Effects Of Continuous Positive Airway Pressure On Cognitive Function And Brain Resting-state Functional Magnetic Resonance Imaging In Patients With Severe OSAHS

Objective: This study was to observe the effect region of nasal continuous positive airway pressure(n CPAP)on improving cognitive function in patients with severe obstructive sleep apnea hypopnea syndrome(OSAHS)based on regional homogeneity(Re Ho)index of resting state functional magnetic resonance imaging(rs-f MRI),and to analyze the correlation and clinical efficacy combined with the change of cognitive function.Methods: 24 patients with severe OSAHS and 22 healthy adults diagnosed by polysomnography(PSG)were included.Montreal cognitive score(Mo CA),Epworth sleepiness scale(ESS)and rs-f MRI were performed before treatment in both groups.The patients with severe OSAHS received n CPAP treatment for more than 4 hours per night for 3 months,and then received PSG examination,scale evaluation and rs-f MRI scanning again.Patients who were lost to follow-up after treatment,refused to take the second MRI examination,or had poor MRI image quality due to excessive head movement were excluded,and 20 patients with severe OSAHS and 20 healthy controls were finally included for statistical analysis.The sleep monitoring parameters,Mo CA score and ESS score and correlation analysis were statistically analyzed in SPSS 23.0environment.The statistical maps of Re Ho ’s different brain regions were obtained by processing rs-f MRI images on Matlab.Results:(1)Cognitive function: Compared with the healthy control group,the Mo CA score of OSAHS group before treatment was significantly lower(P<0.05),and negatively correlated with AHI(r=-0.801,P<0.05)and ODI(r=-0.783,P<0.05);the ESS score of OSAHS group before treatment was significantly higher(P<0.05),and positively correlated with AHI(r=0.687,P<0.05)and ODI(r=0.541,P<0.05).After 3months of n CPAP treatment,ESS score of OSAHS group was significantly lower than that before treatment,Mo CA score was significantly higher than that before treatment,especially in visual space and executive function,attention,language,delayed recall(P<0.05).(2)Re Ho value: Compared with healthy control group,the Re Ho value in right angular gyrus,precuneus and left parahippocompalgyrus,middle frontal gyrus of OSAHS group decreased,and the Re Ho value in right posterior cerebellar lobe increased(GRF correction,P<0.005).After 3 months of n CPAP treatment,the right precuneus,temporal lobe,posterior cingulate gyrus and left limbic lobe increased in OSAHS group(GRF correction,P<0.005).(3)Re Ho value of right posterior cerebellar lobe was positively correlated with Mo CA score(r=0.324,P<0.05)in OSAHS group and healthy control group.Re Ho value of right precuneus was positively correlated with AHI(r=0.478,P<0.05)and negatively correlated with Mo CA score(r=0.484,P<0.05)in OSAHS group before and after n CPAP treatment.Conclusion: Patients with severe OSAHS generally have cognitive dysfunction,and the function of several brain regions have abnormal changes.After 3 months of n CPAP intervention,the cognitive function of patients with severe OSAHS was significantly improved,and the consistency of neural activity in some brain regions was enhanced.There was a significant correlation between the improvement of cognitive function and the consistency of neural activity in brain regions.This study suggests that the changes of local brain function in patients with OSAHS may be an important mechanism of cognitive dysfunction.