Neuromodulation by paired-pulse TMS at an I-wave interval facilitates multiple I-waves
Neuromodulation by paired-pulse TMS at an I-wave interval facilitates multiple I-waves
复制标题
DOI：
10.1007/s00221-008-1590-7
复制
发表时间：
2009-02-01
影响因子：
2
通讯作者：
Thickbroom, G. W.
中科院分区：
文献类型：
--
作者：
Cash, R. F. H.;Benwell, N. M.;Thickbroom, G. W.
经颅磁刺激（TMS）干预可以增加皮质脊髓的兴奋性，该干预以1.5 ms的I（间接）波间隔提供重复的配对TMS脉冲。这被认为是通过加强促进性i波相互作用来靶向兴奋性突触事件，然而，这种干预对各种i波成分的影响仍有待确定。在本研究中，我们比较了在IPI为1.5 ms的配对脉冲TMS干预15分钟之前和之后，包括前三个i波的脉冲间隔（IPI）范围内的i波促进曲线。i波促进曲线的三个峰值出现在干预前和干预后相同的ipi（1.3、2.5和4.3 ms）。干预后，所有三个i波峰的促进曲线幅度均增加（平均增加33%），所有ipi的平均增加与干预后单脉冲MEP幅度的增加相关（r = 0.77）。建模结果表明，干预后曲线的变化与个体i波峰振幅的增加和变宽一致。我们得出结论，IPI为1.5 ms的iTMS干预能够靶向多个i波。这些发现与现有的i波产生模型一致，并表明干预增加了与下行i波齐射产生相关的突触事件的功效。
Corticospinal excitability can be increased by a transcranial magnetic stimulation (TMS) intervention that delivers repeated paired TMS pulses at an I (indirect)-wave interval of 1.5 ms. This is thought to target excitatory synaptic events by reinforcing facilitatory I-wave interaction, however, it remains to be determined what effect this intervention has on the various I-wave components. In the present study we compared I-wave facilitation curves over a range of inter-pulse intervals (IPIs) encompassing the first three I-waves, before and after 15 min of a paired-pulse TMS intervention with an IPI of 1.5 ms. The three peaks in the I-wave facilitation curves occurred at the same IPIs pre- and post-intervention (1.3, 2.5 and 4.3 ms). The facilitation curves were increased in amplitude for all three I-wave peaks post-intervention (mean increase 33%), and the mean increase across all IPIs correlated with the post-intervention increase in single-pulse MEP amplitude (r = 0.77). Modelling showed that the changes in the post-intervention curves were consistent with an increase in amplitude and broadening of the individual I-wave peaks. We conclude that an iTMS intervention with an IPI of 1.5 ms is able to target multiple I-waves. The findings are consistent with existing models of I-wave generation and suggest that the intervention increases the efficacy of synaptic events associated with the generation of descending I-wave volleys.