Spectral signatures of reorganised brain networks in disorders of consciousness.
Spectral signatures of reorganised brain networks in disorders of consciousness.
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DOI：
10.1371/journal.pcbi.1003887
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发表时间：
2014-10
影响因子：
4.3
通讯作者：
Bekinschtein TA
中科院分区：
文献类型：
--
作者：
Chennu S;Finoia P;Kamau E;Allanson J;Williams GB;Monti MM;Noreika V;Arnatkeviciute A;Canales-Johnson A;Olivares F;Cabezas-Soto D;Menon DK;Pickard JD;Owen AM;Bekinschtein TA
意识科学的理论进展已经提出，它是伴随着平衡的皮层整合和分化，通过跨多个尺度的有效信息传输网络实现的。在这里，我们应用图论来比较32例慢性意识障碍患者的高密度脑电图数据中此类网络的关键签名，与健康对照组的正常数据进行比较。基于规范频带内的连通性，我们发现患者网络的局部和全局效率降低，α频带中的枢纽较少。我们设计了一种新的拓扑度量，称为模块跨度，这表明患者的α网络模块也是空间限制的，缺乏健康对照中常见的结构化长距离相互作用。然而，重要的是，图论度量之间的这些差异在delta和theta带网络中部分逆转，这在患者中也比对照组更相似。更进一步，我们发现阿尔法网络效率的指标也与行为意识的程度相关。有趣的是，一些行为反应迟钝的植物人患者通过功能性神经成像显示出了内隐意识的证据，这些患者从这一趋势中脱颖而出：他们的阿尔法网络保存得非常好，与对照组中观察到的相似。总之，我们的研究结果通过突出描述意识障碍的独特大脑网络，为当前对意识障碍的理解提供了信息。在神经影像学测试中遵循命令的少数植物人患者中，他们指出，尽管存在严重的行为障碍，但可以支持认知功能和意识的假定网络机制。意识的神经信号是什么？这对当前的认知神经科学来说是一个难以捉摸而又迷人的挑战，但它在被诊断为植物人和最低意识的患者中具有直接的临床和社会意义。在这些患者中，这让我们不禁要问，我们是否可以在没有任何外部意识迹象的情况下测试这些特征的存在。最近的概念进展表明，意识需要大脑区域之间的信息交换的集成和差异化网络之间的动态平衡。在这里，我们应用这种见解来研究患者的这种网络，并将其与健康成人进行比较。使用图论的科学，我们表明，支持意识的丰富和分散连接的网络在患者中是典型的受损，缺乏通过连接良好的枢纽有效地整合不同区域信息的能力。我们发现，患者网络的质量也与他们的行为反应程度密切相关，一些表现出隐藏意识迹象的植物人患者的网络保存得非常完好，与健康成年人相似。总的来说，我们的研究突出了病理性无意识的独特网络特征，这可以改善临床评估，并帮助识别尽管无法交流但仍有意识的患者。
Theoretical advances in the science of consciousness have proposed that it is concomitant with balanced cortical integration and differentiation, enabled by efficient networks of information transfer across multiple scales. Here, we apply graph theory to compare key signatures of such networks in high-density electroencephalographic data from 32 patients with chronic disorders of consciousness, against normative data from healthy controls. Based on connectivity within canonical frequency bands, we found that patient networks had reduced local and global efficiency, and fewer hubs in the alpha band. We devised a novel topographical metric, termed modular span, which showed that the alpha network modules in patients were also spatially circumscribed, lacking the structured long-distance interactions commonly observed in the healthy controls. Importantly however, these differences between graph-theoretic metrics were partially reversed in delta and theta band networks, which were also significantly more similar to each other in patients than controls. Going further, we found that metrics of alpha network efficiency also correlated with the degree of behavioural awareness. Intriguingly, some patients in behaviourally unresponsive vegetative states who demonstrated evidence of covert awareness with functional neuroimaging stood out from this trend: they had alpha networks that were remarkably well preserved and similar to those observed in the controls. Taken together, our findings inform current understanding of disorders of consciousness by highlighting the distinctive brain networks that characterise them. In the significant minority of vegetative patients who follow commands in neuroimaging tests, they point to putative network mechanisms that could support cognitive function and consciousness despite profound behavioural impairment. What are the neural signatures of consciousness? This is an elusive yet fascinating challenge to current cognitive neuroscience, but it takes on an immediate clinical and societal significance in patients diagnosed as vegetative and minimally conscious. In these patients, it leads us to ask whether we can test for the presence of these signatures in the absence of any external signs of awareness. Recent conceptual advances suggest that consciousness requires a dynamic balance between integrated and differentiated networks of information exchange between brain regions. Here we apply this insight to study such networks in patients and compare them to healthy adults. Using the science of graph theory, we show that the rich and diversely connected networks that support awareness are characteristically impaired in patients, lacking the ability to efficiently integrate information across disparate regions via well-connected hubs. We find that the quality of patients' networks also correlates well with their degree of behavioural responsiveness, and some vegetative patients who show signs of hidden awareness have remarkably well-preserved networks similar to healthy adults. Overall, our research highlights distinctive network signatures of pathological unconsciousness, which could improve clinical assessment and help identify patients who are aware despite being uncommunicative.
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DOI：
10.1073/pnas.0809667106
发表时间：
2009-02-03
影响因子：
11.1
作者：
Bekinschtein, Tristan A.;Dehaene, Stanislas;Naccache, Lionel
通讯作者：
Naccache, Lionel
影响因子：
5.3
作者：
Achard, S;Salvador, R;Bullmore, ET
通讯作者：
Bullmore, ET
影响因子：
4.3
作者：
Achard S;Bullmore E
通讯作者：
Bullmore E
影响因子：
5.7
作者：
Jann, K.;Dierks, T.;Koenig, T.
通讯作者：
Koenig, T.
影响因子：
9.9
作者：
Cruse, D.;Chennu, S.;Owen, A. M.
通讯作者：
Owen, A. M.