Neurovascular coupling, cognitive reserve, and cognitive performance in mild cognitive impairment

Neurovascular coupling (NVC) impairment contributes to mild cognitive impairment (MCI), but its relationship with NVC in MCI remains unclear.

To explore the associations between CR, NVC, and cognition in MCI patients, and to clarify their potential correlational patterns.

We enrolled 113 MCI and 83 healthy controls, all undergoing resting-state fMRI and arterial spin labeling to calculate CBF/neural activity ratios (ALFF, fALFF, ReHo, DC) as NVC measures. Cognitive reserve was assessed using the Cognitive Reserve Index Questionnaire.

Compared to HCs, MCI patients showed heterogeneous NVC alterations: whole-brain CBF-ALFF coupling significantly increased, while CBF-fALFF, ReHo, and DC coupling showed non-significant decreasing trends. Regionally, NVC ratios elevated in visual/subcortical areas but reduced in frontal/temporal lobes. CR, especially education, was the strongest cognitive predictor, with antagonistic interactions among reserve dimensions. CBF-fALFF coupling positively correlated with global cognition, whereas CBF-ALFF negatively correlated with memory. NVC ratios in the right lingual gyrus and medial orbital frontal region significantly mediated the reserve-cognition relationship.

This cross-sectional study suggests two potential patterns of association linking CR to cognitive performance in MCI: a neural reserve pattern weakly related to NVC, and a neural compensation pathway potentially involving NVC as an correlate. Multidimensional CR assessment and NVC may serve as promising indicators of neural compensation in MCI.