Teaching neuroimages: neuroradiologic findings in pontine and extrapontine myelinolysis: clue for the pathogenesis?

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). Based on the MRI findings of enhancement, IV methylprednisolone was started, and there was improvement of her clinical condition.1 Besides the typical MRI abnormalities, our patient showed pontine contrast enhancement, which is uncommon2 and may suggest an inflammatory mechanism or breakdown of the blood-brain barrier due to specific vulnerability of endothelium in the acute phase of the disease. Figure Contrast enhancement onMRI in the early phase of central pontine myelinolysis