Leffler Ann-Sofie, Hansson Per, Kosek Eva
Department of Surgical Sciences, Section of Clinical Pain Research, Karolinska Hospital/Institutet, S-171 76 Stockholm, Sweden.
Eur J Pain. 2002;6(2):149-59. doi: 10.1053/eujp.2001.0312.
In patients with localized musculoskeletal pain, spread of pain and tenderness outside the primarily painful area and sometimes even generalization of pain have been reported, the latter possibly indicating a dysfunction of endogenous pain modulatory systems. The purpose of the study was to use patients with long-term trapezius myalgia as a model to investigate the possible influence of a localized muscle pain on somatosensory processing in a remote pain-free area and the effect of heterotopic noxious conditioning stimulation (HNCS) on 'diffuse noxious inhibitory controls' (DNIC) related mechanisms. Altered somatosensory processing may indicate subclinical derangement of endogenous modulatory systems. Ten patients with long-term (> or = 1 year) trapezius myalgia and 10 age- and sex-matched healthy controls participated. Pressure pain sensitivity, low threshold mechanoreceptive function and thermal sensitivity, including thermal pain, were assessed at the right thigh before, during and following HNCS. Pain was induced in the forearm by the tourniquet test. At rest allodynia to pressure was found at the thigh in conjunction with hypoaesthesia to cold (p<0.03 and p<0.01 respectively), in patients compared with controls. During HNCS, the sensitivity to pressure pain and suprathreshold heat pain decreased in patients and controls alike (p<0.02 and p<0.04 respectively) and returned to baseline following HNCS. In conclusion, in a remote non-painful area allodynia to pressure and hypoaesthesia to cold were found in conjunction with preserved function of DNIC-related mechanisms. Whether altered central somatosensory processing at rest may indicate a predisposition for further spread of pain is at present unclear.
在局部肌肉骨骼疼痛的患者中，已有报道称疼痛和压痛会扩散至主要疼痛区域之外，有时甚至会出现疼痛泛化，后者可能表明内源性疼痛调节系统功能失调。本研究的目的是将长期患有斜方肌肌痛的患者作为模型，以研究局部肌肉疼痛对远处无痛区域体感处理的可能影响，以及异位有害条件刺激（HNCS）对“弥漫性有害抑制控制”（DNIC）相关机制的影响。体感处理的改变可能表明内源性调节系统存在亚临床紊乱。十名患有长期（≥1年）斜方肌肌痛的患者和十名年龄及性别匹配的健康对照者参与了研究。在HNCS之前、期间和之后，对右大腿的压痛敏感性、低阈值机械感受功能和热敏感性（包括热痛）进行了评估。通过止血带试验在前臂诱发疼痛。与对照组相比，患者在休息时大腿出现对压力的痛觉过敏，同时伴有对冷的感觉减退（分别为p<0.03和p<0.01）。在HNCS期间，患者和对照组对压痛和阈上热痛的敏感性均降低（分别为p<0.02和p<0.04），并在HNCS后恢复至基线水平。总之，在远处无痛区域发现了对压力的痛觉过敏和对冷的感觉减退，同时DNIC相关机制的功能保持正常。目前尚不清楚静息时体感处理的改变是否可能表明疼痛进一步扩散的易感性。
