Diffusion Tensor Tractography Reveals Abnormal Topological Organization in Structural Cortical Networks in Alzheimer's Disease
Diffusion Tensor Tractography Reveals Abnormal Topological Organization in Structural Cortical Networks in Alzheimer's Disease
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DOI：
10.1523/jneurosci.4136-10.2010
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发表时间：
2010-12-15
影响因子：
5.3
通讯作者：
Lin, Ching-Po
中科院分区：
文献类型：
--
作者：
Lo, Chun-Yi;Wang, Pei-Ning;Lin, Ching-Po
最近对阿尔茨海默病（AD）的研究表明，认知和记忆功能的下降伴随着以白质（WM）变性为特征的神经元连接中断。然而，AD中WM结构网络拓扑组织的变化在很大程度上仍然未知。本研究采用弥散张量图像神经束成像技术构建了25例AD患者和30例年龄、性别匹配的健康对照者的脑WM网络，并进行了图理论分析。我们发现AD患者和对照组在WM网络中都具有小世界拓扑结构，这表明在结构隔离和整合组织之间存在最佳平衡。更重要的是，与对照组相比，AD患者在WM网络中表现出最短路径长度增加，整体效率降低，这意味着拓扑组织异常。此外，我们发现WM网络包含高度连接的中枢区域，主要位于楔前叶、扣带皮层和背外侧前额叶皮层，这与之前的弥散- mri研究一致。具体来说，阿尔茨海默病患者的淋巴结效率降低主要位于额叶区域。最后，我们发现各种网络属性的改变与行为表现显著相关。总之，本研究首次证明了阿尔茨海默病的大脑与大规模WM结构网络中的拓扑组织破坏有关，从而为该疾病的系统完整性异常提供了结构证据。这项工作也可能对理解阿尔茨海默病患者的结构连接异常是如何导致行为缺陷的产生产生影响。
Recent research on Alzheimer's disease (AD) has shown that the decline of cognitive and memory functions is accompanied by a disrupted neuronal connectivity characterized by white matter (WM) degeneration. However, changes in the topological organization of WM structural network in AD remain largely unknown. Here, we used diffusion tensor image tractography to construct the human brain WM networks of 25 AD patients and 30 age-and sex-matched healthy controls, followed by a graph theoretical analysis. We found that both AD patients and controls had a small-world topology in WM network, suggesting an optimal balance between structurally segregated and integrative organization. More important, the AD patients exhibited increased shortest path length and decreased global efficiency in WM network compared with controls, implying abnormal topological organization. Furthermore, we showed that the WM network contained highly connected hub regions that were predominately located in the precuneus, cingulate cortex, and dorsolateral prefrontal cortex, which was consistent with the previous diffusion-MRI studies. Specifically, AD patients were found to have reduced nodal efficiency predominantly located in the frontal regions. Finally, we showed that the alterations of various network properties were significantly correlated with the behavior performances. Together, the present study demonstrated for the first time that the Alzheimer's brain was associated with disrupted topological organization in the large-scale WM structural networks, thus providing the structural evidence for abnormalities of systematic integrity in this disease. This work could also have implications for understanding how the abnormalities of structural connectivity in AD underlie behavioral deficits in the patients.