Electrophysiologic investigations in Parkinson's disease and other dyskinesias in man

Abstract

As a preliminary to the treatment of dyskinesias, neurophysiologic investigations of various nuclear masses have been carried out. The areas which have been primarily explored include the region of the globus pallidus and its efferent pathways and the nuclei ventralis lateralis and centrum medianum of the thalamus. The physiologic responses, consisting of initiation, augmentation, and suppression of the particular abnormal movement, were useful in locating the surgical target to be destroyed for definitive therapy. In a group of 24 patients, the physiologic responsiveness of target areas correlated with the clinical response to lesions produced in these areas. In accordance with the results of ablation studies, there seems to be a hierarchy of relative importance of certain basal ganglionic and thalamic areas in their ability to maintain the particular abnormal movement. This view is supported by the results of stimulation with the greatest motor activity following stimulation in the regions of ventralis lateralis and centrum medianum of the thalamus. We have found that the region of nucleus centrum medianum and the fibrous pathways in its vicinity appear to be an excellent surgical target in the therapy of both resting and action tremors.