Lefebvre Geneviève, Guay Samuel, Chamard Emilie, Theaud Guillaume, de Guise Elaine, Bacon Benoit Antoine, Descoteaux Maxime, De Beaumont Louis, Théoret Hugo
Department of Psychology and Université de Montréal, Montréal, Québec, Canada.
Sherbrooke Connectivity Imaging Laboratory (SCIL), Université de Sherbrooke, Sherbrooke, Québec, Canada.
J Neurotrauma. 2021 Mar;38(5):529-537. doi: 10.1089/neu.2020.7170. Epub 2020 Aug 10.
Subconcussive hits to the head and physical fitness both have been associated with alterations in white matter (WM) microstructure in partly overlapping areas of the brain. The aim of the present study was to determine whether WM damage associated with repeated exposure to subconcussive hits to the head in university level contact sports athletes is modulated by high levels of fitness. To this end, 72 students were recruited: 24 athletes practicing a varsity contact sport (A-CS), 24 athletes practicing a varsity non-contact sport (A-NCS), and 24 healthy non-athletes (NA). Participants underwent a magnetic resonance imaging session that included diffusion-weighted imaging. Between-groups, statistical analyses were performed with diffusion tensor imaging measures extracted by tractometry of sections of the corpus callosum and the corticospinal tract. Most significant effects were found in A-NCS who exhibited higher fractional anisotropy (FA) values than A-CS in almost all segments of the corpus callosum and in the corticospinal tract. The A-NCS also showed higher FA compared with NA in the anterior regions of the corpus callosum and the corticospinal tracts. No group difference was found between the A-CS and the NA groups. These data suggest that repeated subconcussive hits to the head lead to anisotropic changes in the WM that may counteract the beneficial effects associated with high levels of fitness.
头部的次脑震荡撞击和身体素质都与大脑部分重叠区域的白质（WM）微观结构改变有关。本研究的目的是确定在大学水平的接触性运动运动员中，与反复头部次脑震荡撞击相关的WM损伤是否会受到高水平身体素质的调节。为此，招募了72名学生：24名从事大学接触性运动的运动员（A-CS），24名从事大学非接触性运动的运动员（A-NCS），以及24名健康非运动员（NA）。参与者接受了包括扩散加权成像在内的磁共振成像检查。在组间，使用通过胼胝体和皮质脊髓束切片的纤维束成像提取的扩散张量成像测量进行统计分析。在A-NCS中发现了最显著的影响，他们在胼胝体和皮质脊髓束的几乎所有节段中表现出比A-CS更高的分数各向异性（FA）值。在胼胝体和皮质脊髓束的前部区域，A-NCS与NA相比也显示出更高的FA。在A-CS和NA组之间未发现组间差异。这些数据表明，反复的头部次脑震荡撞击会导致WM的各向异性变化，这可能会抵消与高水平身体素质相关的有益影响。
