Individualized Thalamic Parcellation Reveals Alterations in Shape and Microstructure of Thalamic Nuclei in Patients with Disorder of Consciousness.
Individualized Thalamic Parcellation Reveals Alterations in Shape and Microstructure of Thalamic Nuclei in Patients with Disorder of Consciousness.
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个体化丘脑分区揭示意识障碍患者丘脑核团形状和微观结构的改变
DOI：
10.1093/texcom/tgab024
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发表时间：
2021
影响因子：
--
通讯作者：
Wu D
中科院分区：
文献类型：
--
作者：
Zheng W;Tan X;Liu T;Li X;Gao J;Hong L;Zhang X;Zhao Z;Yu Y;Zhang Y;Luo B;Wu D
摘要 丘脑在意识产生和信息处理中起着至关重要的作用。先前的证据表明，严重脑损伤引起的意识障碍（DOC）可能与丘脑异常有关。然而，DOC患者丘脑亚区和丘脑皮质纤维通路的形态和微观结构如何变化，以及这些变化与意识状态之间的关系仍不清楚。在这里，我们通过基于 7-Tesla 扩散 MRI 的纤维取向分布 (FOD) 的新型丘脑分割框架，生成了 10 名 DOC 患者和 10 名健康对照 (HC) 的个体特异性丘脑分区，并研究了 DOC 患者丘脑核的形状变形以及与丘脑核和丘脑皮质通路相关的微观结构变化。相对于HC组，DOC组观察到右侧丘脑背侧后核增大和右侧丘脑前核萎缩，且前者与患者的意识水平密切相关。我们还发现，在几个丘脑核和大多数丘脑皮质纤维通路内，纤维密度显着减少，但纤维束横截面没有显着减少，这表明轴突的丧失可能是 DOC 患者丘脑皮质连接受损的主要原因，而不是纤维束形态的变化。此外，个体特异性丘脑分区在将最低意识状态和植物人状态的患者分类方面达到了 80% 的准确率，而基于群体水平分区的准确率约为 60%。我们的研究结果为 DOC 患者丘脑核形状变形以及丘脑皮质连接破坏的微观结构基础提供了第一个证据。
Abstract The thalamus plays crucial roles in consciousness generation and information processing. Previous evidence suggests that disorder of consciousness (DOC) caused by severe brain injury, is potentially related to thalamic abnormalities. However, how the morphology and microstructure change in thalamic subfields and thalamocortical fiber pathways in patients with DOC, and the relationships between these changes and the consciousness status remain unclear. Here, we generated the individual-specific thalamic parcellation in 10 DOC patients and 10 healthy controls (HC) via a novel thalamic segmentation framework based on the fiber orientation distribution (FOD) derived from 7-Tesla diffusion MRI, and investigated the shape deformation of thalamic nuclei as well as the microstructural changes associated with thalamic nuclei and thalamocortical pathways in patients with DOC. Enlargement of dorsal posterior nucleus and atrophy of anterior nucleus in the right thalamus were observed in DOC cohort relative to the HCs, and the former was closely linked to the consciousness level of the patients. We also found significant reductions of fiber density, but not fiber bundle cross-section, within several thalamic nuclei and most of the thalamocortical fiber pathways, suggesting that loss of axons might take primary responsibility for the impaired thalamocortical connections in patients with DOC rather than the change in fiber-bundle morphology. Furthermore, the individual-specific thalamic parcellation achieved 80% accuracy in classifying patients at the minimally conscious state from the vegetative state, compared with ~60% accuracy based on group-level parcellations. Our findings provide the first evidence for the shape deformation of thalamic nuclei in DOC patients and the microstructural basis of the disrupted thalamocortical connections.