Transcallosal inhibition (TCI) is a measure of between-hemisphere inhibitory control that can be evaluated with the ipsilateral silent period (iSP) transcranial magnetic stimulation (TMS) paradigm. The study of iSP for the lower extremity has been limited possibly due to the close orientation of the lower extremity motor representations. Change in TCI can provide insights into pathophysiological mechanisms underlying the asymmetry in corticomotor excitability in stroke. Here, we describe a method for iSP quantification and report reliability of iSP parameters for the tibialis anterior (TA) muscle in stroke. 26 individuals with stroke attended three sessions where single pulse TMS was used to measure TCI from the lesioned to non-lesioned hemisphere. A double cone coil was used for stimulating the ipsilateral motor cortex while the participant maintained an isometric contraction of the non-paretic TA. Absolute and relative reliability were computed for iSP latency, duration and area. iSP latency showed the lowest measurement error (absolute reliability) and iSP latency, duration and area showed good relative reliability (intraclass correlation coefficients > 0.6). This study suggests that iSP parameters for the tibialis anterior are reliable and attempts to provide a guideline for evaluating TCI for the lower extremity in stroke and other clinical populations.

经胼胝体抑制 (TCI) 是半球间抑制控制的一种测量方法，可以使用同侧静默期 (iSP) 经颅磁刺激 (TMS) 范例进行评估。下肢 iSP 的研究受到限制，可能是由于下肢运动表征的接近方向。 TCI 的变化可以深入了解中风皮质运动兴奋性不对称性的病理生理机制。在这里，我们描述了一种 iSP 量化方法，并报告了中风中胫骨前肌 (TA) 的 iSP 参数的可靠性。 26 名中风患者参加了三场会议，其中使用单脉冲 TMS 测量从病变半球到非病变半球的 TCI。双锥线圈用于刺激同侧运动皮层，同时参与者保持非麻痹 TA 的等长收缩。计算了 iSP 延迟、持续时间和面积的绝对和相对可靠性。 iSP 潜伏期显示出最低的测量误差（绝对可靠性），iSP 潜伏期、持续时间和面积显示出良好的相对可靠性（组内相关系数 > 0.6）。这项研究表明，胫骨前肌的 iSP 参数是可靠的，并试图为评估中风和其他临床人群的下肢 TCI 提供指南。