Jensen Karin B, Kosek Eva, Petzke Frank, Carville Serena, Fransson Peter, Marcus Hanke, Williams Steven C R, Choy Ernest, Giesecke Thorsten, Mainguy Yves, Gracely Richard, Ingvar Martin
Stockholm Brain Institute, Osher Center for Integrative Medicine, Karolinska Institutet, Stockholm, Sweden.
Pain. 2009 Jul;144(1-2):95-100. doi: 10.1016/j.pain.2009.03.018. Epub 2009 May 1.
Over the years, many have viewed Fibromyalgia syndrome (FMS) as a so-called "functional disorder" and patients have experienced a concomitant lack of interest and legitimacy from the medical profession. The symptoms have not been explained by peripheral mechanisms alone nor by specific central nervous system mechanisms. In this study, we objectively evaluated the cerebral response to individually calibrated pain provocations of a pain-free body region (thumbnail). The study comprised 16 female FMS patients and 16 individually age-matched controls. Brain activity was measured using functional magnetic resonance imaging (fMRI) during individually calibrated painful pressures representing 50 mm on a visual analogue scale (VAS) ranging from 0 to 100 mm. Patients exhibited higher sensitivity to pain provocation than controls as they required less pressure to evoke equal pain magnitudes (U(A)=48, p<.002). Despite lower pressures applied in patients at VAS 50 mm, the fMRI-analysis revealed no difference in activity in brain regions relating to attention and affect or regions with sensory projections from the stimulated body area. However, in the primary link in the descending pain regulating system (the rostral anterior cingulate cortex) the patients failed to respond to pain provocation. The attenuated response to pain in this brain region is the first demonstration of a specific brain region where the impairment of pain inhibition in FMS patients is expressed. These results validate previous reports of dysfunctional endogenous pain inhibition in FMS and advance the understanding of the central pathophysiologic mechanisms, providing a new direction for the development of successful treatments in FMS.
多年来，许多人将纤维肌痛综合征（FMS）视为一种所谓的“功能性障碍”，患者也因此感受到医学界对此缺乏兴趣且未给予应有的重视。其症状既不能仅用外周机制来解释，也不能通过特定的中枢神经系统机制来解释。在本研究中，我们客观评估了大脑对无痛身体部位（拇指指甲）进行个体校准疼痛刺激的反应。该研究包括16名女性纤维肌痛综合征患者和16名年龄匹配的个体对照。在视觉模拟量表（VAS）为0至100毫米的范围内，使用功能磁共振成像（fMRI）测量大脑活动，该量表代表个体校准的疼痛压力为50毫米。患者对疼痛刺激的敏感性高于对照组，因为他们在诱发同等疼痛程度时所需的压力较小（U(A)=48，p<0.002）。尽管在视觉模拟量表为50毫米时患者所承受的压力较低，但功能磁共振成像分析显示，与注意力和情感相关的脑区或来自受刺激身体区域的感觉投射区域的活动没有差异。然而，在下行疼痛调节系统的主要环节（喙部前扣带回皮质），患者对疼痛刺激没有反应。该脑区对疼痛的反应减弱是首次证明纤维肌痛综合征患者疼痛抑制受损在特定脑区的表现。这些结果证实了先前关于纤维肌痛综合征内源性疼痛抑制功能障碍的报道，并推进了对中枢病理生理机制的理解，为纤维肌痛综合征成功治疗方法的开发提供了新方向。
