Pierantoni Luca, Vecchio Fabrizio, Miraglia Francesca, Pecchioli Cristiano, Iodice Francesco, Carrarini Claudia, Pinardi Mattia, Pino Giovanni Di, Micera Silvestro, Rossini Paolo Maria
Brain Connectivity Laboratory, Dept. Neuroscience & Neurorehabilitation, IRCCS San Raffaele, Rome, Italy; The Biorobotics Institute and Department of Excellence in Robotics and AI, Scuola Superiore Sant'Anna, Pontedera, Italy.
Brain Connectivity Laboratory, Dept. Neuroscience & Neurorehabilitation, IRCCS San Raffaele, Rome, Italy; Department of Theoretical and Applied Sciences, eCampus University, Novedrate, Italy.
Clin Neurophysiol. 2024 Dec;168:95-103. doi: 10.1016/j.clinph.2024.10.011. Epub 2024 Oct 25.
To investigate the effects of transcutaneous spinal direct current stimulation (tsDCS) on spinal cord excitability using neurophysiological methods.
Spinal cord motoneuron excitability was assessed using various neurophysiological techniques in a sham-controlled randomized experiment, which involved delivering 2 mA tsDCS and testing four different montages. Transcranial magnetic stimulation (TMS), F-waves to supramaximal ulnar nerve stimulation and somatosensory evoked potentials to upper limb nerves stimulation were measured in the participants with the electrode configuration that yielded the greatest effect, for a total of about 18 min. 18 young volunteers were recruited.
Among the tested ones, the most promising tsDCS montage was the one with the anode placed on the 7th cervical spinous process and the cathode on the glottis. With this configuration, a significant enhancement of motor responses in the hand muscles to TMS of the contralateral hand motor area was observed during tsDCS (p<0.00001), reaching a plateau after 6 min. This facilitation rapidly declined within a few minutes after the tsDCS was stopped.
Results of the different techniques suggest a possible contribution to facilitatory neuromodulation of the motoneurons at the cervical spine level.
The occurrence of enhanced excitability after tsDCS suggests potential application in individuals with partial corticospinal fiber impairment affecting hand motor function.
采用神经生理学方法研究经皮脊髓直流电刺激（tsDCS）对脊髓兴奋性的影响。
在一项假手术对照的随机实验中，使用多种神经生理学技术评估脊髓运动神经元兴奋性，该实验包括施加2毫安的tsDCS并测试四种不同的电极组合。在产生最大效果的电极配置下，对参与者测量经颅磁刺激（TMS）、对尺神经最大刺激的F波以及对上肢神经刺激的体感诱发电位，总共约18分钟。招募了18名年轻志愿者。
在测试的电极组合中，最有前景的tsDCS电极组合是阳极置于第7颈椎棘突、阴极置于声门的那种。采用这种配置时，在tsDCS期间观察到对侧手部运动区TMS诱发的手部肌肉运动反应显著增强（p<0.00001），6分钟后达到平稳状态。tsDCS停止后几分钟内，这种促进作用迅速下降。
不同技术的结果表明，tsDCS可能对颈椎水平的运动神经元起到促进性神经调节作用。
tsDCS后兴奋性增强的现象表明，其在影响手部运动功能的部分皮质脊髓纤维受损个体中具有潜在应用价值。
