Département de Neuroscience, Université de Montréal, H3T 1J4, Canada; Centre d'étude du Sommeil et des Rythmes Biologiques, Hôpital du Sacré-Cœur, Montréal H4J 1C5, Canada.
Département de Stomatologie, Faculté de Médecine Dentaire, Groupe de Recherche sur le Système Nerveux Central (GRSNC), Université de Montréal, H3T 1J4, Canada; Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal (CRIUGM), H3W 1W4, Canada.
Prog Neuropsychopharmacol Biol Psychiatry. 2018 Jul 13;85:33-38. doi: 10.1016/j.pnpbp.2018.03.027. Epub 2018 Apr 6.
Although placebo analgesia is a well-recognized phenomenon with important clinical implications, the possibility that placebo effects occur during sleep has received little attention. This experimental study examined whether responsiveness to acute heat pain stimuli applied during sleep could be reduced following a placebo conditioning procedure administered before sleep. Healthy individuals (n = 9) underwent polysomnographic recordings for one habituation night followed by one placebo analgesia night and one control night in counterbalanced order. Conditioning induced robust analgesia expectations before the placebo night. In the morning after the placebo night, participants reported less nocturnal pain, anxiety, and associated sleep disturbance (all p's < 0.05) compared to the control night. Furthermore, placebo induction produced a 10% reduction in brain arousals evoked by noxious stimuli during rapid-eye-movement (REM) sleep (p = 0.03), consistent with our previous findings suggesting that analgesia expectations are reprocessed during REM sleep. In contrast, arousals increased by 14% during slow wave sleep (SWS) (p = 0.02). In the morning after the last recording night, placebo testing administered as a manipulation check confirmed that typical placebo analgesic responses were produced during waking (p's < 0.05). These results suggest that analgesia expectations developed before sleep reduced nocturnal pain perception and subjective sleep disturbances and activated brain processes that modulate incoming nociceptive signals differentially according to sleep stage. These results need to be replicated in future studies exploring how analgesia expectations may be reactivated during different sleep stages to modulate nociceptive responses.
虽然安慰剂镇痛是一种公认的具有重要临床意义的现象，但安慰剂效应在睡眠期间发生的可能性却很少受到关注。本实验研究考察了在睡眠期间施加急性热痛刺激时，是否可以在睡眠前进行安慰剂条件作用程序来降低对刺激的反应性。健康个体（n=9）进行了多导睡眠图记录，一个适应夜间，然后是一个安慰剂镇痛夜间和一个对照夜间，以平衡顺序进行。在安慰剂夜间之前，条件作用诱导了强烈的镇痛期望。在安慰剂夜间之后的早晨，与对照夜间相比，参与者报告夜间疼痛、焦虑和相关睡眠障碍减少（均 p<0.05）。此外，安慰剂诱导在快速眼动（REM）睡眠期间引起的疼痛刺激引起的脑唤醒减少了 10%（p=0.03），这与我们之前的研究结果一致，表明镇痛期望在 REM 睡眠期间被重新处理。相比之下，在慢波睡眠（SWS）期间唤醒增加了 14%（p=0.02）。在最后一次记录夜间之后的早晨，作为操纵检查进行的安慰剂测试证实，在清醒状态下产生了典型的安慰剂镇痛反应（p<0.05）。这些结果表明，在睡眠前产生的镇痛期望降低了夜间疼痛感知和主观睡眠障碍，并激活了大脑过程，根据睡眠阶段对传入的伤害性信号进行了不同的调节。需要在未来的研究中复制这些结果，以探讨在不同的睡眠阶段如何重新激活镇痛期望以调节伤害性反应。
