周围神经适应缓慢牵伸机理的电生理观察

Electrophysiological Investigation on Adaptive Mechanism of Peripheral Nerve during Limb Lengthening in Rabbits

目的探讨不同幅度缓慢肢体延长对周围神经电生理的影响。方法 20只日本大耳白兔胫骨延长后,行胫后神经复合感觉诱发电位(CSEP)及腓肠肌、胫前肌脊髓诱发肌电图(EEMG)测试。结果延长10%时,胫后神经CSEP及胫前肌EEMG的峰值显著下降。20%时,胫后神经CSEP、胫前肌EEMG的峰值、潜伏期及腓肠肌EEMG的峰值均显著异常。30%时,胫后神经CSEP,胫前肌及腓肠肌EEMG的潜伏期、峰值、面积均显著异常。40%时,上述异常并非机械性迭加,未出现完全性神经传导阻滞。结论该结果与采用同一模型对神经组织学、血循环及血神经屏障功能观察的结果一致,提示肢体延长过程中,虽然神经损害广泛存在,但由于周围神经同步的再生修复,使这种损害仅以亚临床的形式出现。

Objective The study is to assess the influence of different amount of distraction on the electrophysiological function of peripheral nerves during limb lengthening. Methods Compound sensory evoked potential(CSEP) of the posterior tibial nerve and evoked electromyographic (EEMG) studies of both M. tibialis anterior and M. gastronemius were performed in both hind limbs of 20 rabbits with electromyography. Results Significant amplitude (AMP) changes were observed in CSEP and EEMG of M. tibialis anterior in the 10% group. All the LAT and AMP but the LAT of M. gastronemius showed significant difference from the control until 20% lengthening. At 30% lengthening, the LAT, AMP and AREA in CSEP and EEMG were all significantly different from those in the control. As lengthening proceeded up to 40%, the differences were no more obvious and no case of induction blockage was found. Conclusion This result is consistent with the findings of histological observation, blood supply estimation and barrier function examination of the nerve in the same model, which indicated that it is the simultaneous regeneration of peripheral nerve that makes the damage subclinical even though peripheral nerve damage is common during limb lengthening.