目的　探讨不同年龄期儿童周围磁运动诱发电位 (magneticmotorevokedpotential,MMEP)的年龄特征与发育规律。方法　对 2 5 7名 0～ 14岁健康儿童应用磁刺激分段测试 [第 7颈椎 (C7)、第4腰椎 (L4 )、肘和窝 ]周围运动传导通路功能 ,分别在上肢拇短展肌和下肢足母展肌处记录 ,获得各年龄期MMEP各项参数和发育特征。结果　除部分幼婴儿因磁线圈放置困难外 ,在各年龄组正常小儿(包括新生儿 )的上、下肢均可记录到清晰、重复性良好的周围性MMEP反应波。各年龄组上下肢左、右间潜伏期差值较稳定 ,最大值均不超过 2 .2ms。上、下肢校正潜伏期分别于 2岁和 1岁时达成人值的 1/ 2 ,下肢校正潜伏期和周围传导速度在 4岁时先于上肢 (6岁 )达成人水平 ,且上、下肢周围运动神经近段传导速度较远段快。运动神经传导速度以周围段最快 ,脊髓次之 ,颅内最慢。结论　 (1)婴幼儿是人类周围运动神经传导功能发育的关键年龄期 ;(2 )周围运动神经系统发育遵循由近段及远端 ,先下肢后上肢的规律 ;(3)磁刺激无痛无创可安全地用于包括新生儿在内的各年龄段小儿周围运动神经功能的检测 ,尤其磁刺激能直接诱发神经根段电位 ,对周围神经病的诊断 ,有其独特的优越性 Objective To investigate the age characteristics and developmental rules of magnetic mottle evoked potentials (MMEP) in children of different ages. Methods A total of 257 healthy children aged 0-14 years were instructed to perform magnetic stimulation in segmental testing of motor conduction pathways around the seventh cervical vertebra (C7), fourth lumbar vertebra (L4), elbow and popliteal fossa. Muscular and lower extremity musculature at the record, access to all age MMEP parameters and developmental characteristics. Results In addition to the difficulty of placing some coils on the magnetic coils, the peripheral MMEP response waves were recorded clearly and repetitively in the upper and lower limbs of normal children (including newborns) of all age groups. The difference between the left and right upper and lower limb latency was stable in all age groups, with the maximum no more than 2.2ms. The upper and lower limb corrected latency reached 1/2 of the human body at the age of 2 and 1 year respectively. The lower limb corrected latency and the surrounding conduction velocity reached the human level before the upper limb (6 years) at the age of 4, and the upper and lower extremity motor nerves Near conduction speed faster segment. Motor nerve conduction velocity to the fastest peripheral segment, followed by the spinal cord, the slowest intracranial. Conclusions (1) Infants and young children are the key age at which development of motor nerve conduction function around human beings. (2) The development of motor system in the periphery follows the rule of proximal and distal lower extremity upper limbs. (3) Can be safely used for detection of motor nerve function around children at all ages, including newborns, especially magnetic stimulation can directly induce the potential of the nerve root segment, and has unique advantages in the diagnosis of peripheral neuropathy