An fMRI study of expectancy on acupuncture treatment outcomes in knee OA

许多随机临床试验(RCT)表明，针灸是治疗各种疼痛状况的有效方法。仔细观察这些文献就会发现不一致的发现：当RCT将针灸与未治疗或标准护理对照进行比较时，结果可能是确凿的；但当RCT将真正的(真皮)针灸与假针灸进行比较时，结果并不确定，这表明至少有一个愈合成分是由针刺针以外的东西介导的。 最近的一项荟萃分析发现，无论真性或假性分组，患者对疼痛缓解的期望是最有力的预测针灸治疗效果的指标。神经成像研究已经开始确定针灸和安慰剂止痛的可测试机制假说。我们最近对健康受试者的研究表明，在积极预期的背景下，真针和假针刺都能显著缓解疼痛，但每种作用都通过不同的大脑机制发挥作用。目前的建议将测试这些与真针和假针刺后疼痛缓解相关的不同大脑活动模式是否可以在因骨关节炎(OA)而患有慢性膝关节疼痛的患者中复制。 我们建议在膝骨性关节炎患者中进行两个实验，直接建立在我们实验室最近的研究基础上。在第一个实验中，我们将系统地提高患者对真针或假针刺后疼痛缓解的积极期望，然后量化期望、行为和治疗反应的脑成像(BOLD FMRI)措施之间的关系。在第二个实验中，在一项为期6周的纵向机械治疗研究中，对治疗的积极预期的类似提升将与标准治疗和等待名单对照进行比较。在第一次和第六次治疗之前和之后获得的fMRI BOLD数据将根据个人对治疗结果的预期进行检查，以确定潜在的治疗反应预测因素。 他的创新方法的意义在于，它可以为预期如何调节止痛治疗的影响提供明确的科学证据。这些实验的结果不仅将加深我们对针灸和安慰剂止痛机制的理解，还将有助于改进未来的研究方法，并为临床实践提供指导。

Many randomized clinical trials (RCTs) show acupuncture to be an effective treatment for diverse pain conditions. A closer look at this literature shows inconsistent findings: results lend to be confirmatory when RCTs compare acupuncture with ¿not treatment¿ or ¿standard care¿ controls; but inconclusive when RCTs compare genuine (verum) acupuncture with sham acupuncture suggesting that at least one healing component is mediated by something other than the acupuncture needles. A recent meta-analysis identified patient expectation of pain relief as the most robust predictor acupuncture treatment efficacy, regardless of verum or sham group assignment. Neuroimaging studies have begun identifying testable mechanistic hypotheses for both acupuncture and placebo analgesia. Our recent studies on healthy subjects demonstrate that in the context of positive expectation, both verum and sham acupuncture significantly relieve pain, however each functions via separable and distinct brain mechanisms. The current proposal will test whether these distinct brain activity patterns associated with pain relief following verum and sham acupuncture can be replicated in patients suffering from chronic knee pain due to osteoarthritis (OA). We propose two experiments in patients with knee OA that directly build upon recent research in our laboratory. In the first experiment we will systematically boost patients¿ positive expectation for pain relief following verum or sham acupuncture, then quantify the relation between expectation, behavioral , and brain imaging (BOLD fMRI) measures of treatment response. In the second experiment, a similar boost of positive expectation for treatment will be compared to standard treatment and to waitlist control in a 6-week longitudinal mechanistic treatment study of verum acupuncture. fMRI BOLD data obtained before the first and after the 6th treatment sessions will be examined with respect to individual expectation of treatment outcome to identify potential treatment responses predictors. The significance of his innovative approach is that it could provide clear scientific evidence for how expectation modulates the impact of an analgesic treatment. The results of these experiments will advance our understanding of not only acupuncture and placebo analgesia mechanisms, but also help refine future research methods, and inform clinical practice.