Chronic Pontine Dysfunction Following Insulin-Induced Hypoglycemia in an IDDM Patient

Insulin-induced hypoglycemia is associated with significant morbidity and mortality in patients with insulin-dependent diabetes mellitus (IDDM). In addition to cognitive dysfunction, transient neurological abnormalities may result from the neuroglycopenia of acute hypoglycemia and can be protean in their manifestations. In experimental animals, the hippocampus, putamen, caudate, and cerebral cortex display the greatest vulnerability to hypoglycemic neuronal damage (1). In humans, permanent brain damage has been described in survivors of severe and protracted hypoglycemia and is usually localized to the cortex and hippocampus, sparing the cerebellum, brain stem, and spinal cord, which are more resistant to glucose deprivation (2). A man with IDDM is described who developed permanent pontine signs after an episode of severe hypoglycemia.