Hypertensive encephalopathy. Magnetic resonance imaging demonstration of reversible cortical and white matter lesions.

Computed tomographic (CT) and magnetic resonance imaging (MRI) views of the brain were obtained in two adults and one child with hypertensive encephalopathy (HTE). Noncontrast CT was normal in one case and demonstrated decreased density posteriorly in two cases; MRI demonstrated focal, symmetric increased signal intensity in white matter and cortex, with occipital lobe involvement in each case. These lesions were better visualized on T2-weighted than on spin density images and were resolved on follow-up MRI four to five weeks later. These MRI studies support the concept that HTE is caused by the multifocal extravasation of fluid and proteins across the blood-brain barrier during "breakthrough" of cerebral autoregulation. We found that MRI appears more sensitive than CT and better defines the anatomy of cerebral involvement in HTE.