Xu Jian, Chen Fuqin, Lei Du, Zhan Wang, Sun Xiaomeng, Suo Xueling, Peng Zulai, Wang Ting, Zhang Junran, Gong Qiyong
Department of Medical Information Engineering, School of Electrical Engineering and Information, Sichuan University, Chengdu, China.
Department of Radiology, Huaxi MR Research Center, West China Hospital of Sichuan University, Chengdu, China.
Front Neurosci. 2018 Oct 9;12:709. doi: 10.3389/fnins.2018.00709. eCollection 2018.
Neuroimaging studies in children and adolescents with post-traumatic stress disorder (PTSD) have focused on abnormal structures and the functionality of a few individual brain regions. However, little is known about alterations to the topological organization of whole-brain functional networks in children and adolescents with PTSD. To this end, we investigated the topological properties of brain functional networks derived from resting-state functional magnetic resonance imaging (r-fMRI) in patients suffering from PTSD. The r-fMRI data were obtained from 10 PTSD patients and 16 trauma-exposed non-PTSD subjects. Graph theory analysis was used to investigate the topological properties of the two groups, and group comparisons of topological metrics were performed using nonparametric permutation tests. Both the PTSD and non-PTSD groups showed the functional brain network to have a small-world architecture. However, the PTSD group exhibited alterations in global properties characterized by higher global efficiency, lower clustering coefficient, and characteristic path length, implying a shift toward randomization of the networks. The PTSD group also showed increased nodal centralities, predominately in the left middle frontal gyrus, caudate nucleus, and hippocampus, and decreased nodal centralities in the left anterior cingulate cortex, left paracentral lobule, and bilateral thalami. In addition, the clustering coefficient and nodal betweenness of the left paracentral lobule were found to be negatively and positively correlated with the re-experiencing and hyper-arousal symptoms of PTSD respectively. The findings of disrupted topological properties of functional brain networks may help to better understand the pathophysiological mechanism of PTSD in children and adolescents.
针对患有创伤后应激障碍（PTSD）的儿童和青少年的神经影像学研究，主要聚焦于少数个别脑区的结构异常和功能。然而，对于患有PTSD的儿童和青少年全脑功能网络拓扑组织的改变却知之甚少。为此，我们研究了PTSD患者静息态功能磁共振成像（r-fMRI）得出的脑功能网络的拓扑特性。r-fMRI数据取自10名PTSD患者和16名暴露于创伤但未患PTSD的受试者。采用图论分析来研究两组的拓扑特性，并使用非参数置换检验对拓扑指标进行组间比较。PTSD组和非PTSD组的功能性脑网络均呈现小世界架构。然而，PTSD组在全局特性方面表现出改变，其特征为全局效率更高、聚类系数更低以及特征路径长度更长，这意味着网络向随机化转变。PTSD组还显示出节点中心性增加，主要集中在左侧额中回、尾状核和海马体，而左侧前扣带回皮质、左侧中央旁小叶和双侧丘脑的节点中心性降低。此外，发现左侧中央旁小叶的聚类系数和节点介数分别与PTSD的再体验症状和过度唤醒症状呈负相关和正相关。功能性脑网络拓扑特性被破坏的研究结果可能有助于更好地理解儿童和青少年PTSD的病理生理机制。
