RELATIONSHIP BETWEEN COGNITIVE IMPAIRMENTS, EVENT-RELATED POTENTIALS,AND MOTOR DISABILITY SCORES IN PATIENTS WITH PARKINSONS-DISEASE - 2-YEAR FOLLOW-UP-STUDY

We studied event-related potentials and the cognitive state for 2 year s in 29 patients with Parkinson's disease (PD). Of those patients, 11 were at stage II and 18 were at stage III at initial assessment, as me asured on the Hoehn and Yahr scale. The peak latency of P300 in patien ts at stage III was significantly prolonged, as compared with that in age-matched normal controls or PD patients at stage II. There was no s ignificant change in P300 latency among patients whose motor ability r emained unchanged at stage II or stage III during follow-up period. Th e mean P300 latency prolonged significantly in patients whose motor ab ility worsened from stage III to stage IV. The cognitive state in the patients with PD was characterized by impairment in the categories of orientation, recall and constructional ability. The degree of impairme nt of these items increased as the motor disability increased. These r esults suggest that cognitive dysfunctions and abnormality of P300 lat ency increased as the motor disabilities progressed.