Characteristics of the whole-brain white-matter structural network in 2 to 3-year-old children with autism spectrum disorder

Abstract

Objective To investigate the topological property alterations of the whole-brain white-matter (WM) structural network between 2 to 3-year-old children with autism spectrum disorder (ASD) children. Methods This research used diffusion tensor imaging(DTI) tractography to construct the human brain WM networks of 45 ASD children ranging from 2 to 3-year-old and 45 age- and sex-matched DD controls, followed by a graph theoretical analysis to establish topological architecture of the cerebral anatomical network, so as to further show the relationship between topological properties and clinical symptoms of the ASD group. Results The ASD children exhibited abnormal global topological properties, as indicated by decreased global efficiency(P=0.006), and increased characteristic path length (P=0.010). There were 11 hub nodes of the ASD group, 9 of them were the same as the DD controls, while the other two were right middle temporal gyrus and right dorsolateral superior frontal gyrus.Compared with DD controls, regional efficiency in several brain areas of ASD was significantly reduced(P<0.001), including left inferior frontal gyrus(orbital part), left superior frontal gyrus(medial orbital), right posterior cingulate gyrus, left inferior occipital gyrus, right precuneus, left paracentral lobule, bilateral caudate nucleus, left temporal pole and superior temporal gyrus(TPOsup). However, it also exhibited increased regional efficiency (P<0.001)in a few brain regions of ASD such as left supramarginal gyrus, right angular gyrus, and left heschl gyrus.Furthermore, no significant relationship was found between topological properties of the whole-brain WM structural network and clinical symptoms in ASD children. Conclusions The ASD toddlers exhibitedsmall-worldcharacter of the whole-brain WM structural network; the whole brain information transfer and interactions between brain regions are slower and less efficient than DD controls; the ASD group exhibited the phenomenon of coexistence of decreased and increased structural connectivity between different regions. Key words: Autism spectrum disorder; Diffusion tensor imaging; Brain network; Graph theoretical