Functional disconnection of the right anterior insula in obstructive sleep apnea

The right anterior insula (AIns) is an important node of the salience network and serves to switch between two major cognitive-related functional brain networks, ie, the central executive network (CEN) and the default mode network (DMN), both of which show functional deficits in obstructive sleep apnea (OSA) patients. However, the effect of OSA on functional connectivity of the right AIns remains uncertain.

To determine whether the resting-state functional connectivity (rsFC) between the right AIns and the CEN and DMN is disrupted in OSA patients, which may be associated with cognitive deficits in this disorder.

Twenty-four male OSA patients and 21 matched healthy controls underwent functional MRI examinations and clinical and neuropsychologic assessments. The rsFCs between the right AIns and the CEN and DMN were compared between the two groups and were correlated with clinical and neuropsychologic assessments.

Compared with healthy controls, OSA patients showed significantly weakened rsFC between the right AIns and the DMN. Moreover, the functional disconnection between the right AIns and the medial prefrontal cortex was correlated with the severity of the OSA; and the functional disconnection between the right AIns and the posterior cingulate cortex was correlated with depressive scores and working memory performance. However, there were no significant inter-group differences in the rsFC between the right AIns and the CEN.

These findings suggest that OSA selectively impairs the rsFC between the right AIns and the DMN, which may be a candidate substrate for cognitive impairment in OSA patients.