Wits Dial-a-bed Sleep Laboratory, Brain Function Research Group, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
J Pain. 2013 Oct;14(10):1066-76. doi: 10.1016/j.jpain.2013.04.010. Epub 2013 Jun 12.
Primary dysmenorrhea is a common painful condition in women that recurs every month across the reproductive years. The recurrent nociceptive input into the central nervous system that occurs during menstruation each month in women with dysmenorrhea is hypothesized to lead to increased sensitivity to painful stimuli. We investigated whether women with primary dysmenorrhea are hyperalgesic to deep muscle pain induced by a cleanly nociceptive method of hypertonic saline injection. Pain stimulation was applied both within an area of referred menstrual pain (lower back) and at a remote site outside of referred menstrual pain (forearm) in 12 healthy women with severe dysmenorrhea and 9 healthy women without dysmenorrhea, at 3 phases of the menstrual cycle: menstruation and follicular and luteal phases. Women rated their pain severity on a 100-mm visual analog scale every 30 seconds after injection until the pain subsided. In both groups of women, menstrual cycle phase had no effect on the reported intensity and duration of muscle pain. However, women with dysmenorrhea had increased sensitivity to experimental muscle pain both at the site of referred pain and at a remote nonpainful site, as assessed by peak pain severity visual analog scale rating, area under the visual analog scale curve, and pain duration, compared to women without dysmenorrhea. These data show that women with severe primary dysmenorrhea, who experience monthly menstrual pain, are hyperalgesic to deep muscle pain compared to women without dysmenorrhea.
Our findings that dysmenorrheic women are hyperalgesic to a clinically relevant, deep muscle pain in areas within and outside of referred menstrual pain indicates lasting changes in pain sensitivity outside of the painful period during menstruation.
原发性痛经是女性常见的疼痛病症，在生育期每月反复发作。每月痛经女性的中枢神经系统中反复出现的伤害性传入可能导致对疼痛刺激的敏感性增加。我们研究了原发性痛经女性是否对由高渗盐水注射引起的深部肌肉疼痛更敏感。在 12 名严重痛经的健康女性和 9 名无痛经的健康女性中，在月经周期的 3 个阶段（月经期、卵泡期和黄体期），在疼痛区域（下背部）和疼痛区域之外的一个远程部位（前臂）应用疼痛刺激。女性在注射后每 30 秒根据 100 毫米视觉模拟量表评估疼痛严重程度，直到疼痛缓解。在两组女性中，月经周期阶段对肌肉疼痛的报告强度和持续时间均无影响。然而，与无痛经的女性相比，痛经女性对实验性肌肉疼痛的敏感性增加，表现为疼痛严重程度视觉模拟量表评分、视觉模拟量表曲线下面积和疼痛持续时间的峰值。这些数据表明，每月经历月经疼痛的严重原发性痛经女性对深部肌肉疼痛更敏感，不仅在疼痛区域，而且在疼痛区域之外。这表明在月经期间疼痛期之外，疼痛敏感性存在持久变化。
我们的发现表明，痛经女性对疼痛区域内外的深部肌肉疼痛更敏感，这表明在月经期间疼痛期之外，疼痛敏感性存在持久变化。
