Clinical application of electrophysiology in amyotrophic lateral sclerosis

Abstract

This presentation is a general introduction to the clinical application of various neurophysiological examination methods in amyotrophic lateral sclerosis (ALS), including nerve conduction, F wave, needle electrode electromyography (EMG), repetitive electrical nerve stimulation (RNS), single fiber electromyography (SFEMG), and magnetic stimulation of motor evoked potentials (MEP). EMG is an important objective indicator for the early diagnosis of ALS. It is widely abnormal in distribution and characterized by the coexistence of progressive and chronic denervation. The former mainly refers to abnormal spontaneous potential (fibrillation potential, positive sharp wave and fasciculation potentials). The purpose of nerve conduction testing is to exclude peripheral neuropathy and diseases with clinical manifestations similar to ALS. Sensory nerve conduction is usually normal in ALS. RNS and SFEMG are not necessary and specific detection methods for the diagnosis of ALS, RNS mainly reflects neuromuscular transmission of joint function, and the increased jitter, block and high fiber density which suggest progressive loss of nerve by SFEMG support the diagnosis of ALS, but they are not conventional detection methods of ALS. Magnetic stimulation MEP is an objective method to evaluate pyramidal tract damage. Key words: Amyotrophic lateral sclerosis; Electrophysiology; Electromyography; Neural conduction