[HIV encephalopathy].

The early manifestation of HIV infection of the brain, HIV encephalitis, is due to the invasion of HIV infected mono- and multinuclear macrophages into the brain tissue and cerebrospinal fluid. These cells are intensely PAS reactive, auto-fluorescent and express the macrophage antigen CD68. They clearly prefer the white matter of cerebral hemispheres, corpus callosum and internal capsule. Lymphocytic infiltrates and microglial nodules are additional, unspecific changes. HIV encephalopathy following HIV encephalitis is patho-anatomically characterized by brain tissue damage. Its clinical correlate is so-called AIDS dementia complex. It presumably is caused by neurocytotoxic and myelinotoxic factors released by activated macrophages and/or by shedding HIV retrovirus proteins. HIV encephalopathy includes leukoencephalopathy, diffuse poliodystrophy, disseminated basal ganglia damage and brain atrophy. In some cases, granulomatous angiitis may occur.