失独父母脑白质微观结构改变扩散张量研究

A Study on Brain White Matter Microstructural Changes Based on Diffusion Tensor Imaging, of Parents Who Have Lost Their Only Child

目的基于扩散张量成像(DTI)探讨失独父母脑白质微观结构完整性改变及其与失独者各种精神症状之间的关系。方法招募39例失独父母(失独组)和39名年龄、性别比例及受教育年限完全匹配的正常受试者(健康对照组)。所有受试者均接受DTI扫描,并使用症状自评量表(SCL90)评估每位受试者的精神状况。基于纤维束空间统计(TBSS)的方法定量测量两组受试者在脑白质微观结构完整性上的差异,并分析其与SCL90评分的相关关系。结果与健康对照组比较,失独组左侧钩束和上纵束各向异性分数(FA)降低,轴向扩散率(AD)降低、径向扩散率(RD)和平均扩散率(MD)升高。且失独组左侧钩束FA值与SCL90中焦虑、抑郁及人际关系敏感因子评分均呈显著负相关(P<0.001),与失独持续时间亦呈明显负相关(r=-0.515,P=0.024)。进一步分析这种脑白质损伤的性别差异显示,与健康对照组相比,女性失独组左侧钩束FA值降低,而男性失独组左侧上纵束FA值降低。结论失独创伤可造成失独者脑白质微观结构完整性损伤,且存在性别差异性,可能与男、女性面对压力性事件所采取的情绪调节策略不同有关。左侧钩束完整性受损可能影响前额叶皮层与边缘脑区之间信息传递而造成失独者情绪调节障碍,从而出现一系列的精神症状。

Objective The purposes of this study were to study the microstructure changes of white matter(WM) based on diffusion tensor imaging(DTI),in parents who have lost their only child. Methods Thirty-nine participants who had lost their only child(traumatized group) and thirty-nine well-matched healthy controls(HCs) were recruited in our study. There were no significant differences in gender ratio, age and education level between the two groups.All the participants underwent DTI scan, applying the symptom check-list 90(SCL90) to assess the psychologic status of each subject.We quantitatively investigated the microstructural differences of brain white matter through tract-based spatial statistics(TBSS) between the two groups. Results Compared with HCs, the traumatized group showed reduced FA in the left uncinate fasciculus(UF) and superior longitudinal fasciculus(SLF),and there was also AD reduction and RD/MD increase in the same white matter regions. In the traumatized group,the FA values in the left UF was significantly correlated with the subscores of SCL90,including the interpersoalsensitivity,depression,and anxiety( P < 0. 001). There was also negative correlation between FA values in the left UF and time since trauma( r =-0. 515,P < 0. 024). We further investigated the sex difference in WM integrity,which showed the female traumatized group had reduced FA in left UF while the male traumatized group had reduced FA in left SLF relative to HCs. Conclusion Our findings suggested that the trauma of losing one’s only child disrupted the WM integrity and varied by gender,which may be associated with the gender differences in emotion regulation strategies. The compromised WM integrity in left UF may influence the information transmission between prefrontal cortex and limbic regions,which may contribute to the impairments of emotion regulation,leading to a range of psychological symptoms in parents who have lost their only child.