Churchill Nathan W, Hutchison Michael G, Di Battista Alex P, Graham Simon J, Schweizer Tom A
Neuroscience Research Program, St. Michael's Hospital, Toronto, ON, Canada.
Keenan Research Centre for Biomedical Science of St. Michael's Hospital, Toronto, ON, Canada.
Front Neurol. 2017 Aug 22;8:390. doi: 10.3389/fneur.2017.00390. eCollection 2017.
There is growing concern about how participation in contact sports affects the brain. Retrospective evidence suggests that contact sports are associated with long-term negative health outcomes. However, much of the research to date has focused on former athletes with significant health problems. Less is known about the health of current athletes in contact and collision sports who have not reported significant medical issues. In this cross-sectional study, advanced magnetic resonance imaging (MRI) was used to evaluate multiple aspects of brain physiology in three groups of athletes participating in non-contact sports ( = 20), contact sports ( = 22), and collision sports ( = 23). Diffusion tensor imaging was used to assess white matter microstructure based on measures of fractional anisotropy (FA) and mean diffusivity (MD); resting-state functional MRI was used to evaluate global functional connectivity; single-voxel spectroscopy was used to compare ratios of neural metabolites, including -acetyl aspartate (NAA), creatine (Cr), choline, and myo-inositol. Multivariate analysis revealed structural, functional, and metabolic measures that reliably differentiated between sport groups. The collision group had significantly elevated FA and reduced MD in white matter, compared to both contact and non-contact groups. In contrast, the collision group showed significant reductions in functional connectivity and the NAA/Cr metabolite ratio, relative to only the non-contact group, while the contact group overlapped with both non-contact and collision groups. For brain regions associated with contact sport participation, athletes with a history of concussion also showed greater alterations in FA and functional connectivity, indicating a potential cumulative effect of both contact exposure and concussion history on brain physiology. These findings indicate persistent differences in brain physiology for athletes participating in contact and collision sports, which should be considered in future studies of concussion and subconcussive impacts.
人们越来越关注参与接触性运动如何影响大脑。回顾性证据表明，接触性运动与长期负面健康结果相关。然而，迄今为止的许多研究都集中在有重大健康问题的前运动员身上。对于未报告重大医疗问题的当前从事接触性和碰撞性运动的运动员的健康状况，人们了解较少。在这项横断面研究中，先进的磁共振成像（MRI）被用于评估三组参与非接触性运动（n = 20）、接触性运动（n = 22）和碰撞性运动（n = 23）的运动员大脑生理学的多个方面。弥散张量成像用于基于分数各向异性（FA）和平均扩散率（MD）的测量来评估白质微观结构；静息态功能MRI用于评估整体功能连接性；单体素光谱用于比较神经代谢物的比率，包括N-乙酰天门冬氨酸（NAA）、肌酸（Cr）、胆碱和肌醇。多变量分析揭示了能够可靠区分不同运动组的结构、功能和代谢指标。与接触性和非接触性运动组相比，碰撞性运动组的白质FA显著升高，MD降低。相比之下，仅相对于非接触性运动组，碰撞性运动组的功能连接性和NAA/Cr代谢物比率显著降低，而接触性运动组与非接触性和碰撞性运动组均有重叠。对于与接触性运动参与相关的脑区，有脑震荡病史的运动员在FA和功能连接性方面也表现出更大的改变，表明接触暴露和脑震荡病史对大脑生理学可能存在累积效应。这些发现表明，参与接触性和碰撞性运动的运动员在大脑生理学方面存在持续差异，这在未来关于脑震荡和亚脑震荡影响的研究中应予以考虑。
