Mechanism Of Acupuncture Influence On Default Mode Network In Knee Osteoarthritis Patients:A Resting-state Functional Magnetic Resonance Imaging Study

ObjectsIn this study,we conducted a BOLD-f MRI study on the knee osteoarthritis and healthy subjects by focusing on central changes of the brain activities.This study is aimed to 1)investigate the differences in the activities of DMN between patients with knee osteoarthritis and healthy subjects.2)explore the influence of acupuncture on meridian acupoints on the cerebral activities of DMN in KOA patients by cpmparating to puncture at sham acupoints so as to provide scientific evidences for the clinical application of acupuncture in the treatment of knee osteoarthritis.MethodsFirstly,50 patients with knee osteoarthritis and 50 healthy subjects were recruited in this study.The blood Oxygen Level Dependent Functional Magnetic Resonance Imaging(BOLD-f MRI)was performed on these participants.Low frequency amplitude(ALFF)as the data analysis method was used to investigate the functional differences of brain between KOA patients and healthy subjects in resting state.Finally,we explored the central mechanism of acupuncture treating on knee osteoarthritis.Patients with knee osteoarthritis were randomly divided into group A(puncturing on meridian points group)and group B(puncturing on non-meridian and non-acupoints),of which 25 patients were assigned in group A and 25 patients were included in group B.Both group received total 10 sessions of acupuncture treatment in two weeks.We used the VAS(Visual Analog Scale,VAS),MPQ(Mc Gill Pain Questionnaire,MPQ),WOMAC(The Western Ontario and Mc Mmaster Universities Osteoarthritis Index,WOMAC),SAS(Self-rating Anxiety Scale,SAS),(Self-rating Depression Scale,SDS),SF-12(Short Form 12 Questionnaire,SF-12)as endpoints to evaluate the clinical efficacy of acupuncture treatment.BOLD-f MRI scan was performed to detect the cerebral signal changes induced by acupuncture stimulation.Finally,we compared the group A and group B to explore the central mechanism of acupuncture treating on knee osteoarthritis.Results1.Evaluation of the clinical endpoints of group A and group B(1)Baseline comparison.The baseline comparison were comparable between patient group and healthy subjects(P>0.05)except age.The baseline comparison were comparable between group A and group B(P>0.05).(2)Characteristics of cerebral activity changes in KOA patients.The ALFF signals was activated in bilateral middle frontal gyrus,inferior frontal gyrus,left precuneus gyrus,superior marginal gyrus,inferior temporal gyrus,middle temporal gyrus,insula,right fusiform gyrus,angular gyrus and the negatively activated brain areas were bilateral middle occipital gyrus,superior occipital gyrus,hippocampus,thalamus and amygdala of DMN compared with healthy patients.Correlation analysis showed that left middle temporal gyrus was positively correlated with SDS,SAS and negatively correlated with SF-12.Hippocampus was negatively correlated with pain duration of KOA patients.(3)Therapeutic effects of acupuncture treating on KOA patients.There was no significant difference in baseline between group A and group B(P> 0.05).The results of intra-group comparison showed that compared with baseline,both group A and group B could significantly reduce VAS,WOMAC and MPQ scores(P<0.05),improve SF-12 and SDS scores(P<0.05).Acupuncture at meridian acupoints could also significantly reduce SAS scores of patients(P<0.05).Comparison among groups showed that compared with group B,group A could significantly improve the VAS and MPQ knee pain scores of KOA patients(P>0.05).(4)Influence of Acupuncture on brain activity changes of KOA PatientsAfter acupuncture treatment,the ALFF values of central anterior gyrus,middle cingulate gyrus and calcarine gyrus of DMN in group A increased significantly,while medial prefrontal cortex of DMN decreased significantly.There was no significant difference in the ALFF of different brain regions before and after treatment between group A and group B.Correlation analysis showed that there was a negative correlation between the changes of middle cingulate gyrus brain function and the improvement of SDS score after acupuncture treatment in the group A.Conclusions1.In KOA patients,there were significant abnormalities in Default Mode Network(DMN)activities,mainly in the middle frontal gyrus,inferior frontal gyrus,left anterior cuneiform lobe,superior marginal gyrus,inferior temporal gyrus,middle temporal gyrus,right fusiform gyrus,angular gyrus,hippocampus and thalamus gyrus.2.Both group A and group B could improve the clinical symptoms and quality of life of KOA patients.At the same time,acupuncture at group A can improve the anxiety of patients.3.Influencing on functional activities of DMN may be the important mechanism of group A treating on KOA.