Shimony Joshua S, Sheline Yvette I, D'Angelo Gina, Epstein Adrian A, Benzinger Tammie L S, Mintun Mark A, McKinstry Robert C, Snyder Abraham Z
Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA.
Biol Psychiatry. 2009 Aug 1;66(3):245-52. doi: 10.1016/j.biopsych.2009.02.032. Epub 2009 Apr 17.
Many recent studies have identified white matter abnormalities in late life depression (LLD). These abnormalities include an increased volume of discrete white matter hyperintensities on T2-weighted imaging (WMH) and changes in the diffusion tensor properties of water. However, no study of LLD to date has examined the integrity of white matter outside of WMH (i.e., in normal-appearing white matter).
We performed T1- and T2-weighted imaging as well as diffusion tensor imaging (DTI) in depressed elderly subjects (n = 73) and nondepressed control subjects (n = 23) matched for age and cerebrovascular risk factors. The structural images were segmented into white matter, gray matter, cerebrospinal fluid, and WMH. The DTI parameters were calculated in white matter regions of interest after excluding the WMH.
Compared with control subjects, in the LLD group there were widespread abnormalities in DTI parameters, particularly in prefrontal regions. From a comprehensive neuropsychological battery, the strongest correlations were observed between cognitive processing speed and DTI abnormalities.
These results suggest that further investigation is warranted to determine potential reversibility and/or prognosis in LLD.
近期许多研究已确定老年期抑郁症（LLD）存在白质异常。这些异常包括在T2加权成像（WMH）上离散白质高信号体积增加以及水的扩散张量特性改变。然而，迄今为止尚无关于LLD的研究检查WMH以外白质的完整性（即外观正常的白质）。
我们对年龄和脑血管危险因素相匹配的老年抑郁症患者（n = 73）和非抑郁症对照受试者（n = 23）进行了T1加权成像、T2加权成像以及扩散张量成像（DTI）。将结构图像分割为白质、灰质、脑脊液和WMH。在排除WMH后，在感兴趣的白质区域计算DTI参数。
与对照受试者相比，LLD组的DTI参数存在广泛异常，尤其是在前额叶区域。在一套全面的神经心理测试中，观察到认知处理速度与DTI异常之间的相关性最强。
这些结果表明有必要进一步研究以确定LLD的潜在可逆性和/或预后。
