Abnormal Brain Network Degree Centrality In The Patients With Obstructive Sleep Apnea Hypopnea Syndrome:A Resting State FMRI Study

Purpose:Obstructive sleep apnea hypopnea syndrome(OSAHS)has been associated with changes in brain structure and regional function in certain brain areas.However,the functional features of network topological organization in the whole brain remain largely uncertain.The purpose of this study was to identify the OSAHS-related whole brain functional network topological properties and to investigate the potential altered intrinsic functional hubs using voxel-wise degree centrality(DC)method.Methods:Firstly,forty male patients with newly confirmed severe OSAHS on polysomnography,and 40 well-matched good sleepers(GS),participated in this study.All participants underwent a resting-state functional magnetic resonance imaging(fMRI)scan and clinical and cognitive evaluation.Secondly,The resting-state fMRI data were preprocessed using Data Processing &Analysis for Brain Imaging(DPABI)and Statistical Parametric Mapping(SPM8)based on the MATLAB2012 a platform.Then,voxel-wise degree centrality(DC)was measured across the whole brain for each participant,and single sample and two sample t-test were compared within intra-group and between groups parameters.Extracting the abnormal brain regions DC value in OSAHS,the relationship between the abnormal DC value and clinical variables was assessed using a linear correlation analysis.Finally,we used seed-based functional connectivity(FC)approach to further conduct the connectivity abnormality by placing the region-of-interest(ROI)in clusters that exhibited significant reduced DC in patients with OSAHS.Results:(1)Remarkably similar spatial distributions of the high DC(functional hubs)were found in both groups.However,Compared to the GS,OSAHS patients exhibited a pattern of significantly reduced regional DC in the left middle occipital gyrus,posterior cingulate cortex,left superior frontal gyrus,and bilateral inferior parietal lobule,and DC was increased in the right orbital frontal cortex,bilateral cerebellum posterior lobes,and bilateral lentiform nucleus,including the putamen,extending to the hippocampus,and the inferior temporal gyrus,which overlapped with the functional hubs.(2)Seed-based FC analysis revealed widely disrupted functional connectivity between the regions of reduced DC and other brain areas including occipital lobe,frontal lobe,temporal lobe,and cerebellum in OSAHS patients compare to GS.(3)Furthermore,apnea hypopnea index were negatively correlated with the decreased DC in the left MOG(r =-0.535,P = 0.001),left IPL(r =-0.415,P = 0.012),and right IPL(r =-0.351,P = 0.036).Arousal index were negatively correlated with the decreased DC in the left MOG(r =-0.449,P = 0.006),left IPL(r =-0.396,P = 0.017),and right IPL(r =-0.360,P = 0.031).Montreal Cognitive Assessment scores were positively correlated with the decreased DC in the PCC(r = 0.406,P = 0.014)and left SFG(r = 0.570,P < 0.001)in OSAHS patients.Conclusion:(1)OSAHS patients exhibited abnormal intrinsic function network topological properties including relatively reduced DC in the left middle occipital gyrus,posterior cingulate cortex,left superior frontal gyrus,and bilateral inferior parietal lobule,and increased DC in the right orbital frontal cortex,bilateral cerebellum posterior lobes,and bilateral lentiform nucleus,which prompting the abnormal functional network integration and separation,and function hubs nodes existed damage and compensatory changes.(2)Partly of abnormal regions DC values were associated with cognitive function scores and AHI significantly,these is probably the neural mechanism of cognitive dysfunction in the patients with OSAHS,which may provide new insights for our understanding the pathological mechanism of cognitive dysfunction in OSAHS patients.