Handedness is mainly associated with an asymmetry of corticospinal excitability and not of transcallosal inhibition
Handedness is mainly associated with an asymmetry of corticospinal excitability and not of transcallosal inhibition
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DOI：
10.1016/j.clinph.2004.01.014
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发表时间：
2004-06-01
影响因子：
4.7
通讯作者：
Rossini, PM
中科院分区：
文献类型：
--
作者：
De Gennaro, L;Cristiani, R;Rossini, PM
目的：本研究旨在通过配对脉冲经颅磁刺激 (TMS) 技术评估右手受试者 (RH) 和左手受试者 (LH) 样本中的经胼胝体抑制 (TI)。还测量了两组的运动阈值 (MT) 和运动诱发电位 (MEP) 幅度，作为皮质脊髓活动的指标。 方法：使用配对脉冲 TMS 范例（两个脉冲的强度 = MT 的 120%）记录 32 名正常受试者（16 名右侧和 16 名左侧）。两个运动皮层的刺激间间隔 (ISI) 分别为 2、4、6、8、10、12、14、16、18 和 20 毫秒，并从小趾展肌记录 MEP 反应。结果：两组均显示出以 12 毫秒 ISI 为中心的清晰 TI，但未发现惯用手或半球功能存在差异。另一方面，两组在皮质脊髓活动方面存在差异，因为左手运动优势半球的 MT 低于非优势半球，而右手的 MEP 振幅更大。 结论：结果表明，手部优势半球与非优势半球的运动皮层功能不对称，而用手习惯似乎与胼胝体抑制的功能差异无关。半球间配对脉冲 TMS 技术。 (C) 2004 年国际临床神经生理学联合会。由爱思唯尔爱尔兰有限公司出版。保留所有权利。
Objective: The study aims to compare transcallosal inhibition (TI), as assessed by the paired-pulse transcranial magnetic stimulation (TMS) technique, in a sample of right-handed subjects (RH) and left-handed subjects (LH). Motor thresholds (MTs) and motor evoked potential (MEP) amplitudes were also measured in the two groups, as an index of corticospinal activity.Methods: Thirty-two normal subjects (16 RH and 16 LH) were recorded with a paired-pulse TMS paradigm (intensity of both pulses = 120% of MT). The inter-stimulus intervals (ISIs) were 2, 4, 6, 8, 10, 12, 14, 16, 18, and 20 ms for both motor cortices, and MEP responses were recorded from the abductor digiti minimi muscles.Results: Both groups showed a clear TI centred around the 12 ms ISI, but no difference was found as a function of handedness or of hemisphere. On the other hand, the two groups differed in terms of corticospinal activity, since the hand motor dominant hemisphere had lower MTs than the non-dominant one in LH, and larger MEP amplitudes for the right hand were found in RH.Conclusions: Results point to a functional asymmetry of the motor cortex on the hand-dominant versus the non-dominant hemisphere, while handedness does not seem associated with functional differences in callosal inhibition, as measured by the inter-hemispheric paired-pulse TMS technique. (C) 2004 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.