Cognitive performance after progression to AIDS: a longitudinal study from the Multicenter AIDS Cohort Study.

OBJECTIVE

To describe changes in cognitive functioning before and after development of an acquired immune deficiency syndrome (AIDS)-defining illness or CD4+ lymphocyte count < 200/mm3 in participants in the Multicenter AIDS Cohort Study.

METHODS

The study population included participants who either were diagnosed with an AIDS-defining illness (n = 52) or had at least one measurement of CD4+ count < 200/mm3 (n = 57) and who had at least four neuropsychological (NP) evaluations, two or more before and two or more after the AIDS diagnosis. A group of subjects with clinical diagnosis of dementia (n = 29) was also included for comparison. The NP test battery included measures of attention, memory, constructional abilities, and psychomotor speed. Longitudinal data analysis, using the generalized estimating equation, was performed separately for each NP measure. Time was measured in months from the date of clinical AIDS or CD4+ < 200/mm3.

RESULTS

Before AIDS< the dementia group showed significant decline (slope different from zero) only on measures of psychomotor speed. For all other measures, there was no evidence of decline in performance before AIDS for the other groups. After development of AIDS, the group with clinical AIDS showed significant decline on psychomotor speed but none on the other cognitive measures. The group with CD4+ < 200/mm3 did not show significant decline on any of the cognitive measures after AIDS. As expected, the dementia group showed significant decline on all measures. Sensory neuropathy was associated with a significant decline in performance on measures of psychomotor speed after AIDS. Antiretroviral therapy was not associated with any measurable changes in NP performance.

CONCLUSION

These results are consistent with previous findings showing no significant decline in cognitive functions before AIDS, unless overt dementia is present, and no decline in immunosuppressed subjects who have had no AIDS-defining illness. By contrast, in subjects who have developed clinical AIDS, there is mild decline in fine motor skills but no significant change in other cognitive domains.