Dupont Salter Anne-Caroline, Richmond Frances J R, Loeb Gerald E
Queen's University, Kingston, ON K7L 3N6, Canada.
IEEE Trans Neural Syst Rehabil Eng. 2003 Sep;11(3):218-26. doi: 10.1109/TNSRE.2003.817674.
When muscles lose neural drive, they atrophy rapidly. Neuromuscular electrical stimulation (NMS) has been used in attempts to prevent or reverse the atrophy, but optimal stimulation programs and parameters are not well defined. In this study, we investigated the effects of four different stimulation patterns on disuse atrophy produced in the tibialis anterior, lateral gastrocnemius, and soleus muscles of rats paralyzed with tetrodotoxin for seven days. Stimulation paradigms differed from one another by their stimulation frequency (2 or 10 pulses/s) and by their stimulation period (2 or 10 h a day). Results showed that stimulation with 2 pulses/s, paradigms were more effective at preventing disuse muscle atrophy than higher-frequency stimulation. The most marked difference was in the slow soleus muscle, which had only 10% mean atrophy when stimulated at 2 pulses/s for 10 h, compared to 26% atrophy when stimulated at 10 pulses/s for either 2 or 10 h and 32% atrophy in unstimulated, paralyzed controls. The level of atrophic change was not correlated with the levels of serum creatine kinase, used as an index of muscle damage. Results suggest that remediation of disuse atrophy may be accomplished using unphysiologically low rates of motor-unit activation despite the relatively low force produced by such unfused contractions. This may have significant implications for the design of therapies for muscle paralysis consequent to upper-motoneuron lesions.
当肌肉失去神经驱动时，它们会迅速萎缩。神经肌肉电刺激（NMS）已被用于尝试预防或逆转萎缩，但最佳刺激方案和参数尚未明确界定。在本研究中，我们调查了四种不同刺激模式对用河豚毒素麻痹7天的大鼠胫前肌、外侧腓肠肌和比目鱼肌产生的废用性萎缩的影响。刺激模式在刺激频率（2或10脉冲/秒）和刺激时长（每天2或10小时）方面彼此不同。结果表明，2脉冲/秒的刺激模式在预防废用性肌肉萎缩方面比高频刺激更有效。最显著的差异出现在慢肌比目鱼肌中，当以2脉冲/秒刺激10小时时，平均萎缩仅为10%，相比之下，以10脉冲/秒刺激2或10小时时萎缩为26%，未刺激的麻痹对照组萎缩为32%。萎缩变化程度与用作肌肉损伤指标的血清肌酸激酶水平无关。结果表明，尽管这种非融合收缩产生的力量相对较低，但使用非生理性的低运动单位激活率可能实现废用性萎缩的修复。这可能对上运动神经元损伤导致的肌肉麻痹的治疗设计具有重要意义。
