Cortical brain atrophy and intra-individual variability in neuropsychological test performance in HIV disease

Abstract

Objective To characterize the relationship between dispersion-based intra-individual variability (IIVd) in neuropsychological test performance and brain volume among HIV seropositive and seronegative men and to determine the effects of cardiovascular risk and HIV infection on this relationship. Methods Magnetic Resonance Imaging (MRI) was used to acquire high-resolution neuroanatomic data from 147 men age 50 and over, including 80 HIV seropositive (HIV+) and 67 seronegative controls (HIV−) in this cross-sectional cohort study. Voxel Based Morphometry was used to derive volumetric measurements at the level of the individual voxel. These brain structure maps were analyzed using Statistical Parametric Mapping (SPM2). IIVd was measured by computing intra-individual standard deviations (ISD’s) from the standardized performance scores of five neuropsychological tests: Wechsler Memory Scale-III Visual Reproduction I and II, Logical Memory I and II, Wechsler Adult Intelligence Scale-III Letter Number Sequencing. Results Total gray matter (GM) volume was inversely associated with IIVd. Among all subjects, IIVd -related GM atrophy was observed primarily in: 1) the inferior frontal gyrus bilaterally, the left inferior temporal gyrus extending to the supramarginal gyrus, spanning the lateral sulcus; 2) the right superior parietal lobule and intraparietal sulcus; and, 3) dorsal/ventral regions of the posterior section of the transverse temporal gyrus. HIV status, biological, and cardiovascular disease (CVD) variables were not linked to IIVd -related GM atrophy. Conclusions IIVd in neuropsychological test performance may be a sensitive marker of cortical integrity in older adults, regardless of HIV infection status or CVD risk factors, and degree of intra-individual variability links with volume loss in specific cortical regions; independent of mean-level performance on neuropsychological tests.

The Aging Brain With HIV Infection: Effects of Alcoholism or Hepatitis C Comorbidity

“…Cortical areas with gray matter volume deficits in HIV with viral suppression, relative to healthy controls, include frontal, cingulate, sensorimotor, and parietal regions (Heaps et al, 2012 ; Li et al, 2014 ; Pfefferbaum et al, 2014 ; Clark et al, 2015 ; Janssen et al, 2015 ; Wang et al, 2016 ). Those without complete viral suppression exhibit greater volume deficits than virally-suppressed individuals (Cardenas et al, 2009 ; Kallianpur et al, 2013 ; Hines et al, 2016 ). The imaging literature typically reports the effects of HIV on gray matter volume [see the following for exceptions] (Corrêa et al, 2016a ; du Plessis et al, 2016 ; Castillo et al, 2017 ).…”

Intraindividual variability in neurocognitive performance is associated with time-based prospective memory in older adults

“…Fourth, we extend prior studies by utilizing an arguably more naturalistic assessment of IIV that measured performance variability across a battery of well-validated neurocognitive tasks (i.e., dispersion) rather than IIV in RTs. Dispersion correlates reliably with RT IIV (Hilborn, Strauss, Hultsch, & Hunter, 2009; Hultsch, MacDonald, & Dixon, 2002), is sensitive to aging (e.g., Christensen et al, 1999), and is associated with prefrontal gray matter atrophy (Hines et al, 2016). Dispersion is also consistently associated with aspects of daily functioning, including activities of daily living (Christensen et al, 1999), functional disability (Rapp, Schnaider-Beeri, Sano, Silverman, & Haroutunian, 2005), and naturalistic multitasking (Fellows & Schmitter-Edgecombe, 2015).…”

Aging and Apolipoprotein E in HIV Infection

“…While the severe dementia of HAD is far less prevalent, varying degrees of NCI are more prevalent in the HIV-infected population. Neuropsychological symptoms of NCI are variable among and within individuals (Hines et al 2016 ), but an extensive body of neuropsychological evidence suggests that the HIV-infected person is cognitively older than a seronegative person of similar age and medical health. With effective ART, the clinical course of HAND likely reflects the compound effects of age-related decline in neurocognitive reserve (Chang et al 2013 ), genetic factors, medical comorbidities, and treatment efficacy all superimposed on the underlying HIV infection.…”

“…But overall, neuropsychological studies of HIV-infected cohorts have produced conflicting results regarding the impact of ApoE4 or the Apoε4 allele on the course of cognition. Neuropsychological performance in HIV-infected subjects is a very complex outcome measure that is confounded by the individual’s age, medical comorbidities, genetic influences, and within-person variability (Hines et al 2016 ), as well as the intensity of infection itself and treatment side effects. This makes neuropsychology-based studies difficult to design, conduct, analyze, and compare.…”