实验性三叉神经痛慢性缩窄环术动物模型建立

ESTABLISHMENT OF EXPERIMENTAL ANIMAL MODEL FOR TRIGEMINAL NEURALGIA FOLLOWING CHRONIC CONSTRICTION INJURY

摘要:

目的 :为探讨三叉神经痛的发病机制及治疗等提供实验基础 ,建立一种可靠的三叉神经痛模型。方法 :将大鼠随机分为手术组及假手术组 ,手术组用两根铬线疏松环扎大鼠的眶下神经造成慢性缩窄损伤 ,而假手术组只暴露神经 ,但不结扎 ,观察术后不同时段大鼠对机械刺激的反应阈值及相关的痛觉行为变化。结果 :手术组术后 9～ 6 0天左右 ,在眶下神经支配区域内 ,大鼠出现痛觉超敏现象 ,与手术对侧、术前及对照组比较存在显著差异 (P <0 .0 1) ,极低的外在刺激即可激发强烈的疼痛行为反应 ,持续至术后 30天 ,然后逐渐恢复 ,术后 80天左右恢复术前水平。结论 :大鼠眶下神经的慢性环扎损伤可导致三叉神经痛出现 ,压迫解除后疼痛可缓解。该模型成功地模拟了临床因压迫导致三叉神经痛的情况 ,简单易行 ,成功率高。

Abstract:

Objective: To establish a reliable animal model of trigeminal neuralgia for the basic research on the mechanism and therapy. Methods: Rats were randomly divided into two groups: the operative group and the sham-operative group. In the operative group, an unilateral chronic constriction injury (CCI) was produced by placing loose chromic gut ligatures around the infraorbital nerve (ION). In the sham-operative group, the ION was only exposed using the same procedure but not ligated. The behavioral reactions and the mechanical response threshold (pain threshold) were observed at different times after operation. Results: An allodynia to mechanical stimulation on the territory of ligated ION was found from the 9th to the 60th day after operation in the operative group. There was significant difference(P<0.01)in pain threshold, compared with the pre-operation and the contralateral side in operative group and the sham-operative group. Low-intensity mechanical sensory input resulted in hyper-responsiveness. The thresholds started to increase gradually from the 30th day and reached the original level on 80th day after operation. Conclusion: CCI-ION resulted in experimental trigeminal neuralgia, which could be relieved by decompression. This model imitates successfully the clinical trigeminal neuralgia caused by nerve constriction, which could be easily produced with a high success rate.