SUN-271 Prominent Parietal Lobe Brain Injury in a Neonate with Seizure Due to Hyperinsulinemic Hypoglycemia

Abstract

Background: Severe hypoglycemia causes brain injury in neonates, which is most commonly described as white matter (WM) changes in the occipital region. These WM changes can extend anteriorly to involve the parietal regions, which can be equally or less severely affected (1, 2). Early visual impairment can be seen in patients with severe occipital involvement. Clinical Case: A male infant born at 39 weeks gestation via C-section after fetal intolerance of induction presented on day of life (DOL) 4 with seizure. Pregnancy was uncomplicated without gestational diabetes, hypertension, or infection. Birth weight was 3.1 kg. He had an unremarkable postnatal course and was discharged on DOL2. At home, he became sleepier with decreased feeding, and developed abnormal extremity movements. Tonic-clonic seizure activity was observed in the ED with serum glucose level of < 10 mg/dL, anion gap of 13 and trace ketonuria. Cerebral spinal fluid studies were not suggestive of infection. Glucose was corrected with intravenous dextrose. Brain CT scan without contrast showed hypodensity involving the distribution of the right posterior cerebral artery with loss of normal gray white differentiation. MRI brain without contrast showed bilateral WM restricted diffusion more prominent in the right parietal lobe than in the occipital lobes. There were also bilateral areas of cortical restricted diffusion in the occipital and parietal lobes, but no evidence of hypoxic ischemic encephalopathy. Proton MR Spectroscopy showed findings consistent with hypoglycemic brain injury. In the setting of hypoglycemia (serum glucose 37 mg/dL), serum beta-hydroxybutyrate was 0.13 mMol/L (0.02-0.27 mMol/L) and serum insulin was 5.7 mU/L (3.0-25.0 mU/L), consistent with hyperinsulinemic hypoglycemia. Growth hormone level (13.18 mg/mL) and ACTH stimulation test were normal. Treatment with diazoxide was initiated with excellent response. He was discharged and continues to work with Early Intervention. Conclusion: We describe a newborn with hyperinsulinemic hypoglycemia and more significant WM changes in the parietal lobe compared to the occipital lobe on brain MRI. Although occipital WM is thought to be most vulnerable to hypoglycemia, our patient’s findings suggest that parietal WM may also be disproportionally susceptible to injury. Neurodevelopmental deficits may be less obvious soon after injury, and long term surveillance of these patients is required.