Central pontine and extrapontine myelinolysis following correction of severe hyponatremia.

A chronically hyponatremic patient developed neurological features of pontine level disconnection following the raising of serum sodium. At autopsy histopathological examination confirmed the presence of myelinolysis in the central pons and similar symmetrical lesions in the thalamus. In chronic hyponatremic patients, more than the rapidity of correction, the magnitude of the osmolar change may predispose to development of these lesions.