He Meirong, Zhu Hongru, Wang Xiaoyan, Zhou Lijun, Zhang Junran
College of Electrical Engineering, Sichuan University, Chengdu, Sichuan, China.
College of Electrical Engineering, Northwest Minzu University, Lanzhou, Gansu, China.
J Magn Reson Imaging. 2025 Oct;62(4):1069-1078. doi: 10.1002/jmri.29829. Epub 2025 May 24.
Hierarchical architecture is a fundamental organizational principle of the human brain. Previous studies have suggested that posttraumatic stress disorder (PTSD) may be characterized as disorders in the cerebral hierarchical organization. However, the specific abnormalities and underlying mechanisms are unclear.
To investigate whether there are disorders of cerebral hierarchical organization in patients with PTSD and their underlying mechanisms of alteration.
Prospective, case control.
FILED STRENGTH/SEQUENCE: 3.0T, gradient echo echo-planar imaging sequence.
Forty-nine patients with PTSD (11 males and 38 females; Clinician-Administered PTSD Scale (CAPS) score > 40) and 38 trauma-exposed controls (TEC) (13 males and 25 females; CAPS score < 40).
Connectome gradient analysis was used to systematically examine disorders of cerebral hierarchical organization. Gradient metrics included range and variance of gradient scores. Graph theory analysis was also employed to explore underlying mechanisms of gradient abnormalities, and system segregation (quantifying the degree of separation between functional networks) and participation coefficients (PC) (quantifying the degree of connectivity that a given node has to other networks) were calculated.
Two-sample t-tests were used to compare differences in gradient and graph theory metrics between groups. The association between gradient scores and CAPS scores was assessed using partial correlation analysis. p < 0.05 was set as the statistical significance threshold, with false discovery rate (FDR) correction.
Compared with TEC, patients with PTSD showed significantly increased global gradient variance and altered gradient indicators in networks. At global and network levels, patients with PTSD exhibited significantly increased system segregation and significantly reduced PC, which were significantly associated with gradient variance (global system segregation: r = 0.84, global PC: r = 0.93, system segregation in SMN: r = 0.59, PC in DAN: r = -0.62 and PC in FPN: r = -0.53). Moreover, gradient scores in DAN (r = 0.319) and some regions of DMN (ANG.L: r = 0.294), SMN (PreCG.L: r = 0.319), and LIM (HIP.R: r = 0.319) were significantly correlated with CAPS score.
This study, integrating connectome gradient analysis with graph theory, showed hierarchical disruptions across multilevel brain networks in PTSD, potentially explaining clinical symptoms such as hypervigilance and dissociation.
Stage 1.
层次结构是人类大脑的基本组织原则。先前的研究表明，创伤后应激障碍（PTSD）可能表现为大脑层次组织的紊乱。然而，具体的异常情况和潜在机制尚不清楚。
研究PTSD患者是否存在大脑层次组织紊乱及其改变的潜在机制。
前瞻性病例对照研究。
场强/序列：3.0T，梯度回波平面成像序列。
49例PTSD患者（男性11例，女性38例；临床医生管理的PTSD量表（CAPS）评分>40）和38例创伤暴露对照者（TEC）（男性13例，女性25例；CAPS评分<40）。
采用连接组梯度分析系统检查大脑层次组织的紊乱情况。梯度指标包括梯度分数的范围和方差。还采用图论分析来探索梯度异常的潜在机制，并计算系统分离度（量化功能网络之间的分离程度）和参与系数（PC）（量化给定节点与其他网络的连接程度）。
采用两样本t检验比较组间梯度和图论指标的差异。使用偏相关分析评估梯度分数与CAPS评分之间的关联。将p<0.05设定为统计学显著性阈值，并进行错误发现率（FDR）校正。
与TEC相比，PTSD患者的全局梯度方差显著增加，网络中的梯度指标发生改变。在全局和网络水平上，PTSD患者的系统分离度显著增加，PC显著降低，这与梯度方差显著相关（全局系统分离度：r=0.84，全局PC：r=0.93，感觉运动网络中的系统分离度：r=0.59，背侧注意网络中的PC：r=-0.62，额顶叶网络中的PC：r=-0.53）。此外，背侧注意网络（r=0.319）以及默认模式网络的一些区域（左侧角回：r=0.294）、感觉运动网络（左侧中央前回：r=0.319）和边缘系统（右侧海马：r=0.319）的梯度分数与CAPS评分显著相关。
本研究将连接组梯度分析与图论相结合，显示PTSD患者多级脑网络存在层次破坏，这可能解释了过度警觉和解离等临床症状。
2级。
1级。
