Neurovascular coupling alterations in cerebral small vessel disease: A multi-delayed ASL and fMRI perspective on cognitive impairment.

Background: To explore the alteration of neurovascular coupling (NVC), relationships between neuroimaging metrics with clinical assessments, and classification metrics in cerebral small vessel disease (CSVD).

Methods: Participants were grouped into healthy control, CSVD with normal cognition, and CSVD with cognition impairment according to CSVD scales and Montreal Cognitive Assessment. Cerebral blood flow (CBF) adjusted for arterial transit time and dynamic/static amplitude of low-frequency fluctuation (dALFF, ALFF) were combined to evaluate NVC and to determine intergroup differences. Partial Spearman Correlation between measures from abnormal brain areas and scores of clinical assessments were operated. Multivariate pattern analysis was applied to determine the most effective classification metrics among groups.

Results: Cross-voxel correlation was lower in CSVD compared to healthy control. Abnormal brain regions were presented mainly in sensorimotor cortex, limbic/paralimbic system, and basal ganglia in CSVD. Notably, correlations between clinical assessment scores and NVC-related metrics in these areas were significant before correction. CBF/ALFF ratio exhibited superior classification performance between healthy control and CSVD with normal cognition, while a combination of dALFF and CBF effectively differentiated between CSVD patients with normal and impaired cognition.

Conclusions: Our investigation finds neurovascular decoupling using ATT-corrected CBF, dALFF and ALFF, as well as suggests effective classification metrics in CSVD with/without cognition impairment, potentially improving diagnostic and therapeutic strategies.