Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.
Department of Neurology, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, China.
Muscle Nerve. 2024 Oct;70(4):800-807. doi: 10.1002/mus.28220. Epub 2024 Jul 31.
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.
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.
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.
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.
简介/目的：尽管相关报道较少，但 F 波测试常可显示原发性周围神经兴奋性过高综合征（PNHS）患者的各种形态的节后放电。本研究旨在探讨 F 波测试中 PNHS 患者节后放电的形态学特征，并评估节后放电与疾病分类之间的关系。
我们对 2014 年至 2022 年间诊断为 PNHS 的患者进行了回顾性分析。分析 F 波测试中节后放电的形态特征和持续时间。比较莫旺综合征组和非莫旺组之间以及电压门控钾通道（VGKC）复合物抗体阳性或阴性组之间的节后放电。
本研究共纳入 29 例患者，其中 25 例出现节后放电。莫旺患者的所有节后放电均发生在复合肌肉动作电位（CMAP）之后。非莫旺患者的节后放电发生在 F 波（32%）和 CMAP（47%）之后。CMAP 后的节后放电持续时间在莫旺患者（54.2±18.8 ms）明显长于非莫旺患者（34.5±15.0 ms）。20 例抗体阳性患者（18/20）中的大多数出现 CMAP 后的节后放电，而 9 例抗体阴性患者（6/9）中有 67%出现 F 波后的节后放电。
不同表现形式的节后放电，包括其位置（CMAP 后或 F 波后）和节后放电的持续时间，可有助于临床上对 PNHS 进行分类。
