Regional Homogeneity Changes In Pre-operation And Post-operation Patients With Obstructive Sleep Apnea-hypopnea Syndrome By Resting-state Functional MRI

PurposeTo investigate the changes of regional homogeneity(ReHo)in post-operation patients with obstructive sleep apnea-hypopnea syndrome(OSAHS)using resting-state functional magnetic resonance imaging rs-fMRI,and evaluate correlation analysis between changed ReHo and scale score of cognitive competence.SubjectResting-state fMRI data were collected from 26 patients with severe OSAHS in otolaryngology head and neck surgery department of Zhongda Hospital Affiliated to Southeast University and 19 normal controls From November 2014 to January 2017.MethodResting-state fMRI of 26 severe OSAHS patients before operation and 19 normal controls were collected by 3.0 Siemens Verio MRI,PSG and cognitive ability was also assessed.After 26 severe OSAHS patients were performed the same UPPP operations by the same doctor,resting-state fMRI,PSG,and cognitive ability were reassessed six months later.Patients with a big head movement when scanning in the magnetic resonance scanning or refused to come back were removed from the enrolled data.Finally,we enrolled 13 OSAHS patients after operation and 13 healthy controls for the study.Gender,age,education,body mass index(BMI),sleep apnea hypopnea index(AHI)parameters of polysomnography for at least 7 hours of the night,oxygen saturation index(ODI),the cognitive scale score as sample mental scale(MMSE)and sleepiness scale(ESS),complex figure test scale(CFT),delayed memory review test scale(CET-delayed memory),logical memory test scale(LMT),delayed logical memory test scale(LMT-delayed memory)were recorded.All the resting-state fMRI data were computed on the MATLAB platform,We obtained(ReHo)image using REST software and assessed the change of brain function between pre-operation and post-operation OSAHS patients.Finally,we evaluated the effect of surgical treatment.We took ANOVA analysis and SPSS 17.0 statistical software were performed to process the data,assessed the difference among the three groups.The correlation between the cognitive ability and ReHo were also assessed.Results1.Compared with the OSAHS patients,ReHo showed a significant increase(P<0.01,Alphasim correction)in the left superior frontal gyrus,right medial frontal gyrus(t=6.8282,P<0.01),left medial frontal gyrus,frontal gyrus(t=6.83,P<0.01),bilateral precuneusin(t=6.8282,P<0.01)in post-operation OSAHS patients.2.Compared with the healthy controls,ReHo increased(P<0.01,Alphasim correction)in left occipital lobe and cerebellum(t=13.564,P<0.01),left occipital lobe and left cerebellum(t=11.377,P<0.01),reduced in(P<0.05,Alphasim correction)in bilateral superior and middle frontal gyrus(t=-8,807,P<0.01),inferior parietal lobule and angular gyrus(t=-7.176,P<0.01)in pre-operation OSAHS patients.3.Compared with the healthy controls,ReHo increased(P<0.01,Alphasim correction)in left occipital lobe and cerebellum(t=77.81,P<0.01),right occipital lobe and cerebellum(t-5.8529,P<0.01),reduced in the medial prefrontal cortex(t=-7.403,P<0.01),inferior parietal lobule and angular gyrus(t=-12.078,P<0.01)in post-operation OSAHS patients.4.Increased average ReHo of the left medial frontal gyrus and middle and inferior frontal gyrus(t=6.83,P<0.01)between post-operation and pre-operation patients were positively correlated with delayed complex graphics(CFT-delayed)(r=0.547,P=0.029).Increased average ReHo of right occipital lobe and cerebellum(t= 5.8529,P<0.01)between OSAHS patients and healthy ones group were positively correlated with the mini-mental state examination(MMSE)(r=0.547,P<0.046).Reduced average ReHo of the inferior parietal lobule and angular gyrus(t=-12.078,P<0.01)between OSAHS patients and healthy ones were negatively correlated with delayed and complex graphics(CFT-delayed)(r=-0.347.P=0.037).Conclusion1.ReHo changed significantly in patients with severe OSAHS in several brain regions.Compared with healthy controls,ReHo increased in left occipital lobe and cerebellum,suggesting the compensatory brain alteration.ReHo reduced in bilateral middle frontal gyrus,inferior parietal lobule and angular gyrus,suggesting the injured brain function.Changed brain regions such as cerebellum and right middle frontal gyrus were corresponded with the preliminary results of our study group.2.Compared with the pre-operation OSAHS patients,ReHo increased in left superior frontal gyrus,right medial frontal gyrus,left medial frontal gyrus,middle and inferior frontal gyrus,bilateral precuneus in post-operation OSAHS patients,which suggesting the activated brain function.however,the result of our previous study showed that ReHo reduced mainly in frontal gyrus and inferior parietal lobule.Also our study showed that ReHo increased mainly in frontal gyrus and bilateral precuneusin,suggesting surgical treatment in patients with OSAHS may improve function of frontal gyrus significantly.3.Compared with the healthy controls,ReHo increased in left occipital lobe and cerebellum,right occipital lobe and reduced in medial prefrontal cortex,inferior parietal lobule and angular gyrus in post-operation OSAHS patients.Which suggested that after half of a year of operation occipital lobe and cerebellum remained the same and kept compensatory alteration according to our previous research.In addition,the medial prefrontal cortex,inferior parietal lobule and angular gyrus did not improve after operation.