Altered neurovascular coupling in patients with human immunodeficiency virus-associated asymptomatic neurocognitive impairment: a multimodal magnetic resonance imaging study

Background: Human immunodeficiency virus (HIV) infection can lead to HIV-associated neurocognitive disorders (HAND), among which asymptomatic neurocognitive impairment (ANI) represents a critical stage for early intervention. However, neuroimaging biomarkers with high sensitivity and specificity for ANI are lacking. The neurovascular coupling (NVC) characteristic in ANI remains unclear. This study aimed to investigate changes in cerebral blood flow (CBF), functional connectivity strength (FCS), and their coupling in patients with ANI under both resting-state and movie-watching conditions, and to evaluate the discriminative performance of multimodal neuroimaging indicators for ANI. Methods: This study enrolled 75 participants with HIV, including 41 with ANI and 34 who were cognitively normal (CN). All participants underwent multimodal magnetic resonance imaging (MRI), including T1-weighted imaging, arterial spin labeling (ASL), resting-state and movie-watching-state functional MRI (fMRI). CBF, FCS, and CBF-FCS coupling coefficients were calculated. Between-group differences were assessed using independent-samples t-tests, with adjustments for age and years of education, and multiple-comparison correction where applicable. Correlation analyses were conducted to explore their associations with cognitive and clinical indicators. Three machine learning (ML) models [K-Nearest Neighbors (KNN), Random Forest (RF), and Support Vector Machine (SVM)] with leave-one-out cross-validation were constructed to evaluate the classification performance of multimodal neuroimaging metrics for ANI, and SHapley Additive exPlanations (SHAP) were applied to quantify feature importance. Results: =-0.0354), and the coupling coefficients were significantly reduced in the ANI participants compared to the CN participants (resting-state: P=0.004; movie-watching-state: P