A Study On The Functional And Structural Connection Changes Of The Default Patterns Of The Brain In Patients With Generalized Anxiety Disorder

Generalized anxiety disorder(GAD)is a common disorder with increasing prevalence rate.The patient is in the autonomic nervous symptoms such as persistent anxiety,restlessness and tension without cause for a long time,which brings great pain.Its pathogenesis is not clear.The default mode network(DMN)is the basic network of the brain in resting state.The study of brain function and structure in resting state is conducive to understanding the causes and pathology of inactivity anxiety in GAD and providing biological quantitative support for further clinical studies.Currently,the number of brain imaging studies on GAD has gradually increased,but there is no unified conclusion to explain the relationship between resting-state functional connections and structural connections of DMN in GAD.In this study,a total of 26 GAD patients and 26 healthy controls which were age and gender matched were selected,their structural and functional brain imaging data were collected using Siemens 3.0-Tesla Verio MRI scanner with the same parameters,the default mode network was extracted by independent component analysis,and the functional connection and structural connection of the default mode network were studied by seed-point functional connection analysis and diffusion tensor imaging,and Pearson correlation was used to investigate the coupling between the functional connection and structural connection in abnormal brain regions.The results were as follows:(1)Compared with the healthy control group,the functional connection between the bilateral thalamus of gad patients was significantly decreased,while the functional connection between the right thalamus and the left middle temporal gyrus was increased.(2)In the GAD group,the fractional anisotropy of left rectus and left temporal pole:superior temporal gyrus were increased.While the fractional anisotropy of white matter integrity of left middle temporal gyrus,right insula,left parahippocampal gyrus,left middle occipital gyrus,right frontal lobe,left anterior cingulate gyrus and other brain regions were decreased.The mean diffusivity of left temporal lobe,right precuneus,left temporal pole,middle temporal gyrus,bilateral superior frontal gyrus,left precentral gyrus,right inferior frontal gyrus,orbital part,right anterior cingulate gyrus,left superior occipital gyrus and other brain regions were increased.(3)There was a significant correlation between the average fractional anisotropy and functional connection between the orbital part superior frontal gyrus and the right thalamus in patients with GAD,and a significant correlation between the number of fibers and functional connection between the posterior cingulate gyrus and the right thalamus.The above results and analysis have proved that the important brain regions in the default mode network of GAD patients have structural and functional abnormalities,and the brain regions of DMN,mainly the thalamus,temporal lobe and frontal lobe,have structural and functional damage.The abnormal correlation between functional and structural connections of DMN suggests that there aresynchronous changes of function and structure in DMN of GAD.It can be speculated that the disorder of default mode network in GAD patients may be related to the pathogenesis of GAD.