Journal of Vestibular Research - Volume 29, issue 6

Authors: Tamás, László T. | Obrist, Dominik | Avan, Paul | Büki, Béla

Article Type: Research Article

Abstract: BACKGROUND: It has been shown that cold caloric irrigation decreases the vestibulo-ocular reflex (VOR) gain in the vertically positioned lateral canal as measured by head impulse testing. This effect is most probably caused by a sustained deflection of the cupula in the inhibitory direction. OBJECTIVE: The aim of the present experiment was to answer the question if a sustained excitatory deflection increases the gain of the reflex in healthy volunteers. METHODS: In order to deflect the cupula, cold caloric irrigation was applied in prone (forward head hanging) position. In this position cold thermal irrigation elicited an …excitatory caloric nystagmus with an ipsilateral fast phase. RESULTS: When head impulses were applied immediately after cold caloric irrigation, the gain of the VOR decreased in comparison to the values measured before irrigation. CONCLUSIONS: Together with the previous results cited above, these data show that biasing the cupula in either direction decreases its sensitivity with respect to high acceleration stimuli. This might occur because the deviation elicits a partial mechanical and electrophysiological saturation of the cupula. Show more

Keywords: Vestibular, caloric, cupula, vestibulo-ocular reflex

DOI: 10.3233/VES-190681

Citation: Journal of Vestibular Research, vol. 29, no. 6, pp. 281-286, 2019

Authors: Anton, Kristina | Ernst, Arne | Basta, Dietmar

Article Type: Research Article

Abstract: BACKGROUND: Postural stability might be influenced by auditory input as humans utilize spatiotemporal information to localise sound sources. Earlier studies investigated the acoustic influence on posture but unfortunately experimental setup, room acoustics and conditions of participants varied widely. OBJECTIVE: This study aimed at recording body sway velocity under clearly defined acoustic conditions in a homogenous group of young healthy participants. METHODS: Thirty participants performed five stance tasks (standing eyes open/closed, standing on a foam support eyes open/closed, Tandem Romberg test eyes closed) under four acoustic conditions (in quiet, with a loudspeaker presenting continuous/interrupted noise, with ear …protectors) in two different rooms (long/short reverberation time). Body sway velocity was determined close to body’s centre of gravity. RESULTS: Postural stability decreased significantly when continuous noise was applied and increased significantly when interrupted noise was presented in the reverberant room. The usage of ear protectors increased body sway velocity compared to quietness in both rooms. CONCLUSIONS: An impaired auditory input by plugging/acoustic masking reduced postural control. Interrupted noise seems to provide a continuously repeated feedback about the postural position in a reverberant room. Hence, the effect of hearing on posture highly depends on the structure of the auditory signal, the sensorimotor condition and the acoustic environment. Show more

Keywords: Auditory influence, mobile posturography, postural control, body sway, spatial cues

DOI: 10.3233/VES-190674

Citation: Journal of Vestibular Research, vol. 29, no. 6, pp. 287-294, 2019

Authors: Barin, Kamran

Article Type: Research Article

Abstract: BACKGROUND: The vestibulo-ocular reflex (VOR) gain is the primary parameter for quantifying and interpreting the video head impulse test (vHIT). Yet, the relationship between the VOR gain and the extent of canal function is not clear. OBJECTIVE: The goal of this paper was to determine if the loss of canal function in vHIT can be estimated from the VOR gain. METHODS: A model of the VOR was developed that included linear components for the cupula and the velocity storage mechanism as well as nonlinear components for the vestibular nerve and the vestibular nuclei. Multiple simulations were …carried out as the level of function for the right and left VOR pathways was varied systematically over their entire range. RESULTS: Simulation results were similar to the typical findings in normal individuals as well as in patients with unilateral and bilateral loss of canal function. Based on these simulations, a relationship between the canal function and the VOR gains was established. This relationship was surprisingly independent of most model parameters. CONCLUSIONS: The sum of right and left VOR gains (or 2 times the mean of VOR gains) at a given head velocity is an estimate of the total function of the involved canals. This simple formula can estimate the loss of canal function in purely unilateral lesions. For bilateral lesions, the same formula can estimate the total loss of bilateral function but contributions from individual canals cannot be determined without additional information. Show more

Keywords: Head impulse test, vestibular loss, vestibulo-ocular reflex (VOR), VOR Gain

DOI: 10.3233/VES-190688

Citation: Journal of Vestibular Research, vol. 29, no. 6, pp. 295-307, 2019

Authors: Matsuo, Lissa Maira | Nishino, Lucia Kazuko | Ribeiro, Fernando de Andrade Quintanilha

Article Type: Research Article

Abstract: Objective: To measure the time required in patients with tympanic perforation to reverse paradoxical stimulation (reverse pseudo-nystagmus) and to create a physical model of the process. Method: An analytical, observational, cross-sectional study with vestibular evaluation (electronystagmography) of 52 individuals with tympanic membrane perforation without otorrhea or concomitant disease. Increased duration of caloric stimulation in the presence of paradoxical stimulation (reverse pseudo-nystagmus) reverses nystagmic responses. Results: Reversal of nystagmus was observed in 90.9% of patients. The average reversal time was 105.5 seconds. The physical model we prepared provided supporting evidenced for the effects seen in these individuals: …warm stimulation in a moist environment initially caused a decrease in temperature (nystagmus to the unexpected side, which characterizes paradoxical stimulation in the warm caloric test); but, as time passed by, the moisture evaporated, and the temperature gradually increased (reversal of nystagmus). Conclusions: Increasing the stimulation time can be used as a strategy to differentiate reverse nystagmus from paradoxical stimulation. Confusion is thus avoided in diagnostic findings, allowing peripheral alterations to be distinguished from central ones. Show more

