Severe evening dyskinesias in advanced Parkinson's disease: clinical description, relation to plasma levodopa, and treatment.

We report four patients with Parkinson's disease who had an unusual pattern of severe chorea and dystonia in the evenings only. The temporal pattern of abnormal movements and simultaneous monitoring of plasma levodopa and clinical state were consistent with dyskinesias associated with subtherapeutic (low dopa dyskinesias) rather than peak concentrations of levodopa (high dopa dyskinesias). In two patients, addition of a direct-acting dopamine receptor agonist was helpful in ameliorating this complication of antiparkinson therapy.