Center for Neuroplasticity and Pain (CNAP), Department of Health Science and Technology, Faculty of Medicine, Aalborg University, Aalborg 9220, Denmark.
Institute of Science and Technology, Federal University of São Paulo, São Paulo 04021-001, Brazil.
Cereb Cortex. 2023 Sep 9;33(18):9986-9996. doi: 10.1093/cercor/bhad259.
Pain-related depression of corticomotor excitability has been explored using transcranial magnetic stimulation-elicited motor-evoked potentials. Transcranial magnetic stimulation-electroencephalography now enables non-motor area cortical excitability assessments, offering novel insights into cortical excitability changes during pain states. Here, pain-related cortical excitability changes were explored in the dorsolateral prefrontal cortex and primary motor cortex (M1). Cortical excitability was recorded in 24 healthy participants before (Baseline), during painful heat (Acute Pain), and non-noxious warm (Warm) stimulation at the right forearm in a randomized sequence, followed by a pain-free stimulation measurement. Local cortical excitability was assessed as the peak-to-peak amplitude of early transcranial magnetic stimulation evoked potential, whereas global-mean field power measured the global excitability. Relative to the Baseline, Acute Pain decreased the peak-to-peak amplitude in M1 and dorsolateral prefrontal cortex compared with Warm (both P < 0.05). A reduced global-mean field power was only found in M1 during Acute Pain compared with Warm (P = 0.003). Participants with the largest reduction in local cortical excitability under Acute Pain showed a negative correlation between dorsolateral prefrontal cortex and M1 local cortical excitability (P = 0.006). Acute experimental pain drove differential pain-related effects on local and global cortical excitability changes in motor and non-motor areas at a group level while also revealing different interindividual patterns of cortical excitability changes, which can be explored when designing personalized treatment plans.
使用经颅磁刺激诱发的运动诱发电位研究了与疼痛相关的皮质运动兴奋性的抑制。经颅磁刺激-脑电图现在能够评估非运动区皮质兴奋性，为疼痛状态下皮质兴奋性变化提供新的见解。在这里，研究了背外侧前额叶皮质和初级运动皮质（M1）中与疼痛相关的皮质兴奋性变化。在右前臂以随机顺序进行疼痛热（急性疼痛）和非伤害性温暖（温暖）刺激之前和之后，在 24 名健康参与者中记录皮质兴奋性，随后进行无疼痛刺激测量。局部皮质兴奋性评估为早期经颅磁刺激诱发的脑电活动的峰峰值幅度，而全局平均场功率则测量整体兴奋性。与基线相比，急性疼痛与温暖相比降低了 M1 和背外侧前额叶皮质的峰峰值幅度（均 P < 0.05）。仅在急性疼痛期间，与温暖相比，M1 中的全局平均场功率降低（P = 0.003）。在急性疼痛下局部皮质兴奋性降低最大的参与者，背外侧前额叶皮质和 M1 局部皮质兴奋性之间存在负相关（P = 0.006）。急性实验性疼痛导致在运动和非运动区域的局部和整体皮质兴奋性变化方面产生了不同的与疼痛相关的影响，在设计个性化治疗计划时可以探索这些不同的个体皮质兴奋性变化模式。
