基于弥散张量成像对急性精神创伤后早期脑白质变化的研究

White matter microstructural changes shortly after acute stress:A DTI study

目的采用磁共振弥散张量成像(diffusion tensor imaging,DTI)探讨急性精神创伤后早期脑白质微结构的变化及其意义。材料与方法创伤组纳入30例河北医科大学第三医院2020年11月至2022年2月就诊的交通事故受害者,对照组来自同期在社会上招募的年龄、性别、受教育年限与创伤组相匹配的26例健康者,2组受试者均进行临床数据和MRI数据采集,获得DTI数据和汉密尔顿焦虑量表(Hamilton Anxiety Scale,HAMA)评分,创伤组的数据采集在经历交通事故后1周内进行。采用基于纤维束示踪的空间统计方法(tract-based spatial statistics,TBSS)分析两组间脑白质各向异性分数(fractional anisotropy,FA)的差异,继而比较FA有差异脑区的径向弥散系数(radical diffusivity,RD)和轴向弥散系数(axial diffusivity,AD)的差异,结果进行多重比较校正,并分析上述指标与HAMA评分的相关性。结果创伤组左侧外囊、内囊后肢、上纵束和丘脑后辐射的FA值与对照组的差异均有统计学意义,P值均<0.05;这些脑区的RD值两组间差异有统计学意义,P值均<0.05;AD值差异无统计学意义,P>0.05。相关性分析显示左侧丘脑后辐射的FA值与HAMA评分呈负相关(r=-0.40,P=0.03)。结论急性精神创伤后早期即可出现脑白质微结构的改变,可能影响了创伤后的情绪调节,进一步说明创伤后早期干预的必要性。

Objective:To investigate the changes of white matter microstructure shortly after acute stress using diffusion tensor imaging(DTI)and discuss the clinical significance of these changes.Materials and Methods:Thirty motor vehicle accident(MVA)survivors and 26 gender,age and education degree matched healthy subjects were recruited.Along with MRI scan,clinical assessments were also evaluated in both groups.MVA survivors got trauma-specific clinical assessments including Hamilton Anxiety Scale(HAMA)score and received MRI scan within 1week from the MVA.Tract-based spatial statistics(TBSS)was carried out to investigate difference in white matter integrity between 2 groups.White matter integrity was measured using fractional anisotropy(FA),axial diffusivity(AD)and radical diffusivity(RD).A correlation between HAMA score and regional FA value was examined using correlation analysis.Results:Significantly lower FA(P<0.05)values with higher RD(P<0.05)values were found in areas including the left external capsule,posterior limb of internal capsule,superior longitudinal fasciculus and posterior thalamic radiations(including optic radiation)in MVA survivors as compared with those in control group(P<0.05).No AD changes were noted(P>0.05).HAMA score was negatively correlated with FA in the left posterior thalamic radiations(including optic radiation)(r=-0.40,P=0.03).Conclusions:These results indicate changes in white matter microstructure integrity shortly after acute stress which may be related to anxiety symptom.Therefore,highlight the need for early evaluation and intervention for trauma survivors.