Transcranial Direct Current Stimulation (tDCS) over the primary motor cortex (M1) and the Dorsolateral Prefrontal Cortex (DLPFC) seem to improve pain and other symptoms of fibromyalgia (FM), although the evidence on the effectiveness of tDCS and the optimal stimulation target is not robust enough. Our main objective was to establish the optimal area of stimulation, comparing the two classical targets and a novel pain-related area, the Operculo Insular Cortex (OIC), in a sham-controlled trial. Using a double-blind design, we randomly assigned 130 women with FM to four treatment groups (M1, DLPFC, OIC, Sham), each receiving fifteen 20-minute sessions of 2mA anodal tDCS over the left hemisphere. Our primary outcome was pain intensity. The secondary outcomes were the other core symptoms of FM (fatigue, mood, cognitive and sleep disorders, hyperalgesia measured by pressure pain threshold). We performed the assessment at 3 time points (before, immediately after treatment, and at 6 months follow-up). The linear mixed-model ANOVAs showed significant treatment effects across time for clinical pain and for fatigue, cognitive and sleep disturbances, and experimental pain, irrespective of the group. In mood, the three active tDCS groups showed a significantly larger improvement in anxiety and depression than sham. Our findings provide evidence of a placebo effect, support the use of tDCS for the treatment of affective symptoms, and challenge the effectiveness of tDCS as treatment of FM.

中文翻译：

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经颅直流电刺激三个皮质靶点治疗纤维肌痛并不比安慰剂更有效：一项双盲假对照临床试验。

对初级运动皮层 (M1) 和背外侧前额叶皮层 (DLPFC) 进行经颅直流电刺激 (tDCS) 似乎可以改善纤维肌痛 (FM) 的疼痛和其他症状，尽管有关 tDCS 有效性和最佳刺激目标的证据还不清楚。不够稳健。我们的主要目标是建立最佳刺激区域，在假对照试验中比较两个经典目标和一个新的疼痛相关区域，即岛叶皮质 (OIC)。采用双盲设计，我们将 130 名 FM 女性随机分配到四个治疗组（M1、DLPFC、OIC、Sham），每个治疗组在左半球接受 15 次 2mA 阳极 tDCS，每次 20 分钟。我们的主要结果是疼痛强度。次要结果是 FM 的其他核心症状（疲劳、情绪、认知和睡眠障碍、通过压痛阈值测量的痛觉过敏）。我们在 3 个时间点（治疗前、治疗后立即和 6 个月随访时）进行了评估。线性混合模型方差分析显示，无论哪一组，随着时间的推移，对临床疼痛、疲劳、认知和睡眠障碍以及实验疼痛都有显着的治疗效果。在情绪方面，三个活跃的 tDCS 组在焦虑和抑郁方面表现出比假手术组显着更大的改善。我们的研究结果提供了安慰剂效应的证据，支持使用 tDCS 治疗情感症状，并对 tDCS 治疗 FM 的有效性提出了质疑。