Topological Regularization Of Networks In Adult Patients With Moderate To Severe Obstructive Apnea Hypopnea Syndrome:A Structural MRI Study

Objective: In order to understand the neuroimaging mechanism of adult patients with moderate to severe OSAHS from the perspective of connectome,we use graph theory approaches to explore whether the topological properties of structural covariance networks in adult OSAHS is altered and its regularity.Methods: Thirty-one untreated moderate to severe OSAHS patients(41.23±8.22 years old)and 26 age-,gender-,handedness-,and education-matched good sleepers as control group(39.50±7.92 years old)were recruited from Affiliated Zhongshan Hospital of Dalian University.All subjects underwent thin-slice T1 WI scanning of the skull with 3.0T Siemens magnetic resonance.Then a large-scale structural covariance network was constructed based on the gray matter volume of 90 regions of interest(ROI)extracted from structural magnetic resonance imaging.The graph theory approaches was used to analyze topological changes of structural covariant networks of the adult OSAHS patients.Results: Although retaining small-worldness characteristics,structural covariance networks in adult OSAHS patients exhibited topological abnormalities towards a regular architecture evidenced by an increase in clustering coefficient(p=0.009),transfer coefficient(p=0.029)and local efficiency(p=0.031),a local increase in shortest path lengths(p<0.05),and more vulnerability to random failures compared with good sleepers(p=0.044).Additionally,the degree of structural networks in both groups met an exponentially truncated power law distribution.Conclusion: Our results indicate that structural covariance networks in adult OSAHS are abnormal in multiple topological parameters,which provides a new neuroimaging insight into the neurobiological mechanism of cognitive impairment in adult OSAHS patients.