Abstract

Purpose

The purpose of the study was to describe measurements of stimulus-response curves in the anterior digastric muscle (ADM) bilaterally following transcranial magnetic stimulation (TMS) to the right and left hemispheres. The first dorsal interosseous muscle (FDI) was the control muscle.

Materials and methods

The subjects were 20 healthy young adults. Test sessions determined motor thresholds (MT) and stimulus-response curves (1.0, 1.2, 1.4, 1.6 × MT) from either the FDI or ADM following TMS to left and right hemispheres using the double cone coil. Bilateral recordings of MEPs in the left and right ADM allowed us to generate stimulus response curves following ipsilateral and contralateral TMS.

Results

Intraclass correlation coefficients (ICC) for MEP amplitudes from ipsilateral and contralateral ADMs were >0.60 at motor threshold (MT) and >0.90 at stimulus intensities above MT. There was a linear increase in MEP amplitudes across stimulus intensities for the FDI following contralateral TMS, while MEP amplitudes from the ADM following contralateral and ipsilateral TMS increased linearly across stimulus intensities [F_{(3, 57) [Muscle × Recording Site × Stim Intensity]} = 33.57; p < 0.05]; ${(\eta }_p^2$ = 0.64). The slopes of the stimulus-response curve of the contralateral FDI was greater than the slopes of the stimulus response curves of the ipsilateral and contralateral ADM (p < 0.05).

Conclusions

The current study provided insights on the methodology for recording stimulus response curves in the ADM with TMS. These findings may translate into a valid, reliable, and relevant clinical outcome to study the pathophysiology of the corticobulbar motor system.

中文翻译：

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健康受试者双侧前二腹肌经颅磁刺激获得的刺激反应曲线表征

摘要

目的

该研究的目的是描述对左右半球经颅磁刺激 (TMS) 后双侧前二腹肌 (ADM) 刺激-反应曲线的测量。第一背骨间肌 (FDI) 是对照肌肉。

材料和方法

受试者是 20 名健康的年轻人。测试会话确定了从 FDI 或 ADM 之后的 TMS 到使用双锥线圈的左右半球的运动阈值 (MT) 和刺激反应曲线 (1.0、1.2、1.4、1.6 × MT)。左右 ADM 中 MEP 的双边记录使我们能够在同侧和对侧 TMS 之后生成刺激反应曲线。

结果

同侧和对侧 ADM 的 MEP 振幅的类内相关系数 (ICC) 在运动阈值 (MT) 时 >0.60，在高于 MT 的刺激强度时 >0.90。对侧 TMS 后 FDI 的 MEP 振幅在刺激强度上呈线性增加，而对侧和同侧 TMS 后来自 ADM 的 MEP 振幅在刺激强度上呈线性增加 [ F _{(3, 57) [肌肉 × 记录部位 ×}刺激强度_] = 33.57; p  < 0.05]；${(\eta }_p^2$= 0.64）。对侧 FDI 刺激反应曲线的斜率大于同侧和对侧 ADM 刺激反应曲线的斜率 ( p  < 0.05)。

结论

当前的研究提供了关于使用 TMS 在 ADM 中记录刺激反应曲线的方法的见解。这些发现可能转化为有效、可靠和相关的临床结果，以研究皮质延髓运动系统的病理生理学。