center. The chair accelerated at 120 deg/s2 to 120 deg/s, rotated at constant …velocity for one minute, and then decelerated to a stop in similar fashion. RESULTS: On Earth, the stimulation primarily generated torsional VOR. During spaceflight, in one subject torsional VOR became horizontal VOR, and then decayed very slowly. In the other subject, torsional VOR was reduced on orbit relative to pre- and post-flight, but the SPV axis did not rotate. CONCLUSION: We attribute the shift from torsional to horizontal VOR on orbit to a spatial orientation of velocity storage toward alignment with the gravito-inertial force vector, and the inter-individual difference to cognitive factors related to the subjective straight-ahead. Show more

Keywords: Vestibulo-ocular reflex, otoliths, velocity storage, subjective straight-ahead

DOI: 10.3233/VES-170631

Citation: Journal of Vestibular Research, vol. 27, no. 5-6, pp. 243-249, 2017

Authors: Bos, Jelte E. | Lubeck, Astrid J.A. | Vente, P. Eric M.

Article Type: Research Article

Abstract: BACKGROUND: Regular treatments of Ménière’s disease (MD) vary largely, and no single satisfactory treatment exists. A complementary treatment popular among Dutch and Belgian patients involves eyeglasses with weak asymmetric base-in prisms, with a perceived high success rate. An explanatory mechanism is, however, lacking. OBJECTIVE: To speculate on a working mechanism explaining an effectiveness of weak asymmetric base-in prims in MD, based on available knowledge. METHODS: After describing the way these prisms are prescribed using a walking test and its effect reported on, we give an explanation of its underlying mechanism, based on the literature. …RESULTS: The presumed effect can be explained by considering the typical star-like walking pattern in MD, induced by a drifting after-image comparable to the oculogyral illusion. Weak asymmetric base-in prisms can furthermore eliminate the conflict between a net vestibular angular velocity bias in the efferent signal controlling the VOR, and a net re-afferent ocular signal. CONCLUSIONS: The positive findings with these glasses reported on, the fact that the treatment itself is simple, low-cost, and socially acceptable, and the fact that an explanation is at hand, speak in favour of elaborating further on this treatment. Show more

Keywords: Ménière’s disease, treatment, prisms, star-walk, after-image, oculogyral illusion, efference, re-afference

DOI: 10.3233/VES-170630

Citation: Journal of Vestibular Research, vol. 27, no. 5-6, pp. 251-263, 2017

Authors: Tamás, László T. | Lundberg, Yunxia W. | Büki, Béla

Article Type: Research Article

Abstract: BACKGROUND: When viewing a far target, the gain of the horizontal vestibulo-ocular reflex (VOR) is around 1.0, but when viewing a near target there is an increased response. It has been shown that while this convergence-mediated modulation is unaffected by canal plugging and clinically practical transmastoid galvanic stimulation, it is eliminated by a partial peripheral gentamicin lesion. OBJECTIVE: The aim of this study was to determine if convergence increases the gain during peripheral hyposensitivity elicited by cold thermal irrigation. METHODS: The high frequency VOR gain was measured using video head impulse testing immediately after the cold …caloric stimulus in 9 healthy human subjects with the lateral semicircular canals oriented approximately earth-vertical. RESULTS: Before caloric irrigation, near viewing (15 cm) increased the average VOR gain by 28% (from 1 to 1.28). Cold (24°C) water irrigation of the right ear decreased the gain to 0.66 (far viewing) and 0.82 (near viewing) (22% difference). Although vergence also increased the gain for impulses to the left to the same degree before caloric stimulus, the caloric irrigation itself (applied to the right ear) did not influence the gain for contralateral impulses. CONCLUSION: In our experiments vergence increased the gain of the human angular VOR during peripheral hyposensitivity elicited by cold thermal irrigation. These results suggest that cold irrigation does not abolish the function of the nonlinear/phasic vestibular afferent pathway. Show more

Keywords: Thermal irrigation, vestibular, nonlinear, phasic pathway

DOI: 10.3233/VES-170629

Citation: Journal of Vestibular Research, vol. 27, no. 5-6, pp. 265-270, 2017

Authors: Mijovic, Tamara | Remillard, Andrew | Zaia, Erica Helena | Reid, Yvette Marie | Harrington, Jolene Kim | Westerberg, Brian David | Lea, Jane

Article Type: Research Article

Abstract: BACKGROUND: There is a prevailing opinion that spinning sensations signify a peripheral vestibular pathology while non-spinning sensations are not of vestibular origin. OBJECTIVES: 1) Characterize the subjective sensations reported by patients during caloric testing. 2) Assess if the sensation was correlated with the peak slow phase velocity (SPV). METHODS: Retrospective chart review at a Canadian adult tertiary-quaternary care balance centre for patients undergoing diagnostic caloric testing between December 2014 and September 2015. RESULTS: Of 163 patients included, 122 had normal calorics and 41 demonstrated unilateral weakness. Spinning/rotatory movements were the most commonly reported sensations …(55–70%). No sensation was reported among 10–20% of patients. Other non-rotatory sensations were reported 20–25% of the time. Both lack of sensation and other sensations were more likely to be correlated with SPVs that were significantly lower than those associated with spinning/rotating sensations. However, 18% of patients with normal calorics and robust SPVs with warm irrigation still reported non-spinning sensations. CONCLUSIONS: During caloric irrigation, subjective sensations other than spinning and rotating are reported 20–25% of the time and these tend to be associated with lower peak SPV. Non-spinning vertigo is not uncommon as a subjective description of vestibular sensation even in normal patients with strong SPVs. Show more

