Department of Clinical and Cognitive Neuroscience, Central Institute of Mental Health, University of Heidelberg, Mannheim, Germany.
Eur J Pain. 2011 Aug;15(7):716-23. doi: 10.1016/j.ejpain.2010.12.002. Epub 2011 Jan 28.
While the etiology of fibromyalgia syndrome (FMS) remains unclear, it is assumed that both peripheral and central components are involved.
AIMS/METHODS: To investigate central activation patterns following chemically-induced muscle pain we repetitively injected protons (low pH) and prostaglandin E(2) (PGE(2)) in isotonic solution into the left extensor carpi radialis brevis muscle of female FMS patients and female healthy control subjects (HC). The injection of protons/PGE(2) has the advantage that it is not prone to tachyphylaxis compared to capsaicin and hypotonic saline solution. During the repetitive injections continuous pain ratings were recorded and functional magnetic resonance imaging measurements were conducted.
Injection of protons/PGE(2) led to activation of the anterior and medial cingulate cortices, contralateral primary sensory cortex, bilateral insula and thalamus, left basal ganglia, left orbitofrontal cortex and the cerebellum in FMS patients. In HC, activations were found only in the anterior, medial, and posterior cingulate cortices, and the primary somatosensory cortex. The contrast between the groups revealed significantly stronger activation for FMS patients in the left anterior insula. Peak pain ratings were comparable between HC and FMS patients, but pain duration (sustained pain) was prolonged in FM.
Repetitive proton/PGE(2)-induced excitation of muscle tissue led to a more prolonged perception of pain and more wide-spread activation in pain-related brain areas in FMS, especially in the left (ipsilateral) insula, whereas acute protons/PGE(2)-induced pain processing was similar in the two groups. These data provide further evidence for enhanced central pain processing in FMS patients.
尽管纤维肌痛综合征（FMS）的病因仍不清楚，但人们认为外周和中枢成分都参与其中。
目的/方法：为了研究化学诱导的肌肉疼痛后的中枢激活模式，我们反复将质子（低 pH 值）和前列腺素 E2（PGE2）注入到女性 FMS 患者和女性健康对照者（HC）的左侧伸腕短肌。与辣椒素和低渗盐水相比，质子/PGE2 注射不易产生快速耐受，具有优势。在重复注射过程中，连续记录疼痛评分并进行功能磁共振成像测量。
质子/PGE2 注射导致 FMS 患者的前扣带皮质和内侧扣带皮质、对侧初级感觉皮质、双侧岛叶和丘脑、左侧基底节、左侧眶额皮质和小脑激活。在 HC 中，仅在前扣带皮质、内侧扣带皮质和后扣带皮质以及初级体感皮质中发现激活。组间对比显示，FMS 患者左侧前岛叶的激活明显更强。HC 和 FMS 患者的峰值疼痛评分相当，但 FMS 患者的疼痛持续时间（持续疼痛）延长。
重复质子/PGE2 诱导的肌肉组织兴奋导致 FMS 患者对疼痛的感知时间延长，疼痛相关脑区的激活范围更广，尤其是左侧（同侧）岛叶，而两组急性质子/PGE2 诱导的疼痛处理相似。这些数据为 FMS 患者中枢疼痛处理增强提供了进一步证据。
