Osmotic Demyelination Syndrome Secondary to Colonic Pseudo-Obstruction and Resistant Hypokalaemia: A Case Report

Osmotic demyelination syndrome (ODS) commonly occurs following overly rapid correction of chronic hyponatremia; however, other precipitants are described. A 63-year-old female was admitted with abdominal distension and found to have severe hyponatraemia and hypokalaemia. Hypertonic saline was initially administered to correct sodium levels within recommended limits. She subsequently developed colonic pseudo-obstruction and an unexpected rise of serum sodium by 16 mmol/L occurred on day four in the absence of any further hypertonic saline therapy. A few days later she became drowsy and magnetic resonance imaging showed changes consistent with ODS. This case highlights how severe hypokalaemia precipitating colonic pseudo-obstruction, followed by rapid change in sodium from the intestinal third spacing of fluid and repeated phosphate enemas contributed to ODS. Early recognition of compound electrolyte disturbances and strict monitoring of fluid balance are essential to avoid such complications.