Effect And Mechanism Of Baduanjin On Episodic Memory With SCD Patients-Based On The Posterior Default Mode Network

Objective:1.To observe the effects of 24-week regular Baduanjin exercise on the episodic memory function in subjective cognitive decline(SCD)patients.2.Based on the rest-state functional connection(rs FC),the potential mechanism of Baduanjin improvements in episodic memory function in patients with SCD was explored from the perspective of the moderating effect of the posterior default mode network(p DMN)and motor function to improve the cognitive function.Methods:Part 1: Based on the literature research,this part systematically reviewed the TCM theoretical basis on the Baduanjin exercise improve memory function,episodic memory function and the abnormal changes of the brain with SCD patients,physical activity improve motor function,episodic memory function and the related research of FC changes of brain.This study provides a theoretical basis for further exploring the improvement of episodic memory function via the moderating effects of the p DMN improving motor function in patients with SCD by the Baduanjin.Part 2: The effect of Baduanjin on episodic memory function and motor function in patients with SCD.This study was a parallel randomized controlled clinical trial study,involving 102 qualified subjects and randomly divided into three groups: Baduanjin group,brisk walking group or health education group,with 34 patients in each group.Patients in the health education group only received health education,and patients in the Baduanjin group was given Baduanjin on this basis,and brisk walking group were requied to participant in the brisk walking exercise based on this basis,three times a week,60 min each time,lasting for 24 weeks.Changes in the episodic memory and motor function were evalated before and after intervention.The Auditory Vocabulary Learning Test(AVLT),Logistic Memory Test(LMT),and the Metamemory in Adulthood Questionnaire(MIA)were used to evaluate the episodic memory function;the lumbar muscle strength assesment,the center of pressure(COP)of body sway,and the 6 Minute Walk Test(6MWT)were used to evaluate the motor function;and analysis statistically was made.Part 3: Baduanjin improvements in episodic memory function via improved motor function based on the moderating effect of the p DMN.On the basis of the part two,functional MRI scans were performed on all subjects before and after the intervention,and structural images of subjects T1 and resting state functional images were collected.In accordance with the template of Anatomical Automatic Labeling(AAL),bilateral precunes,left precunes and right precunes were selected to conduct functional connection analysis based on Region-of-Interest(ROI),and observe the changes of rs FC between precunes and the whole brain region before and after intervention in three groups of patients,Matlab 2018 b and CONN v19.C software were applied to preprocess MRI image.The correlation betweeen episodic memory and motor function in the three groups of the change before and after intervention was conducted by correlation analysis.Motor function was used as independent variable,the change of rs FC was used as mediating variable,and episodic memory function was used as dependent variables.Based on the moderating effect of the p DMN,the potential mechanism of Baduanjin improvements in episodic memory function via improved motor function in patients with SCD was explored from the perspective of the rs FC.Results:Part 1.Literature research: The theoretical basis of TCM that Baduanjin exercise can improve the memory function of SCD;p DMN plays an important role in the process of encoding and retrieval of episodic memory with SCD;As the core region of p DMN,precuneus plays an important role in the process of encoding and retrieval of episodic memory;Physical activity can improve memory function in patients with SCD;Physical activity improvements in episodic memory function via improved motor function in patients with SCD,and can regulate p DMN.Part 2.Study on intervention effect: A total of 94 participants completed the intervention.Before the intervention,(1)Before the intervention,there were no significant differences in age,gender,education level,duration of subjective memory complaints,and HAMA/HAMD scale scores between the three groups(P > 0.05).The episodic memory function,including the scores of AVLT,LMT,and MIA,there were no significant differences(P > 0.05).The motor function,including the socres of lumbar muscle,the COP test,and the 6MWT also had no significant differences.(2)After 24 weeks of intervention,the results of intra-group comparison of episodic memory function showed that the scores of AVLT immediate recall,short delayed recall,long delayed recall and cue recall,LMT recall and the konwledge and motivation of MIA in Baduanjin group and brisk walking group were higher(P < 0.05).(3)After 24 weeks of intervention,the results of between-group comparison of episodic memory function showed the AVLT and LMT scores of Baduanjin group were significantly higher than that of brisk walking and health education group(P < 0.05).There was no significantly difference in MIA among the three groups(P > 0.05).