Resting-state Functional Magnetic Resonance Imaging(rs-fMRI)study On Cognitive Impairment In Patients With Obstructive Sleep Apnea Hypopnea Syndrome

Objective: To investigate the change of regional homogeneity and voxel-based morphological analysis in patients with moderate-to-severe Obstructive sleep apnea hypopnea syndrome(OSAHS)using resting-state functional magnetic resonance imaging(rs-f MRI),and their relationgships with the changes in cognitive dysfunction.Methods:(1)Montreal Cognitive Assmessiom(Mo CA)and Mini-mental State Examination(MMSE)were performed on 30 patients of moderate-to-severe OSAHS and 20 healthy controls.The correlation of cognitive scores and sleep-related indicators were compared between OSAHS and controls.(2)rs-f MRI were performed on OSAHS patients and heathy controls,the data were analyzed with the Re Ho and GMV.Then compared the difference between OSAHS and controls.The correlation of Re Ho value and GMV with cognitive scores and sleep-related indicators were compared between OSAHS and controls.Results:(1)Comparison of cognitive function: Compared with the healthy control group,the score of MMSE(t=-3.897,P<0.001)and Mo CA(t=-4.245,P<0.001)in OSAHS group were significantly lower than that in the healthy control group.Furthermore,The score of Mo CA in OSAHS group was significantly negatively correlated with Apnea hypopnea index(AHI)(r=-0.486,P=0.006),Oxygen desaturation index(ODI)(r=-0.413,P=0.023),Percentage of time with Sa O2 below90% during total sleep(%TST<90%)(r=-0.399,P=0.029).The score of MMSE in OSAHS group was significantly negatively correlated with AHI(r=-0.476,P=0.008).(2)Re Ho: Compared to the healthy control group,the patients with OSAHS showed significantly increased Re Ho value in the left inferior frontal gyrus,right middle frontal gyrus,right frontal gyrus and significantly decreased in the ight cingulate gyrus.Furthermore,the Re Ho value of the left inferior frontal gyrus was positively correlated with AHI(r=0.383,P=0.037).The Re Ho value of the right cingulate gyrus was positively correlated with the score of MMSE(r=0.628,P<0.001)and the score of Mo CA(r=0.763,P<0.001).(3)VBM: Compared to the healthy control group,the patients with OSAHS showed significantly decreased GMV in the left cerebellar peduncle 2,left insula,left inferior parietal lobe,right insula,right middle frontal gyrus,right frontal gyrus.The GMV of the right middle frontal gyrus was positively correlated with AHI(r=0.410,P=0.024).Conclusion:(1)Cognitive dysfunction is common in patients with moderate-to-severe OSAHS.The severity of the cognitive dysfunction is positively correlated with the severity of the OSAHS.(2)The rs-f MRI indicates that the local brain regions of structure and function have changed significantly in OSAHS patients.These changes are related to the severity of OSAHS and may be one of the important pathogenesis of cognitive dysfunction caused by OSAHS.Timely and effective treatment of OSAHS may be an effective way to prevent and treat the cognitive impairment caused by OSAHS.