Walsh & Hoyt: Cerebellar and Spinocerebellar Disorders

This complex group of disorders characterized by cerebellar dysfunction is mainly genetic in origin, although a few are caused by metabolic disturbances. This group also includes the congenital ataxias. The primarily genetic disorders are associated with dysgenesis of the cerebellum, and they are all nonprogressive. Other progressive and intermittent ataxic disorders are related to various underlying metabolic disturbances, and their clinical diagnosis is important because of possible therapeutic interventions. The categorization of the hereditary ataxias was mainly pathologic until the extensive surveys by Harding that led to a reclassification, largely by phenotypic constellations and age of onset. Subsequent advances in molecular genetics in this group of disorders provide a basis for a genomic classification.