An Experimental Study of Total Hemispherectomy in the Albino Rabbit.

Kim, Youn; Sim, Bo Sung

Original Article

Journal of Korean Neurosurgical Society 1976;5(2): 1-12.

Department of Neurosurgery, College of Medcine, Seoul National University, Seoul, Korea.

ABSTRACT

The purpose of this study is to present the physiological and anatomical observations on the effect of cerebral hemispherectomy and total hemispherectomy including ipsilateral thalamus in albino rabbits. In this study, twenty healthy male albino rabbits weighing 1.8-2.0 kg were subjected to one stage removal of one cerebral hemisphere including unilateral basal ganglia and thalamus (total hemispherectomy) and unilateral cerebral hemisphere preserving basal ganglia (cerebral hemispherectomy). In 8 albino rabbits, cerebral hemispherectomy was performed and in 12, total hemispherectomy. These experimental animals were frequently observed for periods varying from a few days to three weeks. The postoperative physiological findings were as follows : All survived experimental animals demonstrated early and rapid return of consciousness, giving evidence of awareness of environment noting objects in their remaining ipsilateral homonymous visual field. After recovery form anesthesia, all experimental animals were able to move their contralateral limbs, however when they attempted to walk they staggered to the opposite side for a while. A few days later they showed almost same motor function and walked making circle to the operated side. About two weeks later, they could walk as normal rabbits. Following unilateral cerebral hemispherectomy or total hemispherectomy, all animals were able to respond to painful stimuli on the contralateral side when they awoke from aneshesia. The grade of response to painful stimuli was gradually getting better until about one week postoperatively, but there were some deficit in the contalateral side comparing to the ipsilateral side when examined on postoperative three weeks. Contralateral homonymous hemianopsia was considered to be a permanent neurologic deficit in all experimental animals. The brain stem and spinal cord, removed during two or three weeks postoperatively, were stained with Luxol fast blue staining method, however, there was no evidence of bilateral pyramidal innervation in all experimental animals.