创伤后应激障碍的海马亚区体积磁共振成像研究

Hippocampal subfield volume alteration in post-traumatic stress disorder: a magnetic resonance imaging study

本研究纳入大样本创伤后应激障碍(PTSD)患者与创伤暴露对照组(TC),探究其海马亚区体积差异。首先,纳入67名符合《精神疾病诊断与统计手册》(第四版)(DSM-Ⅳ)诊断标准的PTSD患者与性别、年龄匹配的78名同样经历创伤事件的对照人群,使用GE 3.0 T磁共振采集高分辨结构像,随后使用Free Surfer软件进行海马及亚区的分割并获得海马总体积、各亚区(包括CA1、CA2-3、CA4-DG、前下托、下托、海马伞及海马沟)体积数据。以年龄、受教育年限、扫描距地震发生时间、颅内总体积为协变量,左右半球、性别、诊断为固定因子,使用协方差分析比较体积的组间差异;用Pearson相关探索体积与临床创伤后应激障碍诊断量表(CAPS)评分、病程之间的关系。结果发现,PTSD患者海马总体积及各亚区体积与对照组比较均无明显差异(P>0.05)。男性患者CAPS评分与右侧CA2-3体积(R^2=0.197,P=0.034)、下托体积(R^2=0.245,P=0.016)有相关性,病程与右侧海马沟体积(R^2=0.247,P=0.016)有相关性;女性患者CAPS评分与左侧前下托体积(R^2=0.095,P=0.042)、下托体积(R^2=0.090,P=0.048)及CA4-DG体积(R^2=0.099,P=0.037)有相关性。本研究提示应激事件在PTSD患者及TC对照组均可造成海马损伤,同时在PTSD患者中存在性别特异性的偏侧化现象。

In the current study, we aim to investigate whether post-traumatic stress disorder （PTSD） is associated with structural alterations in specific subfields of hippocampus comparing with trauma-exposed control （TC） in a relatively large sample. We included 67 PTSD patients who were diagnosed under Diagnostic and Statistical Manual of Mental Disorders （4th Edition） （DSM-Ⅳ） criteria and 78 age- and sex-matched non-PTSD adult survivors who experienced similar stressors. High resolution T1 weighted images were obtained via a GE 3.0 T scanner. The structural data was automatically segmented using FreeSurfer software, and volume of whole hippocampus and subfield including CA1, CA2-3, CA4-DG, fimbria, presubiculum, subiculum and fissure were extracted. Volume differences between the two groups were statistically compared with age, years of education, duration from the events and intracranial volume （ICV） as covariates. Hemisphere, sex and diagnosis were entered as fixed factors. Relationship between morphometric measurements with Clinician-Administered PTSD Scale （CAPS） score and illness duration were performed using Pearson’s correlation with SPSS. Comparing to TC, PTSD patients showed no statistically significant alteration in volumes of the whole hippocampus and all the subfields （P 〉 0.05）. In male patients, there were significant correlations between CAPS score and volume of right CA2-3 （ R^2 = 0.197, P = 0.034）, right subiculum （R^2 = 0.245, P = 0.016）, and duration statistically correlated with right fissure （R^2 = 0.247, P = 0.016）. In female patients, CAPS scores significant correlated with volume of left presubiculum （R^2 = 0.095, P = 0.042）, left subiculum （R^2 = 0.090, P = 0.048）, and left CA4-DG （R^2 = 0.099, P = 0.037）. The main findings of the current study suggest that stress event causes non-selective damage to hippocampus in both PTSD patients and TC, and gender-specific lateralization may underlie PTSD pathology.