Prevalence of Vestibular Dysfunction with Presbycusis among Elderly in Malaysia

Objectives: This study aims to determine the prevalence of vestibular dysfunction in the Malaysian elderly and its association with presbycusis, age and other associated risk factors. Methods: A cross-sectional study was undertaken in a tertiary otorhinolaryngology department and the community. Adults aged 60 years and above who attended the ORL CLINIC with or without presbycusis were invited to participate. The main outcome measures, including the Malay Version Vertigo Symptoms Scale, pure tone audiometry and vestibular assessment, were obtained using a Video Head Impulse Test (VHIT). Results: The prevalence of vestibular dysfunction with presbycusis in the study population of 135 participants was 46.7 per cent (95 per cent confidence interval, 24.0 to 36.2 per cent). The median age was 68 years (range, 60–86 years). The A chi-square test of independence showed that there was significant association between Presbycusis and Tinnitus, X2 (1, N = 135) = 97.37, p < .001. A chi-square test of independence was performed to examine the relation between presbycusis and dizziness. The relation between these variables was significant, X2 (2, N = 135) = 28.42, p < .001. A chi-square test of independence showed that there was no significant association between presbycusis and VHIT, X2 (1, N = 135) = .01, p = .938. Conclusion: Vestibular dysfunction is independently associated with ageing and presbycusis. More research investigating the advantages of additional screening for vestibular dysfunction in older presbycusis patients is needed. Key words: Elderly; Presbycusis; Vestibular dysfunction; Video Head Impulse Test (VHIT)

Report of oscillopsia in ataxia patients correlates with activity, not vestibular ocular reflex gain

BACKGROUND: Patients with cerebellar ataxia report oscillopsia, “bouncy vision” during activity, yet little is known how this impacts daily function. The purpose of this study was to quantify the magnitude of oscillopsia and investigate its relation to vestibulo-ocular reflex (VOR) function and daily activity in cerebellar ataxia. METHODS: 19 patients diagnosed with cerebellar ataxia and reports of oscillopsia with activity were examined using the video head impulse test (vHIT), Oscillopsia Functional Index (OFI), and clinical gait measures. Video head impulse data was compared against 40 healthy controls. RESULTS: OFI scores in ataxia patients were severe and inversely correlated with gait velocity (r = –0.55, p < 0.05), but did not correlate with VOR gains. The mean VOR gain in the ataxic patients was significantly reduced and more varied compared with healthy controls. All patients had abnormal VOR gains and eye/head movement patterns in at least one semicircular canal during VHIT with passive head rotation. CONCLUSIONS: Patients with cerebellar ataxia and oscillopsia have impaired VOR gains, yet severity of oscillopsia and VOR gains are not correlated. Patients with cerebellar ataxia have abnormal oculomotor behavior during passive head rotation that is correlated with gait velocity, but not magnitude of oscillopsia.

Enhanced Eye Velocity With Backup Saccades in vHIT Tests of a Menière Disease Patient: A Case Report

Reduced eye velocity and overt or covert compensatory saccades during horizontal head impulse testing are the signs of reduced vestibular function. However, here we report the unusual case of a patient who had enhanced eye velocity during horizontal head impulses followed by a corrective saccade. We term this saccade a “backup saccade” because it acts to compensate for the gaze position error caused by the enhanced velocity (and enhanced VOR gain) and acts to return gaze directly to the fixation target as shown by eye position records. We distinguish backup saccades from overt or covert compensatory saccades or the anticompensatory quick eye movement (ACQEM) of Heuberger et al. (1) ACQEMs are anticompensatory in that they are in the same direction as head velocity and so, act to take gaze off the target and thus require later compensatory (overt) saccades to return gaze to the target. Neither of these responses were found in this patient. The patient here was diagnosed with unilateral definite Meniere's disease (MD) on the right and had enhanced VOR (gain of 1.17) for rightward head impulses followed by backup saccades. For leftwards head impulses eye velocity and VOR gain were in the normal range (VOR gain of 0.89). As further confirmation, testing with 1.84 Hz horizontal sinusoidal head movements in the visual-vestibular (VVOR) paradigm also showed these backup saccades for rightwards head turns but normal slow phase eye velocity responses without backup saccades for leftwards had turns. This evidence shows that backup saccades can be observed in some MD patients who show enhanced eye velocity responses during vHIT and that these backup saccades act to correct for gaze position error caused by the enhanced eye velocity during the head impulse and so have a compensatory effect on gaze stabilization.