Neuropathologic observations in acquired immunodeficiency syndrome (AIDS).

Neuropathologic changes are described in eight fatal cases of the acquired immunodeficiency syndrome (AIDS), including four subjects who were i.v. drug abusers (two women, two men), two Haitian men, one bisexual man, and one women who had no known risk factors for AIDS. All cases had significant infections of the brain, with examples of bacterial, fungal, protozoal, and viral disease in the group. Combined infections were observed in three cases, including one case of previously unreported central nervous system (CNS) abscess due to Nocardia (combined with Salmonella). The most frequent CNS pathogen was Toxoplasma gondii, which in both Haitian subjects co-existed with systemic tuberculosis, leading to diagnostic difficulty. Only one case of "subacute encephalitis" was represented, although in other cases microglial nodules were associated with Toxoplasma and Cryptococcus organisms, as well as probable cytomegalovirus. Non-infectious complications included a cerebral infarct (one case), central pontine myelinolysis (one case), and diffuse microcystic change of the white matter (one case).