Quantitative electrodiagnosis of the motor unit.
Handb Clin Neurol
; 195: 271-286, 2023.
Article
en En
| MEDLINE
| ID: mdl-37562872
ABSTRACT
Electromyography (EMG) focuses on assessment of the motor unit (MU), and a given muscle has several hundred MUs, each innervating hundreds of muscle fibers. Assessment is limited by the recording radius of electrodes, 1-2 fibers with single-fiber electrodes and 7-15 fibers with concentric or monopolar electrodes. Routine qualitative EMG studies rely on observing MUs in free-run mode and qualitatively estimating common metrics. In contrast, quantitative EMG (QEMG) applied to routine studies includes assessment of individual MUs by software available in modern EMG machines with extraction of discrete values for common metrics, and also derived metrics. This results in greater precision and statistical interpretation. Other QEMG techniques assess muscle fiber density within the MU and time variability at the neuromuscular junction. The interference pattern can also be assessed. The number of MUs innervating a muscle can be estimated. Advanced signal processing, called near-fiber EMG, allows for extraction of underlying muscle fiber contributions to MU waveforms. It is also possible to use QEMG to make statistical probabilities of the state of a muscle as to whether normal, myopathic, or neuropathic. Time to acquire QEMG data is minimal. QEMG is most useful in situations where pathology is uncertain.
Palabras clave
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Fibras Musculares Esqueléticas
/
Unión Neuromuscular
Tipo de estudio:
Qualitative_research
Límite:
Humans
Idioma:
En
Revista:
Handb Clin Neurol
Año:
2023
Tipo del documento:
Article