Central Pontine Myelinolysis (CPM) in an Adolescent: A Case Report

Abstract

Central pontine myelinolysis (CPM) is an osmotic demyelination disorder typically precipitated by the overly rapid correction of chronic hyponatremia; early neuroimprovement may be followed by new brainstem deficits days later. A 14-year-old girl presented with two weeks of intermittent lower-abdominal pain, one week of constipation, and four months of amenorrhea. She developed three generalized seizures with decreased postictal consciousness. Initial labs showed Na 122 mmol/L, worsening to 104 mmol/L with hypokalemia. A head CT on August 1, 2025, was normal, and a repeat CT on August 22 revealed a well-defined pontine hypodensity. Risk factors included prior malnutrition and electrolyte disturbances. Working diagnosis: decreased consciousness with suspected CPM. Severe hyponatremia was corrected by administering 50 mL of 15% NaCl diluted in D5NS (1,500 mL) over 24 hours. A bowel disimpaction with Niflec® was given for concurrent constipation/ileus. Serum electrolytes were monitored during hospitalization. This case illustrates CPM risk after sodium correction in a malnourished adolescent with profound hyponatremia. The initially normal head CT, followed by a delayed pontine lesion, aligns with the temporal evolution of CPM imaging. Vigilant recognition of vulnerability, careful correction strategies, and timely repeat neuroimaging are crucial for confirming the diagnosis and guiding supportive management in suspected CPM.