Denslow Stewart, Lomarev Mikhail, George Mark S, Bohning Daryl E
Department of Radiology, Center for Advanced Imaging Research and Brain Stimulation Laboratories, Medical University of South Carolina, Charlestown, SC 29425, USA.
Biol Psychiatry. 2005 Apr 1;57(7):752-60. doi: 10.1016/j.biopsych.2004.12.017.
To date, interleaved transcranial magnetic stimulation and functional magnetic resonance imaging (TMS/fMRI) studies of motor activation have not recorded whole brain patterns. We hypothesized that TMS would activate known motor circuitry with some additional regions plus some areas dropping out.
We used interleaved TMS/fMRI (11 subjects, three scans each) to elucidate whole brain activation patterns from 1-Hz TMS over left primary motor cortex.
Both TMS (110% motor threshold) and volitional movement of the same muscles excited by TMS caused blood oxygen level-dependent (BOLD) patterns encompassing known motor circuitry. Additional activation was observed bilaterally in superior temporal auditory areas. Decreases in BOLD signal with unexpected post-task "rebounds" were observed for both tasks in the right motor area, right superior parietal lobe, and in occipital regions. Paired t test of parametric contrast maps failed to detect significant differences between TMS- and volition-induced effects. Differences were detectable, however, in primary data time-intensity profiles.
Using this interleaved TMS/fMRI technique, TMS over primary motor cortex produces a whole brain pattern of BOLD activation similar to known motor circuitry, without detectable differences from mimicked volitional movement. Some differences may exist between time courses of BOLD intensity during TMS circuit activation and volitional circuit activation.
迄今为止，经颅磁刺激与功能磁共振成像（TMS/fMRI）对运动激活的研究尚未记录全脑模式。我们推测，经颅磁刺激会激活已知的运动神经回路，同时还有一些额外区域，另外一些区域则未被激活。
我们采用交替TMS/fMRI（11名受试者，每人进行三次扫描）来阐明对左侧初级运动皮层施加1赫兹经颅磁刺激时的全脑激活模式。
经颅磁刺激（110%运动阈值）以及经颅磁刺激所激发的相同肌肉的自主运动，均引发了包含已知运动神经回路的血氧水平依赖（BOLD）模式。在双侧颞上听觉区域观察到额外激活。在右侧运动区、右侧顶上叶以及枕叶区域，两项任务均观察到任务后出现意外“反弹”时BOLD信号降低。对参数对比图进行配对t检验未能检测到经颅磁刺激和自主运动诱发效应之间的显著差异。然而，在原始数据的时间强度曲线上可以检测到差异。
使用这种交替TMS/fMRI技术，对初级运动皮层施加经颅磁刺激会产生与已知运动神经回路相似的全脑BOLD激活模式，与模拟的自主运动相比未检测到差异。在经颅磁刺激回路激活和自主回路激活期间，BOLD强度的时间进程之间可能存在一些差异。
