Prefrontal over-activation during walking in people with mobility deficits: Interpretation and functional implications
Prefrontal over-activation during walking in people with mobility deficits: Interpretation and functional implications
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DOI：
10.1016/j.humov.2018.03.010
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发表时间：
2018-06-01
影响因子：
2.1
通讯作者：
Clark, David J.
中科院分区：
文献类型：
--
作者：
Hawkins, Kelly A.;Fox, Emily J.;Clark, David J.
背景资料：中枢神经系统对行走的控制包括来自执行控制机制的贡献，例如注意力和运动规划资源。执行控制步行可以客观地估计通过记录前额叶皮质活动，使用功能近红外光谱（fNIRS）。目的：本研究的主要目的是探讨组间差异，前额叶/执行控制的年轻人，老年人和成年人中风后的步行。还评估了步行相关的前额叶活动符合现有的认知框架的前额叶overactivation.Methods：参与者包括24名成年人中风后中度至重度步行缺陷，15名老年人轻度步态缺陷，和9名年轻健康的成年人。步行的执行控制被量化为通过fNIRS测量的前额皮质中的氧合血红蛋白浓度。三个步行任务进行了评估：典型的步行，步行的障碍，步行，同时执行语言流畅性任务。结果：在典型和障碍行走任务中，组对前额叶活动有显著影响（p < 0.001），年轻人表现出最低水平的前额叶活动，其次是老年人，然后是中风后的成年人。在年轻的成年人，典型的步行过程中的前额叶活动远低于言语流畅性双任务，这表明大量剩余的前额叶资源在典型的步行。然而，在老年人和中风后的成年人中，这些剩余的资源显着减少（p < 0.01）。累积起来，这些结果与老年人和中风组的前额叶过度激活一致，伴随着步行速度的急剧下降，因为任务复杂性增加到包括障碍物（p < 0.05）。结论：老年人和中风后成年人在步行过程中，前额叶/执行控制资源的使用增加。前额叶资源的利用水平，特别是在复杂的步行任务，如跨越障碍，可能会接近上限的可用资源的人有行走缺陷。先前的认知研究表明，前额叶过度激活加上有限的前额叶资源会导致认知能力低下。目前的研究表明，类似的情况影响步行的表现。未来的研究应该进一步调查在步行过程中前额过度激活与不良运动结果的关系。
Background: Control of walking by the central nervous system includes contributions from executive control mechanisms, such as attention and motor planning resources. Executive control of walking can be estimated objectively by recording prefrontal cortical activity using functional near infrared spectroscopy (fNIRS).Objective: The primary objective of this study was to investigate group differences in prefrontal/executive control of walking among young adults, older adults, and adults post-stroke. Also assessed was the extent to which walking-related prefrontal activity fits existing cognitive frameworks of prefrontal over-activation.Methods: Participants included 24 adults post-stroke with moderate to severe walking deficits, 15 older adults with mild gait deficits, and 9 young healthy adults. Executive control of walking was quantified as oxygenated hemoglobin concentration in the prefrontal cortex measured by fNIRS. Three walking tasks were assessed: typical walking, walking over obstacles, and walking while performing a verbal fluency task. Walking performance was assessed by walking speed.Results: There was a significant effect of group for prefrontal activity (p < 0.001) during typical and obstacles walking tasks, with young adults exhibiting the lowest level of prefrontal activity, followed by older adults, and then adults post-stroke. In young adults the prefrontal activity during typical walking was much lower than for the verbal fluency dual-task, suggesting substantial remaining prefrontal resources during typical walking. However, in older and post-stroke adults these remaining resources were significantly less (p < 0.01). Cumulatively, these results are consistent with prefrontal over-activation in the older and stroke groups, which was accompanied by a steeper drop in walking speed as task complexity increased to include obstacles (p < 0.05).Conclusions: There is a heightened use of prefrontal/executive control resources in older adults and post-stroke adults during walking. The level of prefrontal resource utilization, particularly during complex walking tasks like obstacle crossing, may approach the ceiling of available resources for people who have walking deficits. Prior cognitive research has revealed that prefrontal over-activation combined with limited prefrontal resources can lead to poor cognitive performance. The present study suggests a similar situation influences walking performance. Future research should further investigate the extent to which prefrontal over-activation during walking is linked to adverse mobility outcomes.