Analysis Brain Structural Networks In Patient With Comitant Exotropia Strabismus Based On DTI

Objective:Using diffusion tensor imaging(DTI)technique to construct the brain structure network of patients with Comitant exotropic strabismus(CES),and to explore the related changes of their topological properties.The purpose of study is to explore the the changes of white matter network in patients with CES,provide a new idea for the further study of the potential neuropathological mechanism of CES.Methods:Fourteen patients in CES group and healthy control group(HCs)matched with their age,sex and education level were scanned by MRI.The individual brain structure network is constructed by 3D T1 sequence and DTI sequence data.The whole brain is divided into 90 brain regions by using the anatomic automatic marking template,and the existence of the edge is determined by the number of the fiber bundles in the brain section,and then the topological property analysis of the structural network is carried out based on the graph theory method.The general linear model(GLM)analysis was used to compare the various network topological properties of the CES group and the HCs group,and to find out the brain regions with statistically significant differences between the groups.Results:1、The global efficiency of the CES group structure network is lower than that of the HCs group,but the overall network construction is still uniform.2、In CES group,the brain regions with significantly decreased nodal efficiency included the right olfactory cortex、caudate nucleus、thalamus、temporal pole of superior temporal gyrus;left Rolandic operculum,olfactory cortex,superior frontal gyrus of medial orbital、gyrus rectus、posterior cingulate gyrus、hippocampus and cuneus.3、CES group node clustering coefficient in the left hippocampus;the right inferior parietal but supramarginal and angular gyri、superior temporal gyrus decrease compared with the HCs group.4、The degree centrality of several brain areas in CES group was lower than that in HCs group.These areas included right orbital part of inferior frontal gyrus,olfactory cortex、caudate nucleus、thalamus、temporal pole of superior temporal gyrus;left central sulcus、olfactory cortex、middle frontal gyrus of orbital region、osterior cingulate gyrus、hippocampus、Cuneus、caudate nucleus.5、Comparing with HCs group,the centrality of right Median cingulate and paracingulate gyri、superior temporal gyrus was increased in CES group.Conclusion:1、The brain structural network of CES group and HCs group both have small-world properties.Although the global efficiency of CES patients decreases,the overall construction of the structural network is still in equilibrium state.2、 In the CES group,the local attributes of several brain regions in the structural network were abnormal,mainly manifested in the visual brain area,and partly involved emotional and cognitive related brain regions.It is suggested that strabismus is not only an ophthalmic disease,but also affects the structure and function of the whole brain.3、In the CES group,the loss of the core node role in the visual and emotional brain area,indicating that there was a certain degree of structural dysfunction in the local area of the brain structure network of CES patients,and may occur corresponding reconstruction.