正常中国人中枢运动系统传导时间的测定

本文应用高电压、低输出阻抗刺激器,经皮给予大脑皮层和脊髓电刺激(BSPES),同时在上肢鱼际(Thenar)和下肢胫骨前肌(Muscle tibialis anterior)上记录诱发肌肉动作电位,测定了64名正常健康中国人(男:46;女:18)的中枢运动系统传导时间。受试者年龄为20—67岁,身高为156—185cm。刺激大脑皮层出现反应的潜伏期与刺激脊髓出现反应的潜伏期之差为中枢运动传导时间(CMCT)。实验测得鱼际的 CMCT 为6.69±1.48ms;胫骨前肌的 CMCT 为12.90±1.59ms。经统计学处理证明,CMCT 与左右侧肢体、性别、年龄及身高无关。说明 CMCT 是无损伤测定与评价中枢运动系统功能的较精确的一种客观指标。本文根据所测数据,计算出脊髓内运动传导速度为71.34±10.89 m/s,与文献报道的锥体束传导速度50—70 m/s 相近。因此,CMCT 反映了锥体束的传导时间。

MEASUREMENT OF CENTRAL MOTOR CONDUCTION TIME(CMCT)IN HEALTHY CHINESE SUBJECTS

Transcutaneous electrical stimulation of the central nervous system was used to measure CMCT between the human cerebral cortex and spinal cord. 64 normal volunteers (46 healthy adult males and 18 females, age of 20-67 years, body height of 156-185 cm) were recruited as experimental subjects. Action potentials of muscles were recorded from upper limb (Thenar) and lower limb (Muscle tibialis anterior) following cortical and spinal stimulation. The cortical and spinal latent periods (Lcor., Lsp.) were measured and CMCT was obtained by subtracting Lsp. from Lcor. for each muscle. The CMCT between the cerebral cortex and the first thoracic (Th1) cord was 6.69 +/- 1.48 ms, while that between the cerebral cortex and the first lumber (L1) cord was 12.90 +/- 1.59 ms. Statistical analysis indicated that CMCT was not related to sex, age, body height and left or right side of the body as well. The motor conduction velocity in spinal cord (MCVsp) between Th1 and L1, distance (Th1 to L1)/CMCT (Muscle tibialis anterior)-CMCT (Thenar)] was found to be 71.34 +/- 10.89 m/s, which corresponds to the conduction velocity of the large fibers in the pyramidal tract. The results of the present study are valuable in diagnosis and prognosis of motor system diseases in CNS.