{"title":"Characteristics of after-discharges following compound muscle action potential or F-wave in primary peripheral nerve hyperexcitability syndrome.","authors":"Youfang Hu, Qingyun Ding, Xinhong Feng, Wu Yimin, Dongchao Shen, Jiayu Shi, Shuang Wu, Liying Cui, Yuzhou Guan","doi":"10.1002/mus.28220","DOIUrl":null,"url":null,"abstract":"<p><strong>Introduction/aims: </strong>F-wave testing frequently reveals after-discharges of varied morphologies in patients with primary peripheral nerve hyperexcitability syndrome (PNHS), although reports are scant. This study aimed to explore the morphological characteristics of the after-discharges during F-wave tests in PNHS, and to assess the association between after-discharges and the disease classification.</p><p><strong>Methods: </strong>We conducted a retrospective analysis of patients diagnosed with PNHS between 2014 and 2022. The morphological characteristic and duration of after-discharges during F-wave tests were analyzed. After-discharges in the Morvan syndrome group were compared with those in non-Morvan group, and between groups with positive or negative voltage-gated potassium channel (VGKC) complex antibodies.</p><p><strong>Results: </strong>Twenty-nine patients were included in the study, of which 25 exhibited after-discharges. All after-discharges in Morvan patients occurred following compound muscle action potential (CMAP). In non-Morvan patients, after-discharges occurred following F-wave (32%) and CMAP (47%). The durations of after-discharges following CMAP were significantly prolonged in Morvan (54.2 ± 18.8 ms) compared to non-Morvan patients (34.5 ± 15.0 ms). The majority of antibody-positive patients (18/20) exhibited after-discharges following CMAP, whereas 67% of antibody-negative patients (6/9) showed after-discharges following F-wave.</p><p><strong>Discussion: </strong>The varying presentations of after-discharges, including their location (after CMAP or F-wave) and the duration of after-discharge can assist in clinically classifying PNHS.</p>","PeriodicalId":18968,"journal":{"name":"Muscle & Nerve","volume":null,"pages":null},"PeriodicalIF":2.8000,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Muscle & Nerve","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1002/mus.28220","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CLINICAL NEUROLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Introduction/aims: F-wave testing frequently reveals after-discharges of varied morphologies in patients with primary peripheral nerve hyperexcitability syndrome (PNHS), although reports are scant. This study aimed to explore the morphological characteristics of the after-discharges during F-wave tests in PNHS, and to assess the association between after-discharges and the disease classification.
Methods: We conducted a retrospective analysis of patients diagnosed with PNHS between 2014 and 2022. The morphological characteristic and duration of after-discharges during F-wave tests were analyzed. After-discharges in the Morvan syndrome group were compared with those in non-Morvan group, and between groups with positive or negative voltage-gated potassium channel (VGKC) complex antibodies.
Results: Twenty-nine patients were included in the study, of which 25 exhibited after-discharges. All after-discharges in Morvan patients occurred following compound muscle action potential (CMAP). In non-Morvan patients, after-discharges occurred following F-wave (32%) and CMAP (47%). The durations of after-discharges following CMAP were significantly prolonged in Morvan (54.2 ± 18.8 ms) compared to non-Morvan patients (34.5 ± 15.0 ms). The majority of antibody-positive patients (18/20) exhibited after-discharges following CMAP, whereas 67% of antibody-negative patients (6/9) showed after-discharges following F-wave.
Discussion: The varying presentations of after-discharges, including their location (after CMAP or F-wave) and the duration of after-discharge can assist in clinically classifying PNHS.
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.