Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, ON, Canada.
Neuroscience Research Program, St. Michael's Hospital, Toronto, ON, Canada.
Sci Rep. 2021 Mar 25;11(1):6862. doi: 10.1038/s41598-021-85811-4.
There is a growing body of literature using functional MRI to study the acute and long-term effects of concussion on functional brain networks. To date, studies have largely focused on changes in pairwise connectivity strength between brain regions. Less is known about how concussion affects whole-brain network topology, particularly the "small-world" organization which facilitates efficient communication at both local and global scales. The present study addressed this knowledge gap by measuring local and global efficiency of 26 concussed athletes at acute injury, return to play (RTP) and one year post-RTP, along with a cohort of 167 athletic controls. On average, concussed athletes showed no alterations in local efficiency but had elevated global efficiency at acute injury, which had resolved by RTP. Athletes with atypically long recovery, however, had reduced global efficiency at 1 year post-RTP, suggesting long-term functional abnormalities for this subgroup. Analyses of nodal efficiency further indicated that global network changes were driven by high-efficiency visual and sensorimotor regions and low-efficiency frontal and subcortical regions. This study provides evidence that concussion causes subtle acute and long-term changes in the small-world organization of the brain, with effects that are related to the clinical profile of recovery.
越来越多的文献使用功能磁共振成像来研究脑震荡对功能脑网络的急性和长期影响。迄今为止，研究主要集中在脑区之间的成对连接强度变化上。关于脑震荡如何影响全脑网络拓扑结构，特别是影响促进局部和全局尺度有效交流的“小世界”组织，人们知之甚少。本研究通过测量 26 名急性脑震荡运动员在受伤、重返赛场（RTP）和 RTP 后 1 年的局部和全局效率，以及 167 名运动对照组，填补了这一知识空白。平均而言，脑震荡运动员的局部效率没有变化，但在急性损伤时的全局效率升高，RTP 时已恢复正常。然而，恢复时间异常长的运动员在 RTP 后 1 年的全局效率降低，表明该亚组存在长期功能异常。节点效率分析进一步表明，全局网络变化是由高效率的视觉和感觉运动区域和低效率的额叶和皮质下区域驱动的。这项研究提供的证据表明，脑震荡导致大脑的小世界组织在急性和长期出现细微变化，其影响与恢复的临床特征有关。
