OBJECTIVE Phrenic nerve conduction study is a marker of hypoventilation in amyotrophic lateral sclerosis. We aimed to evaluate its intra-rater reliability in healthy subjects and in a cohort of Primary Lateral Sclerosis (PLS) patients. METHODS Eighteen healthy subjects and 16 PLS patients were included. All subjects underwent three phrenic nerve conduction evaluations (time interval: 1 week for healthy controls; 1 year for PLS patients). We analyzed intra-rater reliability for five parameters of the diaphragmatic motor response: latency; negative-peak duration, area and amplitude; peak-to-peak amplitude. RESULTS Healthy subjects showed excellent inter-test reliability for most parameters (coefficients of variation <10%). In PLS patients coefficients of variation resulted <10% for latency and peak-to-peak amplitude, <20% for remaining parameters. Inter-test reliability was excellent for latency and peak-to-peak amplitude [intra-class correlation coefficient (ICC) > 0.9] and good for negative-peak amplitude and area (ICC 0.75 ≥ 0.9); duration was not reliable (ICC = 0.383). Negative peak and peak-to-peak amplitude had the least random error (respectively ±0.136 mV and ± 0.177 mV). All parameters showed homoscedasticity (R2 < 0.1). CONCLUSIONS Intra-rater reliability is high for phrenic nerve study, especially for latency, peak-to-peak and negative-peak amplitude. SIGNIFICANCE Phrenic nerve conduction study is a reliable method to monitor respiratory function.

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膈神经传导研究的可靠性：在健康对照和原发性侧索硬化患者中

目的 膈神经传导研究是肌萎缩侧索硬化患者换气不足的标志。我们旨在评估其在健康受试者和一组原发性侧索硬化 (PLS) 患者中的评分者内可靠性。方法 包括 18 名健康受试者和 16 名 PLS 患者。所有受试者均接受了 3 次膈神经传导评估（时间间隔：健康对照为 1 周；PLS 患者为 1 年）。我们分析了膈肌运动反应的五个参数的评分者内可靠性：潜伏期；负峰值持续时间、面积和幅度；峰峰值幅度。结果 健康受试者对大多数参数（变异系数 <10%）表现出出色的测试间可靠性。在 PLS 患者中，潜伏期和峰峰值幅度的变异系数 <10%，< 20% 用于剩余参数。延迟和峰峰值幅度[类内相关系数（ICC）> 0.9]和负峰幅度和面积（ICC 0.75 ≥ 0.9）的测试间可靠性非常好；持续时间不可靠（ICC = 0.383）。负峰值和峰峰值幅度具有最小的随机误差（分别为 ±0.136 mV 和 ± 0.177 mV）。所有参数均表现出同方差性（R2 < 0.1）。结论 对于膈神经研究，评分者内的可靠性很高，尤其是对于潜伏期、峰峰值和负峰幅度。意义 膈神经传导研究是监测呼吸功能的可靠方法。持续时间不可靠（ICC = 0.383）。负峰值和峰峰值幅度具有最小的随机误差（分别为 ±0.136 mV 和 ± 0.177 mV）。所有参数均表现出同方差性（R2 < 0.1）。结论 对于膈神经研究，评分者内的可靠性很高，尤其是对于潜伏期、峰峰值和负峰幅度。意义 膈神经传导研究是监测呼吸功能的可靠方法。持续时间不可靠（ICC = 0.383）。负峰值和峰峰值幅度具有最小的随机误差（分别为 ±0.136 mV 和 ± 0.177 mV）。所有参数均表现出同方差性（R2 < 0.1）。结论 对于膈神经研究，评分者内的可靠性很高，尤其是对于潜伏期、峰峰值和负峰幅度。意义 膈神经传导研究是监测呼吸功能的可靠方法。