Results of vestibular autorotation testing at the end of intratympanic gentamicin treatment for Ménière's disease.

OBJECTIVE: The vestibular autorotation test (VAT) examines the ocular response to voluntary horizontal and vertical head movements at frequencies for which the vestibular system is the main source for eye stabilization. The purpose of this study was to analyse the VAT results in patients with disabling Ménière's disease and to evaluate the change in VAT values once treatment with intratympanic gentamicin had terminated and clinical signs of vestibular hypofunction could be observed.

MATERIAL AND METHODS: The 30 study subjects were patients diagnosed with definitive unilateral Ménière's disease that could not be controlled with medication. The vestibulo-ocular reflexes of each patient were evaluated by means of the VAT before the first injection of gentamicin and after the last injection.

RESULTS: The pattern of abnormalities found in this population conformed to the selection criteria and the findings reflected a severe disabling process, with major modifications in the vestibulo-ocular reflex. At the end of treatment there was a reduction in the peak frequency of head oscillation. Furthermore, we commonly found that, in the horizontal VAT, gain and phase were reduced while in the vertical VAT some subjects registered a normal response. The phase in the horizontal and vertical VATs was most significantly reduced for oscillation frequencies of 2-3.7 Hz.

CONCLUSION: This study provides further evidence that effective control of vertigo in patients with Ménière's disease can be achieved by administering intratympanic gentamicin.