Abstract:
Severe traumatic brain injury can lead to transient or even chronic disorder of consciousness. To increase diagnosis and prognosis accuracy of disorder of consciousness, functional neuroimaging is recommended 1 month post-injury. Here, we investigated brain networks remodelling on longitudinal data between 1 and 3 months post severe traumatic brain injury related to change of consciousness. Thirty-four severe traumatic brain-injured patients were included in a cross-sectional and longitudinal clinical study, and their MRI data were compared to those of 20 healthy subjects. Long duration resting-state functional MRI were acquired in minimally conscious and conscious patients at two time points after their brain injury. The first time corresponds to the exit from intensive care unit and the second one to the discharge from post-intensive care rehabilitation ward. Brain networks data were extracted using graph analysis and metrics at each node quantifying local (clustering) and global (degree) connectivity characteristics. Comparison with brain networks of healthy subjects revealed patterns of hyper- and hypo-connectivity that characterize brain networks reorganization through the hub disruption index, a value quantifying the functional disruption in each individual severe traumatic brain injury graph. At discharge from intensive care unit, 24 patients\' graphs (9 minimally conscious and 15 conscious) were fully analysed and demonstrated significant network disruption. Clustering and degree nodal metrics, respectively, related to segregation and integration properties of the network, were relevant to distinguish minimally conscious and conscious groups. At discharge from post-intensive care rehabilitation unit, 15 patients\' graphs (2 minimally conscious, 13 conscious) were fully analysed. The conscious group still presented a significant difference with healthy subjects. Using mixed effects models, we showed that consciousness state, rather than time, explained the hub disruption index differences between minimally conscious and conscious groups. While severe traumatic brain-injured patients recovered full consciousness, regional functional connectivity evolved towards a healthy pattern. More specifically, the restoration of a healthy brain functional segregation could be necessary for consciousness recovery after severe traumatic brain injury. For the first time, extracting the hub disruption index directly from each patient\'s graph, we were able to track the clinical alteration and subsequent recovery of consciousness during the first 3 months following a severe traumatic brain injury.
摘要:
严重的创伤性脑损伤可导致短暂甚至慢性的意识障碍。为了提高意识障碍的诊断和预后的准确性,建议损伤后1个月进行功能性神经影像学检查.这里,我们研究了与意识改变相关的严重创伤性脑损伤后1~3个月的脑网络重构纵向数据.34例严重创伤性脑损伤患者被纳入一项横断面和纵向临床研究,并将他们的MRI数据与20名健康受试者的数据进行了比较。在脑损伤后的两个时间点,最低意识和有意识的患者获得了长时间的静息状态功能MRI。第一次对应于从重症监护病房离开,第二次对应于从重症监护后康复病房出院。在每个节点使用图分析和度量来量化局部(聚类)和全局(程度)连通性特征来提取脑网络数据。与健康受试者的大脑网络进行比较,揭示了通过集线器破坏指数表征大脑网络重组的超连接性和低连接性模式,在每个严重创伤性脑损伤图中量化功能破坏的值。从重症监护室出院时,对24名患者的图形(9名最低意识和15名有意识)进行了全面分析,并显示出明显的网络中断。聚类和程度节点度量,分别,与网络的隔离和集成特性有关,与区分最低意识和意识群体有关。从重症监护后康复病房出院时,15名患者图(2名最低意识,13有意识)进行了充分分析。意识组与健康受试者仍然存在显着差异。使用混合效果模型,我们展示了意识状态,而不是时间,解释了最低意识和意识组之间的枢纽破坏指数差异。当严重的颅脑外伤患者恢复完全意识时,区域功能连通性朝着健康的模式发展。更具体地说,恢复健康的脑功能隔离对于严重创伤性脑损伤后的意识恢复可能是必要的。第一次,直接从每个患者的图表中提取集线器中断指数,我们能够追踪严重创伤性脑损伤后的前3个月的临床改变和随后的意识恢复。