Diffusion-weighted magnetic resonance imaging in a case of osmotic demyelination syndrome with fatal outcome

Hyponatraemia with rapid correction of serum sodium may cause an osmotic demyelination syndrome (ODS) with damage to pontine and/or extrapontine areas of the brain. The prognosis of ODS can range from complete recovery to death; at present, our ability to predict clinical outcome is very limited. We describe here a patient with ODS and increased signal intensity in the striatum on diffusion-weighted MRI, with corresponding low apparent diffusion coeffi cient values (indicating restricted water diffusion). This case provides a further example of the typical MRI appearance of extrapontine ODS and suggests the potential value of diffusion-weighted MRI in predicting prognosis in ODS.