Effect And Central Mechanism Via FMRI Of Transcutaneous Auricular Vagus Nerve Stimulation On Functional Dyspepsia

ObjectiveThis study observed the efficacy of transcutaneous auricular vagus nerve stimulation to treat patients with functional dyspepsia,and applied resting functional magnetic resonance imaging to observe the immediate and delayed effects of whole-brain hemodynamics before and after treatment,analyze the trend of in brain functional activities changes in brain,and explore the central mechanism of taVNS in treating FD patients.MethodsThis study was a single center,randomized controlled,double-blind clinical trial.In 2018-2019 into the diagnostic standard of 54 cases of FD patients,in accordance with the order of the included studies,using SAS V9.2 design process of random grouping,divided 26 cases into transcutaneous auricular vagus nerve stimulation therapy group and 28 cases into the sham vagus nerve stimulation in the control group.With taVNS as interventions,respectively in the two groups before and after 2 weeks treatment for Scores of major symptoms of dyspepsia,Nippon dyspepsia symptom index,Hamilton anxiety scale,Hamilton depression scale,self-rating anxiety scale and self-rating depression scale,the resting functional magnetic resonance imaging was completed before and after treatment.Results1.The results were analyzed within and between groups:①In the taVNS treatment group before and after treatment,the main symptom score,Nippon dyspepsia symptom index,HAMA,HAMD,SAS and SDS scores of FD patients after treatment were significantly reduced compared with those before treatment(P<0.05);②Before and after treatment in sham-taVNS control group,the score of main symptoms of FD patients after treatment was reduced compared with that before treatment(P<0.05),and there was no difference in Nippin dyspepsia symptom index,HAMA,HAMD,SAS and SDS scores after treatment(P>0.05).③Comparison between the taVNS treatment group and the sham-taVNS control group showed that,compared with the sham-taVNS control group,the main symptom scores,NDI,SAS,SDS,HAMA and HAMD scores of FD in the taVNS treatment group significantly deereased(P<0.001),and the clinical efficacy of FD patients after 2 weeks of treatment in the taVNS treatment group was better(P<0.001).2.Functional magnetic resonance brain function:①Comparison before and after taVNS treatment in the taVNS treatment group:compared with before treatment,ALFF values in the local brain areas of the left hippocampus and the left para-hippocampal gyrus in FD patients were increased after 2 weeks of taVNS treatment(P<0.05).②Comparison before and after treatment in sham-taVNS control group:compared with before treatment,there was no statistically significant difference in whole brain ALFF value in FD patients after 2 weeks of sham-taVNS treatment(P<0.05).③Comparison between taVNS treatment group and sham-taVNS control group before and after treatment:Compared with the sham-taVNS control group,the ALFF value of left inferior temporal gyrus,left para-hippocampal gyrus,left hippocampus,left orbital inferior frontal gyrus,left insula,left superior temporal gyrus temporal pole,left fusiform gyrus and left middle temporal gyrus temporal pole in the taVNS treatment group with FD increased(P<0.05,FWE correction).Conclus ion1.TaVNS can effectively improve the clinical symptoms and psychological conditions of anxiety and depression in FD patients.2.Transcutaneous auricular vagus nerve stimulation can regulate the activity of neurons in brain regions related to visceral sensation,motor integration and cognitive emotion in FD patients,and promote the function of brain regions related to FD symptoms to the normal level.