抑郁症患者杏仁核、海马形态功能变化的MR研究

目的 综合形态学测量及功能MR检查对抑郁症患者杏仁核、海马形态及功能进行研究,探讨其变化规律及其机制.方法 60例抑郁症患者按病情及汉密尔顿抑郁量表(HAMD)分为轻(17分≥HAMD＞8分)、中(24分≥HAMD>17分)及重度组(HAMD>24分),每组20例]及20名健康志愿者行MR形态及fMRI扫描,根据形态图像勾画海马和杏仁核,计算其体积,并进行标准化处理.使用统计参数图(SPM)5软件对功能图像进行后处理,得到受试者脑激活图.体积测量数据采用方差分析及多个试验组与1个对照组均数差别比较的Dunnett-t检验进行分析,并分别对患者组海马、杏仁核体积及信号强度与疾病程度(HAMD评分)进行Pearson相关性分析.结果 抑郁症轻、中及重度组海马体积均小于对照组(左侧2296±202,右侧2283±199),以重度组最为显著(左侧1978±176,Dunnett-t=-10.0,P<0.01;右侧1981±171,Dunnett-t=-9.2,P<0.01),中度组次之(左侧2127±180,Dunnett-t=-3.0,P<0.05;右侧2135±183,Dunnett-t=-3.0,P<0.05),轻度组改变轻微(左侧2207±189,Dunnett-t=-1.4,P>0.05;右侧2210±191,Dunnett-t=-1.6,P>0.05).抑郁症组杏仁核体积依病情由轻到重呈由大至小的趋势,对照组左侧为1762±185,右侧为1749±182.轻度组显著增大(左侧1992±200,Dunnett-t=4.8,P<0.01;右侧1989±191,Dunnett-t=5.0,P<0.01),中度组轻度增大(左侧1889±192,Dunnett-t=2.8,P<0.05;右侧1896±195,Dunnett-t=2.8,P<0.05),重度组显著缩小(左侧1539±178,Dunnett-t=-6.8,P<0.01;右侧1543±180,Dunnett-t=-7.0,P<0.01).功能MR显示抑郁症患者杏仁核、海马对负性图片刺激有着更为显著的脑活动信号,并具有一定的规律,轻度组杏仁核最为显著,中度组信号有所减低,重度组信号最弱,但仍高于对照组.抑郁组海马杏仁核体积、信号强度与疾病程度(HAMD评分)均呈明显的相关性(r值范围为-0.80～-0.90,P值均＜0.05).结论 抑郁症患者海马体积缩小,且这种改变可能与杏仁核有关,杏仁核依病情不同而体积不同;抑郁患者杏仁核、海马对负性图片有着更为显著的脑活动信号.

