Persistent neonatal hypoglycemia due to hyperinsulinism: medical aspects.

Eight neonates with persistent hypoglycemia were seen over a four-year period and a ninth infant with neonatal onset was treated from 9 months of age. Seven infants had high absolute insulin levels (range 12 to 50 microunits/ml) during hypoglycemia whereas two patients had normal levels which were, however, inappropriate for the low blood glucose levels. Six patients with severe intractable hypoglycemia resistant to intensive medical therapy (including high dose diazoxide) had partial or total pancreatectomy, whereas three with relatively controllable hypoglycemia eventually had spontaneous remissions. In one of the medically treated patients, remission occurred at the unusually early age of 4 months. In the six surgically treated patients and in a seventh patient who had a biopsy only, the pancreas showed characteristic pathologic changes compatible with those described as nesidioblastosis or "endocrine-cell dysplasia." Of the six patients followed up for greater than or equal to 24 months, four have normal psychomotor development, despite periods of arrested head growth in early infancy in three of them.