Mennemeier M, Triggs W, Chelette Kc, Woods Aj, Kimbrell T, Dornhoffer J
Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR.
Brain Stimul. 2009 Jul 1;2(3):168-173. doi: 10.1016/j.brs.2009.02.002.
Most methods of sham, repetitive transcranial magnetic stimulation (rTMS) fail to replicate the look, sound, and feel of active stimulation in the absence of a significant magnetic field. OBJECTIVE/HYPOTHESIS: To develop and validate a new method of sham rTMS appropriate for a double-blind, placebo-controlled study with subject crossover. METHODS: The look and sound of active rTMS was replicated using a matched, air-cooled sham TMS coil. Scalp muscle stimulation associated with rTMS was replicated using large rubber electrodes placed over selected muscles. The intensity and pulse width of electrical stimulation necessary to match 1-Hz rTMS was developed in one sample of normal subjects. The sham technique was validated in back-to-back comparisons with active rTMS in new samples of normal subjects who were either naïve or experienced with rTMS. RESULTS: Subjects naïve to TMS could not tell which type of stimulation was active or sham or which was electrical or magnetic. Naïve subjects incorrectly picked sham stimulation as active, when forced to choose, because electrical stimulation felt more focused than magnetic stimulation. Subjects experienced with TMS could correctly identify sham and active stimulation. Experimenters could detect subtle differences between conditions. CONCLUSIONS: This method of sham rTMS closely mimics the look, sound, and feel of active stimulation at 1Hz without creating a significant magnetic field. It is valid for use with naïve subjects and in crossover studies. It can accommodate differences in scalp muscle recruitment at different sites of stimulation, and it could potentially be used with higher frequency stimulation.
在没有显著磁场的情况下，大多数伪重复经颅磁刺激（rTMS）方法无法复制有效刺激的外观、声音和感觉。
目的/假设：开发并验证一种适用于双盲、安慰剂对照且受试者交叉试验的新型伪rTMS方法。
使用匹配的风冷伪TMS线圈复制有效rTMS的外观和声音。通过将大橡胶电极置于选定肌肉上来复制与rTMS相关的头皮肌肉刺激。在一组正常受试者样本中确定了匹配1Hz rTMS所需的电刺激强度和脉冲宽度。在对rTMS不了解或有经验的正常受试者新样本中，将该伪技术与有效rTMS进行背对背比较以进行验证。
对TMS不了解的受试者无法分辨哪种刺激是有效刺激还是伪刺激，也无法分辨是电刺激还是磁刺激。在被迫选择时，不了解的受试者会错误地将伪刺激选为有效刺激，因为电刺激感觉比磁刺激更集中。有TMS经验的受试者能够正确识别伪刺激和有效刺激。实验者能够检测出不同条件之间的细微差异。
这种伪rTMS方法在不产生显著磁场的情况下，紧密模拟了1Hz有效刺激的外观、声音和感觉。它适用于不了解的受试者和交叉试验。它可以适应不同刺激部位头皮肌肉募集的差异，并且有可能用于更高频率的刺激。
