Acquired immunodeficiency syndrome (AIDS) and AIDS-related infection of the brain constitute a large fraction of the most recent research into central nervous system infection. Two major areas of controversy discussed in the past year's literature were the neuroradiologic and neurologic manifestations of early human immunodeficiency virus infection in the central nervous system and differentiation of toxoplasmosis from lymphoma. Other non-AIDS related infections discussed included infectious aneurysms, bacterial abscesses, tuberculosis, cysticercosis, fungal infections, and zoster myelitis.