Altered resting-state neurovascular coupling in patients with pontine infarction.

The risk for motor and cognitive impairment is increased in patients with chronic pontine infarction (PI). In this study, we attempted to explore the alterations of neurovascular coupling (NVC) in order to understand the neural basis of behavioral impairment after PI. Three-dimensional pseudo-continuous arterial spin labeling (3D-pcASL) and resting-state functional magnetic resonance imaging (rs-fMRI) were applied in 49 patients with unilateral PI (left-sided, n = 26; right-sided, n = 23) and 30 matched normal subjects to assess whole-brain cerebral blood flow (CBF) and functional connectivity strength (FCS). We evaluated NVC in each subject by calculating the correlation coefficient between the whole-brain CBF and FCS (CBF-FCS coupling) and the ratio between voxel-wise CBF and FCS (CBF/FCS ratio). The FCS maps were then divided into long-range and short-range FCS to identify the influence of connection distance. The results indicated that the CBF-FCS coupling in the whole-brain level was significantly interrupted in PI patients, and the CBF/FCS ratio in cognition-related brain regions was abnormal. Distance-dependent results demonstrated that PI had a more serious effect on long-range neurovascular coupling. Correlation analysis revealed that the changes in neurovascular coupling were correlated with working memory scores. These findings imply that disruption of neurovascular coupling in the remote-infarction brain regions may underlie the impaired cognitive functions in chronic PI.