Center for Translational Imaging, Department of Radiology, Department of Psychiatry and Behavioral Sciences, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
Edward Hines Jr., VA Hospital, Research Service, Hines, Illinois, USA.
J Neurotrauma. 2021 May 15;38(10):1368-1376. doi: 10.1089/neu.2020.7016. Epub 2021 Feb 24.
Neuroimaging demonstrates that athletes of collision sports can suffer significant changes to their brain in the absence of concussion, attributable to head acceleration event (HAE) exposure. In a sample of 24 male Division I collegiate football players, we examine the relationships between tryptophan hydroxylase 2 (), a gene involved in neurovascular function, regional cerebral blood flow (rCBF) measured by arterial spin labeling, and virtual reality (VR) motor performance, both pre-season and across a single football season. For the pre-season, T-carriers showed lower rCBF in two left hemisphere foci (fusiform gyrus/thalamus/hippocampus and cerebellum) in association with higher (better performance) VR Reaction Time, a dynamic measure of sensory-motor reactivity and efficiency of visual-spatial processing. For CC homozygotes, higher pre-season rCBF in these foci was associated with better performance on VR Reaction Time. A similar relationship was observed across the season, where T-carriers showed improved VR Reaction Time associated with decreases in rCBF in the right hippocampus/amygdala, left middle temporal lobe, and left insula/putamen/pallidum. In contrast, CC homozygotes showed improved VR Reaction Time associated with increases in rCBF in the same three clusters. These findings show that T-carriers have an abnormal relationship between rCBF and the efficiency of visual-spatial processing that is exacerbated after a season of high-impact sports in the absence of diagnosable concussion. Such gene-environment interactions associated with behavioral changes after exposure to repetitive HAEs have been unrecognized with current clinical analytical tools and warrant further investigation. Our results demonstrate the importance of considering neurovascular factors along with traumatic axonal injury to study long-term effects of repetitive HAEs.
神经影像学研究表明，即使在没有脑震荡的情况下，从事碰撞运动的运动员的大脑也会因头部加速事件（HAE）而发生显著变化。在一项对 24 名男性一级大学橄榄球运动员的样本研究中，我们研究了色氨酸羟化酶 2（）与脑区域血流（rCBF）之间的关系，该基因参与神经血管功能，通过动脉自旋标记测量，以及虚拟现实（VR）运动表现，包括赛季前和整个赛季。在赛季前，T 携带者在两个左半球焦点（梭状回/丘脑/海马体和小脑）的 rCBF 较低，与 VR 反应时间（一种动态测量感觉运动反应性和视觉空间处理效率的指标）较高（表现更好）相关。对于 CC 纯合子，这些焦点的 rCBF 较高与 VR 反应时间表现较好相关。在整个赛季中观察到类似的关系，T 携带者的 VR 反应时间改善与右海马体/杏仁核、左颞中回和左岛叶/壳核/苍白球的 rCBF 降低相关。相比之下，CC 纯合子的 VR 反应时间改善与这三个簇的 rCBF 增加相关。这些发现表明，T 携带者的 rCBF 与视觉空间处理效率之间存在异常关系，这种关系在经历了一个赛季的高冲击运动后，在没有可诊断的脑震荡的情况下会加剧。这种与重复 HAE 暴露后行为变化相关的基因-环境相互作用，尚未被当前的临床分析工具所认识，值得进一步研究。我们的研究结果表明，在研究重复 HAE 的长期影响时，考虑神经血管因素和创伤性轴索损伤非常重要。
