Department of Physical Therapy, University of Florida, Gainesville, Florida 32611-0154, USA.
J Pain. 2012 Jan;13(1):81-9. doi: 10.1016/j.jpain.2011.10.006.
Recent reports suggest deficits in conditioned pain modulation (CPM) and enhanced suprathreshold heat pain response (SHPR) potentially play a role in the development of chronic pain. The purpose of this study was to investigate whether central pain processing was altered in 2 musculoskeletal shoulder pain models. The goals of this study were to determine whether central pain processing: 1) differs between healthy subjects and patients with clinical shoulder pain; 2) changes with induction of exercise-induced muscle pain; and 3) changes 3 months after shoulder surgery. Fifty-eight patients with clinical shoulder pain and 56 age- and sex-matched healthy subjects were included in these analyses. The healthy cohort was examined before inducing EIMP, and 48 and 96 hours later. The clinical cohort was examined before shoulder surgery and 3 months later. CPM did not differ between the cohorts, however; SHPR was elevated for patients with shoulder pain compared to healthy controls. Induction of acute shoulder pain with EIMP resulted in increased shoulder pain intensity but did not change CPM or SHPR. Three months following shoulder surgery, clinical pain intensity decreased but CPM was unchanged from preoperative assessment. In contrast, SHPR was decreased and showed values comparable with healthy controls at 3 months. Therefore, the present study suggests that: 1) clinical shoulder pain is associated with measurable changes in central pain processing; 2) exercise-induced shoulder pain did not affect measures of central pain processing; and 3) elevated SHPR was normalized with shoulder surgery. Collectively our findings support neuroplastic changes in pain modulation were associated with decreases in clinical pain intensity only, and could be detected more readily with thermal stimuli.
Longitudinal studies involving quantitative sensory testing are rare. In exploring 2 musculoskeletal shoulder pain models (exercise-induced muscle pain and surgical pain), conditioned pain modulation was unchanged from pre- to post-assessment in both models. Suprathreshold heat pain response decreased after shoulder surgery and was comparable to healthy controls, suggesting this measure may be sensitive to decreases in clinical pain intensity.
最近的报告表明，条件性疼痛调节（CPM）的缺陷和超阈值热痛反应（SHPR）的增强可能在慢性疼痛的发展中起作用。本研究的目的是研究两种肌肉骨骼肩部疼痛模型中是否存在中枢疼痛处理的改变。本研究的目的是确定中枢疼痛处理是否：1）在健康受试者和患有临床肩部疼痛的患者之间有所不同；2）随运动引起的肌肉疼痛的诱导而改变；3）在肩部手术后 3 个月时改变。将 58 例临床肩部疼痛患者和 56 例年龄和性别匹配的健康受试者纳入这些分析。健康组在诱导 EIMP 之前、48 小时和 96 小时后进行检查。临床组在肩部手术前和 3 个月后进行检查。CPM 在两个队列之间没有差异，但是，与健康对照组相比，肩部疼痛患者的 SHPR 升高。急性肩部疼痛的 EIMP 诱导导致肩部疼痛强度增加，但未改变 CPM 或 SHPR。肩部手术后 3 个月，临床疼痛强度降低，但与术前评估相比，CPM 保持不变。相反，SHPR 降低，与 3 个月时的健康对照组值相当。因此，本研究表明：1）临床肩部疼痛与中枢疼痛处理的可测量变化有关；2）运动引起的肩部疼痛不会影响中枢疼痛处理的测量；3）肩部手术后，SHPR 升高并恢复正常。总的来说，我们的研究结果支持疼痛调节中的神经可塑性变化仅与临床疼痛强度的降低有关，并且可以更易于使用热刺激来检测。
涉及定量感觉测试的纵向研究很少。在探索两种肌肉骨骼肩部疼痛模型（运动引起的肌肉疼痛和手术疼痛）时，两种模型的 CPM 在预评估到后评估之间均保持不变。肩部手术后，超阈值热痛反应降低，与健康对照组相当，这表明该测量方法可能对临床疼痛强度的降低敏感。
