Study of Brain Structure in HIV Vertically Infected Adolescents

Neuroimaging studies have focused mainly on human immunodeficiency virus (HIV)-infected adults or younger children, showing abnormal brain structures. In this study, we used voxel-based morphometry to investigate the brain integrity of HIV vertically infected adolescents. Twenty-five HIV vertically infected (HIV+) adolescents and 33 HIV-exposed, but uninfected (HIV-) and demographically matched controls participated in this study. T1 high-resolution anatomical magnetic resonance imaging images were obtained and segmented into gray matter (GM) and white matter (WM) segments. Then, population templates were derived from the entire imaging dataset using the diffeomorphic anatomical registration through exponentiated lie algebra (DARTEL) technique. Between-group GM and WM maps were contrasted using independent two-sample t-tests, with age and sex as nuisance regressors of no interest. Significant effects were identified using voxel-wise p < .001 and cluster-level p < .05 with a family-wise error correction. Whole brain volume between the groups did not demonstrate a significant difference. Relative to HIV- controls, the HIV+ adolescents demonstrated less GM in the bilateral cerebellum, right pallidum, right calcarine, left anterior cingulate cortex (ACC), and right superior occipital lobe. HIV+ adolescents also demonstrated less WM volume in the bilateral cerebellum, right brainstem, and left occipital lobe. Furthermore, the volume of the ACC was positively correlated with the Mini-Mental State Examination (MMSE) and the CD4 cell counts in the HIV+ adolescents. The age of highly active antiretroviral therapy (HAART) onset was positively correlated with GM volume in the right temporal lobe, left occipital lobe, and left precentral gyrus. In HIV+ adolescents, a pattern of less WM density and altered GM and WM volume suggests that early HIV infection combined with neurotoxicity effect of early HAART, a lack of viral control may have a significant effect on the brain structural integrity. The process of corpus callosum formation in the corpus callosum and the frontal WM is more susceptible to HIV infection. Altered ACC integrity may represent a promising biomarker of cognitive dysfunction following HIV infection.