Hemiballism and chorea in a patient with parkinsonism due to a multisystem degeneration.

Dyskinesias associated with dopaminergic treatment in idiopathic Parkinson's disease (PD) can be indistinguishable from those arising spontaneously in other conditions involving degeneration of, or damage to, the basal ganglia. However, those due to levodopa treatment of PD disappear on cessation of therapy. We report a patient with a clinical diagnosis of PD who, on levodopa treatment, developed hemiballism and chorea that were originally thought to be drug induced. However, the dyskinesias persisted despite stopping levodopa. Postmortem analysis showed a multisystem degeneration.