Neurovascular Uncoupling in Mild Cognitive Impairment: Insights from Multiband Multi-echo BOLD-Perfusion Imaging

Motivation: Neurovascular uncoupling (NVU) is increasingly recognized as a critical pathophysiological driver of cognitive decline in the progression of Alzheimer's Disease (AD). Recently developed imaging techniques allow NVU to be non-invasively estimated. Goal(s): Is resting state BOLD-CBF coupling, measured with multiband, multi-echo (MBME) simultaneous BOLD/ASL imaging, altered in individuals with mild cognitive impairment. Approach: BOLD and perfusion-weighted (PW) signals were correlated with each other and the correlation was compared between age and sex-matched control subjects on a vocelwise basis. Results: BOLD-CBF coupling was signficantly lower for the MCI group compared the control group in the precuneus, visual cortex, and middle frontal gyrus. Impact: Resting state BOLD-CBF coupling was lower in MCI individuals compared to age and sex matched control individuals. These results reveal a fundamental disruption in brain-blood flow dynamics in MCI. The physiological underpinnings of these results warrant further investigation.