Department of Neurological and Visual Sciences, Section of Rehabilitative Neurology, University of Verona, Italy Section of Neurology, Pederzoli Hospital, Peschiera del Garda, Verona, Italy.
Pain. 2010 Feb;148(2):227-236. doi: 10.1016/j.pain.2009.10.025. Epub 2009 Dec 8.
Extraterritorial spread of sensory symptoms is frequent in carpal tunnel syndrome (CTS). Animal models suggest that this phenomenon may depend on central sensitization. We sought to obtain psychophysical evidence of sensitization in CTS with extraterritorial symptoms spread. We recruited 100 unilateral CTS patients. After selection to rule out concomitant upper-limb causes of pain, 48 patients were included. The hand symptoms distribution was graded with a diagram into median and extramedian pattern. Patients were asked on proximal pain. Quantitative sensory testing (QST) was performed in the territory of injured median nerve and in extramedian territories to document signs of sensitization (hyperalgesia, allodynia, wind-up). Extramedian pattern and proximal pain were found in 33.3% and 37.5% of patients, respectively. The QST profile associated with extramedian pattern includes: (1) thermal and mechanic hyperalgesia in the territory of the injured median nerve and in those of the uninjured ulnar and radial nerves and (2) enhanced wind-up. No signs of sensitization were found in patients with the median distribution and those with proximal symptoms. Different mechanisms may underlie hand extramedian and proximal spread of symptoms, respectively. Extramedian spread of symptoms in the hand may be secondary to spinal sensitization but peripheral and supraspinal mechanisms may contribute. Proximal spread may represent referred pain. Central sensitization may be secondary to abnormal activity in the median nerve afferents or the consequence of a predisposing trait. Our data may explain the persistence of sensory symptoms after median nerve surgical release and the presence of non-anatomical sensory patterns in neuropathic pain.
腕管综合征（CTS）常出现感觉症状的远隔分布。动物模型表明，这种现象可能取决于中枢敏化。我们试图通过具有远隔症状分布的 CTS 获得敏化的心理物理学证据。我们招募了 100 名单侧 CTS 患者。在选择排除上肢疼痛的其他原因后，纳入 48 名患者。手部症状分布用图表分为正中型和非正中型。患者被问及近端疼痛。在损伤正中神经的区域和非正中区域进行定量感觉测试（QST），以记录敏化的迹象（痛觉过敏、感觉异常、痛觉过敏）。分别有 33.3%和 37.5%的患者出现非正中型症状和近端疼痛。与非正中型相关的 QST 特征包括：（1）损伤正中神经区域以及未损伤的尺神经和桡神经区域的热和机械痛觉过敏；（2）增强的痛觉过敏。具有正中型分布和近端症状的患者没有发现敏化的迹象。手部非正中型和近端症状的扩散可能分别有不同的机制。手部症状的非正中型扩散可能是脊髓敏化的结果，但外周和脊髓上机制可能也有贡献。近端扩散可能代表牵涉痛。中枢敏化可能是正中神经传入异常活动的结果，也可能是易患特质的结果。我们的数据可以解释正中神经手术后感觉症状的持续存在以及神经病理性疼痛中存在非解剖感觉模式。
