Disturbed neurovascular coupling of limbic system in obstructive sleep apnea patients with mild cognitive impairment: A combined fMRI and ASL study.

Obstructive sleep apnea (OSA) is a common sleep disorder that causes long-term intermittent hypoxia and sleep disturbances, negatively affecting cognitive function. The mechanisms underlying cognitive impairment in OSA may involve alterations in both brain structure and function. This study investigates the potential role of disturbed neurovascular coupling (NVC) in cognitive decline among OSA patients. A total of 27 OSA patients with mild cognitive impairment (OSA-MCI) and 26 with normal cognitive function (OSA-NC) were included. We calculated the correlation coefficients for z-transformed amplitude of low-frequency fluctuations (ALFF) and cerebral blood flow (CBF) at global and regional brain voxel levels using resting-state functional magnetic resonance imaging (rs-fMRI) and arterial spin labeling (ASL) to assess NVC. General linear modeling and partial correlation analysis revealed that OSA-MCI patients exhibited disturbed NVC primarily within the limbic system, which was associated with cognitive decline. The ROC curve demonstrated that left hippocampus exhibited the highest classification performance in distinguishing between two groups. In conclusion, this study highlights a strong association between disturbed NVC and cognitive decline in OSA, and underscore the potential of NVC as a biomarker for early detection and intervention in OSA-related cognitive impairment.