Asymptomatic Hyperinsulinemic Hypoglycemia and Grade 4 Intraventricular Hemorrhage in a Late Preterm Infant

Hyperinsulinemic hypoglycemia (HH) has the potential to cause acute neurologic dysfunction and neurodevelopmental impairment. Parieto-occipital neuronal injuries have been reported in hypoglycemic infants, but intraparenchymal hemorrhage is rare. On day 5 of life, a late preterm infant was transferred to our care with recurrent asymptomatic hypoglycemia. Prior to arrival, plasma glucose levels were at a median of 1.25 mmol/L (22.5 mg/dL) in the first 6 hours of life, and he required a glucose infusion rate (GIR) of 22.6 mg/kg/min. Hyperinsulinism was confirmed in the presence of detectable insulin, low ketones, and fatty acid when hypoglycemic. A left grade 4 intraventricular hemorrhage (IVH) was noted in the cranial ultrasound scan during the workup for sepsis on the day of admission. However, magnetic resonance imaging of the brain on day 7 of life revealed extensive bilateral IVH. On day 9, he was initiated on diazoxide, and HH resolved within 48 to 72 hours, allowing increment of feeds while weaning GIR. Ventricular drain for post-hemorrhagic ventriculomegaly was advised but not performed. At 3 months, post-hemorrhagic ventriculomegaly was stable, and there were early signs of neurodevelopmental delay. After discontinuing diazoxide at 4 months of age, he passed an 8-hour fasting study confirming the resolution of HH. Severe hypoglycemia has been associated with cerebral hyperperfusion in preterm infants and potentially could cause IVH. Close monitoring and prompt intervention in preterm infants to prevent severe hypoglycemia are paramount. In addition to long-term neurodevelopmental follow-up, infants with recurrent hypoglycemia may benefit from neuroimaging and thereby early intervention if required.