Keywords: Caloric tests, dizziness, vertigo, vestibular diseases, vestibular function tests

DOI: 10.3233/VES-170624

Citation: Journal of Vestibular Research, vol. 27, no. 5-6, pp. 271-277, 2017

Authors: Nair, Maitreyi A. | Mulavara, Ajitkumar P. | Bloomberg, Jacob J. | Sangi-Haghpeykar, Haleh | Cohen, Helen S.

Article Type: Research Article

Abstract: People with benign paroxysmal positional vertigo (BPPV) probably have otoconial particles displaced from the utricle into the posterior semicircular canal. This unilateral change in the inertial load distributions of the labyrinth may result in visual dependence and may affect balance control. The goal of this study was to explore the interaction between visual dependence and balance control. We compared 23 healthy controls to 17 people with unilateral BPPV on the Clinical Test of Sensory Interaction and Balance on compliant foam with feet together, the Rod-and-Frame Test and a Mental Rotation Test. In controls, but not BPPV subjects, subjects with poor …balance scores had significantly greater visual dependence, indicating that reliance on visual cues can affect balance control. BPPV and control subjects did not differ on the mental rotation task overall but BPPV reaction time was greater at greater orietantions, suggesting that this cognitive function was affected by BPPV. The side of impairment was strongly related to the side of perceived bias in the Earth vertical determined by BPPV subjects, indicating the relationship between the effect of asymmetric otolith unloading with simultaneous canal loading on spatial orientation perception. Show more

Keywords: BPPV, rod and frame test, mental rotation, CTSIB, balance testing, screening, Romberg, vestibular testing, visual dependence

DOI: 10.3233/VES-170623

Citation: Journal of Vestibular Research, vol. 27, no. 5-6, pp. 279-286, 2017

Authors: Yang, Chan Joo | Kim, Yehree | Lee, Hwan Seo | Park, Hong Ju

Article Type: Research Article

Abstract: The aim of this study was to evaluate the relationship between bone mineral density (BMD) and 25-hydroxyvitamin D with the occurrence and recurrence of BPPV. The records of 130 idiopathic BPPV patients (55±12 years old, 30 men and 100 women) and 130 age- and sex-matched controls who underwent bone mineral densitometry between April 2012 and September 2015 were reviewed retrospectively. We compared the BMD and serum 25-hydroxyvitamin D between the patients and controls, and also compared the BMD between recurrent and non-recurrent BPPV groups. Among the female subjects, the BPPV group showed a significantly decreased BMD compared to the controls …(p  < 0.05). The men in the control group had significantly higher 25-hydroxyvitamin D levels than the men with BPPV (p  < 0.05). Sixty-three patients (48%) reported recurrent attacks of BPPV. The women with recurrent BPPV were significantly older and showed a significantly lower BMD than non-recurrent women (p  < 0.001). However, multiple regression analysis revealed that age alone was significantly associated with the recurrence of BPPV in women. BMD in women and serum 25-hydroxyvitamin D levels in men are associated with the occurrence of BPPV. Only age is an independent predictor of recurrence, though a low BMD and age correlate with the recurrence of BPPV. Show more

Keywords: Benign paroxysmal positional vertigo, osteoporosis, bone mineral density, 25-hydroxyvitamin D

DOI: 10.3233/VES-170625

Citation: Journal of Vestibular Research, vol. 27, no. 5-6, pp. 287-294, 2017

Authors: MacDowell, Sara G. | Wellons, Rachel | Bissell, Ashlen | Knecht, Lisa | Naquin, Caitlin | Karpinski, Aryn

Article Type: Research Article

Abstract: BACKGROUND: Anxiety and depression are common in individuals with vestibular disorders and anecdotally symptoms of these disorders have been associated with poorer scores on subjective outcome measures of dizziness and balance. It is unknown if symptoms of psychological distress impact individual outcomes with vestibular rehabilitation therapy (VRT). OBJECTIVE: To compare subjective and objective outcome measures in subjects with vestibular disorders who have symptoms of anxiety and/or depression to those who do not exhibit those symptoms. METHODS: A retrospective chart review was performed at two outpatient vestibular rehabilitation clinics. Data recorded included demographics, scores on the Positive …and Negative Affective Scale (PANAS), and subjective and objective outcome measures of balance and gait. RESULTS: The PANAS scale was utilized to group subjects (N = 118) into two groups: Subjects with abnormal affect (SAA) (18.6%; N = 22) and subjects with normal affect (SNA) (81.4%; N = 96). Both groups demonstrated a statistically significant improvement in all outcome measures (p  < 0.001 ) from evaluation to discharge. SAA subjects took longer than SNA subjects to achieve goals (p  < 0.05). SAA subjects tended to have poorer outcome measure scores at both initial and final assessment, but this was not statistically significant (p  > 0.05). CONCLUSIONS: Results from this study indicate that VRT is effective in treating vestibular disorders in individuals with symptoms of psychological distress such as anxiety and depression. However, individuals with these symptoms may not achieve as high of outcomes as those that do not report symptoms of psychological distress. Show more

