Abstract:Objective To investigate the diagnostic value of needle electromyography in amyotrophic lateral sclerosis. Methods Totally 33 patients with amyotrophic lateral sclerosis treated in our hospital from June 2014 to June 2017 were enrolled in this study. The amplitude of compound muscle action potential and EMG of different regions were compared in patients with different nerve stimulation (RNS), and the effects of respiratory disorders on EMG of patients were compared. Results Among the 33 patients, the RNS of accessory nerve decreased gradually at low frequencies in 16 patients (48.48%), ranging from 15% to 46%. The number of decreasing positive cases at 1 Hz and 3 Hz was 9 (27.27%) and 16 (48.48%), respectively, but decreasing cases with 3 Hz covered all positive results. EMG showed extensive neurogenic damage, positive sharp wave and fibrillation potential, and bundle fibrillation potential appeared in 15 patients. The incidence of EMG spontaneous potential of rectus abdominis needle pole in the group with respiratory disorder was higher than that in the group without respiratory disorder (P < 0.05). Conclusions The amplitude of compound muscle action potential will decrease gradually in patients with amyotrophic lateral sclerosis when there are low frequencies in the RNS of accessory nerve. There were extensive neurogenic damages in patients with amyotrophic lateral sclerosis. The main spontaneous potentials were positive sharp wave and fibrillation potential, and EMG can help to diagnose respiratory disorders.