Dyskinesias associated with lithium therapy in parkinsonism.

Five patients with the "on-off" phenomenon of parkinsonism who developed dyskinesias associated with a reduction in akinesia during treatment with lithium carbonate are described. The data show that lithium-induced dyskinesias may occur in the absence of lithium neurotoxicity and at normal serum lithium concentrations. These observations are interpreted in the context of recent evidence that indicates that lithium may "stabilize" dopaminergic and cholinergic receptor sensitivity.