TEMPORAL TRENDS IN THE INCIDENCE OF HTV-1-RELATED NEUROLOGIC DISEASES- MULTICENTER AIDS COHORT STUDY, 1985-1992

Objective: To describe temporal trends in the incidence of human immun odeficiency virus (HIV)-related neurologic diseases in the Multicenter AIDS Cohort Study from 1985 to 1992. Methods: The incidence rates of six neurologic disorders were examined: toxoplasmosis, cryptococcal me ningitis, primary CNS lymphoma, progressive multifocal leukoencephalop athy, HIV dementia, and sensory neuropathy. Poisson modeling was used to test linear trends over time and the effects of progressive immunos uppression, antimicrobial prophylaxis, and antiretroviral drug therapy . Results: There was an upward temporal trend in all incidence rates, except for HN dementia. Progressive immunosuppression in the cohort ex plained all calendar trends except for sensory neuropathy, where an in creasing temporal trend remained even after adjusting for CD4(+) cell count, and for HIV dementia where a slight decline was noted, although the effects were not statistically significant. We noted a protective trend of antimicrobial prophylaxis on toxoplasmosis and cryptococcal meningitis, but, in contrast, use of antiretroviral agents was not pro tective against HIV dementia. Men receiving didanosine, zalcitabine, o r stavudine were more likely to develop sensory neuropathy. Conclusion : Despite the earlier and more widespread use of antimicrobial and ant iretroviral agents, neurologic conditions still occurred frequently in this cohort, with annual rates above 1.5 per 100 person-years for HIV dementia and sensory neuropathy. Sensory neuropathy seems to be incre asing in incidence and HIV dementia declining slightly in this cohort. As the epidemic matures and more people with profound immunosuppressi on live longer, the overall incidence of HIV-related neurologic diseas es can be expected to rise.