title: Altered brain structural connectivity in post-traumatic stress disorder: a diffusion tensor imaging tractography study.
abstract: BACKGROUND
  Post-traumatic stress disorder (PTSD) is characterized by dysfunction of several discrete brain regions such as medial prefrontal gyrus with hypoactivation and amygdala with hyperactivation. However, alterations of large-scale whole brain topological organization of structural networks remain unclear.
  
  
  METHODS
  Seventeen patients with PTSD in motor vehicle accident survivors and 15 normal controls were enrolled in our study. Large-scale structural connectivity network (SCN) was constructed using diffusion tensor tractography, followed by thresholding the mean factional anisotropy matrix of 90 brain regions. Graph theory analysis was then employed to investigate their aberrant topological properties.
  
  
  RESULTS
  Both patient and control group showed small-world topology in their SCNs. However, patients with PTSD exhibited abnormal global properties characterized by significantly decreased characteristic shortest path length and normalized characteristic shortest path length. Furthermore, the patient group showed enhanced nodal centralities predominately in salience network including bilateral anterior cingulate and pallidum, and hippocampus/parahippocamus gyrus, and decreased nodal centralities mainly in medial orbital part of superior frontal gyrus.
  
  
  CONCLUSIONS
  The main limitation of this study is the small sample of PTSD patients, which may lead to decrease the statistic power. Consequently, this study should be considered an exploratory analysis.
  
  
  CONCLUSIONS
  These results are consistent with the notion that PTSD can be understood by investigating the dysfunction of large-scale, spatially distributed neural networks, and also provide structural evidences for further exploration of neurocircuitry models in PTSD.
authors.affiliation: Key Laboratory for Neuroinformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, PR China.
authors.forename: Zhiliang
authors.initials: Z
authors.lastname: Long
authors.forename: Xujun
authors.initials: X
authors.lastname: Duan
authors.forename: Bing
authors.initials: B
authors.lastname: Xie
authors.forename: Handan
authors.initials: H
authors.lastname: Du
authors.forename: Rong
authors.initials: R
authors.lastname: Li
authors.forename: Qiang
authors.initials: Q
authors.lastname: Xu
authors.forename: Luqing
authors.initials: L
authors.lastname: Wei
authors.forename: Shao-xiang
authors.initials: SX
authors.lastname: Zhang
authors.forename: Yi
authors.initials: Y
authors.lastname: Wu
authors.forename: Qing
authors.initials: Q
authors.lastname: Gao
authors.forename: Huafu
authors.initials: H
authors.lastname: Chen
mesh_terms: D000328:Adult; D000679:Amygdala / Q000473:pathology; D016880:Anisotropy; D001921:Brain / Q000648:ultrastructure*; D001931:Brain Mapping; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D008297:Male; D013313:Stress Disorders, Post-Traumatic / Q000473:pathology*; D055815:Young Adult
keywords: Diffusion tensor tractography; Post-traumatic stress disorder; Small-worldness; Structural connectivity network