A 58-year-old woman presented with subacute onset of tetraparesis, anarthria, and dysphagia after rapid correction of hyponatremia caused by repeated vomiting. Brain MRI showed pontine and extrapontine lesions typical for the osmotic demyelination syndrome (figure, A and B). The pontine lesion showed nonhomogeneous contrast enhancement (figure, C), which diminished after 15 days (figure, D). Ba...