Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Germany.
Neuroimage. 2010 May 1;50(4):1589-98. doi: 10.1016/j.neuroimage.2009.12.060. Epub 2009 Dec 23.
The cortical, cerebellar and brainstem BOLD-signal changes have been identified with fMRI in humans during mental imagery of walking. In this study the whole brain activation and deactivation pattern during real locomotion was investigated by [(18)F]-FDG-PET and compared to BOLD-signal changes during imagined locomotion in the same subjects using fMRI. Sixteen healthy subjects were scanned at locomotion and rest with [(18)F]-FDG-PET. In the locomotion paradigm subjects walked at constant velocity for 10 min. Then [(18)F]-FDG was injected intravenously while subjects continued walking for another 10 min. For comparison fMRI was performed in the same subjects during imagined walking. During real and imagined locomotion a basic locomotion network including activations in the frontal cortex, cerebellum, pontomesencephalic tegmentum, parahippocampal, fusiform and occipital gyri, and deactivations in the multisensory vestibular cortices (esp. superior temporal gyrus, inferior parietal lobule) was shown. As a difference, the primary motor and somatosensory cortices were activated during real locomotion as distinct to the supplementary motor cortex and basal ganglia during imagined locomotion. Activations of the brainstem locomotor centers were more prominent in imagined locomotion. In conclusion, basic activation and deactivation patterns of real locomotion correspond to that of imagined locomotion. The differences may be due to distinct patterns of locomotion tested. Contrary to constant velocity real locomotion (10 min) in [(18)F]-FDG-PET, mental imagery of locomotion over repeated 20-s periods includes gait initiation and velocity changes. Real steady-state locomotion seems to use a direct pathway via the primary motor cortex, whereas imagined modulatory locomotion an indirect pathway via a supplementary motor cortex and basal ganglia loop.
在人类进行行走想象时，功能磁共振成像（fMRI）已经发现了皮质、小脑和脑干的 BOLD 信号变化。在这项研究中，通过 [(18)F]-FDG-PET 研究了真实运动期间整个大脑的激活和去激活模式，并与同一组受试者在进行想象运动期间的 fMRI 中的 BOLD 信号变化进行了比较。16 名健康受试者在运动和休息时接受 [(18)F]-FDG-PET 扫描。在运动范式中，受试者以恒定速度行走 10 分钟。然后，[(18)F]-FDG 静脉注射，同时受试者继续行走 10 分钟。为了进行比较，在同一组受试者中进行了想象行走时的 fMRI。在真实和想象的运动中，显示了一个基本的运动网络，包括额叶皮层、小脑、桥脑被盖运动区、海马旁回、梭状回和枕叶回的激活，以及多感觉前庭皮质（特别是颞上回、下顶叶）的去激活。作为一个区别，在真实运动期间，初级运动和躯体感觉皮层被激活，而在想象运动期间，辅助运动皮层和基底节被激活。想象运动中脑干运动中心的激活更为明显。总之，真实运动的基本激活和去激活模式与想象运动的模式相对应。这些差异可能是由于测试的运动模式不同。与 [(18)F]-FDG-PET 中的恒定速度真实运动（10 分钟）相反，运动想象在重复的 20 秒期间包括步态开始和速度变化。真实的稳态运动似乎使用了经由初级运动皮层的直接途径，而想象中的调制运动则使用了经由辅助运动皮层和基底节环路的间接途径。
