Acute Effects and Long-Term Neurological Consequences of Insulin-Induced Hypoglycaemia in the Newborn Rabbit

Abstract

Insulin-induced hypoglycaemia was studied in neonatal rabbits which were survived for long-term follow-up of neurological development. During hypoglycaemia there was a high incidence of convulsions, respiratory abnormalities and death. Temporary neurological defects suggestive of cerebellar damage were seen in some of the survivors who were normal by 3 weeks of age. A permanent defect of the limbs was seen in a few cases from 4 to 7 weeks of age, its nature suggesting damage in the hemispheres. Both types of abnormality are discussed in relation to perinatal brain growth spurts in the rabbit. It is suggested that brain hypoxia following clonic convulsions and serious repiratory difficulty is the most important contributory factor in this damage. A direct link between blood glucose level and respiratory performance in hypoglycaemia is postulated and a mechanism suggested for the initiation of gasping and apnoea following hypoglycaemic convulsions. Attention is drawn to the role hypoxia may play in the production of so-called hypoglycaemic brain damage in the human infant.