Keywords: Caloric tests, ear, middle, nystagmus, physiologic, tympanic membrane perforation

DOI: 10.3233/VES-190685

Citation: Journal of Vestibular Research, vol. 29, no. 6, pp. 309-314, 2019

Authors: Zhang, Daogong | Lv, Yafeng | Han, Yuechen | Li, Yawei | Li, Xiaofei | Wang, Jing | Song, Yongdong | Kong, Ligang | Jian, Huirong | Fan, Zhaomin | Wang, Haibo

Article Type: Research Article

Abstract: INTRODUCTION: Meniere’s disease is a common chronic inner ear disease. Because the definitive pathogenesis is still unknown, there is currently no cure for this disorder. Semicircular canal plugging (SCP), first used to treat patients with intractable benign paroxysmal positional vertigo, has since been applied to patients with intractable peripheral vertigo. This study was aimed to explore the long-term efficacy of triple semicircular canal plugging (TSCP) in the treatment of intractable Meniere’s disease (MD) so as to provide a new method in the framework of treatment with MD. METHODS: Three hundred and sixty-one unilateral MD patients, who were treated …with TSCP in our hospital between Dec. 2010 and Sep. 2016, were recruited in this study for retrospective analysis. Vertigo control and auditory function were monitored during a period of two-year follow-up. Seventy three patients who were subjected to intratympanic gentamicin were selected as a control group. Pure tone audiometry, caloric test, vestibular evoked myogenic potential (VEMP) were performed in two-year follow-up. RESULTS: The total control rate of vertigo in TSCP group was 97.8% (353/361) in the two-year follow-up, with complete control rate of 80.3% (290/361) and substantial control rate of 17.5% (63/361). The rate of hearing loss was 26.3% (95/361). The total control rate of vertigo in intratympanic gentamicin group was 83.6% (61/73), with complete control rate of 63.0% (46/73) and substantial control rate of 20.5% (15/73). The rate of hearing loss was 24.7% (18/73). The vertigo control rate of TSCP was significantly higher than that of chemical labyrinthectomy(χ 2  = 24.798, p  <  0.05). There was no significant difference of hearing loss rate between two groups. (χ 2  = 0.087, p  >  0.05). CONCLUSION: Triple semicircular canal plugging (TSCP), which can reduce vertiginous symptoms in patients with intractable Meniere’s disease (MD), represents an effective therapy for this disorder. It might become a new important method in the framework of treatment with MD. Show more

Keywords: Meniere’s disease, Semicircular canal plugging, Vertigo

DOI: 10.3233/VES-190682

Citation: Journal of Vestibular Research, vol. 29, no. 6, pp. 315-322, 2019

Authors: Bao, Tian | Klatt, Brooke N. | Carender, Wendy J. | Kinnaird, Catherine | Alsubaie, Saud | Whitney, Susan L. | Sienko, Kathleen H.

Article Type: Research Article

Abstract: BACKGROUND AND OBJECTIVE: This pilot study aimed to investigate the effects of incorporating vibrotactile sensory augmentation (SA) on balance performance among people with unilateral vestibular disorders (UVD). METHODS: Eight participants with UVD were recruited. Participants completed 18 balance training sessions across six weeks in a clinical setting. Four participants (68.1±7.5 yrs) were randomized to the experimental group (EG) and received trunk-based vibrotactile SA while performing the balance exercises, and four participants (63.1±11.3 yrs) were assigned to the control group (CG); CG participants completed the balance training without SA. Clinical and kinematic balance performance measures were collected before training; …midway through training; and one week, one month, and six months after training. RESULTS: All participants, regardless of group, demonstrated improvements in a subset of the clinical or balance metrics immediately following completion of the balance training protocol. The EG showed significantly greater improvements than the CG for the Activities-specific Balance Confidence Scale and postural stability during the two standing balance exercises with head movements. The EG also had larger improvements than the CG for the Sensory Organization Test (SOT), Mini Balance Evaluations Systems Test, Gait Speed Test, Dynamic Gait Index, Functional Gait Assessment, and vestibular reliance metric calculated based on the SOT. CONCLUSIONS: Incorporating vibrotactile SA into vestibular rehabilitation programs may lead to additional benefits that may be retained up to six months after training compared to training without vibrotactile SA. A larger study is warranted to demonstrate statistical significance between the groups. Show more

Keywords: Sensory augmentation, unilateral vestibular disorders, balance, vestibular rehabilitation, biofeedback, Clinical trial registration Number: NCT02867683

DOI: 10.3233/VES-190683

Citation: Journal of Vestibular Research, vol. 29, no. 6, pp. 323-334, 2019