Xiong G-X, Zhang J-W, Hong Y, Guan Y, Guan H
Department of Spine Surgery, China Rehabilitation Research Center, School of Rehabilitation Medicine, Capital Medical University, Beijing, China.
Spinal Cord. 2008 Oct;46(10):696-702. doi: 10.1038/sc.2008.7. Epub 2008 Mar 11.
Case-control study.
To investigate the number of motor units from the tibialis anterior (TA) muscle in normal subject and its change after SCI.
China Rehabilitation Research Center, Beijing, China.
Motor unit number estimation (MUNE) in 45 control subjects (35 young subjects with an average age of 36 years, and 10 elderly subjects with an average age of 65 years) was performed by using adapted multiple point stimulation method (AMPS). Twenty patients with SCI (10 subacute patients with an average age of 39 years, and 10 chronic patients with an average age of 34 years) were also examined for three times in 3 months with the same method.
The mean MUNE value of the TA muscle was 188+/-20 in the control group, and 40+/-33 in subacute SCI patients (P<0.01 vs young controls). A continuous increase in the MUNE value was observed in subacute SCI patients during the later follow-up period. In the chronic SCI group, the mean MUNE value was 173+/-29 which was similar to that of young control group.
AMPS could be a useful procedure for quantifying changes of MUNE values after SCI. Changes in functional motor unit number may occur distal to the site of lesion in SCI patients. These phenomena may be caused by neuronal plasticity in motor units, reversible transsynaptic degeneration and/or local functional depression. Owing to the limited sample size and a wide age range of subjects recruited in this study, future study are warranted for revealing detailed changes of MUNE parameters after SCI and exploring the underlying mechanisms.
病例对照研究。
调查正常受试者胫前肌运动单位数量及其脊髓损伤后的变化。
中国北京中国康复研究中心。
采用改良多点刺激法（AMPS）对45名对照受试者（35名平均年龄36岁的年轻受试者和10名平均年龄65岁的老年受试者）进行运动单位数量估计（MUNE）。20例脊髓损伤患者（10例平均年龄39岁的亚急性患者和10例平均年龄34岁的慢性患者）也在3个月内用相同方法进行了3次检查。
对照组胫前肌MUNE平均值为188±20，亚急性脊髓损伤患者为40±33（与年轻对照组相比，P<0.01）。在亚急性脊髓损伤患者的后期随访中观察到MUNE值持续增加。慢性脊髓损伤组的平均MUNE值为173±29，与年轻对照组相似。
AMPS可能是量化脊髓损伤后MUNE值变化的有用方法。脊髓损伤患者功能性运动单位数量的变化可能发生在损伤部位的远端。这些现象可能是由运动单位中的神经元可塑性、可逆性跨突触变性和/或局部功能抑制引起的。由于本研究样本量有限且招募的受试者年龄范围较广，有必要进行进一步研究以揭示脊髓损伤后MUNE参数的详细变化并探索其潜在机制。
