HIV encephalopathy
General description
HIV encephalopathy, also recognized as HIV-associated dementia, constitutes a cognitive disorder ensuing from HIV infection. Following exposure, HIV breaches the CNS, establishing residency within microglial cells and macrophages. The pathogenesis of neuronal dysfunction is attributed to the virulence of HIV coupled with the release of toxins by immune cells. Such mechanisms precipitate perivascular infiltration by inflammatory cells, leading to symptoms indicative of HIV-induced encephalitis. Concurrently, HIV may provoke leukoencephalopathy, characterized primarily by demyelination.
Periventricular hyperintensity
-
CerebrumCerebral white matterPeriventricular white matter
MRI reveals abnormalities in cerebral white matter signal intensity. The observation of bilateral periventricular white matter hyperintensity on T2WI and FLAIR sequences, with a relative preservation of U-fibers, is traditionally described as a "butterfly pattern." Notably, T1WI abnormal signal and contrast enhancement is typically absent in these presentations.
Atrophy
-
Cerebrum
In advanced cases, the disease progresses to involve the cerebrum and cerebellum, culminating in atrophy over time.