MOTOR RESPONSE TO APOMORPHINE AND LEVODOPA IN ASYMMETRIC PARKINSONS-DISEASE

The motor responses of 14 patients with Parkinson's disease (six previ ously untreated and eight chronically receiving levodopa) with pronoun ced asymmetry in the severity of motor signs between the left and righ t sides of the body were studied. The effects of a short (60 minutes) and a long (16-22 hours) intravenous levodopa infusion as web as of su bcutaneous apomorphine (1-6 mg bolus) were assessed. Four different ta pping tests were used to measure motor function. For all pharmacologic al tests, the more affected side showed a shorter response duration, i ncreased latency, and greater response magnitude than the less affecte d side. These differences were more pronounced in those patients recei ving chronic levodopa treatment. As apomorphine is not dependent on do pamine storage capacity, these findings suggest that postsynaptic mech anisms play an important part in the origin of motor fluctuations in P arkinson's disease.