Longitudinal intra-individual variability in neuropsychological performance relates to white matter changes in HIV.

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