A study on higher-order gait control and its dysfunction using neuroimaging technique

本研究旨在结合神经成像和电生理学等多种无创性脑地形图技术，研究高阶步态控制及其可能导致步态障碍的异常的神经机制。首先，提出了一种假想的人体步态控制神经机制，作为后续研究的理论框架。该模型由两个基本系统组成：基底节-脑干系统和基底节-丘脑-皮质系统。在这一理论发展的同时，方法论的发展也为步态的神经成像研究提供了辅助。这些技术进展包括功能磁共振成像(FMRI)在认知、语言和运动行为方面的应用，扩散张量成像(DTI)，以及同时测量经颅磁刺激(TMS)-肌电-fMRI。此外，本研究在理解…方面取得了两个主要成果更多的是步态控制。(1)为了研究步态控制系统中的视觉-运动交互作用，用功能磁共振成像技术研究了受试者在观看第三人称视角下的另一个人的行走行为的电影时或想象他们从第一人称视角模拟行走行为的视觉体验的视觉环境下行走时的大脑活动。结果表明，在观察步态和想象步态的过程中，辅助运动区和运动前区都处于活跃状态。这项研究表明，运动皮质中的步态规划中心也参与了对其他人行走行为的理解。(2)20例缺血性脑白质改变患者分为步态障碍11例和行走行为正常9例。当这些患者在跑步机上行走时，测量了血流量。步态障碍组的主要结果是右侧丘脑和辅助运动区活动不足。通过神经成像了解人体步态控制系统，对于神经康复和脑机接口的发展具有重要意义。较少

The present study aimed at studying neural mechanisms of higher-order gait control and its abnormality, which may lead to gait disorders, by combining multiple non-invasive brain mapping techniques such as neuroimaging and electrophysiology. To begin with, a hypothetical neural mechanism of human gait control was proposed as a theoretical framework of following studies. This model was composed of two fundamental systems: basal ganglia-brainstem system and basal ganglia-thalamo-cortical system. In parallel to this theoretical development, effort was made for the methodological development to subserve the neuroimaging study of gait. These technical developments include the application of functional magnetic resonance imaging(fMRI) on cognitive, linguistic and motor behavior, diffusion tensor imaging(DTI), and simultaneous measurement of transcranial magnetic stimulation(TMS) -electromyography- fMRI. Moreover, the present study yielded two major achievements specific to the understanding … More of gait control. (1) To investigate the visuo-motor interaction in the gait control system, brain activity was investigated with functional magnetic resonance imaging while subjects watched a movie of another person's walking behavior from the third-person perspective or they imagined them walking under the visual environment mimicking visual experience of walking behavior from the first-person perspective. The results revealed that supplementary motor areas and premotor areas were active during both observation and imagination of gait. This study suggests that gait planning centers in the motor cortex are also involved in understanding of other persons' walking behavior. (2) Twenty patients with ischemic white matter changes were classified into 11 patients with gait disorder and 9 patients with normal walking behavior. Blood flow was measured while these patients were walking on a treadmill. The main results were underactivity in the right thalamus and supplementary motor areas in the gait disordered group. Understanding of human gait control system with neuroimaging will be important for the development of neuro-rehabilitation and brain-machine interface. Less