Altered Static and Dynamic Structure-function Coupling in Young and Middle-Aged Adults With Vascular Mild Cognitive...

ObjectiveVascular mild cognitive impairment (VaMCI) is an early stage of vascular dementia, yet its neuroimaging characteristics are not fully understood. This study examined alterations in structural-functional connectivity (SC-FC) coupling and their relationships with cognition in young and middle-aged patients with VaMCI.MethodsWe acquired diffusion tensor imaging and resting-state functional MRI data from 83 young and middle-aged patients with VaMCI and 82 healthy controls (HCs). Based on the Brainnetome Atlas (BNA246), static and dynamic SC-FC coupling metrics (Static Coupling, Dynamic Mean, Variance, Bias, and Probability) were calculated using a time point-by-time point edge-centric co-fluctuation analysis. Group differences in these metrics and their partial correlations with neuropsychological scores were assessed, with false discovery rate (FDR) correction applied.ResultsCompared with HCs, young and middle-aged patients with VaMCI exhibited significantly poorer performance in memory, language, and attention. At the regional level, Static Coupling, Bias, and Probability showed significant group differences, whereas Dynamic Mean and Variance did not. At the network level, significant differences in Static Coupling and Bias were found in the default mode network (DMN). In addition, the Probability metric in the left inferior parietal lobule (IPL) within the dorsal attention network (DAN) was negatively correlated with Verbal Fluency Test scores (r = -0.414, p = 0.0001, FDR-corrected q < 0.05).ConclusionYoung and middle-aged patients with VaMCI present a multilevel profile of SC-FC coupling alterations, along with impairments in memory, attention, and language. The DMN appears to be a key network showing SC-FC coupling differences. The Probability metric in the left IPL within the DAN may represent a potential imaging correlate of language dysfunction and an exploratory region of interest for future network-based intervention research. These findings warrant further validation in larger, multicenter, longitudinal, and interventional cohorts.