Changes Of Brain Function And Its Effect On Cognitive Function In Patients With Obstructive Sleep Apnea Hypopnea Syndrome

Objective: In this study,we hypothesized that obstructive sleep apnea hypopnea syndrome(OSAHS)may impair cognitive function by affecting resting state brain networks,and used resting state functional magnetic resonance imaging(rs-f MRI)to examine the areas of altered brain function in OSAHS patients.We have used resting state functional magnetic resonance imaging(rs-f MRI)to examine the areas of altered brain function in OSAHS patients and analyze the correlation between the differential brain areas and polysomnography(PSG)parameters,cognitive scores,and white matter volume changes to provide clinicians with new ideas for early diagnosis and intervention of OSAHS.Methods: This study included 61 subjects who completed PSG in the Second Hospital of Dalian Medical University Hospital from September 2020 to December 2022,including 31 in OSAHS group and 30 in normal control group.The general data,brain MRI,PSG parameters,Montreal Cognitive Assessment scale(Mo CA),Mini Mental State examination(MMSE),The Epworth Sleeping Scale,(ESS)data were collected in the OSAHS group and the normal control group,and the low frequency oscillation amplitude(ALFF)and fractional ALFF(f ALFF)of rs-f MRI were monitored.The differences of the above indexes between the two groups were analyzed.Partial correlation analysis was carried out between the differential brain regions and PSG parameters and cognitive scale scores to study their correlation.At the same time,the white matter of different brain regions was divided by voxel-based morphological measurements(VBM),and the functional changes of white matter volume in patients with OSAHS were analyzed.The difference of test level was statistically significant(P < 0.05).Results: 1.Comparison between OSAHS group and control group:1.1 There were no significant differences in gender,age,education level,hypertension history and diabetes history(P > 0.05);BMI was higher,the difference was statistically significant(P < 0.05)1.2 Apnea Hypopnea Index(AHI),oxygen desaturation index(ODI)and diastolic blood pressure before bedtime were increased,and the differences were statistically significant(P < 0.05).Minimum nocturnal oxygen saturation,Mo CA score and subitem score,MMSE score and subitem score decreased,and the difference was statistically significant(P < 0.05).1.3 ALFF values of bilateral precentral gyrus,left lingual gyrus,left cuneate lobe,left postcentral gyrus,left paracenter lobule,right supraoccipital gyrus and right superior parietal gyrus in OSAHS group were lower than those in normal control group,while those in right paracpocampal gyrus and right middle temporal gyrus were higher than those in normal control group(P < 0 05).1.4 f ALFF values of the peri-Talar fissure cortex,bilateral superior occipital gyrus,bilateral fusiform gyrus,left middle occipital gyrus,right supramarginal gyrus,right lingual gyrus and right precentral gyrus in the OSAHS group were lower than those in the normal control group(P < 0.05).1.5 ALFF and fALFF values showed no significant difference in white matter volume(p > 0.05).2.OSAHS group after correction of BMI,2.1 Correlation between cognitive score and PSG parameters:(1)The total Mo CA score and its subitems,visuospatial and executive ability,delayed memory were negatively correlated with AHI level(r=-0.510、-0.415、-0.496,P<0.05).The total score of MMSE and the subitems of attention and computation were negatively correlated with AHI level(r=-0.525、-0.447,P<0.05).(2)The total Mo CA score,visuospatial and executive ability and delayed memory were negatively correlated with ODI level(r=-0.510、-0.477、-0.470,P<0.05).The total score of MMSE and its subitems,attention and computing power,were negatively correlated with ODI level(r=-0.487、-0.367,P<0.05).(3)The total Mo CA score of OSAHS group and its subterms recognisual-spatial and executive ability,delayed memory and deep sleep duration were positively correlated(r=0.506、0.486、0.364,P<0.05).The total score of MMSE and its subitems,attention and computing power,were positively correlated with the length of deep sleep(r=0.435、0.500,P<0.05).(4)Attention in Mo CA score of OSAHS patients was positively correlated with sleep efficiency(r=0.522,P<0.05);The concentration and computation power of MMSE subitem were positively correlated with sleep efficiency(r=0.384,P<0.05).(5)The visuospatial and executive ability in the Mo CA subitem of OSAHS patients were positively correlated with the lowest oxygen saturation level(r=0.397,P<0.05).2.2 Correlation between ALFF value of different brain regions and PSG parameters and cognitive scores:(1)PSG parameters: ALFF of the left lingual gyrus was negatively correlated with AHI and ODI(r=-0.518、-0.451,P<0.05).It was positively correlated with deep sleep duration and mean blood oxygen saturation(r=0.547、0.505,P<0.05).ALFF value of left anterior central gyrus was positively correlated with mean systolic blood pressure(r=0.365,P<0.05).ALFF value of right parahippocampal gyrus was negatively correlated with preoperative systolic blood pressureand mean systolic blood pressure(r=-0.463、-0.383,P<0.05).(2)Cognition scale: the ALFF of the right middle temporal gyrus was negatively correlated with the attention in the Mo CA scale(r = 0.425,P<0.05).2.3 Correlation between f ALFF values in different brain regions and PSG parameters and cognitive scores:(1)PSG parameters: f ALFF values in the right and left fusiform gyrus were positively correlated with deep sleep duration(r=0.388、0.448,p<0.05).f ALFF value was positively correlated with effective sleep rate(r=0.369,P<0.05).f ALFF value of right anterior central gyrus was positively correlated with post-waking diastolic blood pressure and mean diastolic blood pressure(r=0.474、0.468,P<0.05).(2)Cognitive parameters: Attention and numeracy were positively correlated with the left fusiform gyrus(r=0.387、P<0.05);Language ability in MMSE subitem was positively correlated with right fusiform gyrus,left fusiform gyrus,left suproccipital gyrusand right lingual gyrus(r=0.434、0.364、0.490、0.472,P<0.05).Verbal retelling and fluency in Mo CA were positively correlated with left fusiform gyrus,right fusiform gyrus,right superior limbal gyrus and right suprapital gyrus(r=0.585、0.516、0.440、0.466,P<0.05).The total score of Mo CA was positively correlated with the left fusiform gyrus and the right lingual gyrus(r=0.385、0.392,P<0.05).Conclusion: 1.Excitatory changes of local neuronal activity in multiple brain regions were found in patients with OSAHS,which were related to hypoxia at night,deep sleep duration and sleep efficiency.2.Reduced excitability of spontaneous neuronal activity in OSAHS patients affecting resting-state brain networks may be one of the mechanisms of their cognitive decline.3.The excitatory changes of local neuron activity in patients with OSAHS are not related to the changes of white matter volume in corresponding brain regions.