抑郁症患者脑代谢改变的磁共振波谱观察

目的 利用磁共振波谱(MRS)评价抑郁症患者是否存在认知相关脑功能区代谢物的异常改变以及MRS代谢指标与认知测试之间的相关性。方法 12例首次发作的抑郁症患者(2组)、10例复发的抑郁症患者(3组)及12名正常志愿者(1组)均于MR检查前接受威斯康星卡片分类测试(WCST),记录测试结果;之后接受双侧前额叶及扣带回的 ¹H-MRS,记录N-乙酰天门冬氨酸(NAA)、胆碱(Cho)、肌醇(mIns)、谷氨酸和谷氨酰胺复合物(Glx)曲线下面积与肌酸(Cr)的比值。结果 与1组比较,3组双侧前额叶Glx/Cr减低、mIns/Cr升高,2组双侧前额叶Glx/Cr减低,右侧前额叶mIns/Cr升高;2组、3组均存在WCST中完成总应答数、持续错误数和非持续错误数增加。2组患者右侧前额叶Glx/Cr与持续错误数呈负相关,3组患者双侧前额叶Glx/Cr与持续错误数均呈负相关。结论 抑郁症患者均存在双侧前额叶的异常代谢变化及认知功能障碍,谷氨酸能系统异常可能是抑郁症患者认知障碍的病理生理学基础。

Magnetic resonance spectroscopy observation on brain metabolic changes in patients with depression

Objective To assess the correlation between abnormal metabolic changes and Wisconsin card sorted test(WCST) in patients with depression using magnetic resonance spectroscopy (MRS). Methods Twelve healthy volunteers (group 1), 12 first-episode patients (group 2) and 10 recurrent patients (group 3) underwent WCST before MR examination. Localized magnetic resonance spectra were acquired in bilateral prefrontal lobe and cingulated cortex with single voxel 1-hydrogen MRS (¹H-MRS). The ratio of all metabolte including N-acetyl-asparta (NAA), choline (Cho), glutamate and glutamine (Glx) were recorded, using creatine (Cr) as reference. Results Compared to group 1, Glx/Cr decreased and mIns/Cr increased in both bilateral prefrontal lobes in group 3, while Glx/Cr decreased in bilateral prefrontal lobes and mIns/Cr increased in right side in group 2. Response administered (RA), perseverative errors (PE) and non perseverative errors (NPE) were higher in group 2 and 3 in WCST. Glx/Cr of right prefrontal lobe correlated negatively with PE significantly in group 2, Glx/Cr of bilateral prefrontal lobes all correlated negatively with PE significantly in group 3. Conclusion The depressive patients have abnormal metabolic changes in bilateral prefrontal lobes as well as cognitive impairment, and glutamatergic system dysregulation may be the pathophysiologic basis of cognitive impairement in patients with depression.