Regional Morphometric Abnormalities And Small-world Network Research On Subcortical Structures

First-episode schizophrenia and developmental dyslexia are both chronic neurological diseases.Not only changes have taken place in the physical morphology of brain regions related to them,but also the functional connection or structural connection between different brain regions is disordered.This paper mainly takes these two diseases as examples,and uses nuclear magnetic resonance imaging technology to automatically segment 12 subcortical structures,aiming at exploring the subcortical structures affected by these two diseases and their changing trends,as well as the changes of small-world network.In the volume analysis,the gray matter volume of cortical structure was calculated by voxel-based method,and disease-versus-control volume differences of each subcortical structure was calculated.It was found that the bilateral amygdala and bilateral hippocampal structure of first-episode schizophrenia had significant overall volume reduction and local shape atrophy.In children's developmental dyslexia,the volume in bilateral amygdala,bilateral hippocampus and right globus pallidus decreased significantly.In the morphological analysis,based on large differential homeomorphism deformation method,this paper calculates Jacobian deformation values at each vertex of each cortical structure,and calculates inter-group morphological difference of each subcortical structure between patient group and control group respectively.In order to better identify the sub-regions related to pathology of first-episode schizophrenia and children's developmental dyslexia,the subcortical structures of interest are divided into sub-regions,and the shape atrophy of the sub-regions is observed.In morphological analysis,we found that amygdala morphological abnormalities in firstepisode schizophrenia mainly occurred in lateral basal region and medial central region,while hippocampal morphological abnormalities mainly concentrated in CA1 and CA2 regions.For the same structure,the right hemisphere is more affected than the left hemisphere.The surfaces of bilateral amygdala,left hippocampus and bilateral globus pallidus in children's developmental dyslexia are significantly atrophic.Under the same structure,the surface of left hemisphere structure in children's developmental dyslexia patients is more atrophic,and Basolateral and Basomedial regions of amygdala and CA1 and Subiculum regions of hippocampus are greatly affected by children's developmental dyslexia.In the small world network analysis,12 subcortical structures are also constructed using Jacobian deformation markers.The small world network,quantitative analysis of the entire network and each node related attributes.In addition to the group comparison at the cortical structure level,this paper also constructs a small world network at the sub-regional level and analyzes the small world network of the sub-regional network.In small-world network analysis,clustering coefficient and local efficiency of first-episode schizophrenia patients decreased.At the cortical structure level,the local efficiency and clustering coefficient of children's developmental dyslexia are improved,and the local efficiency of the sub-network has significant difference between groups under partial density,which is consistent with the trend of the cortical structure network.The Nodal local efficiency of the left amygdala and bilateral putamen in the main network of children's developmental dyslexia was different between groups.However,in the sub-network,the nodal local efficiency of the left amygdala's Centromedial region has significant differences between groups.