副肿瘤性周围神经病模型建立及其电生理变化特点

Establishment of carcinoma model and study of electrophysiology in paraneoplastic peripheral neuropathy

目的探讨肝癌兔周围神经的神经电图变化特征,为副肿瘤性周围神经病早期发现提供可靠的方法。方法将25只健康中国白兔随机分成观察组(1组,n=13)和对照组(2组,n=12),观察组采用开腹行瘤组织小块移植法建立VX2肝癌兔副肿瘤性周围神经病模型,对照组同样接受该手术处理,但无瘤组织小块植入。之后,应用超声仪对1组实验兔进行监测,同时检测肝功能变化,VX2肝癌兔死亡后,取其肝脏及瘤组织完善病理学检查。定期采用美国尼高力肌电诱发电位仪予两组实验动物进行腓总神经的神经电图检查。对监测结果进行统计学分析。结果 (1)各时间节点的B超结果、实验兔的体重变化结合尸检及病理组织学结果可证实癌肿的存在,2个模型失败,1个模型兔术后2 d死亡,成瘤率76.9%(10/13)。(2)术前及术后1周,两组间腓神经末端潜伏期(DL)、复合肌肉动作电位(CMAP)波幅均无明显差异(P> 0.05);1组术后3周、5周,均出现CMAP波幅较前减低(P <0.01);术后3周,1组DL较2组无明显差异,术后5周较2组明显延长(P <0.05)。结论 (1)开腹瘤组织小块移植法是一种异位种植少、成功率高、稳定性强的建立兔VX2肝癌模型的方法。(2)副肿瘤性周围神经病首发以轴索变性为主,继之出现脱髓鞘病变。(3)可疑肿瘤病变时,应关注周围神经电图波幅及DL的变化,尤以波幅为著。

Objective The characteristics of electroneurogram in rabbits with VX2 hepatic carcinoma were analyzed,for the purpose of providing a more sensitive electrophysiological index for diagnosis of PPN.Methods 25 healthy rabbits were randomly divided into experimental group(group 1,n=13)and control group(group 2,n=12).In group 1,under conditions of a sterile sub-xyphoid laparotomy,several tumor fragments were inoculated into the liver parenchyma to establish VX2 hepatic carcinoma model.The control group received the same surgical treatment,but no tumor fragments were implanted into the wound in the liver.After the tumor transplantation,ultrasonography was applied to check the size and echo of tumors in group 1,and liver function was also detected to estimate the growth of tumors.After the rabbits died,specimens were resected from both the liver and tumor aiming at pathological examination.Electroneurogram was detected regularly in the two groups with KEYPOINT myoelectric/evoked potential instrument.Statistical analyses were taken,using data of the monitoring results of the rabbit VX2 carcinomas and electrophysiological examination.Results①The ultrasound images of different intervals after the inoculation,weight changes,autopsy and pathological findings all confirmed the presence of tumors in the experimental group.In two rabbits,the establishment of VX2 hepatic carcinoma model failed and two days after the implantation,one rabbit died.The success rate was 76.9%.②Distal latency(DL)of peroneal nerve showed no difference between the two groups both before inoculation and one week after the surgery,the same as the amplitude of CMAP.3 weeks and 5 weeks after the implantation,there were statistical differences in the amplitude between the two groups.There was no statistical difference in DL between the two groups 3 weeks after the surgery.But two weeks later,there was a significant difference in DL between the two groups.Conclusion①Inoculation of tumor fragments under conditions of a sterile sub-xyphoid laparotomy is a stable method with high success rate and low dystopia implantation rate.②Electrophysiological results suggest that the electrophysiological pattern of paraneoplastic peripheral neuropathy is mainly axonal degeneration,accompanied by demyelination.3.In screening for paraneoplastic peripheral neuropathy,emphasis should be put on the amplitude of CMAP and DL,especially the amplitude of CMAP.