Structural connectome differences in HIV infection: brain network segregation associated with nadir CD4 cell count

Abstract

This study investigated structural brain organization using diffusion tensor imaging (DTI) in 35 HIV-positive and 35 HIV-negative individuals. We used global and nodal graph theory metrics to investigate whether HIV was associated with differences in brain network organization based on fractional anisotropy (FA) and mean diffusivity (MD). Participants also completed a comprehensive neuropsychological testing battery. For global network metrics, HIV-positive individuals displayed a lower FA clustering coefficient relative to HIV-negative individuals. For nodal network metrics, HIV-positive individuals had less MD nodal degree in the left thalamus. Within HIV-positive individuals, the FA global clustering coefficient was positively correlated with nadir CD4 cell count. Across the sample, cognitive performance was negatively correlated with characteristic path length and positively correlated with global efficiency for FA. These results suggest that, despite management with combination antiretroviral therapy, HIV infection is associated with altered structural brain network segregation and thalamic centrality and that low nadir CD4 cell count may be a risk factor. These graph theory metrics may serve as neural biomarkers to identify individuals at risk for HIV-related neurological complications.

Changes in resting-state functional brain activity are associated with waning cognitive functions in HIV-infected children

“…We suggest that this may be due to the small sample size which might be considered a limitation of the current study. Future studies will explore the data in multiple dimensions measuring topological properties using graph theoretical methods ( Abidin et al, 2018 ; Bell et al, 2018 ; Thomas et al, 2015 ) and evaluate the effect of working memory training on neurocognitive performance of HIV patients. The present study did not observe any significant correlations of age with ALFF and FC in either HIV+ or HIV- participants and there was no interaction effect between HIV and aging, suggesting that HIV may not have an age related neurodegeneration effect.…”

Whole‐brain computational modeling reveals disruption of microscale brain dynamics in HIV infected individuals

“…We and others did not find significant topology difference in structural network of HIV infected individuals (Samboju et al, 2018; Zhuang et al, 2017). However, two studies (Baker et al, 2017; Bell et al, 2018) have shown disrupted structural networks in HIV‐infected subjects compared to HC in terms of reduced global clustering coefficient, global network efficiency, and connection strength. These two studies differ from our study in the population enrolled.…”

“…Both FA and MD abnormalities have been previously reported in HIV‐infected subjects (Stebbins et al, 2007; Underwood et al, 2017; Zhu et al, 2013). Graph theoretical analysis of structural and functional connectome has also been used to show brain network topological changes in HIV‐infection (Abidin et al, 2018; Bell et al, 2018; Chockanathan, AM, Abidin, Schifitto, & Wismuller, 2018; Thomas, Brier, Ortega, Benzinger, & Ances, 2015).…”

Whole-brain computational modeling reveals disruption of microscale brain dynamics in HIV infected individuals

“…We and others did not find significant topology difference in structural network of HIV infected individuals (Samboju, Philippi, Chan, Cobigo, Fletcher, Robb, Hellmuth, Benjapornpong, Dumrongpisutikul, Pothisri, Paul, Ananworanich, Spudich, Valcour, Search, et al, 2018; Zhuang et al, 2017). However, two studies (Baker et al, 2017; Bell et al, 2018a) have shown disrupted structural networks in HIV-infected subjects compared to HC in terms of reduced global clustering coefficient, global network efficiency, and connection strength. These two studies differ from our study in the population enrolled.…”

“…Both FA and MD abnormalities have been previously reported in HIV-infected subjects (Stebbins et al, 2007; Underwood et al, 2017; Zhu et al, 2013). Graph theoretical analysis of structural and functional connectome has also been used to show brain network topological changes in HIV-infection (Abidin et al, 2018; Bell et al, 2018b; Chockanathan, AM, Abidin, Schifitto, & Wismuller, 2018; Thomas, Brier, Ortega, Benzinger, & Ances, 2015).…”