老年抑郁症脑白质异常的磁共振扩散张量研究

Study of white matter microstructural abnormalities in late-life depression by MR-diffusion tensor imaging

目的应用磁共振扩散张量成像(DTI)研究老年抑郁症脑白质异常,探讨其发病机制。方法DTI扫描31例老年抑郁症和15例正常老年人的脑部,测量前额叶、颞叶、胼胝体的各向异性分数值(FA),对两组之间各部位的相应取值分别进行t检验,并与临床资料进行相关性分析。结果老年抑郁症组右侧海马旁回、双侧背外侧额叶FA值低于正常对照组相应部位FA值(P<0.05),差异存在显著性,且与其他因素无关。结论老年抑郁症存在额、颞叶白质损伤,提示存在边缘系统-皮层-纹状体环路的神经纤维束完整性破坏,证实该神经环路在其发病机制中的重要作用。

Objective To evaluate with diffusion tensor imaging （DTI） the location white matter is damaged in late-life depression, and to determine the relationship between the extent of the damage and clinical data. Methods Thirty-one patients with late-life depression and fifteen healthy volunteers received MR diffusion tensor scanning. The fractional anisotropy （FA） values of white matter were measured respectively in frontal, temporal, corpus callosum. Results FA values significantly decreased in temporal （right hippocampal gyrus） and frontal （superior and middle frontal gyrus） of the geriatric depression patients than comparison subjects （P〈0.05）. There was no correlations between decreased FA values and clinical data. Conclusion Microstructural changes in the matter of dorsolateral prefrontal and temporal （right hippocampal gyrus） are associated with late-life depression.