Male, 58 years old, with altered mental status. New onset seizure. History of HIV on HAART with strokes. Extensive signal abnormality and encephalomalacia affects the right cerebral hemisphere. Encephalomalacia is most notable in the right parietal lobe (both precuneus and inferior parietal lobule), the cingulate gyrus, the opercular parenchyma and insula, and the superior temporal lobe.Extensive subcortical and periventricular T2 hyperintensity is seen on the left without significant encephalomalacia. Patchy T2 hyperintensities are also evident within the brainstem and the cerebellum. The right cerebral peduncle is atrophic and there is evidence of Wallerian degeneration through the right brainstem.No evidence of restricted diffusion is seen to suggest acute ischemia. Many of the areas of encephalomalacia demonstrate hemosiderin staining on susceptibility weighted images. No evidence of acute intracranial hemorrhage is seen. The right lateral ventricle demonstrates ex vacuo dilatation. The remainder of the ventricular system is relatively unremarkable.On postcontrast images, no pathologic parenchymal or extra-axial enhancement is seen.
1.Sequelae of extensive chronic microvascular and territorial ischemic injury in the right cerebral hemisphere. Large areas of parenchyma demonstrate encephalomalacia, with signal abnormality suggesting gliosis throughout the remainder of the hemisphere.2.Findings compatible with advanced chronic microvascular ischemic disease in the left cerebral hemisphere.3.No evidence is seen to suggest an active or acute intracranial process.