[THE HIDDEN VESTIBULAR FEATURES OF MACHADO JOSEPH DISEASE (SPINOCEREBELLAR ATAXIA 3)].

INTRODUCTION: Machado-Joseph disease (MJD) is an inherited neurodegenerative disease with progressive cerebellar ataxia manifested through lack of coordination and balance. MJD patients also present significant Vestibulo-Ocular Reflex (VOR) deficit but their whole vestibular features have not been previously evaluated. We aimed to evaluate whether MJD patients have vestibular features fitting the diagnostic criteria of Bilateral Vestibulopathy established by the International Society for Neuro-otology. METHODS: Sixteen MJD patients and 21 healthy controls underwent a detailed clinical neuro-otological examination including a quantitative evaluation of the VOR gain using the video Head Impulse Test (vHIT). Vestibular-related symptoms were evaluated by the Dizziness Handicap Inventory (DHI), the Activities-specific Balance Confidence Scale (ABC), the Vertigo Visual Scale (VVS). In addition, anxiety that is frequently present in vestibular disorders, was evaluated by the Beck Anxiety Inventory (BAI). RESULTS: MJD patients had significantly reduced horizontal VOR gain with significantly higher scores in all vestibular-related symptoms questionnaires. These symptoms scores were like those reported in studies evaluating patients with bilateral peripheral vestibular loss. CONCLUSIONS: Beyond the cerebellar deficits, MJD patients have vestibular signs and symptoms fitting the diagnostic criteria of Bilateral Vestibulopathy established by the International Society for Neuro-otology. These findings are of relevance not only for the diagnosis and evaluation of progressive cerebellar diseases but also for the possible beneficial effect of vestibular rehabilitation techniques on dizziness, balance and the emotional, physiological and functional aspects of MJD.