Department of Physical Medicine and Rehabilitation, Harvard Medical School, Boston, MA 02129, USA.
Department of Psychology, University of Georgia, Athens, GA 30602, USA.
J Int Neuropsychol Soc. 2019 Oct;25(9):950-960. doi: 10.1017/S1355617719000754. Epub 2019 Aug 6.
Multiple concussions sustained in youth sport may be associated with later-life brain changes and worse cognitive outcomes. We examined the association between two or more concussions during high school football and later-life white matter (WM) microstructure (i.e., 22-47 years following football retirement) using diffusion tensor imaging (DTI).
Forty former high school football players aged 40-65 who received 2+ concussions during high school football (N = 20), or denied concussive events (N = 20) were recruited. Participants underwent neurocognitive testing and DTI scanning.
Groups did not statistically differ on age, education, or estimated pre-morbid intelligence. Tract-based Spatial Statistics (TBSS) correcting for Family-Wise Error (FWE)(p < .05) did not yield differences between groups at the whole-brain level. Region of interest analyses showed higher mean diffusivity (MD) in the anterior limb of the internal capsule (ALIC) in the concussed group compared to the non-concussed former players. More liberal analyses (i.e., p < .001, uncorrected for multiple comparisons, ≥8 voxels) also revealed that former players endorsing 2+ concussions had higher MD in the ALIC. Analyses that covaried for age did not reveal differences at either threshold. Concussive histories were not associated with worse cognitive functioning, nor did it impact the relationship between neuropsychological scores and DTI metrics.
Results suggest only minimal neuroanatomical brain differences in former athletes many years following original concussive injuries compared to controls.
青少年时期多次遭受脑震荡可能与晚年大脑变化和认知功能下降有关。我们使用弥散张量成像（DTI）研究了高中橄榄球期间发生两次或两次以上脑震荡与晚年白质（WM）微观结构（即橄榄球退役后 22-47 年）之间的关联。
招募了 40 名年龄在 40-65 岁之间的前高中橄榄球运动员，他们在高中橄榄球期间遭受了 2 次或 2 次以上脑震荡（N = 20），或否认有脑震荡事件（N = 20）。参与者接受了神经认知测试和 DTI 扫描。
两组在年龄、教育程度或估计的发病前智力方面没有统计学差异。基于体素的空间统计学（TBSS）校正全脑水平的组间差异（FWE 校正，p <.05）未得出结果。感兴趣区域分析显示，在脑震荡组中，内囊前肢（ALIC）的平均弥散度（MD）较高，而非脑震荡的前橄榄球运动员。更宽松的分析（即，p <.001，未校正多重比较，≥8 个体素）也表明，有 2 次或 2 次以上脑震荡史的前橄榄球运动员 ALIC 的 MD 更高。在这两个阈值下，对年龄进行协方差分析并未显示出差异。脑震荡史与认知功能下降无关，也不影响神经心理学评分与 DTI 指标之间的关系。
结果表明，与对照组相比，多年前发生过脑震荡的前运动员在原始脑震荡损伤后，大脑的神经解剖结构差异极小。
