PARKINSONS-DISEASE, COGNITION AND AGING CLINICAL, NEUROPSYCHOLOGICAL,ELECTROPHYSIOLOGICAL AND CRANIAL COMPUTERIZED TOMOGRAPHIC ASSESSMENT

Forty-three patients with Parkinson's disease (PD) and thirty-seven no rmal volunteers were subjected to clinical, neuropsychological, neurop hysiological (P300 component of the event-related potentials ERP) and radiological (cranial computerized tomographic scanning CCT) evaluatio n. Intentional memory was more impaired in PD than in normal controls, more so in the demented group of patients, and was related to enlarge ment of third ventricular size in CCT. While intentional memory was ag e related in PD patients, perception was age-related in normal control s. Neither global nor specific cognitive functions were related to dur ation, severity of parkinsonian motor disability, or depression. Howev er, depression in PD was significantly related to parkinsonian motor d isability. P300 latency was more prolonged in PD patients than normal controls. P300 parameters of PD patients were not influenced by age, c ognitive functions, duration or severity of motor disability, or depre ssion. The reaction time was the only P300 parameter that was age-rela ted in normal controls. Subcortical atrophy as indicated by CCT was mo re marked in PD and correlated with age in both patients and controls. Subcortical atrophy was significantly related to cognitive functions in PD but not in normal controls. It was concluded that cognitive impa irment in PD could be attributed to complex cognitive changes rather t han age. It is a disease process, though not directly related to parki nsonian motor disability or depression. PD differed from normal aging as regards the effect of age on the specific cognitive functions, wher e in PD patients, age was related to intentional memory, yet in normal controls, it was related to perception. Intentional memory deteriorat ion was found to be specific of PD, being related to subcortical atrop hy as well as being more pronounced in the demented group of patients.