title: MAPPING ABNORMAL SUBCORTICAL BRAIN MORPHOMETRY IN AN ELDERLY HIV+ COHORT.
abstract: Over 50% of HIV+ individuals exhibit neurocognitive impairment and subcortical atrophy, but the pattern of brain abnormalities associated with HIV is still poorly understood. Using parametric surface-based shape analyses, we mapped the 3D profile of subcortical morphometry in 63 HIV+ participants and 31 uninfected controls. The thalamus, corpus striatum, hippocampus, amygdala, brainstem, callosum and ventricles were segmented from brain MRIs. To investigate subcortical shape, we analyzed the Jacobian determinant (JD) and radial distances (RD) for structure surfaces. We also investigated effects of nadir CD4+ T-cell counts, viral load, and illness duration on subcortical morphology. Our results characterize subcortical morphometry in older HIV+ people, where participants showed significant volumetric enlargements in the thalamus, left pallidum and the ventricles while showing a reduction in the callosum. Further, RD maps revealed atrophy of the left thalamus and expansion of the brainstem in HIV. RD and JD maps of the right pallidum identified tissue expansion associated with illness duration while the left pallidum showed anterior atrophy and posterior expansion associated with viral load.
authors.affiliation: Imaging Genetics Center, University of Southern California, Los Angeles, CA, USA.
authors.forename: Benjamin S C
authors.initials: BS
authors.lastname: Wade
authors.affiliation: Memory and Aging Center, Dept. of Neurology, University of California, San Francisco, CA, USA.
authors.forename: Victor G
authors.initials: VG
authors.lastname: Valcour
authors.affiliation: Memory and Aging Center, Dept. of Neurology, University of California, San Francisco, CA, USA.
authors.forename: Lauren
authors.initials: L
authors.lastname: Wendelken-Riegelhaupt
authors.affiliation: Memory and Aging Center, Dept. of Neurology, University of California, San Francisco, CA, USA.
authors.forename: Pardis
authors.initials: P
authors.lastname: Esmaeili-Firidouni
authors.affiliation: Ahmanson-Lovelace Brain Mapping Center, Department of Neurology, UCLA, CA, USA.
authors.forename: Shantanu H
authors.initials: SH
authors.lastname: Joshi
authors.affiliation: School of Computing, Informatics, and Decision Systems Engineering, Arizona State University, Tempe, AZ, USA.
authors.forename: Yalin
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Imaging Genetics Center, University of Southern California, Los Angeles, CA, USA.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Thompson
keywords: HIV; MRI; classification; random forest; regularization; shape analysis; subcortical