[Central side effects of long-term treatment of Parkinson disease with levodopa preparations]

198 patients with Parkinson's disease on long-term treatment with L-dopa were evaluated for the presence of dyskinesias and psychiatric side-effects of the treatment. Dyskinesias were present in 53% of the patients. In a majority of them they appeared already during the first 2 years of the treatment. Younger patients seemed more susceptible to develop dyskinesias. Hallucinations, confusion, or delusions were observed in 22.2% of the patients. Older patients seemed more susceptible to develop these side-effects of the treatment. It seems that parkinsonian patients with later and earlier onset of the disease have different type of neuronal lesion responsible for the central side-effects of L-dopa.