Central pontine myelinolysis without hyponatraemia.

Central pontine myelinolysis is an acquired demyelinating disorder of uncertain origin that predominantly affects the centre of the basilar portion of the pons. Several theories have been proposed to account for this condition, prominent among them being abnormalities in serum sodium concentration. We report on a patient who had central pontine myelinolysis with extrapontine lesions and Wernicke's encephalopathy but who maintained a normal or high serum sodium concentration throughout his hospital admission.