Vestibular ocular reflexes in Ménière's disease patients evaluated by passive high frequency head rotation (yaw) and sidewards acceleration.
Despite the fact that vertigo is the most apparent complaint at the onset of Ménière's disease, standard vestibular examination seldom shows vestibular function loss in the early phase. In this study, three relatively advanced diagnostic tests (passive high frequency head shaking, passive head impulse test and sidewards linear acceleration) were applied to trace vestibular function loss in the early phase in 25 patients with possible Ménière's disease (American Academy of Otolaryngology-Head and Neck Surgery 1995 criteria); one test (passive high frequency head shaking) was also conducted in 20 chronic definite Ménière's disease patients. Head movements were induced by a head shaker and whole-body linear translation by a motor-driven linear slit. Eye movements were detected by electro-oculography (head shaking) and the scleral coil technique (impulse test and linear translation). Standard vestibular examination showed no vestibular function loss in the early phase patient group. In contrast, 17 out of 25 patients (68%) showed a phase lag upon head shaking that was 1-2 degrees larger than the 95% confidence interval in healthy subjects; the remaining 8 patients showed a normal phase lag. Gain was normal in all 25 patients. In the chronic patient group, standard vestibular examination was abnormal (calorics) in 16 out of 20 patients (60%) and 18 out of 20 (90%) showed an abnormal phase on passive head shaking. In 11 of the 25 early phase patients (44%), an increased latency was observed in the response to a passive head impulse to one side. The side to which the abnormal latency occurred did not correspond to the documented or reported side of the hearing loss in 2 out of the 11 patients. The amplitude of ocular counter rolling induced by sidewards sinusoidal translation was reduced in 17 out of the 25 early phase Ménière's disease patients, of whom 6 showed a normal head impulse and head shaking test. Our findings indicate that vestibular function loss occurs in Ménière's disease patients within 9 months of the first vertigo attack. Also, the results support the hypothesis that, at least in some patients, function loss in the statolith system might precede function loss in the horizontal canals.