Worsening of levodopa-induced dyskinesias by motor and mental tasks.

Ten patients who had Parkinson's disease with disabling dyskinesia were included in this study to evaluate the role of mental (mental calculation) and motor (flexion/extension of right fingers, flexion/extension of left fingers, flexion/extension of the neck, speaking aloud) tasks on the worsening of peak-dose dyskinesia following administration of an effective single dose of apomorphine. Compared with the score at rest (1.3+/-0.3), a significant aggravation of the dyskinesia score was observed during speaking aloud (5.2+/-1.1, p<0.05), movements of right (4.5+/-1.0, p<0.05) and left (3.7+/-0.8, p<0.05) fingers, movements of the neck (5.1+/-1.0, p<0.05), and mental calculation (3.1+/-1.0, p<0.05). These results suggest that activation tasks such as "speaking aloud" could be used for objective assessment of dyskinesia severity.