Acute stress has substantial impact on white matter microstructure of people exposed to trauma. Its long-term consequence and how the brain changes from the stress remain unclear. In this study, we address this issue via diffusion tensor imaging (DTI). Twenty-two trauma-exposed individuals who did not meet post-traumatic stress disorder (PTSD) diagnostic criteria were recruited from the most affected area of Wenchuan earthquake and scanned twice (within twenty-five days and two years after the quake, respectively). Their emotional distress was evaluated with the Self-Rating Anxiety/Depression Scales (SAS/SDS) at both scans. Automatic fiber quantification was used to examine brain microstructure alterations. Correlation analyses were also conducted to investigate relationships between brain microstructure changes and symptom improvement. A group of demographically matched healthy controls (N = 22) from another project were scanned once before the quake using the same imaging protocols as used with trauma-exposed non-PTSD (TENP) participants. Two years after the earthquake, TENP individuals exhibited significantly reduced FA in the parietal portion of left superior longitudinal fasciculus and high FA in the parietal portion of left corticospinal tract. Over the follow-up, increased FA of the left uncinate fasciculus and the left corticospinal tract with parallel reduction of SAS and SDS were observed in TENP. No significant association was found between brain microstructure changes and symptom improvement. These results indicate changes in WM microstructure integrity of TENP brains parallel with symptom improvement over time after acute stress. However, the change would be a long-term process without external intervention.

急性压力对遭受创伤的人的白质微观结构有重大影响。它的长期后果以及大脑如何因压力而变化仍不清楚。在这项研究中，我们通过扩散张量成像 (DTI) 解决了这个问题。从汶川地震受灾最严重的地区招募了 22 名不符合创伤后应激障碍 (PTSD) 诊断标准的创伤暴露者，并进行了两次扫描（分别在地震后 25 天和 2 年内）。在两次扫描中，他们的情绪困扰都用焦虑/抑郁自评量表 (SAS/SDS) 进行了评估。自动纤维量化用于检查大脑微结构的变化。还进行了相关性分析以研究大脑微观结构变化与症状改善之间的关系。ñ = 22) 在地震前使用与暴露于创伤的非 PTSD (TENP) 参与者相同的成像协议对来自另一个项目的扫描一次。地震发生两年后，TENP 个体的左上纵束顶叶 FA 显着降低，左侧皮质脊髓束顶叶 FA 升高。随访期间，TENP 观察到左侧钩束和左侧皮质脊髓束 FA 增加，SAS 和 SDS 平行减少。未发现脑微结构变化与症状改善之间存在显着关联。这些结果表明 TENP 大脑的 WM 微结构完整性的变化与急性应激后症状的改善平行。但是，这种变化将是一个长期的过程，没有外部干预。