Neurocognitive impairment remains prevalent in HIV infected (HIV+) individuals despite highly active anti-retroviral therapy (HAART). We assessed the impact of HIV, HAART, and aging using structural neuroimaging.
Seventy-eight participants (HIV− (n=26), HIV+ on stable HAART (HIV+/HAART+; n=26), HIV+ naive to HAART (HIV+/HAART−; n=26)) completed neuroimaging and neuropsychological testing. A subset of HIV+ 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 (NPZ-4). Volumetrics were evaluated for the amygdala, caudate, thalamus, hippocampus, putamen, corpus callosum, cerebral grey and white matter. A three-group one 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 self-reported duration of HIV infection on brain structure.
HIV+ individuals had significant reductions in brain volumetrics within select subcortical regions (amygdala, caudate, and corpus callosum) compared to HIV− participants. However, HAART did not affect brain structure as regional volumes were similar for HIV+/HAART− and HIV+/HAART+. 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 self-reported seroconversion.
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 MRI studies, especially within older HIV+ participants, are required.