Computational, Cognitive and Clinical Neuroimaging Laboratory, Centre for Neuroscience, Division of Experimental Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK.
Nat Rev Neurol. 2014 Mar;10(3):156-66. doi: 10.1038/nrneurol.2014.15. Epub 2014 Feb 11.
Diffuse axonal injury after traumatic brain injury (TBI) produces neurological impairment by disconnecting brain networks. This structural damage can be mapped using diffusion MRI, and its functional effects can be investigated in large-scale intrinsic connectivity networks (ICNs). Here, we review evidence that TBI substantially disrupts ICN function, and that this disruption predicts cognitive impairment. We focus on two ICNs--the salience network and the default mode network. The activity of these ICNs is normally tightly coupled, which is important for attentional control. Damage to the structural connectivity of these networks produces predictable abnormalities of network function and cognitive control. For example, the brain normally shows a 'small-world architecture' that is optimized for information processing, but TBI shifts network function away from this organization. The effects of TBI on network function are likely to be complex, and we discuss how advanced approaches to modelling brain dynamics can provide insights into the network dysfunction. We highlight how structural network damage caused by axonal injury might interact with neuroinflammation and neurodegeneration in the pathogenesis of Alzheimer disease and chronic traumatic encephalopathy, which are late complications of TBI. Finally, we discuss how network-level diagnostics could inform diagnosis, prognosis and treatment development following TBI.
创伤性脑损伤（TBI）后的弥漫性轴索损伤通过断开脑网络导致神经功能障碍。这种结构损伤可以使用扩散 MRI 进行映射，其功能影响可以在大规模的内在连接网络（ICN）中进行研究。在这里，我们回顾了 TBI 大量破坏 ICN 功能的证据，以及这种破坏预测认知障碍的证据。我们专注于两个 ICN——突显网络和默认模式网络。这些 ICN 的活动通常紧密耦合，这对于注意力控制很重要。这些网络的结构连接损伤会产生可预测的网络功能和认知控制异常。例如，大脑通常表现出一种“小世界架构”，这是优化信息处理的，但 TBI 会使网络功能偏离这种组织。TBI 对网络功能的影响可能很复杂，我们讨论了如何通过先进的大脑动力学建模方法为网络功能障碍提供见解。我们强调了轴索损伤引起的结构网络损伤如何与神经炎症和神经退行性变相互作用，这是 TBI 的晚期并发症阿尔茨海默病和慢性创伤性脑病的发病机制。最后，我们讨论了网络级别的诊断如何为 TBI 后的诊断、预后和治疗发展提供信息。
