Different neurologic outcomes in two patients with neonatal hyperinsulinemic hypoglycemia.

The authors report the cases of two patients with neonatal onset of hypoketotic hypoglycemia with hyperinsulinism and a poor response to diazoxide. Pancreatic venous sampling showed a diffuse pancreatic hyperplasia in one patient and a focal lesion in the other. The second patient, diagnosed after a significant delay, suffered severe long-term neurological sequelae, despite having more limited hyperplasia; the brain MRI also showed severe pathological changes in cortex and white matter, predominantly in the parieto-occipital region. Early and accurate diagnosis is critical in these patients in whom hypoglycemia is compounded by a lack of the ketone bodies which represent a vital alternative source of energy for the central nervous system.