Event-related potential and EEG measures in Parkinson's disease without and with dementia

Nondemented Parkinson's disease (PD) patients showed increased amplitude of event-related potential component P3. We recorded 18-channel spontaneous e yes-closed resting EEG and auditory oddball event-related potentials in 29 PD patients and 11 age-matched controls. Combining Mini-Mental State Examin ation score and oddball P3 counting performance, 15 patients were intellect ually normal, 7 moderately, and 7 severely demented. P3 and N1 amplitude an d latency, mean amplitude of 1,024 ms post-stimulus (separate after rare an d after frequent stimuli), and resting EEG total power for 40 s were comput ed, a nd linearly regressed for age, sex, and L-dopa dosage. In nondemented PD patients, increased P3 amplitude was confirmed, but N1 amplitude and me an amplitude after rare and frequent stimuli were also increased as well as - most important - resting EEG total power. With increasing dementia, ampl itude and power decreased, and P3 latency increased. Task demands cannot ex plain increased P3 amplitude, since similarly increased EEG total power was found during no-task resting. Prospective studies must determine whether P 3 amplitude and EEG power in nondemented PD patients can serve as predictor s of dementia. Copyright (C) 2000 S. Karger AG, Basel.