Keywords: Vestibular disorders, anxiety, depression, vestibular rehabilitation, outcome measures

DOI: 10.3233/VES-170627

Citation: Journal of Vestibular Research, vol. 27, no. 5-6, pp. 295-303, 2017

Authors: Morisod, Benoît | Mermod, Maxime | Maire, Raphaël

Article Type: Research Article

Abstract: INTRODUCTION: Chronic subjective dizziness (CSD) is frequently encountered in neurotology clinics. This diagnosis is mainly clinical, but computerized dynamic posturography (CDP) could be a helpful instrumental tool in the identification of these patients and validation of the treatment. This study was aimed to look for a specific posturographic pattern among patients diagnosed with CSD, and to eventually visualize improvement after vestibular rehabilitation. METHODS: Single center, retrospective review from 2009 to 2014. We included patients diagnosed with CSD who underwent CDP in their neurotologic assessment. For those patients who benefited from vestibular rehabilitation, we compared their pre- and post-rehabilitation …posturographies. RESULTS: We included 114 patients, of whom 74% had known anxiety disorders and 33% a history of past vestibular disorder. 62% of the assessment posturographies were abnormal. The most affected sub-items were limit of stability, composite score of sensory organization tests and condition 5 in respectively 34%, 23% and 20% of the cases. In univariate analysis, only pathologic videonystagmography and history of unilateral vestibular dysfunction were significantly related to abnormal posturography. In the 42 patients who had vestibular rehabilitation and a post rehabilitation posturography, the proportion of abnormal posturography significantly dropped from 79% to 33% (p  < 0.001). When it was assessed, 79% of the patients reported a subjective improvement. CONCLUSION: Patients with CSD have a high rate of abnormal posturography, but without a specific pattern. Vestibular rehabilitation is an effective tool in the therapeutic armamentarium. Show more

Keywords: Chronic subjective dizziness, posturography, vestibular rehabilitation

DOI: 10.3233/VES-170628

Citation: Journal of Vestibular Research, vol. 27, no. 5-6, pp. 305-311, 2017

Authors: Tjernström, Fredrik | Fransson, Per-Anders | Kahlon, Babar | Karlberg, Mikael | Lindberg, Sven | Siesjö, Peter | Magnusson, Måns

Article Type: Research Article

Abstract: OBJECT: To evaluate post-surgical postural stability when treating patients with remaining vestibular function with intratympanic gentamicin (PREHAB) prior to schwannoma surgery. METHOD: 44 consecutive patients with some form remaining vestibular function scheduled for vestibular schwannoma surgery. 20 were medically deafferented with intratympanic gentamicin before surgery and 24 were not. Both groups were of the same age, had the same tumor size, same type of surgery, and same perioperative sensory rehabilitation (training exercises), and no surgical complications. Postural stability measured as energy expenditure while standing on a force platform during vibratory stimulation of the calf muscles, performed prior to …surgery (or gentamicin treatment) and 6 months after surgery. RESULTS: Patients pretreated with gentamicin had significantly better postural stability at the time for follow-up (p  < 0.05) and displayed a better adaptive capacity when faced with a postural challenge (p  < 0.01). They were also able to use vision more efficiently to control their stability (p  < 0.05). CONCLUSIONS: By separating the sensory loss (through intratympanic gentamicin, that ablates the remaining vestibular function) from the intracranial surgical trauma, the postural control system benefited from a better short-term (adaptation) and long-term (habituation) recovery, when experiencing a postural challenge or resolving a sensory conflict. The benefits could be attributed to; active and continuous motor learning as the vestibular function slowly attenuates; no concomitant central nervous dysfunction due to effects from neurosurgery, thus allowing time for a separate unimpeded recovery process with more limited challenges and objectives; and the initiation and certain progression of sensory reweighting processes allowed prior to surgery. In contrast, worse compensation could be due to; immobilization from nausea after surgery, harmful amount of stress and cognitive dysfunction from the combination of surgical and sensory trauma and an abrupt vestibular deafferentation and its consequences on sensory reweighting. Show more

Keywords: Schwannoma, rehabilitation, postural control, gentamicin

DOI: 10.3233/VES-170626

Citation: Journal of Vestibular Research, vol. 27, no. 5-6, pp. 313-325, 2017