A Rare case Presentation of Osmotic Demyelination Syndrome Secondary to Postpartum Hypernatremia and Hypertensive Encephalopathy

Abstract

Background: Osmotic Demyelination Syndrome (ODS) is a rare neurological disorder typically linked to rapid correction of hyponatremia, but its occurrence due to hypernatremia, especially in the postpartum period, is exceedingly uncommon. Case Presentation: A 23-year-old woman, 14 days post–caesarean section, presented with altered sensorium, slurred speech, and reduced responsiveness. Laboratory findings revealed severe hypernatremia (Na⁺ 201 mmol/L), hypokalemia, and hyperchloremia, suggestive of profound osmotic stress. Imaging showed extrapontine myelinolysis involving the basal ganglia and subcortical regions, consistent with ODS. Despite supportive management with fluids, electrolytes, and intensive care, the patient’s condition deteriorated, resulting in a fatal outcome. Discussion: Postpartum hypernatremic ODS likely results from combined factors such as dehydration, electrolyte imbalance, and altered renal regulation. Even minor osmotic shifts can disrupt glial integrity, causing demyelination. Preceding gastroenteritis and possible restricted fluid intake may have precipitated the severe hypernatremia. Conclusion: This case underscores that ODS can arise from acute hypernatremia in postpartum women, independent of sodium correction. Early recognition, cautious sodium management, and preventive hydration are crucial to avoid fatal neurological outcomes in this vulnerable population.