Supraspinal Modulation of Nociceptive Reactions in Fibromyalgia

描述(申请人提供)：纤维肌痛综合征(FMS)是一种潜伏性疾病，70%的患者会导致残疾，并极大地损失工作和生产力。据估计，美国有800万至1200万成年人受到FMS的影响，使其成为最常见的慢性广泛性疼痛综合征。导致纤维肌痛发生和维持的确切机制尚不清楚。但是，越来越多的证据表明，中枢神经系统(CNS)的伤害性处理异常可能是脊髓上调制异常所致。我们的实验室已经开发了一套程序来评估生理和主观伤害性反应(伤害性屈曲反射、皮肤电导、心率、疼痛报告)的脊髓上调制。标准化的图片观看范式被用来实验性地操纵情绪价态(不愉快、中性、愉快)，而生理-情绪操纵检查验证情绪反应。在观看图片的过程中，伤害性电刺激被传递(平衡图片价格)，伤害性反应被记录下来，并通过图片价格进行平均。在健康对照组中，我们已经证明，伤害性反应可以可靠地受到图片价格的平行调节。不愉快的图片会促进伤害性反应，而愉快的图片会抑制伤害性反应(这一效应可以解释47-52%的组合反应差异)。由于伤害性屈曲反射(一种脊椎反射)受到调制，这表明下行调制电路也参与其中。因此，这些程序为研究脊髓上调制提供了一种非侵入性的方法。本研究将使用图片观看范式来研究FMS患者、类风湿性关节炎(RA)患者和无疼痛对照组的脊髓上调节。RA患者对慢性疼痛病史和其他可能影响情绪-疼痛关系的共病变量(如心理困扰、健康/身体功能、适应不良应对)提供了重要的控制。此外，情绪因素在RA和FMS疼痛中也很重要，但目前尚不清楚情绪在这两种情况下是否起到同样重要的作用。此外，尽管类风湿性关节炎也与痛觉过敏有关，但有有限的人类证据表明类风湿性关节炎存在脊髓上调节功能障碍。本研究的具体目的是：(1)研究FMS患者伤害性反应的脊髓上调制；(2)评估FMS和RA患者的痛觉过敏。

DESCRIPTION (provided by applicant): Fibromyalgia syndrome (FMS) is an insidious disease that results in disability for 70% of those who suffer from it and tremendous loss of work and productivity. It is estimated that 8-12 million adults in the U.S. are affected by FMS, making it the most common chronic widespread pain syndrome. The exact mechanisms leading to the development and maintenance of fibromyalgia are unknown. But, accumulating evidence suggests abnormal nociceptive processing in the central nervous system (CNS) that could result from aberrations in supraspinal modulation. Our laboratory has developed procedures to assess supraspinal modulation of physiological and subjective nociceptive reactions (nociceptive flexion reflex, skin conductance, heart rate, pain report). A standardized picture-viewing paradigm is used to experimentally manipulate emotional valence (unpleasant, neutral, pleasant), and physiological-emotional manipulation checks verify emotional reactions. During picture-viewing, noxious electric stimuli are delivered (balanced across picture valence) and nociceptive reactions are recorded and averaged by picture valence. In healthy controls, we have shown that nociceptive reactions are reliably modulated in parallel by picture valence. Unpleasant pictures facilitate nociceptive reactions and pleasant pictures inhibit nociceptive reactions (an effect that explains 47-52% of the combined variance in the reactions). Because the nociceptive flexion reflex (a spinal reflex) is modulated, this suggests descending modulatory circuits are involved. Therefore, these procedures provide a non-invasive way to study supraspinal modulation. The present study will use the picture-viewing paradigm to study supraspinal modulation in FMS patients, rheumatoid arthritis (RA) patients, and no-pain controls. RA patients provide important controls for chronic pain history and other comorbid variables (eg, psychological distress, health/physical functioning, maladaptive coping) that could influence the emotion-pain relationship. Also, emotional factors are important in RA and FMS pain, but it is unclear whether emotion plays an equally potent role in both conditions. Further, there is limited human evidence for dysfunctional supraspinal modulation in RA, although RA is also associated with hyperalgesia. The specific aims of this study are: (1) To examine supraspinal modulation of nociceptive reactions in FMS patients and (2) To assess for hyperalgesia in FMS and RA patients.