Secondary Degemeration of the Pyramidal Trat following Cerebral Hemispherectomy in a Man

Abstract

Dandy8) in 1928 performed the first cerebal hemipherectomy in patients with infiltrating gliomas and Krynauw~O) in 1950 carried out a similar operative procedure in patients with infantile type hemiplegia associated with uncontrollable convulsions and mental aberrations. Subsequently many surgeons have performed the procedure (Table I and II.) and it is this material that has permitted further assessment of the various tracts and reflex arcs in the central nervous system. Among the observed phenomena has been the postoperative retention of some of the contralateral motor and sensory functions , especially in those patients who preoperatively had partial loss of these abilities. Karnosh17) (1937) made sections of the lower pons just above the pyramidal decussation in a patient who survived 29 days after riiht cerebral hemispherectomy for a brain tumor. He used myelin sheath staining methods. These sections revealed a demyelinized pyramidal tract at the decussation , but those fibers which were destined to remain uncrossed showed no such defect. Lassek and Evans2D (1945) reported that of three cases of human cerebral hemispherectomy for the removal of brain tumors, one patient survived for 330 days after operation. Stained sections of the brain stem in this case showed fibers in the pyramidal tract other than those originating in the cerebral cortex. PoweW29)(1952) described the residual neurons in the thalamus in a patient who survived for 24 days after the cerebral hemidecortication. Austin and Grant2) (1955) described their observations in four patients of right-sided hemispherectomy in adults. In one patient who survived two and one-half months postoperatively, thalamie sections revealed a complete ipsilateral degeneration of the nucleus ventralis posteromedialis. Except for these four reports no anatomical study of the cenetral nervous system after cerebral hemispherectomy has been reported in human cases. The purpose of this study is to present clinical and anstomical observations on the effect of cerebral hemispherectomy in a man.