Hemiparesis, encephalopathy, and extrapontine osmotic myelinolysis in the setting of hyperosmolar hyperglycemia.

Osmotic demyelination syndrome (ODS) is a recognized complication of rapid correction of hyponatremia. However, other medical conditions have been associated recently with the development of ODS in the absence of changes in serum sodium. We present a 23-year-old man who developed left hemiparesis and encephalopathy after treatment of hyperglycemia. MRI demonstrated changes in the splenium of the corpus callosum and the posterior limb of the right internal capsule. This report, together with others, suggests that the full spectrum of lesions of ODS, pontine and extrapontine, can occur in the setting of any rapid change in osmolar state.