UCLA

Objectives

Recent studies suggest that intraindividual variability (IIV) of neuropsychological performance may be sensitive to HIV-associated neurologic compromise. IIV may be particularly dependent upon the integrity of frontal-subcortical systems, and therefore may be a meaningful phenotype in HIV. We examined the relationship between change in IIV and white matter integrity among HIV seropositive (HIV+) and HIV seronegative (HIV-) individuals.

Method

The sample consisted of 38 HIV+ participants and 26 HIV- control participants who underwent neuroimaging and a neuropsychological evaluation at baseline and at 2-year follow-up evaluation.

Results

Among HIV+ participants, increases in IIV (greater dispersion) were related to lower fractional anisotropy (FA) values in the anterior thalamic radiations (ATR) and the superior longitudinal fasciculus (SLF). Changes in mean-level global cognitive functioning were not significantly related to white matter integrity. Additionally, there was a significant Group × IIV interaction effect in the SLF demonstrating that the relationship between IIV and white matter integrity was specific to HIV.

Conclusions

Overall, findings suggest that IIV may be more sensitive, relative to mean-level global cognitive functioning, in the detection of neurologic compromise among HIV+ individuals. (PsycINFO Database Record