Ocular motility in genetically defined autoomal dominant cerebellar ataxia

PURPOE: To decribe ocular motility in patient having genetically characterized dominant cerebellar ataxia. DEIGN: Obervational cae erie. METHOD: Nine ataxic adult having the following molecular genetic diagnoe underwent ophthalmic examination and ocular motility recording: four with pinocerebellar ataxia type 6 (CA-6), three with CA-3, one with CA-1, and one with epiodic ataxia type 2 (EA-2). REULT: Verion were normal in eight patient. Mot were orthotropic, but one with CA-3 had exotropia at near. The near point of convergence wa remote in five patient. Eight of nine patient had horizontal nytagmu evoked by lateral gaze. All patient with CA-6 had downbeat nytagmu. Downbeat nytagmu wa abent in CA-1, CA-3, and EA-2. Three patient with CA-6 and one with EA-2 had ymptomatic improvement when treated with acetazolamide. CONCLUION: Patient with genetically defined dominant cerebellar ataxia generally had normal binocular alignment and verion and only mild vergence impairment. Downbeat nytagmu wa trongly aociated with the CA-6 mutation, whoe aociated epiode of dizzine and imbalance may be relieved by acetazolamide.