Changes in topological properties of brain structural network in patients with neuromyelitis optica spectrum disorder based on diffusion tensor imaging

Objective To explore the topological properties of the brain structural network in patients with neuromyelitis optica spectrum disorder (NMOSD). Methods Diffusion tensor imaging was performed in 41 NMOSD patients (patient group) and 40 age- and sex-matched healthy volunteers (control group) who were admitted to the Department of Neurology, The Third Affiliated Hospital to Sun Yat-sen University from September 2014 to October 2017. The deterministic fiber tracking techniques were used to construct the white matter structural weighted network. Topological properties of the brain structural network were then calculated based on complex graph theory analysis. The 2 groups were compared in terms of global and local parameters of the brain structural network using statistical methods. Results The brain structural networks in both groups exhibited small world properties. Compared with the control group, the global efficiency of the brain structural network in the patient group was significantly decreased and the shortest path length significantly increased (P=0.002, P= 0.002, FDR correction). There were no statistically significant differences between the brain structural networks of the 2 groups in terms of clustering coefficient, the shortest path length on average, value of small world property, average clustering coefficient or local efficiency (P=0.780, P=0.496, P=0.279, P=0.269, P= 0.050, FDR correction). Compared with the control group, the nodal efficiency of the brain structural network of the patient group was significantly decreased in the frontal lobe (bilateral precentral gyrus, middle frontal gyrus of the right orbital part, inferior frontal gyrus of the right opercular part, right rolandic operculum, bilateral median cingulate and paracingulate gyri), parietal lobe (right posterior cingulate gyrus, right superior parietal gyrus, left inferior parietal of angular gyri, right angle gyrus, and right precuneus), temporal lobe (bilateral hippocampus and right parahippocampal gyrus), occipital lobe (left cuneus, left superior occipital gyrus, bilateral middle occipital gyrus, and left inferior occipital gyrus) and subcortical region (right caudate nucleus and right thalamus) (P<0.05, FDR correction). Conclusion There is abnormal connection in brain structural network in NMOSD patients. Key words: Neuromyelitis optica spectrum disorder; Diffusion tensor imaging; Brain structural network; Topological property