(4)After 24 weeks of intervention,the results of intra-group comparison of motor function showed that the lubar muscle strength in Baduanjin group were higher(P < 0.05);and the extension of the lubar muscle strength in brisk walking group were higher(P < 0.05).Under both eyes-open and eyes-closed trials,the mean displacement of X-axis of the COP in the health education group was lower(P < 0.05).The distance and speed of 6MWT in Baduanjin group and brisk walking group were higher(P< 0.05).(5)After 24 weeks of intervention,the results of between-group comparison of motor function showed the lumbar muscle strength including left flexor and right flexor,the mean displacement of X-axis of COP test scores under eyes-closed trials and the distance and speed of 6MWT in Baduanjin group and the brisking walking group were significantly higher than that of health education group(P < 0.05);There was no significant difference between Baduanjin group and brisk walking group(P > 0.05).Part 3.Study on mechanism:(1)A total of 79 participants completed functional Magnetic Resonance Imaging(f MRI)before and after the intervention.There were no significant differences of three groups in the baseline and before the intervention(P > 0.05).(2)After the24 weeks of intervention,the results of between-group comparison of episodic memory function showed that the AVLT long delayed recall and LMT delayed recall scores of Baduanjin group were significantly higher than that of brisk walking and health education group(P < 0.05).The results of between-group comparison of motor function showed that the left flexore of the lumbar muscle strength and the mean displacement of X-axis of COP test of Baduanjin group were significantly higher than that of health education group(P < 0.05),while the distance and speed of 6MWT test of brisking walking group were significantly higher than that of health education group(P < 0.05).There was no significant difference between Baduanjin group and brisk walking group(P > 0.05).(3)After the 24 weeks of intervention,the results of the rs FC between the precuneus and the whole brain showed that,we found the rs FC between the bilateral precuneus and right inferior temporal gyrus,left angular gyrus in Baduanjin group were significantly decrease than control group;Subjects in walking group showed a significantly decrease between the bilateral precuneus and right temporal pole/middle temporal gyrus,left angular gyrus,right pars orbitalis gyris frontalis inferiois /right pars triangularis gyris frontalis inferiois,and left medial prefrontal gyrus than control group.We also found that the rs FC between the left precuneus and right inferior temporal gyrus,left angular gyrus and left middle temporal gyrus in Baduanjin group were significantly decrease than control group;Subjects in walking group showed a significantly decrease between the left precuneus and left angular gyrus,right inferior temporal gyrus than control group.There was no significant difference between the right precuneus and the whole brain FC between the three groups(P > 0.05).(4)The results of correlation analysis between the AVLT delayed recall and the left flexor showed significant positive correlation(r=0.434,P=0.015)in Baduanjin group;We also found that there was significant positive correlation between the AVLT delayed recall and the right flexor(r = 0.491,P = 0.015)in brisk walking.(5)In the Baduanjin group,there was an interactive effect between the left flexor lumbar muscle strength and bilateral precuneus to left angular gyrus(r =-0.515,P=0.019),and there was an interactive effect between the left flexor lumbar muscle strength and left precuneus to left angular gyrus(r =-0.515,P=0.019).In the brisk walking group,neither an interactive effect between the right flexor lumbar muscle strength and bilateral precuneus to right temporal pole/middle temporal gyrus,left angular gyrus,right pars orbitalis gyris frontalis inferiois /right pars triangularis gyris frontalis inferiois,and left medial prefrontal gyrus(P >0.05),nor an interactive effect between the right flexor lumbar muscle strength and left precuneus to left angular gyrus,right inferior temporal gyrus(P > 0.05).Conclusion:1.24-week regular Baduanjin exercise have potential protect effect of the episodic memory-delayed recall function and lumar muscle,eye-closed standing balance function,walking endurance and speed in SCD patients.2.24-week regular Baduanjin exerciese could modulate the changes of rs FC between the bilateral precuneus and right inferior temporal gyrus,left angular gyrus,and between the left precuneu and right inferior temporal gyrus/temporal pole,left angular gyrus,middle temporal gyrus.3.The change in the rs FC between the precuneus and the whole brain,a core brain region of p DMN,may have a potential moderating effect on improvements in episodic memory-delayed recall function via improved lumbar muscle strength in patients with SCD in Baduanjin.