Motivation: White matter hyperintensity (WMH) burden is associated with vascular risk and impaired default mode network (DMN) function in aging. However, mechanisms underlying these relationships remain unclear. Goal(s): Cerebrovascular reactivity (CVR), an indicator of vascular reserve, could provide mechanistic insight into how vascular injury in white matter affects functional connectivity (FC). Approach: We leverage a novel CVR technique based on resting-state functional MRI to investigate how vascular injury (WMH) affects white matter cerebrovascular function and gray matter FC. Results: Global WMH burden is negatively associated with relative CVR in the cingulum. Furthermore, cingulum relative CVR is positively associated with FC within the DMN. Impact: This study provides mechanistic insight into how WMH burden affects cerebrovascular reactivity (measured by resting-state functional MRI) and functional connectivity in brain injury. This knowledge can help identify brain networks vulnerable to cerebrovascular injury and inform prevention of cognitive decline.
Hsu et al. (Tue,) studied this question.