Hypertensive brainstem encephalopathy without parieto-occipital lesion--two case reports.

Two patients presented with malignant hypertension associated with encephalopathy predominantly manifesting as brainstem lesion. T(2)-weighted and fluid-attenuated inversion recovery magnetic resonance (MR) imaging revealed diffuse hyperintense areas in the pons and scattered lesions in the cerebellum, basal ganglia, and cerebral subcortex without parieto-occipital lesions. Diffusion-weighted MR imaging demonstrated these lesions as normal intensity, indicating vasogenic edema. These lesions resolved rapidly once hypertension was controlled. Review of clinical findings for 14 other patients with hypertensive brainstem encephalopathy without parieto-occipital lesions suggested that anterior circulation structures supplied by the carotid artery are frequently involved in such patients.