Graph theory analysis reveals functional brain network alterations in HIV-associated asymptomatic neurocognitive impairment in virally suppressed homosexual males.

BACKGROUND

This study aimed to investigate the global and nodal functional network alterations, abnormal connections of brain regions, and potential imaging biomarkers in virally suppressed people living with HIV (PLH) with asymptomatic neurocognitive impairment (ANI) using graph theory analysis.

METHODS

The study included 64 men with ANI (mean age 32.45 years) and 64 healthy controls (HC) (mean age 31.31 years). The functional network was established through the graph theory method and Automated Anatomic Labeling (AAL) 90 atlas, which provides a cerebrum parcellation framework. Moreover, hub regions were identified based on betweenness centrality (Bc). Functional connectivity (FC) differences were investigated between the two groups, these connections were located in the resting-state network (RSN). Neuropsychological (NP) tests were performed, and relationships between graph theory measures, clinical data, and NP tests were analyzed. Multiple comparisons were used to correct for false-positive findings.

RESULTS

On the global level, small-worldness, global efficiency (Eg), and local efficiency (Eloc) were significantly decreased in ANI subjects. On a nodal level, brain regions in the frontal and subcortical regions showed significantly decreased nodal measures, while regions in the parietal, temporal, and occipital lobes showed increased nodal measures. Increased FCs were found between brain regions in the visual, frontoparietal, and somatomotor networks. Hub regions overlapped highly between the two groups. Age was negatively correlated with graph theory measures.

CONCLUSION

Our findings demonstrate the global and nodal alterations in the functional network of virally suppressed homosexual males in the ANI stage. Frontal and subcortical brain regions may be important for finding the imaging biomarkers for HIV-associated neurocognitive disorder.