Abstract

There is evidence regarding the presence of alterations in both the stress response and the endogenous pain modulation systems of people with fibromyalgia (FM). However, research on pain modulation under induced stress on FM patients is scarce and contradictory. The present study analyzes stress-induced changes in pain and intolerance thresholds among FM patients, examining the possible existence of differences linked to PTSD comorbidity and gaining insights into the role of cardiovascular reactivity. Eighteen women diagnosed with FM and comorbid PTSD (FM + PTSD), 18 women diagnosed with FM and no PTSD (FM-PTSD), and 38 healthy women (HC) were exposed to the Social Stress Test task. Pressure pain thresholds and intolerance thresholds were measured before and during stress induction, and after a recovery period, while systolic blood pressure and heart rate were simultaneously recorded. Overall, while pain thresholds decreased during stress and recovery for HC, no significant changes were observed for women with FM. The intolerance threshold decreased for HC during stress, but was maintained at basal level during recovery. FM-PTSD women exhibited a delayed response, with a drop at recovery. For FM + PTSD, tolerance levels remained unchanged. In addition, cardiovascular reactivity did not seem to explain these results. This performance of the pain modulation system seems to follow the same pattern of hypoactive responsiveness under stressors that has previously been observed in FM patients on the autonomic and neuroendocrine axes. Such a hypoactive pattern may involve a non-adaptive response that may contribute to the development and maintenance of chronic pain.

摘要

有证据表明，纤维肌痛 (FM) 患者的压力反应和内源性疼痛调节系统都存在变化。然而，对 FM 患者诱导压力下的疼痛调节的研究很少且相互矛盾。本研究分析压力引起的 FM 患者疼痛和不耐受阈值的变化，检查与 PTSD 合并症相关的差异的可能存在，并深入了解心血管反应性的作用。18 名被诊断患有 FM 和共病 PTSD (FM + PTSD) 的女性、18 名被诊断患有 FM 且没有 PTSD (FM-PTSD) 的女性和 38 名健康女性 (HC) 接受了社会压力测试任务。在压力诱导之前和期间以及恢复期之后测量压力疼痛阈值和不耐受阈值，同时记录收缩压和心率。总体而言，虽然 HC 的疼痛阈值在压力和恢复期间降低，但 FM 女性没有观察到显着变化。HC 的不耐受阈值在应激期间降低，但在恢复期间保持在基础水平。FM-PTSD 女性表现出延迟反应，在恢复时下降。对于 FM + PTSD，容差水平保持不变。此外，心血管反应性似乎不能解释这些结果。疼痛调节系统的这种表现似乎与先前在 FM 患者的自主神经和神经内分泌轴上观察到的压力源下反应迟钝的模式相同。