[Movement-related cortical potentials upon forward-stepping in patients with Parkinson disease].

We investigated movement-related cortical potentials(MRCPs) in 20 patients with Parkinson disease(PD group) and 6 normal age-matched controls when they were stepping forward volitionally from standing position. PD group was divided in three groups according to the clinical courses and motor function scores in Langston's criteria: Ia; within 6 years and higher than 20 points, Ib; within 6 years and within 20 points, II; over 6 years. In Ia group their negative slope(NS') was larger than those in the other three groups, while their Bereitschaftspotential showed no statistical difference. The results of our investigation shows that, in these cases, the function of cerebral cortex and/or cerebellum can be enhanced compensating the dysfunction of basal ganglia.