Topological Regularization of Networks in Adult Patients with Moderate-to-Severe Obstructive Sleep Apnea-Hypopnea Syndrome: A Structural MRI Study

Abstract

Objective

Patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) exhibit neurocognitive impairments; however, the neuroimaging mechanism of neurocognitive impairments remains unclear. The aim of this study was to understand the neuroimaging mechanism in adult patients with moderate-to-severe OSAHS, from the perspective of the connectome.

Patients and Methods

Thirty-one untreated patients with moderate-to-severe OSAHS (mean age: 41.23±8.22) were compared with 26 good sleepers (GS) (mean age: 39.50±7.92) matched according to age, gender, handedness, and education level. All subjects underwent thin-slice T1WI scanning of the skull using a 3.0T MRI. Then, a large-scale structural covariance network was constructed based on the gray matter volume extracted from the structural MRI. Graph theory was then used to determine the topological changes in the structural covariance network of OSAHS patients.

Results

Although small-world networks were retained,the structural covariance network exhibited topological irregularities in regular architecture as evidenced by an increase in the clustering coefficient (p=0.009), transfer coefficient (p=0.029) and local efficiency (p=0.031), and a local increase in the shortest path length (p<0.05) compared with the GS group. Locally, OSAHS patients showed a decrease in nodal betweenness and degree in the left inferior parietal gyrus, left angular gyrus and right anterior cingulate cortex compared with the GS group (p<0.05, uncorrected). In addition, the resistance of structural covariance networks in OSAHS patients to random fault is significantly lower than that of the GS group (p=0.044).

Conclusion

Structural covariance networks are abnormal in terms of multiple network parameters, which provide network-level insight into the neuroimaging mechanism of cognitive impairments in adult OSAHS patients.

Keywords:

• obstructive sleep apnea-hypopnea syndrome
• cognitive impairment
• connectome
• graph theory
• gray matter volume

Ethical Statement

All procedures followed were in accordance with the National Health and Family Planning Commission “Biomedical Research Involving Human Ethics Review Approach” (the National Health Commission Order No. 11), “Helsinki Declaration” of the World Medical Association, the ethical principle of CIOMS “International Ethical Guidelines for Biomedical Research Involving Human Subjects”. Informed consent was obtained from all subjects for being included in the study.

Acknowledgments

This study was supported by Dalian Medical Science Research Plan Project (No. 20181811107).

Disclosure

None of the authors have any conflict of interest to disclose.