BACKGROUND Theta burst stimulation (TBS) and quadripulse stimulation (QPS) are known to induce synaptic plasticity in humans. There have been no head-to-head comparisons of the efficacy and variability between TBS and QPS. OBJECTIVE To compare the efficacy and interindividual variability between the original TBS and QPS protocols. We hypothesized that QPS would be more effective and less variable than TBS. METHODS Forty-six healthy subjects participated in this study. Thirty subjects participated in the main comparison experiment, and the other sixteen subjects participated in the experiment to obtain natural variation in motor-evoked potentials. The facilitatory effects were compared between intermittent TBS (iTBS) and QPS5, and the inhibitory effects were compared between continuous TBS (cTBS) and QPS50. The motor-evoked potential amplitudes elicited by transcranial magnetic stimulation over the primary motor cortex were measured before the intervention and every 5 min after the intervention for one hour. To investigate the interindividual variability, the responder/nonresponder/opposite-responder rates were also analyzed. RESULTS The facilitatory effects of QPS5 were greater than those of iTBS, and the inhibitory effects of QPS50 were much stronger than those of cTBS. The responder rate of QPS was significantly higher than that of TBS. QPS had a smaller number of opposite responders than TBS. CONCLUSION QPS is more effective and stable for synaptic plasticity induction than TBS.

中文翻译：

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直接比较 TBS 和 QPS 之间运动皮质可塑性诱导的功效和个体差异

背景已知Theta脉冲刺激(TBS)和四脉冲刺激(QPS)在人类中诱导突触可塑性。没有对 TBS 和 QPS 之间的疗效和变异性进行直接比较。目的 比较原始 TBS 和 QPS 方案之间的功效和个体间差异。我们假设 QPS 会比 TBS 更有效且可变性更小。方法 46 名健康受试者参加了这项研究。30 名受试者参加了主要的比较实验，另外 16 名受试者参加了获得运动诱发电位自然变异的实验。比较间歇TBS（iTBS）和QPS5的促进作用，比较连续TBS（cTBS）和QPS50的抑制作用。在干预前和干预后每 5 分钟测量一次由经颅磁刺激在初级运动皮层上引起的运动诱发电位幅度，持续一小时。为了研究个体间变异性，还分析了响应者/无响应者/相反响应者的比率。结果QPS5的促进作用大于iTBS，QPS50的抑制作用远强于cTBS。QPS的有效率明显高于TBS。QPS 的相反反应者数量少于 TBS。结论 QPS 对突触可塑性诱导比 TBS 更有效、更稳定。为了研究个体间变异性，还分析了响应者/无响应者/相反响应者的比率。结果QPS5的促进作用大于iTBS，QPS50的抑制作用远强于cTBS。QPS的有效率明显高于TBS。QPS 的相反反应者数量少于 TBS。结论 QPS 对突触可塑性诱导比 TBS 更有效、更稳定。为了研究个体间变异性，还分析了响应者/无响应者/相反响应者的比率。结果QPS5的促进作用大于iTBS，QPS50的抑制作用远强于cTBS。QPS的有效率明显高于TBS。QPS 的相反反应者数量少于 TBS。结论 QPS 对突触可塑性诱导比 TBS 更有效、更稳定。QPS 的相反反应者数量少于 TBS。结论 QPS 对突触可塑性诱导比 TBS 更有效、更稳定。QPS 的相反反应者数量少于 TBS。结论 QPS 对突触可塑性诱导比 TBS 更有效、更稳定。