Department of Clinical Neurophysiology, Georg-August University, Göttingen, Germany.
Restor Neurol Neurosci. 2012;30(3):191-8. doi: 10.3233/RNN-2012-110175.
Transcranial direct current stimulation (tDCS) has proven to be a useful tool for fundamental brain research as well as for attempts in therapy of neurological and psychiatric diseases by modulating neuronal plasticity. Little is understood about the effects of tDCS are influenced by hemispheric dominance, even less in terms of handedness. The aim of our pilot study was to investigate whether tDCS induced neuroplastic changes may be different in right- and left-handed individuals due to existing differences in hemispheric lateralisation.
We measured changes in motor evoked potentials (MEPs) after application of tDCS in 8 right-handers, 8 left-handers and 8 mixed-handers according to the Edinburgh Handedness Inventory (EHI). In double-blind sessions, we applied either anodal or cathodal tDCS for 5 minutes for each hemisphere.
While motor thresholds (MT) seem to be not influenced by handedness significantly, in right-handed subjects we reproduced the well-known effects of tDCS: anodal stimulation increased while cathodal stimulation decreased MEP amplitudes. However, left-and mixed-handed subjects differed from right-handed subjects. After anodal stimulation of the left hemisphere the increase of the MEP amplitudes was stronger in right handed subjects than in left and mixed handed subjects. Interestingly, after cathodal stimulation of the left hemisphere this difference was less marked. The stimulation of the right hemisphere showed the same tendency, but results were not significant.
For the first time, we are able to demonstrate that the modulating effects of tDCS on corticospinal excitability differ moderately in the left-and mixed-handed population compared to right-handed subjects. The shown differences according to handedness should be taken into account in further studies.
经颅直流电刺激（tDCS）已被证明是一种有用的工具，可用于基础脑研究以及通过调节神经元可塑性尝试治疗神经和精神疾病。尽管 tDCS 的影响受优势半球影响，但人们对此知之甚少，更不用说与利手有关的影响了。我们的初步研究旨在调查由于半球侧化存在差异，tDCS 诱导的神经可塑性变化是否会因右利手和左利手个体的不同而有所不同。
我们根据爱丁堡手性量表（EHI），对 8 名右利手、8 名左利手和 8 名混合利手者在应用 tDCS 后测量运动诱发电位（MEPs）的变化。在双盲治疗中，我们分别对每个半球进行 5 分钟的阳极或阴极 tDCS。
虽然运动阈值（MT）似乎不受利手的显著影响，但在右利手受试者中，我们重现了 tDCS 的已知效果：阳极刺激增加，而阴极刺激减少 MEP 幅度。然而，左利手和混合利手受试者与右利手受试者不同。在对左半球进行阳极刺激后，右利手受试者的 MEP 幅度增加幅度大于左利手和混合利手受试者。有趣的是，在对左半球进行阴极刺激后，这种差异不那么明显。对右半球的刺激也表现出相同的趋势，但结果并不显著。
我们首次能够证明，与右利手受试者相比，tDCS 对皮质脊髓兴奋性的调节作用在左利手和混合利手人群中存在适度差异。应在手性差异方面考虑到所显示的差异。
