Department of Exercise and Sport Science, Matthew Gfeller Sport-Related Traumatic Brain Injury Research Center, The University of North Carolina at Chapel Hill, 2207 Stallings-Evans Sports Medicine Center, Chapel Hill, NC, USA.
Curriculum in Human Movement Science, Department of Allied Health Sciences, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
Ann Biomed Eng. 2021 Feb;49(2):793-801. doi: 10.1007/s10439-020-02604-y. Epub 2020 Sep 17.
The purpose of this study was to investigate how concussion history affects neurovascular coupling in Special Operations Forces (SOF) combat Soldiers. We studied 100 SOF combat Soldiers [age = 33.5 ± 4.3 years; height = 180.4 ± 6.0 cm; 55 (55.0%) with self-reported concussion history]. We employed transcranial Doppler (TCD) ultrasound to assess neurovascular coupling (NVC) via changes in posterior cerebral artery (PCA) velocity in response to a reading and a visual search task. Baseline TCD data were collected for 2 min. NVC was quantified by the percent change in overall PCA response curves. We employed linear mixed effect models using a linear spline with one knot to assess group differences in percent change observed in the PCA velocity response curves between SOF combat Soldiers with and without a concussion history. Baseline PCA velocity did not significantly differ (t = 1.28, p = 0.20) between those with and without concussion history. Relative PCA velocity response curves did not differ between those with and without a concussion history during the reading task (F = 0.80, p = 0.37) or the visual search task (F = 0.52, p = 0.47). When assessing only SOF combat Soldiers with a concussion history, differential response to task was significantly greater in those with 3 or more concussions (F = 27.24, p < 0.0001) relative to those with 1-2 concussions. Despite no main effect of concussion history on neurovascular coupling response in SOF combat Soldiers, we observed a dose-response based on lifetime concussion incidence. While long-term neurophysiological effects associated with head impact and blast-related injury are currently unknown, assessing NVC response may provide further insight into cerebrovascular function and overall physiological health.
本研究旨在探讨脑震荡史如何影响特种作战部队（SOF）作战士兵的神经血管耦合。我们研究了 100 名 SOF 作战士兵[年龄=33.5±4.3 岁；身高=180.4±6.0cm；55 名（55.0%）有自我报告的脑震荡史]。我们采用经颅多普勒（TCD）超声评估通过大脑后动脉（PCA）速度变化对阅读和视觉搜索任务的神经血管耦合（NVC）。采集 2 分钟的 TCD 数据。通过整体 PCA 反应曲线的百分比变化来量化 NVC。我们采用线性混合效应模型，使用带有一个结的线性样条来评估有和无脑震荡史的 SOF 作战士兵之间 PCA 速度反应曲线中观察到的百分比变化的组间差异。有和无脑震荡史的患者之间的 PCA 速度基线无显著差异（t=1.28，p=0.20）。在阅读任务（F=0.80，p=0.37）或视觉搜索任务（F=0.52，p=0.47）中，两组之间的相对 PCA 速度反应曲线没有差异。当仅评估有脑震荡史的 SOF 作战士兵时，与有 1-2 次脑震荡的士兵相比，有 3 次或更多脑震荡的士兵的任务反应差异明显更大（F=27.24，p<0.0001）。尽管脑震荡史对 SOF 作战士兵的神经血管耦合反应没有主要影响，但我们观察到基于终身脑震荡发生率的剂量反应。虽然与头部撞击和爆炸相关伤害相关的长期神经生理影响尚不清楚，但评估 NVC 反应可能为脑血管功能和整体生理健康提供进一步的见解。
