Cerebral pathology in AIDS: a new nomenclature and pathogenetic concepts.

Complementary to a clinical classification of human immunodeficiency virus (HIV)-associated nervous system syndromes, a neuropathology-based terminology defines entities at tissue level, including the new HIV-specific diseases, HIV encephalitis and HIV leukoencephalopathy. Poor clinico-neuropathological correlation may be explained by complex pathogenetic mechanisms in which several factors, including virus load, neurotoxicity, vascular changes, and metabolic abnormalities, may act together to damage both white and gray matter of the brain.