Olivopontocerebellar atrophy (OPCA) refers to a group of ataxias characterized by progressive neurological degeneration affecting the cerebellum, the pons and the inferior olives. OPCA may be classified based on clinical, genetic, or neuropathological findings; thus, there are many classifications of the disorder. Among the different classifications there is wide variation in severity and age of onset. The symptoms of OPCA differ from person to person. Most patients experience difficulty with balance and coordination of the legs and arms (ataxia) and slurred speech (dysarthria).