ANALYSIS OF PREMOVEMENT COMPONENTS OF MOVEMENT-RELATED CORTICAL POTENTIALS IN PATIENTS WITH PARKINSONS-DISEASE OR BRAIN-TUMORS

We have recorded movement-related cortical potentials (MRCPs) preceding voluntary finger extension in patients with Parkinson's disease and in patients with brain tumors that may involve the motor system. Three components of potential shifts preceding the voluntary movement were identified in all subjects. There were no differences between the healthy subjects and those with Parkinson’s disease, or between pre- and postoperative recordings from the same parkinsonian patients in terms of onset latencies and gradients of these potential shifts. There was no evidence of MRCPs from the depth electroencephalogram recorded from the thalamic ventrolateral (VL) nucleus. After removal of the cerebellar dentate nucleus along with a tumor, MRCPs were still identified. After removal of tumors from the supplementary motor cortex and frontal association cortex, a part of the MRCPs preceding the voluntary movement was absent. The generation of MRCPs was considered not to be greatly affected by the cerebellar system because: (I) no MRCPs were detected from the thalamic VL nucleus, which is the relay nucleus of the dentato-rubro-thalamic pathway, believed to be related to voluntary movement; (2) destruction of the VL nucleus did not cause any changes in the MRCPs recorded at other sites, and (3) the MRCPs did not disappear when the dentate nucleus, an output system, was excised. © 1990 S. Karger AG, Basel.