Factors associated with neuropsychological performance in HIV-seropositive subjects without AIDS.

Background. Previous research has suggested that several factors may influence the presence of cognitive impairment in human immunodeficiency virus (HIV) infection. The objective of this study was to assess the impact of cognitive reserve capacity and other variables on neuropsychological performance in early HIV infection. Methods. The neuropsychological performance of 100 HIV-seropositive subjects without AIDS (71 men and 29 women) was compared with that of 63 seronegative controls (51 men and 12 women). Measures included a neuropsychological battery, a medical examination and a psychiatric assessment. Cognitive reserve scores were based on a combination of years in school, a measure of educational achievement, and an estimate of pre-morbid intelligence. Results. HIV-positive subjects had longer reaction time latencies than HIV-negative subjects. Those in the HIV-positive group with low cerebral reserve scores showed the poorest performance on the neuropsychological tests. The prevalence of cognitive impairment was significantly higher in the HIV-positive group (27%) than in the controls (3.2 %). Multiple regression analysis and logistic regression analysis were used to identify factors associated with global neuropsychological performance and cognitive impairment. Older age, lower cerebral reserve scores and not being on zidovudine treatment were associated with lower global neuropsychological scores and with the presence of cognitive impairment. Conclusions. Our results suggest that although cognitive impairment is not characteristic of early HIV infection, there is a subgroup of subjects who perform more poorly than expected. A lower reserve capacity, older age and not being on zidovudine treatment are factors that lower the threshold for neuropsychological abnormalities in cases of early HIV infection.