Neuroglycopenia

Specialty: Endocrine and metabolic.

• cerebral suffering from hypoglycemia
• neuroglycopenic symptoms of low glucose
• brain glucose deprivation

Why it occurs

• Insulinoma (benign or malignant pancreatic neuroendocrine tumor that autonomously secretes insulin unrelated to plasma glucose levels)
• Errors in the administration of exogenous insulin or sulfonylureas in the treatment of diabetes mellitus
• Non-insulinoma pancreatogenic hypoglycemia syndrome or adult nesidioblastosis (diffuse hyperplasia of pancreatic beta cells)
• Primary adrenal insufficiency or Addisonian crisis (cortisol deficiency annuls hormonal counterregulation and compromises hepatic gluconeogenesis)
• Large extrapancreatic tumors such as fibrosarcomas or mesotheliomas that aberrantly produce IGF-2 (Doege-Potter syndrome)
• Severe acute liver failure or decompensated cirrhosis (massive failure in glycogen storage capacity and neoglycogenesis)

Initial workup

Formal demonstration of Whipple's Triad (presence of typical neuroglycopenic symptoms, simultaneous documentation of plasma glucose less than 55 mg/dL, and immediate and complete disappearance of the symptoms after raising glucose levels); determination of plasma insulin, C-peptide, proinsulin, and anti-insulin antibodies during a spontaneous or provoked hypoglycemic episode in a 72-hour supervised fasting test; screening for sulfonylureas in plasma and urine; and endoscopic ultrasound, magnetic resonance imaging, or pancreatic computed tomography with triphasic protocol.

Standard management

• 50% hypertonic glucose — immediate administration of 1-2 20 ml ampoules by direct and slow intravenous route, followed by a continuous infusion of 10% glucose to maintain stable glycemic levels above 100 mg/dL
• Glucagon — 1 mg intramuscularly or subcutaneously as emergency rescue therapy at home if venous access is not available
• Diazoxide — drug agonist of ATP-sensitive potassium channels in pancreatic beta cells that inhibits active insulin secretion, used at doses of 3-15 mg/kg/day in the medical management of inoperable insulinoma
• Octreotide — short-acting somatostatin analog, administered subcutaneously to suppress endogenous insulin secretion in sulfonylurea overdoses unresponsive to intravenous glucose