Zhao Chengshui, Chen Lun, Tao Yuan-Xiang, Tall Jill M, Borzan Jasenka, Ringkamp Matthias, Meyer Richard A, Raja Srinivasa N
Department of Anesthesiology and Critical Care Medicine, Baltimore, Maryland, USA.
J Pain. 2007 Dec;8(12):931-7. doi: 10.1016/j.jpain.2007.06.008. Epub 2007 Aug 13.
In certain patients with neuropathic pain, the pain is dependent on activity in the sympathetic nervous system. To investigate whether the spared nerve injury model (SNI) produced by injury to the tibial and common peroneal nerves and leaving the sural nerve intact is a model for sympathetically maintained pain, we measured the effects of surgical sympathectomy on the resulting mechanical allodynia, mechanical hyperalgesia, and cold allodynia. Decreases of paw withdrawal thresholds to von Frey filament stimuli and increases in duration of paw withdrawal to pinprick or acetone stimuli were observed in the ipsilateral paw after SNI, compared with their pre-SNI baselines. Compared with sham surgery, surgical lumbar sympathectomy had no effect on the mechanical allodynia and mechanical hyperalgesia induced by SNI. However, the sympathectomy significantly attenuated the cold allodynia induced by SNI. These results suggest that the allodynia and hyperalgesia to mechanical stimuli in the SNI model is not sympathetically maintained. However, the sympathetic nervous system may be involved, in part, in the mechanisms of cold allodynia in the SNI model.
The results of our study suggest that the SNI model is not an appropriate model of sympathetically maintained mechanical allodynia and hyperalgesia but may be useful to study the mechanisms of cold allodynia associated with sympathetically maintained pain states.
在某些神经性疼痛患者中，疼痛依赖于交感神经系统的活动。为了研究由胫神经和腓总神经损伤而保留腓肠神经完整所产生的 spared 神经损伤模型（SNI）是否是交感神经维持性疼痛的模型，我们测量了手术性交感神经切除术对由此产生的机械性异常性疼痛、机械性痛觉过敏和冷异常性疼痛的影响。与 SNI 术前基线相比，SNI 术后同侧爪对 von Frey 细丝刺激的爪退缩阈值降低，对针刺或丙酮刺激的爪退缩持续时间增加。与假手术相比，手术性腰交感神经切除术对 SNI 诱导的机械性异常性疼痛和机械性痛觉过敏没有影响。然而，交感神经切除术显著减轻了 SNI 诱导的冷异常性疼痛。这些结果表明，SNI 模型中对机械刺激的异常性疼痛和痛觉过敏不是由交感神经维持的。然而，交感神经系统可能部分参与了 SNI 模型中冷异常性疼痛的机制。
我们的研究结果表明，SNI 模型不是交感神经维持性机械性异常性疼痛和痛觉过敏的合适模型，但可能有助于研究与交感神经维持性疼痛状态相关的冷异常性疼痛的机制。
