Enhanced affect/cognition-related brain responses during visceral placebo analgesia in irritable bowel syndrome patients
Enhanced affect/cognition-related brain responses during visceral placebo analgesia in irritable bowel syndrome patients
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DOI：
10.1016/j.pain.2012.03.018
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发表时间：
2012-06-01
期刊：
影响因子：
7.4
通讯作者：
Chang, Full-Young
中科院分区：
文献类型：
--
作者：
Lee, Hsing-Feng;Hsieh, Jen-Chuen;Chang, Full-Young
安慰剂止痛是一种心理社会背景效应，很少在内脏疼痛中进行研究。肠易激综合征(IBS)患者在内脏刺激时表现出内脏痛觉过敏和情感/认知脑区域的高度激活。心理因素改变了疼痛和大脑激活模式，这些变化在IBS患者中更为明显。期望构成了安慰剂效应的主要神经心理学机制。这项研究证实，在内脏安慰剂镇痛期间，IBS患者的情感/认知脑反应增强，这一模型带有期望，并通过暗示和条件反射增强。17名IBS患者和17名年龄/性别匹配的对照组入选。完成心理物理问卷(医院焦虑和抑郁量表[HADS]、视觉模拟量表和简式麦吉尔问卷)。使用3T功能磁共振成像评估安慰剂干预和预期期间的大脑活动对直肠扩张的反应。建议/条件增强的安慰剂被用来说服对照组/患者相信一种新开发的静脉药物(实际上是生理盐水)缓解直肠扩张引起的内脏疼痛的效果。在IBS患者和对照组中观察到了类似的内脏安慰剂止痛。IBS患者表现出较高的HADS焦虑评分，这预示着较弱的安慰剂效应。提示/条件作用增强的安慰剂在IBS患者的情感/认知脑区域(脑岛、中扣带皮质和腹外侧额前皮质[VLPFC])比健康对照组诱发更多的活动。在IBS患者的预期期间，VLPFC也更加活跃。总而言之，IBS患者和对照组在实验诱导的直肠疼痛中获得了类似的安慰剂止痛效果。内脏安慰剂镇痛剂在IBS患者的情感/认知脑区产生更高的活动。(C)2012年国际疼痛研究协会。爱思唯尔出版，版权所有。
Placebo analgesia is a psychosocial context effect that is rarely studied in visceral pain. Patients with irritable bowel syndrome (IBS) exhibit visceral hyperalgesia and heightened affective/cognitive brain region activation during visceral stimuli. Psychological factors alter the pain and brain activation pattern, and these changes are more pronounced in IBS patients. Expectation constitutes the major neuropsychological mechanism in the placebo effect. This study confirmed the heightened affective/cognitive brain responses in IBS patients during visceral placebo analgesia using a placebo model with expectation, which was enhanced by suggestion and conditioning. Seventeen IBS patients and 17 age-/sex-matched controls were enrolled. Psychophysical inventories (Hospital Anxiety and Depression Scale [HADS], visual analogue scale, and short-form McGill questionnaire) were completed. Brain activity during placebo intervention and anticipation was assessed in response to rectal distension using 3T-functional magnetic resonance imaging. Suggestion-/conditioning-enhanced placebo was used to convince controls/patients of the efficacy of a newly developed intravenous drug (saline, in actuality) for the relief of rectal distension-induced visceral pain. A comparable visceral placebo analgesia was observed in IBS patients and control subjects. IBS patients demonstrated a higher HADS-anxiety score, which was predictive of a weak placebo effect. Suggestion-/conditioning-enhanced placebo evoked more activity in affective/cognitive brain regions (insula, midcingulate cortex, and ventrolateral prefrontal cortex [VLPFC]) in IBS patients than in healthy controls. VLPFC was also more active during anticipation in IBS patients. In conclusion, IBS patients and control subjects achieved comparable placebo analgesia during experimentally induced rectal pain. The visceral placebo analgesia produced heightened activity in affective/cognitive brain regions in IBS patients. (C) 2012 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.