Post Andrew, Hoshizaki T Blaine, Zemek Roger, Gilchrist Michael D, Koncan David, Dawson Lauren, Chen Wesley, Ledoux Andrée-Anne
Children's Hospital of Eastern Ontario Research Institute, Ottawa.
Human Kinetics, University of Ottawa, Ontario, Canada ; and.
J Neurosurg Pediatr. 2017 Jun;19(6):641-651. doi: 10.3171/2016.11.PEDS16383. Epub 2017 Mar 28.
OBJECTIVE Currently, little is known about the biomechanics of head impact for concussion in youths (ages 5 to 18 years). Even less is known about the biomechanical characteristics and variables related to head impacts that may be useful in differentiating between transient and persistent postconcussion symptoms in a youth population. The purpose of this research was to examine the differences in biomechanics of youth head impact for transient postconcussion symptoms (TPCSs) and persistent postconcussion symptoms (PPCSs) by using data from a hospital population. METHODS In a laboratory setting and using physical, computational, and finite element models, the authors reconstructed falling events in a large cohort of patients who had sustained a brain injury that resulted in transient or persistent postconcussion symptoms. The falling events and resulting concussions for the TPCS and PPCS patient groups were analyzed in terms of force, energy, peak resultant linear and rotational accelerations, and maximum principal strain in the gray and white matter of the brain, as well as measurements of cumulative strain damage. RESULTS The results indicated that there were no significant differences between the groups for any of the variables analyzed. CONCLUSIONS With methods derived for use in an adult population, the magnitudes of peak linear acceleration for the youth data set were determined to be above the 50% risk of injury. The youth data set showed higher brain tissue strain responses for lower energy and impact velocities than measured in adults, suggesting that youths are at higher risk of concussive injury at lower event severities. A trend shown by some variables indicated that larger magnitudes of response were associated with PPCSs, but no single measurement variable consistently differentiated between the TPCS and PPCS groups. It is possible that using the biomechanics of head and brain responses to predict a subjective symptom load may not be appropriate. To enhance future biomechanical analyses, further investigations should include the use of quantifiable measures of brain injury linked to clinical outcomes and possible confounding factors such as history of brain injury and patient predisposition.
目的 目前，对于青少年（5至18岁）脑震荡时头部撞击的生物力学了解甚少。对于可能有助于区分青少年群体中短暂性和持续性脑震荡后症状的与头部撞击相关的生物力学特征和变量更是知之甚少。本研究的目的是利用来自医院人群的数据，研究青少年头部撞击导致短暂性脑震荡后症状（TPCSs）和持续性脑震荡后症状（PPCSs）时生物力学的差异。方法 在实验室环境中，作者使用物理、计算和有限元模型，重建了一大群因脑损伤导致短暂性或持续性脑震荡后症状的患者的跌倒事件。从力、能量、峰值合成线性和旋转加速度、大脑灰质和白质中的最大主应变以及累积应变损伤测量等方面，分析了TPCS和PPCS患者组的跌倒事件及由此导致的脑震荡。结果 结果表明，所分析的任何变量在两组之间均无显著差异。结论 使用适用于成人人群的方法，确定青少年数据集的峰值线性加速度大小高于50%的损伤风险。青少年数据集显示，与成人相比，在较低能量和撞击速度下脑组织应变反应更高，这表明青少年在较低事件严重程度下遭受脑震荡损伤的风险更高。一些变量显示出的一种趋势表明，较大的反应幅度与PPCSs相关，但没有单一测量变量能始终区分TPCS和PPCS组。使用头部和大脑反应的生物力学来预测主观症状负荷可能不合适。为了加强未来的生物力学分析，进一步的研究应包括使用与临床结果相关的可量化脑损伤测量方法以及可能的混杂因素，如脑损伤史和患者易感性。
