Forms of dystonia in patients with Parkinson's disease.

We studied various forms of dystonia associated with Parkinson's disease (PD) in 207 patients who were on levodopa therapy for more than 1 year. Dystonia, sometimes more than one type, occurred in 63 (30%). In five patients, dystonia preceded initiation of treatment. Fifteen patients had peak-dose dystonia, 33 had early-morning dystonia, and 20 had "off-period" dystonia. The different clinical features of the dystonias are presented and compared. Findings indicate that dystonia is a frequent feature of levodopa-treated PD patients.