Disturbed brain anatomical networks and functional directed connection in temporal lobe tumor patients based on dti and resting-state fMRI

Abstract:
This study aims to apply graph theory measures of fiber tracking derived from diffusion tensor imaging (DTI) and resting-state fMRI data to investigate the cognitive alternation and functional restructuring mechanism in patients with temporal lobe tumor. Twenty patients with temporal lobe tumor and seventeen aged- and sex-matched healthy volunteers were recruited in this study. Initially, brain anatomical networks of all subjects were constructed, then the global and regional efficiency of whole-brain anatomical networks were compared. In addition, betweenness centrality (Bi) was used to identify hubs of two groups, granger causality analysis (GCA) based on resting-state fMRI were utilized to obtain information flow directions between hub brain regions. The results of topological properties show that the patient's small-world characteristics have declined. Tumor patients lose 4 hub regions and add 4 new hubs when compared to normal controls, the information flow directions were significantly changed between different functional areas and inside default mode network. The results revealed that the directions of spontaneous information flow and causal influences in directed brain networks and the topological properties in undirected anatomical brain network, thus providing new insights into understanding the structural plasticity and compensatory mechanism of the brain in patients with temporal lobe tumors.