We predicted that accelerometry would be a viable alternative to electromyography (EMG) for assessing fundamental Transcranial Magnetic Stimulation (TMS) measurements (e.g. Resting Motor Threshold (RMT), recruitment curves, latencies). 21 participants were tested. TMS evoked responses were recorded with EMG on the First Dorsal Interosseus muscle and an accelerometer on the index fingertip. TMS was used to determine the (EMG-defined) RMT, then delivered at a range of intensities allowing determination of both the accelerometry-defined RMT and measurement of recruitment curves. RMT assessed by EMG was significantly lower than for accelerometry (t(19)=-3.84, p<.001, mean±SD EMG = 41.1±5.28% MSO (maximum stimulator output), Jerk = 44.55±5.82% MSO), though RMTs calculated for each technique were highly correlated (r(18)=.72, p<.001). EMG/Accelerometery recruitment curves were strongly correlated (r(14)=.98, p<.001), and Bayesian model comparison indicated they were equivalent (BF>9). Latencies measured with EMG were lower and more consistent than those identified using accelerometry (χ(1)=80.38, p<.001, mean±SD EMG=27.01±4.58 ms, Jerk=48.4±15.33 ms). EMG is used as standard by research groups that study motor control and neurophysiology, but accelerometry has not yet been considered as a potential tool to assess measurements such as the overall magnitude and latency of the evoked response. While EMG provides more sensitive and reliable measurements of RMT and latency, accelerometry provides a reliable alternative to measure of the overall magnitude of TMS evoked responses.

中文翻译：

---

加速度计作为测量经颅磁刺激效果的工具

我们预测，加速度测量将成为肌电图 (EMG) 的可行替代方案，用于评估基本经颅磁刺激 (TMS) 测量（例如静息运动阈值 (RMT)、募集曲线、潜伏期）。 21 名参与者接受了测试。通过第一背侧骨间肌的肌电图和食指尖的加速度计记录 TMS 诱发反应。 TMS 用于确定（肌电图定义的）RMT，然后以一系列强度进行传输，从而可以确定加速度计定义的 RMT 和招募曲线的测量。通过 EMG 评估的 RMT 显着低于加速度测量法（t(19)=-3.84，p<.001，平均值±SD EMG = 41.1±5.28% MSO（最大刺激器输出），Jerk = 44.55±5.82% MSO），但每种技术计算的 RMT 高度相关 (r(18)=.72，p<.001）。 EMG/加速度计招募曲线强相关（r(14)=.98，p<.001），贝叶斯模型比较表明它们是等效的（BF>9）。使用 EMG 测量的潜伏期比使用加速测量法确定的潜伏期更低且更一致 (χ(1)=80.38，p<.001，平均值±SD EMG=27.01±4.58 ms，Jerk=48.4±15.33 ms）。研究运动控制和神经生理学的研究小组将肌电图用作标准，但加速度测量尚未被视为评估诱发反应的总体幅度和延迟等测量的潜在工具。虽然 EMG 提供了更灵敏、更可靠的 RMT 和潜伏期测量，但加速度测量提供了一种可靠的替代方案来测量 TMS 诱发反应的总体幅度。