复合神经动作电位与神经再生纤维数目之间的相关性研究

The correlation between compound nerve action potential and the number of the regenerated nerve fibers

目的研究大鼠正中神经切断缝合后神经再生期间，其复合神经动作电位（CNAP）与神经再生纤维数目之间的相关性。方法大鼠上臂正中神经中段切断后，用6种不同型号的缝线进行缝合，切断缝合后2周和8周，进行CNAP检测，观察其参数变化，然后切取大鼠正中神经组织标本（正常、缝合口近端、缝合口远端），用半薄切片甲苯胺蓝染色、免疫组化、luxolfastblue染色三种形态学检测方法进行有髓神经纤维计数，用线性回归方法分析他们之间的相关性。结果神经切断缝合术后2周和8周，再生神经记录的CNAP波幅与正常的CNAP相比，差异有统计学意义（P〈0．01）。波幅面积（Area）也显著低于正常（P〈0．01）。不同型号缝线的各组之间的正中神经有髓纤维再生恢复率之间的差异都有统计学意义（P〈0．05）。线性回归分析，远端记录的CNAP波幅和有髓纤维的计数之间有线性关系，拟合的线性方程，即2周：Y=250．859x＋27．826；8周：Y=265．584x＋2721．462。结论大鼠正中神经切断缝合后早期和成熟期，再生神经远端的CNAP波幅与相应的有髓纤维计数之间均有线性关系，线性方程斜率的相近，仅截距有明显差异，可以在神经损伤后再生早期或晚期，根据电生理CNAP的波幅，通过线性方程计算出损伤远端的有髓纤维计数，确定神经再生的轴索通畅率，定量评定损伤神经的功能。

Objective To explore the correlation between compound nerve action potential and the number of regenerrated nerve fibers in rat median nerve at the different time points after transection and repair. Methods The rat median nerve was transected at mid-upper arm level and repaired with six types of sutures. Compound nerve action potentials （CNAPs） were recorded 2 or 8 weeks postoperatively and its parameters analyzed. Median nerve samples from normal nerves, proximal to suture site and distal to suture site were harvested and fixed. Semi-thin sections were stained with toluidine blue, luxol fast blue and immunohistochemistry staining. Myelinated nerve fiber counts were obtained. Finally, the correlation between CNAP parameters and the number of regenerated nerve fibers was analyzed by linear regression analysis method. Results CNAP could be recorded at 2 and 8 weeks after nerve repair. CNAP amplitude and area were significantly lower than those of the control group （ P 〈 0.01）. The recovery rates of myelinated nerve fiber count among the various suture groups were significantly different （ P 〈 0.05）. CNAP amplitude and the myelinated nerve fiber count had a linear conelatiun. The linear fitting line equation was y = 250. 859x ＋ 27. 826 for 2- week data and y = 265.584x ＋ 2721.462 for 8-week data. Conclusion There is a positive linear correlation between CNAP amplitude and myelinated nerve fiber count at the early regeneration period and the maturation period following median nerve transection and repair. And the slope of the linear equation fitted between CNAP amplitude and myelinated nerve fiber count was sinfilar, except for the different intercepts. The number of myelinated nerve fibers distal to the injury and repair site can be calculated via CNAP amplitude using the linear regression equation, thus the extent of injury and regeneration can be estimated.