Abstract：
Myalgic encephalomyelitis is an invalidating chronic disease often associated with exercise-induced alterations of muscle membrane excitability (M wave). No simultaneous measurements of maximal isometric force production and sarcolemma fatigue in the same muscle group have been previously reported. We hypothesized that M wave alterations could be partly responsible for the reduced muscle force present in this invalidating disease.
This retrospective study compared two groups of patients who presented (n = 30) or not (n = 28) alterations of M waves evoked by direct muscle stimulation during and after a cycling exercise bout. The maximal handgrip strength was measured before and after exercise, concomitantly with electromyogram recordings from flexor digitorum longus muscle. The patients also answered a questionnaire to identify eventual exacerbation of their clinical symptoms following the exercise test.
The M wave amplitude significantly decreased in muscles and the M wave duration significantly increased in the group of patients with M wave alterations after exercise. Resting values of handgrip were significantly lower in patients with exercise-induced M-wave alterations than in patients without M-wave abnormalities. In patients with exercise-induced M-wave alterations, handgrip significantly decreased after exercise and the changes in handgrip and M wave were positively correlated. The frequency of post-exertion malaise, increased fatigue, myalgia, headache and cognitive dysfunction was significantly higher in patients with M-wave alterations and variations in handgrip after exercise.
These data suggest that post-exercise sarcolemma fatigue often measured in patients with myalgic encephalomyelitis could be the cause of muscle failure.
This retrospective study compared two groups of patients who presented (n = 30) or not (n = 28) alterations of M waves evoked by direct muscle stimulation during and after a cycling exercise bout. The maximal handgrip strength was measured before and after exercise, concomitantly with electromyogram recordings from flexor digitorum longus muscle. The patients also answered a questionnaire to identify eventual exacerbation of their clinical symptoms following the exercise test.
The M wave amplitude significantly decreased in muscles and the M wave duration significantly increased in the group of patients with M wave alterations after exercise. Resting values of handgrip were significantly lower in patients with exercise-induced M-wave alterations than in patients without M-wave abnormalities. In patients with exercise-induced M-wave alterations, handgrip significantly decreased after exercise and the changes in handgrip and M wave were positively correlated. The frequency of post-exertion malaise, increased fatigue, myalgia, headache and cognitive dysfunction was significantly higher in patients with M-wave alterations and variations in handgrip after exercise.
These data suggest that post-exercise sarcolemma fatigue often measured in patients with myalgic encephalomyelitis could be the cause of muscle failure.
摘要：
背景：肌痛性脑脊髓炎是一种无效的慢性疾病，通常与运动引起的肌膜兴奋性改变（M波）有关。以前没有同时测量同一肌肉群中的最大等距力产生和肌膜疲劳的报道。我们假设M波改变可能是这种无效疾病中肌肉力量降低的部分原因。
方法：这项回顾性研究比较了两组患者在骑自行车运动期间和之后出现（n=30）或没有（n=28）直接肌肉刺激引起的M波改变。运动前后测量最大握力，伴随着指长屈肌的肌电图记录。患者还回答了问卷调查，以确定运动测试后其临床症状的最终恶化。
结果：运动后出现M波改变的患者组，肌肉中M波振幅显著降低，M波持续时间显著增加。运动引起的M波改变的患者的手柄静息值显着低于无M波异常的患者。在运动引起的M波改变的患者中，运动后握力显着下降，握力和M波的变化呈正相关。运动后不适的频率，增加疲劳，肌痛，运动后M波改变和握力变化的患者头痛和认知功能障碍明显升高。
结论：这些数据表明，肌能性脑脊髓炎患者经常测量的运动后肌膜疲劳可能是肌肉衰竭的原因。
方法：这项回顾性研究比较了两组患者在骑自行车运动期间和之后出现（n=30）或没有（n=28）直接肌肉刺激引起的M波改变。运动前后测量最大握力，伴随着指长屈肌的肌电图记录。患者还回答了问卷调查，以确定运动测试后其临床症状的最终恶化。
结果：运动后出现M波改变的患者组，肌肉中M波振幅显著降低，M波持续时间显著增加。运动引起的M波改变的患者的手柄静息值显着低于无M波异常的患者。在运动引起的M波改变的患者中，运动后握力显着下降，握力和M波的变化呈正相关。运动后不适的频率，增加疲劳，肌痛，运动后M波改变和握力变化的患者头痛和认知功能障碍明显升高。
结论：这些数据表明，肌能性脑脊髓炎患者经常测量的运动后肌膜疲劳可能是肌肉衰竭的原因。
