Evoked potentials, reaction time and cognitive performance in on and off phases of Parkinson's disease

Seven patients with Parkinson's disease and severe motor fluctuations were studied with event-related potentials, reaction and movement times and neuropsychological tests while in "off" and "on" phases. While there was a significant decrement in the P300 latency of the event-related potentials and in the duration of movement time in the "on" phase, no significant differences between on and off phases were observed in reaction time and neuropsychological tasks.