Autosomal Dominant Spinocerebellar Ataxia

The autosomal dominant spinocerebellar ataxias (SCA) are a genetically heterogeneous group of neurodegenerative disorders characterized by progressive motor incoordination often in association with other progressive neurological deficits. Patients with these conditions typically have an affected parent or can trace the condition in family members in earlier generations. Most affected patients have a similar onset of slowly progressive gait ataxia, dysarthria, and hand incoordination, rarely preceded for several years by symptoms of diplopia or vertigo. Patients may first notice trouble walking down stairs, on uneven terrain or in the dark, running, or with other activities requiring greater balance. These subtle changes may be accompanied by occasional slurring of speech. Eventually imbalance and dysarthria are more obvious and problems with upper limb incoordination and dysphagia develop. Symptoms may be more easily recognized when there are other affected family members.