Psychiatric Neuroimaging, Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts.
Program in Placebo Studies and Therapeutic Encounter, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts.
J Pain. 2018 May;19(5):515-527. doi: 10.1016/j.jpain.2017.12.260. Epub 2018 Jan 8.
Placebo treatments and healing rituals share much in common, such as the effects of expectancy, and have been used since the beginning of human history to treat pain. Previous mechanistic neuroimaging studies investigating the effects of expectancy on placebo analgesia have used young, healthy volunteers. Using functional magnetic resonance imaging (fMRI), we aimed to investigate the neural mechanisms by which expectancy evokes analgesia in older adults living with a chronic pain disorder and determine whether there are interactions with active treatment. In this fMRI study, we investigated the brain networks underlying expectancy in participants with chronic pain due to knee osteoarthritis (OA) after verum (genuine) and sham electroacupuncture treatment before and after experiencing calibrated experimental heat pain using a well tested expectancy manipulation model. We found that expectancy significantly and similarly modulates the pain experience in knee OA patients in both verum (n = 21, 11 female; mean ± SD age 57 ± 7 years) and sham (n = 22, 15 female; mean ± SD age 59 ± 7 years) acupuncture treatment groups. However, there were different patterns of changes in fMRI indices of brain activity associated with verum and sham treatment modalities specifically in the lateral prefrontal cortex. We also found that continuous electroacupuncture in knee OA patients can evoke significant regional coherence decreases in pain associated brain regions. Our results suggest that expectancy modulates the experience of pain in knee OA patients but may work through different pathways depending on the treatment modality and, we speculate, on pathophysiological states of the participants.
To investigate the neural mechanisms underlying pain modulation, we used an expectancy manipulation model and fMRI to study response to heat pain stimuli before and after verum or sham acupuncture treatment in chronic pain patients. Both relieve pain and each is each associated with a distinct pattern of brain activation.
安慰剂治疗和愈合仪式有很多共同之处，例如期望的影响，并且自人类历史开始以来一直用于治疗疼痛。以前的机制神经影像学研究调查了期望对安慰剂镇痛的影响，使用了年轻，健康的志愿者。使用功能磁共振成像（fMRI），我们旨在研究期望在患有慢性疼痛障碍的老年人中引起镇痛的神经机制，并确定与主动治疗是否存在相互作用。在这项 fMRI 研究中，我们研究了膝骨关节炎（OA）慢性疼痛参与者在经历校准实验性热痛后，在接受真实和假性电针治疗前后，基于期望的大脑网络，使用经过充分测试的期望操纵模型。我们发现，在接受真实（n = 21，女性 11 人；平均年龄±标准差为 57±7 岁）和假性（n = 22，女性 15 人；平均年龄±标准差为 59±7 岁）电针治疗的膝 OA 患者中，期望都能显著且相似地调节疼痛体验。治疗组。但是，与真实和假性治疗方式相关的 fMRI 脑活动指数的变化模式不同，特别是在外侧前额叶皮层。我们还发现，在膝 OA 患者中持续电针可以引起与疼痛相关的大脑区域的显着区域相干性降低。我们的结果表明，期望可以调节膝骨关节炎患者的疼痛体验，但可能会根据治疗方式以及我们推测的参与者的病理生理状态而通过不同途径起作用。
为了研究疼痛调节的神经机制，我们使用了期望操纵模型和 fMRI，在接受真实或假性针刺治疗前后，研究慢性疼痛患者对热痛刺激的反应。两者都能缓解疼痛，并且每种治疗方法都与大脑激活的独特模式相关联。
