Pure cerebello-olivary degeneration of Marie, Foix, and Alajouanine presenting with progressive cerebellar ataxia, cognitive decline, and chorea.

Parenchymatous cerebellar cortical atrophy (CCA) usually presents with a "pure" cerebellar ataxia. We describe a patient with a sporadic, late-onset progressive cerebellar ataxia plus cognitive decline and chorea who had CCA at post mortem. We discuss this unique case in the current context of classification of idiopathic cerebellar ataxia.