From Medical Biophysics (K.Y.M., R.B., R.S.M.), School of Kinesiology (J.S.B., J.P.D.), Microbiology and Immunology (K.B.), Health and Rehabilitation Sciences (A.H.), Anatomy and Cell Biology (A.B.), Physical Medicine and Rehabilitation (T.D.), and School of Occupational Therapy (J.H.), Western University; Centre for Functional and Metabolic Mapping (K.Y.M., R.B., R.S.M.) and Molecular Medicine Research Laboratories (K.B., C.B., A.B., G.A.D.), Robarts Research Institute; Primary Care Sport Medicine (L.F., T.J.), Fowler Kennedy Sport Medicine; and Paediatrics Critical Care Medicine (D.F.), London Health Sciences Centre, Ontario, Canada.
From Medical Biophysics (K.Y.M., R.B., R.S.M.), School of Kinesiology (J.S.B., J.P.D.), Microbiology and Immunology (K.B.), Health and Rehabilitation Sciences (A.H.), Anatomy and Cell Biology (A.B.), Physical Medicine and Rehabilitation (T.D.), and School of Occupational Therapy (J.H.), Western University; Centre for Functional and Metabolic Mapping (K.Y.M., R.B., R.S.M.) and Molecular Medicine Research Laboratories (K.B., C.B., A.B., G.A.D.), Robarts Research Institute; Primary Care Sport Medicine (L.F., T.J.), Fowler Kennedy Sport Medicine; and Paediatrics Critical Care Medicine (D.F.), London Health Sciences Centre, Ontario, Canada
Neurology. 2020 Jul 28;95(4):e402-e412. doi: 10.1212/WNL.0000000000009821. Epub 2020 Jun 17.
To longitudinally assess brain microstructure and function in female varsity athletes participating in contact and noncontact sports.
Concussion-free female rugby players (n = 73) were compared to age-matched (ages 18-23) female swimmers and rowers (n = 31) during the in- and off-season. Diffusion and resting-state fMRI (rs-fMRI) measures were the primary outcomes. The Sports Concussion Assessment Tool and head impact accelerometers were used to monitor symptoms and impacts, respectively.
We found cross-sectional (contact vs noncontact) and longitudinal (in- vs off-season) changes in white matter diffusion measures and rs-fMRI network connectivity in concussion-free contact athletes relative to noncontact athletes. In particular, mean, axial, and radial diffusivities were increased with decreased fractional anisotropy in multiple white matter tracts of contact athletes accompanied with default mode and visual network hyperconnectivity ( < 0.001). Longitudinal diffusion changes in the brainstem between the in- and off-season were observed for concussion-free contact athletes only, with progressive changes observed in a subset of athletes over multiple seasons. Axial diffusivity was significantly lower in the genu and splenium of the corpus callosum in those contact athletes with a history of concussion.
Together, these findings demonstrate longitudinal changes in the microstructure and function of the brain in otherwise healthy, asymptomatic athletes participating in contact sport. Further research to understand the long-term brain health and biological implications of these changes is required, in particular to what extent these changes reflect compensatory, reparative, or degenerative processes.
纵向评估参与接触性和非接触性运动的女性大学生运动员的大脑微观结构和功能。
在赛季内和赛季外，将无脑震荡的女子英式橄榄球运动员（n=73）与年龄匹配的（18-23 岁）女子游泳运动员和赛艇运动员（n=31）进行比较。扩散和静息态功能磁共振成像（rs-fMRI）测量是主要结果。使用运动性脑震荡评估工具和头部冲击加速度计分别监测症状和冲击。
我们发现无脑震荡接触性运动员相对于非接触性运动员存在横断面（接触与非接触）和纵向（赛季内与赛季外）的白质扩散测量和 rs-fMRI 网络连接变化。特别是，接触运动员的多个白质束的平均、轴向和径向扩散率增加，而各向异性分数降低，伴有默认模式和视觉网络的超连接（<0.001）。在无脑震荡接触运动员中，仅在脑干部位观察到了赛季内和赛季外的纵向扩散变化，并且在多个赛季中，观察到了一部分运动员的进展性变化。接触运动员的胼胝体膝部和压部的轴向扩散率明显较低，这些运动员曾有过脑震荡史。
这些发现共同表明，在健康、无症状的参与接触性运动的运动员中，大脑的微观结构和功能存在纵向变化。需要进一步研究来了解这些变化对大脑长期健康和生物学的影响，特别是这些变化在多大程度上反映了代偿、修复或退行性过程。
