A rare case of an osmotic demyelination syndrome in a 16-year-old girl is p
resented. MRI in the acute stage revealed a focal abnormal signal within th
e basis pontis and both caudate nuclei and putamina. Two years later brain
lesions had disappeared on T1- and T2-weighted imaging, indicating that cen
tral pontine and extrapontine myelinolysis may be completely reversible.