- 作者：Mark S. Mennemeier ; William J. Triggs ; Kenneth C. Chelette ; A.J. Woods ; Timothy A. Kimbrell ; John L. Dornhoffer
- 关键词：TMS ; rTMS ; sham
- 刊名：Brain Stimulation
- 出版年：2009
- 出版时间：July 2009
- 年：2009
- 卷：2
- 期：3
- 页码：168-173
- 全文大小：201 K
Background
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 with the use of 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, healthy subjects. The sham technique was validated in back-to-back comparisons with active rTMS in new samples of normal, healthy 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.