Emergency Medicine, Neurology, Neurosurgery, Community and Preventive Medicine, University of Rochester School of Medicine, Rochester, NY 14642, USA.
Magn Reson Imaging. 2012 Feb;30(2):171-80. doi: 10.1016/j.mri.2011.10.001. Epub 2011 Nov 12.
Current approaches to diffusion tensor imaging (DTI) analysis do not permit identification of individual-level changes in DTI indices. We investigated the ability of wild bootstrapping analysis to detect subject-specific changes in brain white matter (WM) before and after sports-related concussion.
A prospective cohort study was performed in nine high school athletes engaged in hockey or football and six controls. Subjects underwent DTI pre- and postseason within a 3-month interval. One athlete was diagnosed with concussion (scanned within 72 h), and eight suffered between 26 and 399 subconcussive head blows. Fractional anisotropy (FA) and mean diffusivity (MD) were measured in each WM voxel. Bootstrap samples were generated, and a permuted t test was used to compare voxel-wise FA/MD changes in each subject pre- vs. postseason.
The percentage of WM voxels with significant (p<.05) pre-post FA changes was highest for the concussion subject (3.2%), intermediary for those with subconcussive head blows (mean 1.05%±.15%) and lowest for controls (mean 0.28%±.01%). Similarly, the percentage of WM voxels with significant MD changes was highest for the concussion subject (3.44%), intermediary for those with subconcussive head blows (mean 1.48%±.17%) and lowest for controls (mean 0.48%±.05%). Significantly changed FA and MD voxels colocalized in the concussion subject to the right corona radiata and right inferior longitudinal fasciculus.
Wild bootstrap analysis detected significantly changed WM in a single concussed athlete. Athletes with multiple subconcussive head blows had significant changes in a percentage of their WM that was over three times higher than controls. Efforts to understand the significance of these WM changes and their relationship to head impact forces appear warranted.
目前的扩散张量成像（DTI）分析方法无法确定 DTI 指标的个体水平变化。我们研究了野生自举分析在运动相关脑震荡前后检测脑白质（WM）个体变化的能力。
一项前瞻性队列研究纳入了 9 名从事曲棍球或足球运动的高中生运动员和 6 名对照者。受试者在 3 个月的时间内进行了 DTI 前后扫描。1 名运动员被诊断为脑震荡（在 72 小时内扫描），8 名运动员遭受了 26 至 399 次亚临床性头部撞击。在每个 WM 体素中测量了分数各向异性（FA）和平均扩散系数（MD）。生成了自举样本，并使用置换 t 检验比较了每个受试者前后 FA/MD 变化的体素差异。
在运动相关脑震荡受试者中，WM 体素 FA 变化具有显著意义（p<.05）的比例最高（3.2%），其次是亚临床性头部撞击受试者（平均 1.05%±.15%），最低的是对照组（平均 0.28%±.01%）。同样，WM 体素 MD 变化具有显著意义的比例在运动相关脑震荡受试者中最高（3.44%），其次是亚临床性头部撞击受试者（平均 1.48%±.17%），最低的是对照组（平均 0.48%±.05%）。在运动相关脑震荡受试者中，FA 和 MD 变化显著的体素在右侧放射冠和右侧下纵束中重合。
野生自举分析检测到了单一脑震荡运动员的 WM 明显变化。多次亚临床性头部撞击的运动员 WM 中有显著变化的比例比对照组高出三倍多。有必要努力了解这些 WM 变化的意义及其与头部撞击力的关系。
