STEREOENCEPHALOTOMY

Abstract

The exposure of subcortical structures by the classical methods of neurosurgery usually is associated with considerable damage to the overlying cerebral tissue. Nevertheless, therapeutic procedures in the depth of the brain can be carried out with minimum injury to the cerebral hemispheres if needle electrodes are introduced by means of an apparatus that permits the exact regulation of their position, direction, and depth. The apparatus we devised, the stereoencephalotome (SET),¹is an adaptation to the human brain of the so-called stereotaxic method used by Horsley and Clarke²in animal experiments. Our apparatus consists of a base and a frame (Fig. 1). The base (B) is anchored to the skull in a position parallel to Reid's base line by various plugs and auxiliary holders. On the frame (F) the needle carrier is fixed which can be moved in any plane and direction. In order to place the lesions correctly