Opportunistic infections of the central nervous system in the course of acquired immune deficiency syndrome (AIDS). Morphological analysis of 172 cases.

A neuropathological analysis of 172 cases of AIDS in adults was carried out, to determine the occurrence and nature of the opportunistic infections of the central nervous system (CNS). The material comprised 155 cases of men, and 17 women. Mean age of patients was 38 years. Collection under study originated from the period between 1987 and 1997. Opportunistic infections were present in 57.5 percent of cases being in 38.4 percent the only pathological process, whereas in 19.1 percent they coexisted with HIV-dependent pathology or with neoplastic growth. Cytomegalovirus infection (22.7%), toxoplasmosis (16.3%), cryptococcosis (8.1%) and progressive multifocal leukoencephalopathy (9.3%) were the most common opportunistic infections of CNS. The remaining viral (herpetic encephalitis, tick-borne encephalitis and herpes zoster multifocal encephalitis), bacterial (lues, metastatic encephalitis connected with heart valvular changes) and fungal (candidiasis) infections were present only in single cases. It is worth mentioning 3 cases of brain aspergillosis and 5 cases of leptomeningeal tuberculosis. Great morphological variability in the most common opportunistic infections found in our material (cytomegaly, toxoplasmosis, cryptococcosis and PML) was the most striking phenomenon. Neuropathological abnormalities in cases of toxoplasmosis and cryptococcosis revealed remarkable dependence on clinical medication used. Cases of PML were characterized by strong variances of the type and intensity of demyelination, ranging from disseminated foci of various size to diffuse complete myelin loss in the white matter involving uni- or bilaterally cerebral or cerebellar hemispheres. The coexistence of opportunistic infections with HIV-dependent cerebral pathology or other types of opportunistic processes was a very characteristic feature. Concomitance of HIV-dependent pathology with viral opportunistic processes was common. The frequency of this concomitance and more severe HIV-dependent pathology in cases with other viral cerebral infections may suggest pathogenetic interaction of viral infections. Cerebral tuberculosis was less frequent as compared with other neuropathological collections, especially those from the United States. However, it seems worth mentioning that 3 of 5 cases occurred in the last year of observation.