Characteristics of motor potentials on impairment of the function of subcortical human brain motor structures.

We have investigated the characteristics of motor potentials (MPs) in patients with impaired function of subcortical motor structures of the brain, causing symptoms of parkinsonism. We have isolated the MP components that precede movement, such as "the readiness potential" (N1), "the motor potential" (N2), and MP components which are electrophysiological correlates of processes of execution (P2 component) and of completion (N3 component) of movement. We established that in parkinsonism patients the MPs are changed compared to the normal; the most significant changes were observed in components N1, P2, and N3 as shown by a prolongation and certain decrease in the amplitude of these components. Component N2, regarded to be an electrophysiological correlate, reflecting the triggering of movement, has amplitude-time related parameters that are the most similar to the normal. We believe that this component is of cortical origin.