Correlation Between Cognitive Impairment And Brain Structure And Function In Patients With Spinal Cord Injury

Background Spinal cord injury(SCI)is a stressful event that makes patients suffer serious physical and psychological trauma,and individuals are faced with immediate and potential permanent life changes.Studies have found that patients with SCI have not only structural and functional disorders of spinal cord,but also cognitive impairment to a certain extent,and affect the prognosis of patients.Basic studies have confirmed that extensive changes in the brain,which are closely related to the structure and function of the spinal cord,occur after the occurrence of SCI,which may be an important cause of cognitive impairment in SCI.However,the results of basic research have some limitations,and the correlation between cognitive impairment and brain structure and function in patients with SCI is not clear.With the development of multimodal magnetic resonance imaging technology,it provides a non-invasive method for the study of brain structural and functional changes in patients with SCI.What are the characteristics and potential risk factors of cognitive impairment in patients with SCI? What is the mechanism of cognitive impairment in patients with SCI? The purpose of this study is to explore the characteristics,potential risk factors and possible neural mechanism of cognitive impairment in patients with SCI by using neuropsychological evaluation method combined with multimodal magnetic resonance imaging,in order to provide reference basis for clinical intervention,delay or even prevent the occurrence of cognitive impairment in patients with SCI.Objective Combined with the evaluation of cognitive function and multimodal magnetic resonance data of gray matter structure and neural activity in patients with SCI,the characteristics,potential risk factors and possible neural mechanism of cognitive impairment in patients with SCI were explored.(1)To investigate the occurrence of cognitive impairment in patients with SCI and to explore the characteristics and influencing factors of cognitive impairment in patients with SCI.(2)To explore the characteristics of structural changes of cerebral gray matter and the relationship between gray matter structure and cognitive function score in patients with SCI.(3)To explore the characteristics of neural activity changes in patients with SCI and the relationship between neural activity and cognitive function score.Methods(1)Study 1: By general data survey Scale,Chang Sha version of Montreal cognitive assessment Scale(Mo CA),Visual Analogue Scale method(VAS))of 115 patients with SCI and age,gender,education level matching to evaluate 115 cases of healthy controls,analysis the incidence of cognitive dysfunction in patients with SCI,characteristics and influencing factors.(2)Study 2: Collection of 31 patients with SCI and 30 cases of age,gender,education level of the healthy controls matched high resolution 3D T1 structure and resting state functional magnetic resonance imaging data,By combining voxel based morphometry(VBM)and fractional amplitude of low frequency fluctuation(f ALFF),SCI group and healthy control group changes gray matter volume and neural activity in the brain,Meanwhile,the correlation between gray matter volume and neural activity parameters and cognitive function scores in SCI group was analyzed.Results(1)Study 1: The Mo CA score of SCI group was significantly lower than that of healthy control group(P<0.05),and there were significant differences in visual space /executive ability,attention,language abstraction and delayed recall function between SCI group and healthy control group(P<0.05),but there was no significant difference in naming and orientation function(P>0.05).Cognitive impairment occurred in 76 cases(66.1%)in SCI group.Univariate analysis showed that age,education level,smoking,drinking,injury site,ASIA grade and pain score were potential risk factors of cognitive impairment in SCI patients(P<0.05).Multivariate logistic regression analysis showed that age,ASIA grade and education level were significantly correlated with cognitive impairment in SCI patients(P<0.05).(2)Study 2: The Mo CA score of SCI group was significantly lower than that of healthy control group(P<0.05).There were significant differences in visual space /executive ability,attention,language abstraction and delayed recall between),SCI group and healthy control group(P<0.05).The gray matter volume of left middle frontal gyrus,inferior triangular frontal gyrus,precentral gyrus and right triangular inferior frontal gyrus in SCI patients was significantly smaller than that in healthy controls(P<0.05).At the same time,the gray matter volume of right triangular inferior frontal gyrus in SCI patients was positively correlated with attention function(P<0.05).The f ALFF of left orbital middle frontal gyrus,right middle frontal gyrus,right dorsolateral superior frontal gyrus,right anterior wedge lobe and right inferior parietal angular gyrus in SCI patients was significantly lower than that in healthy controls(P<0.05).In addition,f ALFF in left orbital middle frontal gyrus was positively correlated with visual space executive function in SCI patients,and f ALFF in right middle frontal gyrus was positively correlated with Mo CA score and visual space executive function.The f ALFF of the left anterior cuneiform lobe was positively correlated with visual spatial executive function,delayed recall and orientation;the right anterior wedge lobe was positively correlated with Mo CA score and visual spatial executive function;the f ALFF of the right inferior parietal angular gyrus was positively correlated with Mo CA score,visual spatial executive function and abstract function;and the f ALFF of the right dorsolateral superior frontal gyrus was positively correlated with attention function and abstraction(P<0.05).Conclutions(1)Patients with SCI have cognitive impairment,which is mainly manifested in visual space / executive ability,attention,language abstraction,delayed recall and so on.(2)Age and degree of injury are the risk factors of cognitive impairment in patients with SCI.The older the age and the higher the degree of injury,the higher the risk of cognitive impairment in patients with SCI.(3)SCI caused atrophy of local cerebral gray matter,mainly in the left brain region,including middle frontal gyrus,inferior triangular frontal gyrus,precentral gyrus and right triangular inferior frontal gyrus,and the volume of gray matter in right triangular inferior frontal gyrus was correlated with attention function,suggesting that local brain structural atrophy in patients with SCI may lead to cognitive impairment.(4)The decrease of nerve activity in local brain area from SCI was mainly manifested in left orbital middle frontal gyrus,right middle frontal gyrus,right dorsolateral superior frontal gyrus,left and right anterior cuneate lobe,right inferior parietal angular gyrus.The changes of cognitive function in patients with SCI were closely related to abnormal brain activity,suggesting that cerebral nerve activity may provide some objective basis for the occurrence of cognitive dysfunction in patients with SCI.