W. G. van Gorp

Neuropsychological performance in HIV‐1‐infected homosexual men The Multicenter AIDS Cohort Study (MACS)*

We administered a battery of standardized neuropsychological measures to assess cognitive functions in a group of 769 HIV-1 seronagative, 727 asymptomatic HIV-1 seropositive (CDC Groups 2 and 3), and 84 symptomatic HIV-1 seropositive (CDC Group 4) homosexual/bisexual men enrolled in the Multicenter AIDS Cohort Study (MACS). Measures included tests of attention, memory, and psychomotor speed. Comparison of group means revealed significant differences in performance between HIV-1 seropositive and symptomatic HIV-1 seropositive subjects on measures of memory and on measures with strong motor and psychomotor timed components. These findings support the sensitivity of these neuropsychological instruments for detecting cognitive changes that may be related to HIV-1, and are consistent with other reports of neuropsychological abnormalities in symptomatic HIV-1-infected individuals. Asymptomatic seroropositive men, on the other hand, did not differ significantly from seronegative subjects on any of the neuropsychological measures. Only 5.5% of the asymptomatic HIV-1 seropositive men showed abnormal performance on individual tests. This proportion did not differ significantly from that of seronegative controls. Further, among asymptomatic seropositive subjects, we found no statistically significant differences as a function of duration of HIV infection or level of immune system functioning. Thus, results from this study support the hypothesis that the frequency of neuropsychological abnormalities in asymptomatic HIV-1-infected homosexual men is low, and not statistically different from that of seronegative controls.

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 neuropsycho-logical (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. ARer 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.

Neurocognitive functioning is associated with employment status: a quantitative review.

Neurocognitive assessment is frequently used as a basis for making determinations regarding a person’s ability to work; yet, to our knowledge, a review of the association between neurocognition and employment status has not been conducted. For this review, we utilized meta-analysis to quantify objectively the association between eight neurocognitive domains and employment status. The meta-analysis revealed that performance in each domain was significantly associated with employment status, and that the associations were greatest for the following domains: intellectual functioning, executive functioning, and memory. These findings support the ecological validity of neurocognitive assessment.

The relationship between age and cognitive impairment in HIV-1 infection : findings from the Multicenter AIDS Cohort Study and a clinical cohort

Article abstract–Previous studies have identified age as a risk factor for many neurologic disorders, and a “cerebral reserve” factor has been postulated to explain these findings. This study examined whether age represents a risk factor for HIV-1-related neuropsychological dysfunction. Subjects for study 1 were primarily asymptomatic seropositive (n = 1,066) and seronegative (n = 1,004) nonelderly male community volunteers who completed neuropsychological and reaction time measures. Data analyses revealed a significant effect for age on reaction time and timed neuropsychological measures, but no interaction between age and serostatus. Study 2, employing a similar neuropsychological battery, consisted of 76 seropositive men (29 over age 55) recruited from community outpatient clinics and 47 seronegative controls. We found serostatus and age to have main effects on a number of measures, but a trend for an effect of age-serostatus interaction on only one measure.