Extra pontine myelinolysis in a tetraplegic patient: case report

Hyposmolar hyponatremia (serum sodium < 130 mmol/l) is a common phenomenon in the spinal cord injury (SCI) patient population and in most cases, it is of relatively little consequence. However, rapid correction or over correction of hyponatremia (a change in serum sodium > 25 mmol/l within 48 h) has been linked to Central Pontine Myelinolysis (CPM) and Extra Pontine Myelinolysis (EPM), usually along with other recognized predisposing factors. We report the first case of isolated Extra Pontine Myelinolysis in an SCI patient without any of the recognized predisposing factors, following correction of hyponatremia. The signs and symptoms of Extra Pontine Myelinolysis were not very remarkable in our patient because of prior spinal cord injury. The diagnosis was confirmed by the typical finding of myelinolysis in the basal ganglion region on MRI. Hyponatremia occurs frequently in the SCI patient population, thus placing them at increased risk for Extra Pontine Myelinolysis. Therefore, we emphasize the importance of watching for this entity during the management of hyponatremia in the SCI patient population and recommend the use of MRI scans to confirm the clinical diagnosis.