Cortical and Subcortical Effects of Transcutaneous Spinal Cord Stimulation in Humans with Tetraplegia
Cortical and Subcortical Effects of Transcutaneous Spinal Cord Stimulation in Humans with Tetraplegia
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DOI：
10.1523/jneurosci.2374-19.2020
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发表时间：
2020-03-25
影响因子：
5.3
通讯作者：
Perez, Monica A.
中科院分区：
文献类型：
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作者：
Benavides, Francisco D.;Jo, Hang Jin;Perez, Monica A.
越来越多的研究支持经皮电刺激脊髓(TESS)促进脊髓损伤(SCI)患者功能恢复的观点。然而，对这些影响的神经机制仍然知之甚少。在这里，我们检测了男性和女性慢性不完全性颈椎损伤患者在TESS(30赫兹脉冲，载波频率为5 kHz)和假TESS作用于C5和C6棘突之间20min前后，刺激皮质和皮质下皮质脊髓轴突诱发的臂肌运动诱发电位。在TESS后75min，对照组和SCI受试者的上臂近端和远端肌肉的皮层下运动诱发电位的波幅增加，但皮质下的运动诱发电位的波幅没有增加，这表明这些效应来自皮质下。TESS后，两组患者皮层内由双刺激引起的抑制均增加。当TESS不使用5 kHz载频时，皮层下和皮层运动诱发电位均被促进，但不改变皮层内抑制，提示5 kHz载频参与了皮层抑制效应。当使用TESS时，与不使用5 kHz载波相比，手和手臂功能有很大改善。这些新颖的观察表明，TESS影响皮质和脊髓网络，在脊髓水平具有兴奋效应，在皮质水平具有抑制效应。我们假设这些平行效应有助于脊髓损伤后肢体功能的进一步恢复。
An increasing number of studies supports the view that transcutaneous electrical stimulation of the spinal cord (TESS) promotes functional recovery in humans with spinal cord injury (SCI). However, the neural mechanisms contributing to these effects remain poorly understood. Here we examined motor-evoked potentials in arm muscles elicited by cortical and subcortical stimulation of corticospinal axons before and after 20 min of TESS (30 Hz pulses with a 5 kHz carrier frequency) and sham-TESS applied between C5 and C6 spinous processes in males and females with and without chronic incomplete cervical SCI. The amplitude of subcortical, but not cortical, motor-evoked potentials increased in proximal and distal arm muscles for 75 min after TESS, but not sham-TESS, in control subjects and SCI participants, suggesting a subcortical origin for these effects. Intracortical inhibition, elicited by paired stimuli, increased after TESS in both groups. When TESS was applied without the 5 kHz carrier frequency both subcortical and cortical motor-evoked potentials were facilitated without changing intracortical inhibition, suggesting that the 5 kHz carrier frequency contributed to the cortical inhibitory effects. Hand and arm function improved largely when TESS was used with, compared with without, the 5 kHz carrier frequency. These novel observations demonstrate that TESS influences cortical and spinal networks, having an excitatory effect at the spinal level and an inhibitory effect at the cortical level. We hypothesized that these parallel effects contribute to further the recovery of limb function following SCI.