目的:使用双部位经颅磁刺激(dsTMS)研究半球内背侧运动前皮质(PMd)-初级运动皮质(M1)连接的最佳刺激间期(ISI)和24小时重测可靠性。
方法:在21个惯用右手的成年人中,在ISI为3、5-8和10ms时,已使用堆叠线圈dsTMS设置(条件刺激:静息运动阈值的75%;测试刺激:引发1-1.5mV的MEP)研究了左半球内PMd-M1的连通性。此外,研究了M1-M1短间隔皮质内抑制(SICI)和皮质内促进(ICF),以评估与标准成对脉冲设置的可比性。
结果:调节PMd导致在ISI为3和5ms时M1输出的显着抑制,而10ms导致促进(所有,p<0.001),在3(ICC:0.47)和6ms(ICC:0.44)ISI下具有公平的重测可靠性。SICI(p<0.001)和ICF(p=0.017)复制成功,具有出色的SICI重测可靠性(ICC:0.81)。
结论:此dsTMS设置可以探测抑制性和促进性PMd-M1连接,以及可靠地复制SICI和ICF范式。
结论:用于研究半球内PMd-M1连通性的堆叠线圈dsTMS设置为更好地了解运动控制提供了有希望的可能性。
OBJECTIVE: Investigating the optimal interstimulus interval (ISI) and the 24-hour test-retest reliability for intrahemispheric dorsal premotor cortex (PMd) - primary motor cortex (M1) connectivity using dual-site transcranial magnetic stimulation (dsTMS).
METHODS: In 21 right-handed adults, left intrahemispheric PMd-M1 connectivity has been investigated with a stacked-coil dsTMS setup (conditioning stimulus: 75% of resting motor threshold; test stimulus: eliciting MEPs of 1-1.5 mV) at ISIs of 3, 5-8, and 10 ms. Additionally, M1-M1 short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF) were investigated to assess comparability to standard paired-pulse setups.
RESULTS: Conditioning PMd led to significant inhibition of M1 output at ISIs of 3 and 5 ms, whereas 10 ms resulted in facilitation (all, p < 0.001), with a fair test-retest reliability for 3 (ICC: 0.47) and 6 ms (ICC: 0.44) ISIs. Replication of SICI (p < 0.001) and ICF (p = 0.017) was successful, with excellent test-retest reliability for SICI (ICC: 0.81).
CONCLUSIONS: This dsTMS setup can probe the inhibitory and facilitatory PMd-M1 connections, as well as reliably replicate SICI and ICF paradigms.
CONCLUSIONS: The stacked-coil dsTMS setup for investigating intrahemispheric PMd-M1 connectivity offers promising possibilities to better understand motor control.