The choreoathetoid movement disorder induced by levodopa

Dyskinesia as a side effect induced by long‐term treatment with levodopa is reported on the basis of experience with 100 patients with Parkinson's disease receiving the agent for at least one year. The sex ratio of the patients was approxirrwtely 2:1 male to ferrwle, and their ages, duration of illness, and the etiologic distribution of idiopathic to postencephalic types were characteristic of a parkinsonian population. Concomitant with clinical improvement demonstrated by patients under levodopa treatment, choreoathetosis appeared as irregularly occurring involuntary movements, involVing head, face, jaw, tongue, shoulder, limbs, or trunk. These movements were usually exaggerated by voluntary movements, and the dyskinesia varied in severity throughout the day, being most severe soon after taking a regular dose of the drug. Since for most patients the dosage producing choreoathetoid movements is at or just below the effective dose of symptom control, a compromise between partial control of symptoms and disabling drug‐induced movements seems inevitable. Measures to control dyskinesia consisted mainly of lowering the dosage. No correlation was noted between the development of dyskinesia and previous stereotaxic surgery, etiology of Parkinson's disease, or its duration or severity. Choreoathetoid movements did not occur in normal control subjects receiving the drug or in patients with dystonia musculorum deformans or spastic torticollis, suggesting a strong specific predisposition in parkinsonian patients to this side effect.