Cognitive risk factors and neuropsychological performance in HIV infection

Almost all investigations examining the effects of early HIV infection on neuropsychological functioning in homosexual males have excluded subjects with cognitive risk factors such as recreational drug use and head injury. While insuring that results reflect the influence of the virus on cognition, this selection bias limits the ability to generalize findings. Comprehensive neuropsychological evaluations were compared between two groups of homosexual males with a variety of cognitive risk factors. Subjects were 132 HIV seropositive males (108 CDC class II & III and 24 CDC class IVA & IVC2) and 65 HIV seronegative controls. Recreational drug use in the six months prior to exam was found to interact with HIV infection and was associated with selective areas of cognitive decline and a significantly worse overall neuropsychological performance. Although significantly lower functioning in the domains of Verbal Memory and Attention and Speed of Information processing was noted for subjects with CDC class IVA and IVC2 compared to seropositives with CDC class II & III, overall neuropsychological performance was similar in these two groups. At this early stage of HIV infection, we did not find indication of association between neuropsychological performance and decreased immunological status. A history of head injury and recent recreational drug use emerged as primary cognitive risk factors associated with decreased neuropsychological performance. As 50% of our HIV seropositive subjects reported active recreational drug use, this cognitive risk factor in particular may contribute to the appearance of HIV-related cognitive deficits during early stages of HIV infection.