Hypertensive brainstem encephalopathy.

A 45-year-old man developed severe arterial hypertension associated with unusual hyperintensity in the brainstem, around the right internal capsule and in the deep white matter around the bilateral anterior horn of the lateral ventricle on T2-weighted and fluid-attenuated inversion-recovery images. The characteristic clinical findings were mild left hepiparesis and altered mental status which corresponded to the lesions of MR imagings. The lesions improved gradually with improvements in hypertension, which suggested that edema could be the principal cause of the unusual hyperintensity on MR images.