Abstract
Spinocerebellar degeneration (SCD) is a progressive ataxia disease that can affect the spine, the cerebellum, the nervous system and the muscles. Recently, many of the dominantly inherited ataxias have been renamed Spinocerebellar Ataxia or SCA. The SCAs are usually followed by a number which indicates that the ataxia is caused by a specific genetic defect. New subtypes are found each year based on ongoing genetic studies. We now distinguish more than 60 SCA subtypes. In general, the main features of the clinical presentation of the patient with SCA are family history suggestive of autosomal-dominant traits, adult onset, mostly between 30-50 years, cerebellar ataxia with signs and symptoms of extra-cerebellar involvement in the majorities of cases, slow progression resulting in progressive impairment and variable phenotypes within one family. The patients frequently reveal unsteadiness of gait associated with nystagmus. Brainstem and cerebellar lesions affect physiological eye movements, e.g., saccade, smooth pursuit and VOR suppression. For this, some of them visit the otolaryngologist at their first hospital visit. To distinguish the SCA diseases from other peripheral vestibular disorder, it is necessary for otolaryngologists to understand the characteristics of the SCA diseases.
