A Preliminary Study Of Cognitive Impairment And Brain Structural Changes In Patients With Stable Chronic Obstructive Pulmonary Disease

Objective:To investigate the morphological changes of the white matter and gray matter microstructures in the patients with chronic obstructive pulmonary disease（COPD）,and to analyze the cognitive function and the related factors of the patients with stable COPD.The pathophysiological mechanism of COPD is revealed from a new point of view,which provides important reference for clinical diagnosis and treatment.Methods:35 stable non-hypoxemic patients with COPD and 35 healthy volunteers（control group）matched by sex,age and educational level were selected to evaluate the cognitive function,anxiety and depression by using MOCA,MMSE,SAS and SDS clinical scales.The incidence and related factors of cognitive dysfunction in COPD patients were statistically analyzed.3.0T magnetic resonance imaging was used to scan the whole brain DTI（Diffusion Tensor Imaging）and T1 structural sequence.Tract based spatial statistics（TBSS）and voxel based morphological analys is（voxel-based morphometry,VBM）were used to compare the differences of the white matter fiber bundles and gray matter density between groups.Results:1.The score of COPD group was significantly lower than that of the control group（P<0.05）,and the incidence of cognitive impairment（60%）was higher than that of the control group（28.6%）（p<0.05）.According to the classification of lung function,there was no significant difference in the inc idence of cognitive impairment between the middle group（FEV1>50%）and the recombinant（FEV1<50%）COPD（p>0.05）.However,there were significant differences in the incidence of cognitive impairment in COPD patients according to the degree of dyspnea（MMRC）（p<0.05）.There was a positive correlation between the Mo CA scale score of COPD and the value of PaO₂（r=0.386,p=0.047）,and there was a negative correlation between the Mo CA scale score and the PaCO₂ value（r=-0.398,p=0.040）.Single factor analysis showed that education blood oxygen partial pressure（PaO2）,CO2 partial pressure（PaCO2）and CAT were associated with cognitive ysfunction in patients with COPD（p<0.05）。Logistic regression analysis showed that education level and smoking index were significantly correlated with cognitive impairment in patients with COPD stable stage（p<0.05）。2.TBSS results showed that:compared with the normal control group,the corpus callosum,bilateral anterior thalamic radiation,corticospinal tract,left inferior occipcipital fasciculus and left superior longitudinal bundle FA were significantly decreased in COPD group（p<0.05,TFCE corrected）.The MD value of corpus callosum,bilateral inferior frontal and inferior occipital tract,right thalamus anterior radiation and left hook tract were significantly increased（p<0.05,TFCE corrected）.3.Based on the voxel morphological analysis（VBM）,it was found that the density of gray matter in the bilateral spindle gyrus,lingual gyrus,inferior temporal gyrus,parahippocampal gyrus,hippocampus,upper frontal gyrus,middle frontal gyrus,left c ingulate anterior gyrus in stable COPD patients decreased significantly（p<0.001,FDR correction）compared with the normal control group.Conclusion:The risk of cognitive dysfunction in patients with stable COPD is significantly increased.There are many morphological changes in the white matter fiber and gray matter area related to cognitive function and emotion regulation,which can be used as an important biological marker for brain injury in stable COPD patients.