Jammes Y, Pouget J, Grimaud C, Serratrice G
Muscle Nerve. 1985 Sep;8(7):586-94. doi: 10.1002/mus.880080708.
Ten adult myotonic dystrophy patients underwent measurements of lung function, maximal dynamic and static ventilatory efforts, and respiratory muscle electromyography (EMG). EMG studies were performed during spontaneous breathing or when subjects breathed through high inspiratory or expiratory resistive loads. Present results show that (1) a moderate restriction of lung volumes with hypoxemia plus normocapnia is often observed; (2) patients sustain dynamic ventilatory efforts more easily than static work; and (3) abnormalities in respiratory muscle EMG exist with spontaneous expiratory and inspiratory intercostal activities during quiet breathing and changes in muscular response to resistive loads. Inspiratory loading evokes contraction of expiratory muscles, with a marked decrease in inspiratory activities. Expiratory resistive loads prolong the diaphragmatic contraction throughout the expiratory time, and in some patients, relaxation of the diaphragm does not occur during the loaded run. These EMG data suggest that the reciprocal inhibition among respiratory neurons is enhanced in myotonic dystrophy and that myotonia also occurs in the diaphragm when loads oppose its relaxation.
十名成年强直性肌营养不良患者接受了肺功能、最大动态和静态通气功能以及呼吸肌肌电图（EMG）测量。肌电图研究在自主呼吸期间或受试者通过高吸气或呼气阻力负荷呼吸时进行。目前的结果表明：（1）常观察到肺容量有中度受限，伴有低氧血症和正常碳酸血症；（2）患者维持动态通气功能比静态通气功能更容易；（3）在安静呼吸时，呼吸肌肌电图存在异常，表现为自发性呼气和吸气肋间活动，以及肌肉对阻力负荷反应的变化。吸气负荷会引起呼气肌收缩，吸气活动明显减少。呼气阻力负荷会使膈肌在整个呼气时间内持续收缩，在一些患者中，负荷期间膈肌不会放松。这些肌电图数据表明，强直性肌营养不良患者呼吸神经元之间的交互抑制增强，并且当负荷阻碍膈肌放松时，膈肌也会出现强直性收缩。
