Huang Ying-Zu, Rothwell John C
Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK.
Clin Neurophysiol. 2004 May;115(5):1069-75. doi: 10.1016/j.clinph.2003.12.026.
To explore the effect of applying a short burst of high-frequency repetitive transcranial magnetic stimulation (rTMS) to the human motor cortex as a preparatory investigation before attempting theta burst stimulation in humans.
Five or 15 pulses of 50 Hz rTMS were given at 50-80% active motor threshold (AMT). The time course of changes in motor-evoked potential (MEP) size and short interval intracortical inhibition (SICI) were evaluated from 20 to 300 ms after the end of each burst in the relaxed first dorsal interosseous muscle of 15 healthy volunteers.
No subjects noted any adverse effects. MEPs were enhanced and SICIs were reduced at 20 ms after a burst of either 5 or 15 pulses at 70 or 80% AMT, but not at 50% AMT. Subsequent experiments used a 5 pulse burst at 80% AMT. The threshold for producing SICI increased from 60 to 80% AMT when tested 10 or 20 ms after the end of the burst. MEPs were enhanced for 100 ms, whereas SICI was reduced for 200-300 ms.
A short burst of low-intensity 50 Hz rTMS over the hand motor area transiently increases MEP amplitude with a longer lasting decrease in SICI.
This means that it may be possible in future experiments to apply theta burst conditioning safely to the human cortex.
在尝试对人类进行theta爆发刺激之前，探索对人类运动皮层施加短串高频重复经颅磁刺激（rTMS）的效果，作为一项预备性研究。
在50%-80%的主动运动阈值（AMT）下给予50Hz的rTMS，每次5或15个脉冲。在15名健康志愿者放松的第一背侧骨间肌中，在每次刺激串结束后20至300毫秒内评估运动诱发电位（MEP）大小和短间隔皮质内抑制（SICI）的变化时间进程。
没有受试者注意到任何不良反应。在70%或80%AMT下给予5或15个脉冲的刺激串后20毫秒时，MEP增强，SICI降低，但在50%AMT时未出现这种情况。后续实验采用80%AMT下的5个脉冲刺激串。在刺激串结束后10或20毫秒进行测试时，产生SICI的阈值从60%AMT增加到80%AMT。MEP增强持续100毫秒，而SICI降低持续200 - 300毫秒。
在手运动区施加短串低强度50Hz的rTMS会短暂增加MEP幅度，同时使SICI出现更持久的降低。
这意味着在未来的实验中可能可以安全地对人类皮层施加theta爆发条件刺激。
