Neuropsychological effects of early HIV-1 infection: assessment and methodology.

Studies of neuropsychological performance early in the course of human immunodeficiency virus-type 1, infection are reviewed. The studies differed on reporting the presence and severity of neuropsychological changes, and comparisons among studies are hampered by variations in the study populations, sample sizes, assessment methods, approaches to data analysis, and definitions of thresholds for abnormality. Recommendations that would facilitate comparisons among future studies include using markers for disease state, applying longitudinal designs, using common instruments for assessing neuropsychological status, selecting appropriate controls, controlling for co-factors, reporting raw scores as well as presumed indices of impairment, and relating impairment on neuropsychological tests to affected individuals' daily activities, if possible.