van den Broeke Emanuel N, Koeslag Lonneke, Arendsen Laura J, Nienhuijs Simon W, Rosman Camiel, van Rijn Clementina M, Wilder-Smith Oliver H G, van Goor Harry
Department of Anesthesiology, Pain & Palliative Medicine, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
Department of Surgery, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
PLoS One. 2013 Dec 23;8(12):e82701. doi: 10.1371/journal.pone.0082701. eCollection 2013.
High Frequency electrical Stimulation (HFS) of the skin induces enhanced brain responsiveness expressed as enhanced Event-Related Potential (ERP) N1 amplitude to stimuli applied to the surrounding unconditioned skin in healthy volunteers. The aim of the present study was to investigate whether this enhanced ERP N1 amplitude could be a potential marker for altered cortical sensory processing in patients with persistent pain after surgery.
Nineteen male patients; 9 with and 10 without persistent pain after inguinal hernia repair received HFS. Before, directly after and thirty minutes after HFS evoked potentials and the subjective pain intensity were measured in response to electric pain stimuli applied to the surrounding unconditioned skin.
The results show that, thirty minutes after HFS, the ERP N1 amplitude observed at the conditioned arm was statistically significantly larger than the amplitude at the control arm across all patients. No statistically significant differences were observed regarding ERP N1 amplitude between patients with and without persistent pain. However, thirty minutes after HFS we did observe statistically significant differences of P2 amplitude at the conditioned arm between the two groups. The P2 amplitude decreased in comparison to baseline in the group of patients with pain.
The ERP N1 effect, induced after HFS, was not different between patients with vs. without persistent pain. The decreasing P2 amplitude was not observed in the patients without pain and also not in the previous healthy volunteer study and thus might be a marker for altered cortical sensory processing in patients with persistent pain after surgery.
对皮肤进行高频电刺激（HFS）可增强大脑反应性，在健康志愿者中表现为对施加于周围未受刺激皮肤的刺激，其事件相关电位（ERP）N1波幅增强。本研究的目的是调查这种增强的ERP N1波幅是否可能是手术后持续性疼痛患者皮质感觉处理改变的潜在标志物。
19名男性患者，9名腹股沟疝修补术后有持续性疼痛，10名无持续性疼痛，接受了HFS。在HFS之前、之后立即以及之后30分钟，测量对施加于周围未受刺激皮肤的电痛刺激的诱发电位和主观疼痛强度。
结果显示，HFS后30分钟，所有患者中，在受刺激手臂观察到的ERP N1波幅在统计学上显著大于对照手臂的波幅。有和无持续性疼痛的患者之间，在ERP N1波幅方面未观察到统计学上的显著差异。然而，HFS后30分钟，我们确实观察到两组之间受刺激手臂的P2波幅存在统计学上的显著差异。与基线相比，疼痛患者组的P2波幅降低。
HFS后诱发的ERP N1效应在有和无持续性疼痛的患者之间没有差异。在无疼痛的患者中未观察到P2波幅降低，在之前的健康志愿者研究中也未观察到，因此这可能是手术后持续性疼痛患者皮质感觉处理改变的一个标志物。
