Analysis of L-dopa induced dyskinesias in 51 patients with Parkinsonism.

An analysis of 51 patients with Parkinsonism who have developed L-dopa induced dyskinesias is presented. The cause has not been proven, although various hypotheses are discussed. One third of the total number of patients treated developed dyskinesia. These patients tend to respond better to L-dopa than the other group. There is a tendency for the older patient or the patient with long-standing disease to develop dyskinesias. There appears to be no way of predicting which patients will develop dyskinesia by analysis of the symptoms or the aetiology of the Parkinsonism syndrome. The unilateral characteristic of the dyskinesia in patients with hemi-Parkinsonism and patients with unilateral thalamotomies suggests that structural abnormalities are critical in determining the presence and localization of dyskinesias. This is supported by non-occurrence of similarly treated patients without Parkinsonism.