Background: Neurocognitive impairment remains prevalent in HIV-infected (HIV1) individuals despite highly active antiretroviral therapy (HAART). We assessed the impact of HIV, HAART, and aging using structural neuroimaging. Methods: Seventy-eight participants [HIV2 (n = 26), HIV1 on stable HAART (HIV1/HAART1; n = 26), HIV1 naive to HAART (HIV1/HAART2; n = 26)] completed neuroimaging and neuropsychological testing. A subset of HIV1 subjects (n = 12) performed longitudinal assessments before and after initiating HAART. Neuropsychological tests evaluated memory, psychomotor speed, and executive function, and a composite neuropsychological score was calculated based on normalized performances (neuropsychological summary Z score, NPZ-4). Volumetrics were evaluated for the amygdala, caudate, thalamus, hippocampus, putamen, corpus callosum, and cerebral gray and white matter. A 3-group 1-way analysis of variance assessed differences in neuroimaging and neuropsychological indices. Correlations were examined between NPZ-4 and volumetrics. Exploratory testing using a broken-stick regression model evaluated selfreported duration of HIV infection on brain structure. Results: HIV1 individuals had significant reductions in brain volumetrics within select subcortical regions (amygdala, caudate, and corpus callosum) compared with HIV2 participants. However, HAART did not affect brain structure as regional volumes were similar for HIV1/HAART2 and HIV1/HAART1. No association existed between NPZ-4 and volumetrics. HIV and aging were independently associated with volumetric reductions. Exploratory analyses suggest caudate atrophy due to HIV slowly occurs after selfreported seroconversion. Conclusions: HIV associated volumetric reductions within the amygdala, caudate, and corpus callosum occurs despite HAART. A gradual decline in caudate volume occurs after self-reported seroconversion. HIV and aging independently increase brain vulnerability. Additional longitudinal structural magnetic resonance imaging studies, especially within older HIV1 participants, are required.
- Brain volume