Callosal effects of transcranial magnetic stimulation (TMS): the influence of gender and stimulus parameters
Callosal effects of transcranial magnetic stimulation (TMS): the influence of gender and stimulus parameters
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DOI：
10.1016/j.neures.2003.10.004
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发表时间：
2004-02-01
影响因子：
2.9
通讯作者：
Rossini, PM
中科院分区：
文献类型：
--
作者：
De Gennaro, L;Bertini, M;Rossini, PM
经颅磁刺激(TMS)一侧大脑半球的运动皮质(条件性刺激，CS)抑制手部远端肌肉的肌电反应，该反应是通过在对侧大脑半球给予适当间隔的磁刺激(测试刺激，TS)引起的。通常的解释将这种效应归因于皮质水平上通过经颧骨通路产生的抑制作用。为了比较CS阈值下和阈值上的强度(分别为个体运动阈值的80%和120%)，对健康受试者用大脑半球间双脉冲(PP)技术测量的皮质兴奋性的变异性进行了评估。结果表明，在以12ms为中心的间隔范围内，一侧大脑半球的磁性CS可以有效地抑制TS对对侧大脑半球传递的TS刺激的小指展肌(ADM)的肌电反应。这些减少是由120%的阈值上的CS引起的，而80%的阈值下的CS并不影响EMG的反应。女性表现出比男性更高的跨颧骨抑制，这表明在大脑半球之间的连接方面存在性别差异，这涉及到穹隆体干的前半部分。(C)2003年爱思唯尔爱尔兰有限公司和日本神经科学学会。版权所有。
Transcranial magnetic stimulation (TMS) of the motor cortex of one hemisphere (conditioning stimulus, CS) inhibits EMG responses evoked in distal hand muscles by a magnetic stimulus given at appropriate interval later over the opposite hemisphere (test stimulus, TS). The common interpretation attributes this effect to an inhibition produced at cortical level via a transcallosal route. The variability of cortical excitability as measured by the interhemispheric paired-pulse (PP) technique has been assessed in healthy subjects in order to compare sub- and supra-threshold intensity of CS (80% versus 120% of individual motor threshold, MT). Within- and between-subject variability relating, respectively, to interhemispheric and gender differences were also assessed.Results point to an efficacy of a magnetic CS on one hemisphere in inhibiting EMG responses of the abductor digiti minimi (ADM) stimulated by a TS delivered over the opposite hemisphere in a range of intervals centered at 12 ms. These reductions were produced by the 120% suprathreshold CS, while the 80% subthreshold CS did not affect EMG responses.Females showed a higher transcallosal inhibition than males, suggesting gender differences in interhemispheric connectivity that concern the anterior half of the trunk of the corpus callosum. (C) 2003 Elsevier Ireland Ltd and The Japan Neuroscience Society. All rights reserved.