Diaphragmatic Compound Muscle Action Potentials Correlate With the Clinical Severity of Myasthenia Gravis.

IF 2.8 3区医学 Q2 CLINICAL NEUROLOGY

Muscle & Nerve Pub Date : 2025-06-01 Epub Date: 2025-03-19 DOI:10.1002/mus.28397

Hirotomo Suehiro, Kenji Sekiguchi, Yoshikatsu Noda, Shun Matoba, Shunsuke Watanabe, Masahiro Hayashi, Masaaki Yoshikawa, Ryosuke Sugisawa, Riki Matsumoto

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引用次数: 0

Abstract

Introduction/aims: Patients with myasthenia gravis (MG) often experience impairment of respiratory function. Some case reports have explored the diaphragmatic compound muscle action potential (DCMAP) amplitudes in patients with MG using single-stimulus phrenic nerve conduction studies. Herein, we aimed to investigate whether the DCMAP amplitude correlated with the clinical severity of MG and whether this improved with treatment.

Methods: We retrospectively evaluated patients with MG who underwent right phrenic nerve conduction studies. We evaluated the patients' clinical characteristics and the clinical severity of MG, as assessed by compound muscle action potential (CMAP) amplitudes, and compared the CMAP amplitudes before and after treatment in patients with generalized MG (gMG).

Results: This study included 76 patients with MG (30 with ocular MG [OMG] and 46 with gMG). The median DCMAP amplitudes were significantly higher in OMG than in gMG (364 vs. 212 μV, p < 0.01). Receiver operating characteristic analysis showed that DCMAP amplitude < 256 μV distinguished gMG from OMG with 71.7% sensitivity and 93.3% specificity. The DCMAP amplitudes were moderately correlated with the MG activities of daily living score (p < 0.01, r = -0.52) and quantitative myasthenia gravis score (p < 0.01, r = -0.60). Median DCMAP amplitudes significantly increased in patients with gMG after treatment (from 184 to 336 μV, p < 0.01).

Discussion: DCMAP amplitudes may correlate with the clinical severity of MG, differentiate gMG from OMG, and reflect the treatment response. We propose that DCMAP measurement be included in the evaluation of patients with MG.

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膈复合肌动作电位与重症肌无力的临床严重程度相关。

简介/目的：重症肌无力（MG）患者经常出现呼吸功能障碍。一些病例报告利用单刺激膈神经传导研究了MG患者的膈复合肌动作电位（DCMAP）振幅。在这里，我们的目的是研究DCMAP振幅是否与MG的临床严重程度相关，以及这种相关性是否随着治疗而改善。方法：我们回顾性评估接受右膈神经传导检查的MG患者。我们评估了患者的临床特征和MG的临床严重程度，通过复合肌肉动作电位（CMAP）振幅来评估，并比较了广泛性MG （gMG）患者治疗前后的CMAP振幅。结果：本研究纳入76例MG患者（30例眼部MG [OMG]， 46例gMG）。OMG组DCMAP的中位振幅明显高于gMG组（364 μV vs 212 μV）。讨论：DCMAP振幅可能与MG的临床严重程度相关，可以区分gMG和OMG，并反映治疗效果。我们建议将DCMAP测量纳入MG患者的评估中。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Muscle & Nerve 医学-临床神经学

CiteScore

6.40

自引率

5.90%

发文量

287

审稿时长

3-6 weeks

期刊介绍： Muscle & Nerve is an international and interdisciplinary publication of original contributions, in both health and disease, concerning studies of the muscle, the neuromuscular junction, the peripheral motor, sensory and autonomic neurons, and the central nervous system where the behavior of the peripheral nervous system is clarified. Appearing monthly, Muscle & Nerve publishes clinical studies and clinically relevant research reports in the fields of anatomy, biochemistry, cell biology, electrophysiology and electrodiagnosis, epidemiology, genetics, immunology, pathology, pharmacology, physiology, toxicology, and virology. The Journal welcomes articles and reports on basic clinical electrophysiology and electrodiagnosis. We expedite some papers dealing with timely topics to keep up with the fast-moving pace of science, based on the referees'' recommendation.