DOPAMINERGIC INFLUENCES ON THE P300 ABNORMALITY IN PARKINSONS-DISEASE

This study was designed to evaluate the contribution of central dopami nergic mechanisms to the P300 event-related potential (P300) abnormali ty in Parkinson's disease. We measured the P300 in 37 non-demented pat ients with Parkinson's disease (19 de novo and 18 levodopa-treated) an d 15 age-matched healthy volunteers. The P300 measurement was repeated in 14 de novo patients, after 6-12 months levodopa therapy. The sever ity of parkinsonian symptom was assessed using the UPDRS-motor scale. De novo patients showed prolonged P300 latency compared with levodopa- treated patients, as well as healthy volunteers. The levodopa therapy for 6-12 months significantly shortened the P300 latency and reduced t he UPDRS-motor examination score in de novo patients. However, the per cent changes in the P300latency were not correlated with those in the UPDRS-motor examination score.These results indicate that the central dopaminergic mechanisms apart from those responsible for motor symptom s, may contribute to the P300 abnormality in Parkinson's disease. (C) 1998 Elsevier Science B.V.