Brain damage in the monkey, Macaca mulatta, by asphyxia neonatorum

Abstract

Asphyxia neonatorum was induced in monkeys near term by detaching the placenta at hysterotomy under local anesthesia, keeping the fetal membranes intact. Eleven to 16 minutes later the fetuses were delivered from their membranes and resuscitated by pulmonary insufflation with oxygen. The infant monkeys showed neurologic deficits during life. Five were killed by perfusion-fixation at 2 to 9 days of age. Brains of these and of 2 which were not asphyxiated were studied. A common pattern of structural alteration was encountered in the nervous system of the asphyxiated monkeys. Nuclei were symmetrically affected; those most consistently and severely damaged were the nucleus of the inferior colliculus, gracile and medial cuneate nuclei, roof nuclei of cerebellum, ventral posterior group of thalamic nuclei, globus pallidus, putamen, and vestibular nuclei. The cerebral cortex was severely damaged in only one monkey. Lesions began with primary nerve cell and, less frequently, neuroglia cell lysis and loss. Secondary damage of myelin sheaths, and reactions of astrocytes, endothelial cells, vascular adventitial cells, and phagocytes were noted. A relation of lesions to vascular distribution was not apparent. Hemorrhages were seldom encountered.