Extrapontine myelinolysis in a child with nephrotic syndrome.

Extrapontine myelinolysis is rare in children. We describe a 6-year-old girl with nephrotic syndrome who presented with symptomatic hyponatremia, and who developed acute quadriparesis with pseudobulbar palsy during rapid correction of the hyponatremia. Cranial magnetic resonance imaging demonstrated bilateral, symmetric basal ganglia lesions (extrapontine myelinolysis). The extrapontine myelinolysis was caused by rapid correction of severe and prolonged hyponatremia with intravenous 3% sodium chloride. The child demonstrated complete neurologic recovery. Prevention of this rare condition involves recognizing patients at risk for the disorder, and avoiding rapid correction of severe and prolonged hyponatremia. To the best of our knowledge, this is the first case report of extrapontine myelinolysis in a child with nephrotic syndrome.