Disease severity is correlated to tract specific changes of fractional anisotropy in MD and CM thalamus-A DTI study in major depressive disorder
Disease severity is correlated to tract specific changes of fractional anisotropy in MD and CM thalamus-A DTI study in major depressive disorder
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DOI：
10.1016/j.jad.2012.12.026
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发表时间：
2013-07-01
影响因子：
6.6
通讯作者：
Walter, Martin
中科院分区：
文献类型：
--
作者：
Osoba, Annemarie;Haenggi, Juergen;Walter, Martin
背景：抑郁症通常被概念化为皮质边缘调节失调。由于在正常老年人群中的研究不足，尤其是皮质下连接中断的来源与潜在的全身性顶叶白质(WM)缺陷形成对比，目前尚不清楚。这可能是由于可变的患者特征的重要影响，最重要的是发作的严重性。尤其是丘脑的连接中断已经在功能上被揭示，然而，由于其亚核的高度多样性，其结构相关性还没有得到明确的研究。方法：我们比较了20例严重抑郁障碍(MDD)患者和对照组的弥散张量成像(DTI)得出的分数各向异性(FA)的HAMD严重程度。稳健地获取限制在12个方向上的4个重复，也是为了匹配Eckert等人使用的相同参数。(2011)，他描述了丘脑中央正中(CM)和背内侧(MD)连接的优先结构。结果：在全脑分析中，仅在右侧顶叶WM发现显著的FA缺陷(p<；0.05，校正后)。严重程度对丘脑FA升高有影响。事后分析显示，这种影响仅限于CM特异区。相反，我们发现在FA中，MD到背外侧前额叶皮质(DLPFC)的束减少。MD和CM之间对杏仁核的非特异性减少与初级杏仁核FA减少平行。限制：TOI方法和异质样本的特异性。结论：在MDD中发现了强劲的顶叶FA减少，并控制了年龄效应。此外，我们还揭示了丘脑束中FA对皮层下疾病状态的依赖性，这是前述优先连接所特有的。(C)2013年爱思唯尔。版权所有。
Background: Depression is commonly conceptualized as corticolimbic dysregulation. Due to insufficient studies in normal aged populations especially subcortical sources of disconnection are unclear in contrast to potentially general parietal white matter (WM) deficits. This may be due to important influences of variable patient characteristics, most importantly episode severity. Especially thalamic disconnections have been functionally revealed, however, their structural correlates have not been distinctly investigated for its highly diverse subnuclei.Methods: We compared 20 major depressive disorder (MDD) patients with mixed Hamilton depression rating scale (HAMD) severity to matched controls in fractional anisotropy (FA) derived from diffusion tensor imaging (DTI). Robust acquisition of 4 repetitions restricted to twelve directions, also to match the same parameters used by Eckert et al. (2011) who described a preferential architecture of centromedian (CM) and mediodorsal (MD) thalamic connections. Second to whole brain analysis, we tested for group differences within the preferred structural network of these two nuclei using a tract of interest (TOI) approach.Results: Significant FA deficits in a whole brain analysis were only found in right parietal WM (p < 0.05, corrected). Effects of severity were found for increasing thalamic FA. Post hoc analysis revealed this effect to be restricted to CM specific tracts. In contrast, we found MD to dorsolateral prefrontal cortex (DLPFC) tracts to be decreased in FA. Unspecific decreases between MD and CM towards amygdala were paralleled by primary amygdala FA reductions.Limitations: Specificity of the TOI approach and heterogenous sample.Conclusions: Robust parietal FA reductions, controlled for age effects were found in MDD. Further we revealed subcortical disease state dependency of FA in thalamic tracts, specific to predescribed preferential connections. (C) 2013 Elsevier BY. All rights reserved.