Université de Montréal, Montréal, Québec, Canada.
Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montréal, Québec, Canada.
Am J Clin Hypn. 2021 Apr;63(4):329-354. doi: 10.1080/00029157.2020.1863184.
The mechanisms underlying pain modulation by hypnosis and the contribution of hypnotic induction to the efficacy of suggestions being still under debate, our study aimed, (1) to assess the effects of identical hypoalgesia suggestions given with and without hypnotic induction, (2) to compare hypnotic hypoalgesia to distraction hypoalgesia and (3) to evaluate whether hypnotic suggestions of increased and decreased pain share common psychophysiological mechanisms. To this end, pain ratings, nociceptive flexion reflex amplitude, autonomic responses and electroencephalographic activity were measured in response to noxious electrical stimulation of the sural nerve in 20 healthy participants, who were subjected to four conditions: suggestions of hypoalgesia delivered with and without hypnosis induction (i.e. hypnotic-hypoalgesia and suggested-hypoalgesia), distraction by a mental calculation task and hypnotic suggestions of hyperalgesia. As a result, pain ratings decreased in distraction, suggested-hypoalgesia and hypnotic-hypoalgesia, while it increased in hypnotic-hyperalgesia. Nociceptive flexion reflex amplitude and autonomic activity decreased during suggested-hypoalgesia and hypnotic-hypoalgesia but increased during distraction and hypnotic-hyperalgesia. Hypnosis did not enhance the effects of suggestions significantly in any measurement. No somatosensory-evoked potential was modulated by the four conditions according to strict statistical criteria. The absence of a significant difference between the hypnotic hypoalgesia and hyperalgesia conditions suggests that brain processes as evidenced by evoked potentials are not invariably related to pain modulation. Time-frequency analysis of electroencephalographic activity showed a significant differentiation between distraction and hypnotic hypoalgesia in the theta domain. These results highlight the diversity of neurophysiological processes underlying pain modulation through different psychological interventions.
催眠对疼痛的调节机制以及催眠诱导对暗示疗效的贡献仍存在争议，本研究旨在：(1)评估在催眠诱导和不使用催眠诱导的情况下给予相同的镇痛暗示的效果；(2)比较催眠镇痛和分心镇痛；(3)评估增加和减少疼痛的催眠暗示是否共享共同的心理生理机制。为此，我们在 20 名健康参与者中测量了对腓肠神经的有害电刺激的疼痛评分、伤害性屈反射幅度、自主反应和脑电图活动，他们接受了四种条件的处理：在催眠诱导和不使用催眠诱导的情况下给予镇痛暗示（即催眠镇痛和暗示镇痛）、进行心算任务的分心和催眠镇痛暗示的痛觉过敏。结果表明，在分心、暗示镇痛和催眠镇痛的情况下，疼痛评分降低，而在催眠痛觉过敏的情况下则增加。伤害性屈反射幅度和自主活动在暗示镇痛和催眠镇痛时降低，但在分心和催眠痛觉过敏时增加。催眠并没有显著增强任何测量条件下暗示的效果。根据严格的统计标准，四种条件均未调制体感诱发电位。催眠镇痛和痛觉过敏条件之间没有显著差异表明，如诱发电位所示的大脑过程不一定与疼痛调节有关。脑电图活动的时频分析显示，在 theta 域中，分心和催眠镇痛之间存在显著差异。这些结果强调了通过不同心理干预对疼痛调节的神经生理过程的多样性。
