INFLUENCE OF COGNITIVE RESERVE ON NEUROPSYCHOLOGICAL FUNCTIONING IN ASYMPTOMATIC HUMAN IMMUNODEFICIENCY VIRUS-1 INFECTION

Objective: To evaluate the influence of cognitive reserve or brain res erve capacity on neuropsychological performance in early human immunod eficiency virus (HIV)-1 infection. Design: Cross-sectional group compa rison study, based on neuropsychological performance, of HIV-1 seropos itive and HIV-1 seronegative participants. Subjects: Seventy-five medi cally asymptomatic HIV-1-seropositive homosexual or bisexual men and 5 0 HIV-1-seronegative homosexual or bisexual male controls. Subjects we re grouped by HIV-1 status (seropositive vs seronegative) and by cogni tive reserve scores (low reserve vs high reserve). Measures: Cognitive reserve scores were based on a combination of years of education, a m easure of occupational attainment, and an estimate of premorbid intell igence. Performance on a battery of neuropsychological tests was summa rized by empirically derived factor scores and clinical summary rating s. Results: The HIV-1-seropositive subjects with low cognitive reserve scores exhibited significantly greater deficits on measures of attent ion and information processing speed, verbal learning and memory, exec utive functioning, and visuospatial performance than did the HIV-1-ser opositive subjects with high cognitive reserve scores. In contrast, th ere were no significant group differences on these measures between bo th groups of HIV-1-seronegative subjects. Conclusions: Early neuropsyc hological impairments in HIV-1 infection are most evident in individua ls with lower cognitive reserve. As has been found in other neurologic disorders, such as Alzheimer's disease, individuals with greater cogn itive reserve may be less sensitive to the initial clinical effects of the underlying neuropathologic process.