31 / 2017-07-04 21:28:33

The correlation between the CNAP amplitude and the number of myelinated nerve at various time points of the rat regenerated median nerve

CNAP,nerve injury,amplitude,median nerve,myelinated nerve fibers

Background: CNAP has been applied to diagnose and evaluate the extent of nerve injury intraoperative. But it has not been established that the relationship between the CNAP amplitude and the number of myelinated nerve though some authors had the same theoretical conjecture. Objective: To explore the relationship between the CNAP amplitude and the number of myelinated nerve at various time points of regenerated rat median nerve. Methods: The model that the median nerve was transected and sutured on the rat upper arm was established. At different time points postoperative, the electrophysiological (CNAP) and were performed under anesthesia, then median nerve were harvested for histological examination and myelinated nerve count. Finally the correlation between them were analyzed by the linear regression analysis.Results: The CNAP amplitudes were lower significantly at 2, 3 weeks than 6, 8 ,12 weeks (p<0.01). And 6 weeks later, the CNAP amplitudes were inclined to be stable and the recovery rate of CNAP amplitudes was close to those of week 8, 12 postoperation(p>0.01). There have been a weak correlation coefficient of 0.39 between the amplitude of CNAP and the number myelinated nerve fibers at various time points. However, a strong correlation coefficient of 0.953 at every time point revealed that a linear relationship exist between them.Conclusion: There exists a linear relationship between at every time point after nerve repair. There is only a weak correlation and is a non-linear relationship between the amplitude of CNAP and the number myelinated nerve fibers at various time points.