创伤后应激障碍的海马容积和氢质子波谱研究

The study of the volume and 1H MRS of the hippocampus in posttraumatic stress disorder

目的运用MRI研究创伤后应激障碍(PTSD)海马的容积和波谱改变,探讨PTSD海马损伤可能存在的病理生理机制。方法17例PTSD患者和17例年龄匹配的健康志愿者(对照组),用1.5T超导MR扫描系统进行MRI及双侧海马多体素氢质子波谱(1HMRS)采集,测定N乙酰天门冬氨酸(NAA)、肌酸(Cr)、胆碱(Cho)代谢物浓度,各代谢物水平的测定以波谱覆盖的面积为准。用容积分析软件测量海马和颅内容积大小,并根据颅内容积的大小对海马容积进行标准化处理。把PTSD组代谢物的浓度和海马的容积分别和对照组进行配对比较。结果PTSD组左右侧海马的容积分别是(2130±221)mm3、(2571±190)mm3,对照组左右侧海马的容积分别是(2382±157)mm3、(2572±186)mm3,左侧海马的容积与健康对照组左侧海马容积差异有统计学意义(P<0.001);右侧海马容积两组间差异无统计学意义(P>0.05)。PTSD组两侧海马NAA和Cr均明显下降(左侧:NAA为2.8±0.7,Cr为2.3±0.6;右侧:NAA为2.9±0.9,Cr为2.3±0.7),与对照组(左侧:NAA为3.8±0.8,Cr为2.7±0.5;右侧:NAA为3.9±0.8,Cr为2.8±0.5)差异均具有统计学意义(P<0.05)。Cho两组两侧差异均无统计学意义(P>0.05)。结论结果支持海马参与了PTSD的病理生理过程,海马容积和(或)代谢的改变对PTSD的临床诊断和PTSD海马损伤的病理生理机制的探讨具有重要的价值。

Objective To study the changes of the hippocampus metabolites and the hippocampus volume with MRI, and to explore the posibble pathophysiology of the hippocampus injure in posttraumatic stress disorder（PTSD）. Methods Seventeen cases of PTSD and 17 age-matched normal subjects （control subjects） were examined on a clinical 1.5 T MRI/MRS system. Proton multi-voxel spectroscopy imaging （IH-MRSI） was obtained from two sides of the hippocampus region. The metabolites included Nacetylaspartate （NAA）, creatine and phosphocreatine （Cr）, and choline-containing compounds （Cho）. The values of NAA, Cr, and Cho were calculated by integration of their peaks. The volume of the hippocampus of the two sides and the brain volume were measured with volume analysis software, and the resulting data were normalized according to the individual brain volume. Both the value of the metabolites and volume of the hippocampus were compared between the two groups respectively. Results The volumes of left and right hippocampus were （2130 ± 221 ）mm^3 and （2571 ± 190 ） mm^3 in PTSD cases, and they were （2382 ± 157） mm^3 and （2572 ± 186） mm^3 in the control subjects. The volume of left hippocampus of PTSD was smaller than that of the control subjects （ P 〈 0. 001 ）, but there was no significant difference between PTSD and control subjects in the right hippocampus （ P 〉 0. 05 ） . NAA and Cr was significantly reduced in PTSD （ Left ： NAA = 2.8 ± 0. 7, Cr = 2.3 ± 0. 6 ; Right ： NAA = 2. 9 ± 0. 9, Cr = 2. 3 ± 0. 7 ） bilaterally when compared with those of control subjects （Left： NAA = 3.8 ± 0.8, Cr = 2.7 ± 0.5; Right： NAA = 3.9 ± 0. 8, Cr = 2. 8 ± 0. 5 ） （ P 〈 0. 05 ）. But Cho had no significant difference in the bilateral hippocampus between PTSD and control subjects （ P 〉 0. 05 ）. Conclusion The results of this study add support to the view that the hippocampus may participate in the pathophysiology of PTSD, and the findings of volume and metabolite changes in the hippocampus has great value in diagnosing PTSD and in exploring the posibble pathophysiology mechanisms of hippocampus injure in PTSD.