应用表面电极测试小儿桡神经传导功能的研究

Testing the conductive function of radial nerve in children with surface electrode

目的 探讨用表面电极测试小儿桡神经传导功能的可靠性 ,获取不同年龄期小儿桡神经运动、感觉传导功能正常值及发育规律。方法 同时采用表面电极和针电极对 4 0名不同年龄小儿桡神经运动传导功能作对比测试 ,以确认前者准确性 ;再以表面电极获取 12 8名 0～ 14岁不同年龄期健康小儿桡神经运动、感觉传导功能各项参数 ,分析发育规律 ;并对其临床应用作初步验证。结果(1)表面电极可在任何年龄小儿获得清晰的桡神经运动肌肉复合动作电位 (CMAP) ,其传导速度(MCV)及潜伏期与针电极测试结果高度一致 (r分别为 0 95、0 84 )。 (2 )以表面电极测试 ,可在任何年龄小儿中获 10 0 %的桡神经CMAP出波率 ;向近端移动记录电极后可使～ 3岁和～ 14岁年龄组F波出波率增高到 10 0 %。然而 ,半岁前很难以表面电极记录到感觉神经动作电位 (SNAP) ,3岁前出波率约 5 0 % ,年长儿仍不超过 90 %。 (3)获得各个年龄组小儿桡神经运动和感觉传导功能的正常参数 ,包括MCV、远端潜伏期、波幅、时程等。出生时MCV已达年长儿的 2 / 3,～ 3岁组与～ 14岁组差异不再有显著意义 ;感觉神经传导速度与MCV有类似发育规律。 (4)以获得的正常值范围为依据 ,明确了 2 2名桡神经损伤患儿的诊断和病变性质。结论 表面电极能较好地替代针电极?

Objective To explore the reliability of recording nerve conduction with surface electrode along radial nerve in children and to investigate the norms and the maturation of radial conduction in children aged 0-14 years Methods (1) We conducted a comparative study in 40 children with different ages on radial nerve for the reliability of recording radial motor nerve conduction with surface electrode and also needle electrodes. (2) Maturation pace and norms of motor and sensory conduction along radial nerve were recorded by surface electrode on the basis of data from 128 children 0-14 years old. (3) A preliminary evaluation was done on clinical application for the norms Results (1) A clear pattern of (compound muscle action potential, CMAP) was equally recorded by surface and needle electrodes in all the tested children regardless their age Both the value of MCVs and latencies were highly consistent ( r = 0 95 and 0 84, respectively). (2) With surface recording, CMAPs were well presented in all age groups including neonate F waves could be obtained in all subjects when recording electrode was moved to the proximity of upper extremity However it was hard to record a sensory nerve action potential (SNAP) of radial nerve in infant younger than 6 months of age, but the incidence of SNAPs were increased to 50% in subjects less than 3 years of age and still less than 90% in older children. (3) A series of norms of radial nerve conduction tested with surface electrode in children, including MCV, SCV, distal latencies, amplitudes and duration of CMAPs and SNAPs were obtained MCV level reached two third of that of young adults at birth[(36 7±6 8) m/s], there was no significant difference between the levels of MCV in 3 year age group[(56 0 ±6 7 )m/s] and in the older age groups As MCVs, a similar maturational pace for SCV was demonstrated It would be the important period for the maturation of nerve conduction along radial nerve in children under 3 years of age; (4) Diagnosis of radial nerve injury in 22 patients were well identified after a study of nerve conduction with surface electrode as compared to the norms from our data, and their pathological patterns were indicated Conclusion Motor nerve conduction of radial nerve could be satisfactorily recorded with surface electrode as compared to needle electrode in children at any age This could be the highest advantage to promote its clinical use in pediatric population due to its non invasive procedure However, a definitive diagnosis for the disorders of radial sensory nerve conduction can be made only with an additional study with needle electrode when a SNP is not obtainable with surface electrode