Helme R D
Monash University Department of Medicine, Prince Henry's Hospital, Melbourne, Vic.
Clin Exp Neurol. 1987;24:201-5.
Pain is a sensory and emotional experience and, as such, is always subjective. However, for many patients pain results from stimulation of nociceptors in somatic structures. Polymodal nociceptors also mediate flare responses to noxious stimuli. In this study skin flare responses overlying the painful region in patients with pain from degenerative spine disease (16), cancer (12) and osteomyelitis (1) were examined, and compared with control areas in the same patients. Flares were induced with capsaicin (0.2 g/L in 70% ethanol) and the area was measured by planimeter after 30 minutes of exposure to the chemical. Patients with chronic pain had reduced flare responses over the pain site compared with control areas (p less than 0.1; Wilcoxon two-sample test). There was no difference between patients with acute on chronic pain and with chronic pain alone. Acute pain alone produced an increased flare response. The results suggest increased nociceptor activity in acute pain and reduced activity in chronic pain. This may reflect sensitisation and desensitisation of the nociceptor, as has been demonstrated in experimental studies in animals.
疼痛是一种感觉和情感体验，因此总是主观的。然而，对许多患者来说，疼痛是由躯体结构中的伤害感受器受到刺激引起的。多模式伤害感受器也介导对有害刺激的 flare 反应。在本研究中，对患有退行性脊柱疾病（16 例）、癌症（12 例）和骨髓炎（1 例）疼痛的患者疼痛区域上方的皮肤 flare 反应进行了检查，并与同一患者的对照区域进行了比较。用辣椒素（70%乙醇中 0.2 g/L）诱导 flare，在接触该化学物质 30 分钟后用面积仪测量面积。与对照区域相比，慢性疼痛患者疼痛部位的 flare 反应降低（p 小于 0.1；Wilcoxon 双样本检验）。急性加重慢性疼痛的患者与单纯慢性疼痛的患者之间没有差异。单纯急性疼痛会产生增强的 flare 反应。结果表明，急性疼痛时伤害感受器活性增加，慢性疼痛时活性降低。这可能反映了伤害感受器的敏化和脱敏，正如在动物实验研究中所证明的那样。
