采用基于纤维骨架的空间统计方法分析创伤后应激障碍患者急性期全脑白质结构变化情况

The whole brain diffusion tensor imaging study on acute phase of the posttraumatic stress disorder resulting from the single-prolonged stress based on tract based spatial statistics

目的探讨单次长时间应激导致的创伤后应激障碍（PTSD）急性期的全脑白质微观结构的改变。方法应用3．0TMR分别对山西王家岭矿难中深埋超过190h的17例幸存者（PTSD组）及17名正常对照者（对照组）进行DTI扫描，并采用基于纤维骨架的空间统计（TBSS）方法分析两组全脑DTI的各向异性分数（FA）图，使用基于非参数的随机排列检验（RPT）对两组FA数据进行统计学比较，得出PSTD患者FA值有差异的脑区。结果与对照组比较，急性PTSD组双侧胼胝体膝部及胼胝体部嘴侧FA值降低，而左侧丘脑及双侧皮质脊髓束区的后、上放射冠，左侧内囊后肢，左侧大脑脚FA值较正常组增高，其差异有统计学意义（P值均〈0．01）。结论TBSS方法能全面、准确地分析PTSD患者的全脑DTI改变，特别是PTSD急性期的胼胝体膝部、体部嘴侧、左侧丘脑前辐射的纤维结构出现了异常改变，可为PTSD的早期诊断、早期干预提供客观的依据。

Objective To study the changes of the brain white matter microstructure at the acute stage of posttraumatic stress disorder （PTSD） resulting from a single-prolonged stress. Methods DTI scans were performed on 17 survivors buried more than 190 h in Shanxi Wangjialing mine disaster and 17 cases of normal controls using Siemens 3.0 T MR. The differences of the FA values measured from the whole brain DTI between the two groups were analyzed based on tract based spatial statistics （ TBSS ）. FA data were statistically compared between the two groups based on nonparametric random permutation test （RPT）, and the brain areas of the PTSD patients with abnormal FA were defined. Results Compared with control group, FA values in the PTSD （ at acute stage） group decreased in genu, rostral body of corpus callosum, and increased in the left thalamic and corticospinal tract region of bilateral corona radiata and the posterior limb of the left internal capsule, the left cerebral peduncle. The differences were statistically significant （P 〈 0. 01 TFCE-corrected）. Conclusions TBSS is a comprehensive and accurate method for evaluating the changes of whole brain DTI in PTSD cases. The fiber structural abnormalities in the genu, rostral body of bilateral corpus callosum, anterior radiation of left thalamic may be due to stress. TBSS can provide a more objective basis for the early diagnosis and intervention of PTSD.