Ribeiro Hugo, Sesterhenn Ricardo Bertol, Souza Andressa de, Souza Ana Claudia de, Alves Monique, Machado Jessica Catarina, Burger Nathalia Bofill, Torres Iraci Lucena da Silva, Stefani Luciana Cadore, Fregni Felipe, Caumo Wolnei
Department of Clinical Research Center, Laboratory of Pain & Neuromodulation, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
Surgery Department, Hospital Independência, Porto Alegre, Rio Grande do Sul, Brazil.
PLoS One. 2017 Nov 30;12(11):e0187013. doi: 10.1371/journal.pone.0187013. eCollection 2017.
An imbalance in the excitatory/inhibitory systems in the pain networks may explain the persistent chronic pain after hallux valgus surgery. Thus, to contra-regulate this dysfunction, the use of transcranial direct current stimulation (tDCS) becomes attractive.
We tested the hypothesis that two preoperative active(a)-tDCS sessions compared with sham(s)-tDCS could improve the postoperative pain [as indexed by Visual Analogue Scale (VAS) at rest and during walking (primary outcomes)]. To assess their effect on the change in the Numerical Pain Scale (NPS0-10) during Conditioned Pain Modulation (CPM-task), disability related to pain (DRP) and analgesic consumption (secondary outcomes). Also, we assessed if the brain derived neurotrophic factor (BDNF) in the cerebral spinal fluid (CSF) after tDCS could predict the intervention's effect on the DRP.
It is a prospective, double blind, sham-controlled, randomized single center, 40 women (18-70 years-old) who had undergone hallux valgus surgery were randomized to receive two sessions (20 minutes each) of anodal a-tDCS or s-tDCS on the primary motor cortex at night and in the morning before the surgery. To assess the DRP was used the Brazilian Profile of Chronic Pain: Screen (B-PCP:S).
A-tDCS group showed lower scores on VAS at rest and during walking (P<0.001). At rest, the difference between groups was 2.13cm (95%CI = 1.59 to 2.68) while during walking was 1.67cm (95%CI = 1.05 to 2.28). A-tDCS, when compared to s-tDCS reduced analgesic doses in 73.25% (P<0.001), produced a greater reduction in B-PCP:S (mean difference of 9.41 points, 95%CI = 0.63 to 18.21) and higher function of descending pain modulatory system (DPMS) during CPM-task.
A-tDCS improves postoperative pain, the DRP and the function of DPMS. Also, the CSF BDNF after a-tDCS predicted the improvement in the DRP. In overall, these findings suggest that a-tDCS effects may be mediated by top-down regulatory mechanisms associated with the inhibitory cortical control.
ClinicalTrials.gov NCT02360462.
疼痛网络中兴奋性/抑制性系统的失衡可能解释拇外翻手术后持续的慢性疼痛。因此，为了对抗这种功能障碍，经颅直流电刺激（tDCS）的应用变得具有吸引力。
我们检验了这样一个假设，即与假刺激（s）-tDCS相比，术前进行两次主动（a）-tDCS治疗可改善术后疼痛[以静息和行走时的视觉模拟评分（VAS）为指标（主要结局）]。评估其对条件性疼痛调制（CPM任务）期间数字疼痛量表（NPS0 - 10）变化、疼痛相关残疾（DRP）和镇痛药物消耗（次要结局）的影响。此外，我们评估了tDCS后脑脊液（CSF）中的脑源性神经营养因子（BDNF）是否可以预测干预对DRP的效果。
这是一项前瞻性、双盲、假刺激对照、随机单中心研究，40名接受拇外翻手术的女性（18 - 70岁）被随机分为两组，在手术前一晚和早晨接受两次（每次20分钟）阳极a - tDCS或s - tDCS，刺激部位为初级运动皮层。使用巴西慢性疼痛概况筛查量表（B - PCP:S）评估DRP。
a - tDCS组在静息和行走时的VAS评分较低（P<0.001）。静息时，两组之间的差异为2.13cm（95%CI = 1.59至2.68），行走时为1.67cm（95%CI = 1.05至2.28）。与s - tDCS相比，a - tDCS使镇痛药物剂量减少了73.25%（P<0.001），B - PCP:S的降低幅度更大（平均差异为9.41分，95%CI = 0.63至18.21），并且在CPM任务期间下行疼痛调制系统（DPMS）的功能更高。
a - tDCS可改善术后疼痛、DRP和DPMS的功能。此外，a - tDCS后的脑脊液BDNF可预测DRP的改善情况。总体而言，这些发现表明a - tDCS的作用可能由与皮质抑制性控制相关的自上而下调节机制介导。
ClinicalTrials.gov NCT02360462。