Abstract：

Objective To explore the morphometric and functional alterations of amygdale and hippocampus in patients with depression by anatomical and functional MRI, and try to reveal the pattern and pathogenesis of the changes in depression. Methods Sixty patients (divided equally into mild, moderate and major groups according to patient′s scores of HAMD) and 20 healthy control groups were scanned using T1WI and fMRI. The outlines of hippocampus and amygdale were drawn manually by observer and the volumes were calculated and normalized subsequently. Functional MRI was processed using SPM5 and individual activation map was got subsequently. Dunnett-t test and Pearson correlation analysis were separately used to analyze the morphometric and functional changes and the correlations between cerebral changes and clinical severity. Results The hippocampal volumes of control groups were 2296±202 left for left side and 2283±199 for right side. The hippocampal volumes of depressive patients were smaller than those of control groups, especially for the major group (left 1978±176,Dunnett-t=-10.0,P<0.01,right 1981±171,Dunnett-t=-9.2,P<0.01). The moderate group showed moderate reduced volume(left 2127±180,Dunnett-t=-3.0,P<0.05,right 2135±183,Dunnett-t=-3.0,P<0.05), while the mild ones showed slightly decreased volume (left 2207±189,Dunnett-t=-1.4,P>0.05,right 2210±191,Dunnett-t=-1.6,P>0.05). The amygdale′s volumes of control groups was 1762±185,the right was 1749±182, while those in patient group reduced along with the patient′s condition, i.e., the mild groups (left 1992±200,Dunnett-t=4.8,P<0.01,right 1989±191, Dunnett-t=5.0,P<0.001), the moderate groups (left 1889±192, Dunnett-t=2.8,P<0.05,right 1896±195,Dunnett-t=2.8,P<0.05), and the major groups (left 1539±178,Dunnett-t=-6.8,P<0.01,right 1543±180,Dunnett-t=-7.0,P<0.01).For fMRI study, patient group demonstrated more activation of the amygdale and hippocampus under the stimulations of negative images than controls. Furthermore, the strengthens of activation decreased along with the patient′s condition, i.e., the major ones showed the weakest activation among the patients, though it was higher than that of control group. In patient group, both the volumes and activations of hippocampus and amygdale showed significant negative correlations with HAMD scores(r=-0.80--0.90,P＜0.05). Conclusion The hippocampal volumes of depressive patients reduced, which may be due to the change of the amygdale, and the amygdale′s volumes were changed along with the patient′s condition. There were more activation in the amygdale and hippocampus of depressive patients under the stimulations of negative images.

Morphometric and functional alterations of amygdale and hippocampus in patients with depression: a MRI study

Objective To explore the morphometric and functional alterations of amygdale and hippocampus in patients with depression by anatomical and functional MRI, and try to reveal the pattern and pathogenesis of the changes in depression. Methods Sixty patients (divided equally into mild, moderate and major groups according to patient′s scores of HAMD) and 20 healthy control groups were scanned using T1WI and fMRI. The outlines of hippocampus and amygdale were drawn manually by observer and the volumes were calculated and normalized subsequently. Functional MRI was processed using SPM5 and individual activation map was got subsequently. Dunnett-t test and Pearson correlation analysis were separately used to analyze the morphometric and functional changes and the correlations between cerebral changes and clinical severity. Results The hippocampal volumes of control groups were 2296±202 left for left side and 2283±199 for right side. The hippocampal volumes of depressive patients were smaller than those of control groups, especially for the major group (left 1978±176,Dunnett-t=-10.0,P<0.01,right 1981±171,Dunnett-t=-9.2,P<0.01). The moderate group showed moderate reduced volume(left 2127±180,Dunnett-t=-3.0,P<0.05,right 2135±183,Dunnett-t=-3.0,P<0.05), while the mild ones showed slightly decreased volume (left 2207±189,Dunnett-t=-1.4,P>0.05,right 2210±191,Dunnett-t=-1.6,P>0.05). The amygdale′s volumes of control groups was 1762±185,the right was 1749±182, while those in patient group reduced along with the patient′s condition, i.e., the mild groups (left 1992±200,Dunnett-t=4.8,P<0.01,right 1989±191, Dunnett-t=5.0,P<0.001), the moderate groups (left 1889±192, Dunnett-t=2.8,P<0.05,right 1896±195,Dunnett-t=2.8,P<0.05), and the major groups (left 1539±178,Dunnett-t=-6.8,P<0.01,right 1543±180,Dunnett-t=-7.0,P<0.01).For fMRI study, patient group demonstrated more activation of the amygdale and hippocampus under the stimulations of negative images than controls. Furthermore, the strengthens of activation decreased along with the patient′s condition, i.e., the major ones showed the weakest activation among the patients, though it was higher than that of control group. In patient group, both the volumes and activations of hippocampus and amygdale showed significant negative correlations with HAMD scores(r=-0.80--0.90,P＜0.05). Conclusion The hippocampal volumes of depressive patients reduced, which may be due to the change of the amygdale, and the amygdale′s volumes were changed along with the patient′s condition. There were more activation in the amygdale and hippocampus of depressive patients under the stimulations of negative images.