Clinical, Metabolic and Molecular Physiology, MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, University of Nottingham, Nottingham, United Kingdom.
Department of Physical Medicine and Rehabilitation - Clinical Neurophysiology, Jiménez Díaz Foundation University Hospital, Madrid, Spain.
Clin Neurophysiol. 2021 May;132(5):1089-1104. doi: 10.1016/j.clinph.2021.02.008. Epub 2021 Mar 10.
Describe and evaluate the concepts of near fiber electromyography (NFEMG), the features used, including near fiber motor unit potential (NFMUP) duration and dispersion, which relate to motor unit distal axonal branch and muscle fiber conduction time dispersion, and NFMUP segment jitter, a new measure of the temporal variability of neuromuscular junction transmission (NMJ), and axonal branch and muscle fibre conduction for the near fibres (i.e. NF jitter), and the methods for obtaining their values.
Trains of high-pass filtered motor unit potentials (MUPs) (i.e. NFMUP trains) were extracted from needle-detected EMG signals to assess changes in motor unit (MU) morphology and electrophysiology caused by neuromuscular disorders or ageing. Evaluations using simulated needle-detected EMG data were completed and example human data are presented.
NFEMG feature values can be used to detect axonal sprouting, conduction slowing and NMJ transmission delay as well as changes in MU fiber diameter variability, and NF jitter. These changes can be detected prior to alterations of MU size or numbers.
The evaluations clearly demonstrate and the example data support that NFMUP duration and dispersion reflect MU distal axonal branching, conduction slowing and NMJ transmission delay and/or MU fiber diameter variability and that NFMUP jiggle and segment jitter reflect NF jitter.
NFEMG can detect early changes in MU morphology and/or electrophysiology and has the potential to augment clinical diagnosis and tracking of neuromuscular disorders.
描述和评估近纤维肌电图（NFEMG）的概念，包括近纤维运动单位电位（NFMUP）的持续时间和离散度，这些与运动单位末梢轴突分支和肌纤维传导时间的离散度有关，以及 NFMUP 节距抖动，这是一种新的神经肌肉接头（NMJ）传递时间变异性的测量方法，以及近纤维的轴突分支和肌纤维传导（即 NF 抖动），以及获得其值的方法。
从针检测肌电图信号中提取高通滤波的运动单位电位（MUP）（即 NFMUP 列车），以评估神经肌肉疾病或衰老引起的运动单位（MU）形态和电生理学的变化。使用模拟针检测肌电图数据完成了评估，并展示了示例人类数据。
NFEMG 特征值可用于检测轴突发芽、传导减慢和 NMJ 传输延迟以及 MU 纤维直径变异性和 NF 抖动的变化。这些变化可以在 MU 大小或数量发生变化之前检测到。
评估结果清楚地表明，示例数据支持 NFMUP 持续时间和离散度反映 MU 末梢轴突分支、传导减慢和 NMJ 传输延迟和/或 MU 纤维直径变异性，而 NFMUP 抖动和节距抖动反映 NF 抖动。
NFEMG 可以检测 MU 形态和/或电生理学的早期变化，并有可能增强神经肌肉疾病的临床诊断和跟踪。
