Localization of Stereotaxic Lesions in the Treatment of Parkinsonism: A Clinico-Pathological Comparison

Abstract

p ARKINSONISM is a well-documented syndrome and its pathology has been widely studied. The current surgical treatment of this disorder is carried out by focal interruption of nerve pathways in the region of the thalamus and basal ganglia. In the Department of Surgical Neurology, Edinburgh, the stereotax~.c method employed is that described in 1958 by Guiot 2 and modified in 1960 by Gillingham. 1 A posterior approach is used, and thalamic, capsular, or pallidal lesions can be achieved through one track (Fig. 1 ). A thermal lesion is made by electrocoagulation at the planned target areas, which are usually in the ventrolateral nucleus of the thalamus in the midcommissural plane, 5 mm above the intercommissural plane and 12 to 17 mm from the midsagittal plane, and in the medial segment of the globus pallidus 3 mm behind the anterior commissure, 1 mm below the intercommissural plane and 12 to 17 mm from the midsagittal plane. A stainless steel ball is inserted at the target point after coagulation (Fig. 2) , and its position can be charted on the stereotaxic atlas of Schaltenbrand and Bailey. 3 The purpose of this paper is to compare the planned positions of the surgical lesions with their actual positions as determined by postmortem examination.