[The characteristics of endogenous evoked potentials during normal psychomotor reactions and during basal ganglionic dysfunction in man].

Averaged cortical EPs (or the ERPs) in response to light stimuli were analysed in the Fz, Pz and Oz leads in healthy subjects and in Parkinsonian patients. The largest CNV and Nd (negative difference) were recorded in the Fz, the negative waves being inversely related to each other. A delay in psychomotor responses was accompanied by a decrease in the endogenous ERPs in all the leads in Parkinsonian patients. The ERp attenuation seems to be connected with the cortical hypoactivation due to the basal ganglia disfunction.