NORMAL ACTIVATION OF THE SUPPLEMENTARY MOTOR AREA IN PATIENTS WITH PARKINSONS-DISEASE UNDERGOING LONG-TERM TREATMENT WITH LEVODOPA

Regional cerebral blood flow (rCBF) changes in cortical motor areas we re measured during a movement of the dominant right hand in 15 patient s with Parkinson's disease deprived of their usual levodopa treatment, in 11 patients with Parkinson's disease undergoing long-term treatmen t with levodopa, and in 15 normal volunteers. The supplementary motor areas were significantly activated in the normal subjects and in the p atients receiving levodopa but not in the patients deprived of levodop a. The contralateral primary sensory motor area was significantly acti vated in all three groups. The ipsilateral primary sensory motor corte x was not activated in the normal subjects and the non-treated patient s but was in the patients treated with levodopa. It is concluded that the supplementary motor area hypoactivation which is observed in akine tic nontreated patients with Parkinson's disease is not present in pat ients undergoing long-term treatment with levodopa. This result sugges ts that (a) levodopa improves the functional activity of supplementary motor areas in Parkinson's disease and (b) there is no pharmacologica l tolerance to this effect. The ipsilateral primary motor cortex activ ation observed in the patients treated with levodopa could be related to levodopa-induced induced abnormal involuntary movements.