Altered topological properties of brain functional networks in drug-resistant epilepsy patients with vagus nerve stimulators

Purpose: To explore abnormalities of topological properties in drug-resistant epilepsy (DRE) patients after vagus nerve stimulation (VNS) by analyzing brain functional networks using graph theory.Methods: Fifteen and eight healthy controls (HC) were scanned separately with resting-state magnetic resonance imaging (rs-fMRI). Graph theoretical analyses chosen to compare the global (small-world parameters [γ, λ, σ, Cp, Lp], network efficiency [Eg Eloc]), nodal (BC, DC, NE) preoperative (EPpre), postoperative (EPpost) HC.Results: HC, EPpre EPpost all satisfied criteria for small-world (σ > 1) within sparsity range 0.05–0.5. Compared EPpre, performed higher λ Eloc but lower γ, Cp. exhibited decreased BC, DC or NE right inferior frontal gyrus, superior temporal bilateral cingulate gyri, supplementary motor area, occipital Heschl left calcarine fissure; increased BC postcentral/precentral paracentral lobule, rolandic operculum, supramarginal caudate nucleus. showed middle gyrus fusiform gyrus.Conclusion: VNS downregulated DRE, caused changes some key nodes reorganize transmission ability large-scale network.