Central pontine and extrapontine myelinolysis associated with type 2 diabetic patient with hypokalemia

Central pontine myelinolysis (CPM) is a demyelinating disease of the pons often associated with the demyelination of extrapontine areas of the central nervous system. Although the etiology and pathogenesis are unclear, CPM is usually associated with hyponatremia or its rapid correction, and chronic alcoholism is also a common underlying condition. We observed a 43-year-old man with diabetes mellitus who developed central pontine and extrapontine myelinolysis with no apparent evidence of hyponatremia, serum hyperosmolality or associated rapid correction, or history of alcohol abuse. On admission, the patient was lethargic with dysarthria, dysphagia, and mild tetraparesis and his face and lower extremities were severely edematous. Laboratory examination showed normoglycemia and normonatremia, although hypokalemia, elevated HbA1c, and nephrotic syndrome were also present. Magnetic resonance imaging (MRI) revealed abnormal signal intensity in the pons, the deep layers of the cerebral cortex, and the adjacent white matter consistent with central pontine and extrapontine myelinolysis. Generalized edema was reduced by the use of diuretics and extracorporeal ultrafiltration without significant changes of serum sodium or osmolality. His consciousness level and paresis gradually improved within a few weeks. Our patient is a rare case of CPM associated with diabetes without apparent evidence of sodium or glucose imbalances.