Diaphragm weakness in Charcot‐Marie‐Tooth disease 1A (CMT1A) is usually associated with severe disease manifestation. This study comprehensively investigated phrenic nerve conductivity, inspiratory and expiratory muscle function in ambulatory CMT1A patients. Nineteen adults with CMT1A (13 females, 47 ± 12 years) underwent spiromanometry, diaphragm ultrasound, and magnetic stimulation of the phrenic nerves and the lower thoracic nerve roots, with recording of diaphragm compound muscle action potentials (dCMAP, n = 15), transdiaphragmatic and gastric pressures (twPdi and twPgas, n = 12). Diaphragm motor evoked potentials (dMEP, n = 15) were recorded following cortical magnetic stimulation. Patients had not been selected for respiratory complaints. Disease severity was assessed using the CMT Neuropathy Scale version 2 (CMT‐NSv2). Healthy control subjects were matched for age, sex, and body mass index. The following parameters were significantly lower in CMT1A patients than in controls (all P < .05): forced vital capacity (91 ± 16 vs 110 ± 15% predicted), maximum inspiratory pressure (68 ± 22 vs 88 ± 29 cmH₂O), maximum expiratory pressure (91 ± 23 vs 123 ± 24 cmH₂O), and peak cough flow (377 ± 135 vs 492 ± 130 L/min). In CMT1A patients, dMEP and dCMAP were delayed. Patients vs controls showed lower diaphragm excursion (5 ± 2 vs 8 ± 2 cm), diaphragm thickening ratio (DTR, 1.9 [1.6‐2.2] vs 2.5 [2.1‐3.1]), and twPdi (8 ± 6 vs 19 ± 7 cmH₂O; all P < .05). DTR inversely correlated with the CMT‐NSv2 score (r = −.59, P = .02). There was no group difference in twPgas following abdominal muscle stimulation. Ambulatory CMT1A patients may show phrenic nerve involvement and reduced respiratory muscle strength. Respiratory muscle weakness can be attributed to diaphragm dysfunction alone. It relates to neurological impairment and likely reflects a disease continuum.

中文翻译：

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Charcot-Marie-Tooth病1A患者的神经受累和呼吸肌无力。

Charcot-Marie-Tooth疾病1A（CMT1A）的肌无力通常与严重的疾病表现有关。这项研究全面调查了非卧床CMT1A患者的nerve神经传导性，吸气和呼气肌肉功能。19名CMT1A成人（13名女性，47±12岁）接受了旋压计，diaphragm肌超声检查以及ultrasound神经和胸下部神经根的磁刺激，并记录了diaphragm肌复合肌肉动作电位（dCMAP，n = 15），经dia肌和胃压（twPdi和twPgas，n = 12）。皮层磁刺激后记录下肌运动诱发电位（dMEP，n = 15）。尚未选择呼吸道疾病患者。使用CMT神经病变量表2版（CMT-NSv2）评估疾病的严重程度。将健康对照受试者的年龄，性别和体重指数进行匹配。CMT1A患者的以下参数显着低于对照组（所有P  <.05）：强制肺活量（预测的91±16 vs 110±15％），最大吸气压力（68±22 vs 88±29 cmH ₂ O），最大呼气压力（91±23 vs 123±24 cmH ₂ O）和峰值咳嗽流量（377±135 vs 492±130 L / min）。在CMT1A患者中，dMEP和dCMAP被延迟。患者vs对照者显示较低的lower肌偏移（5±2 vs 8±2 cm），diaphragm肌增厚率（DTR，1.9 [1.6-2.2] vs 2.5 [2.1-3.1]）和twPdi（8±6 vs 19±7 cmH ₂ O；所有P  <.05）。DTR与CMT-NSv2分数成反比关系（r = −.59，P= .02）。腹部肌肉刺激后，twPgas两组无差异。动态CMT1A患者可能显示involvement神经受累，呼吸肌力量降低。呼吸肌无力可单独归因于diaphragm肌功能障碍。它与神经功能障碍有关，可能反映出疾病的连续性。