[Double discharges of motor unit -- importance in electromyographic diagnosis]

The prevalence of double-discharge motor unit potentials (DD) in patients with neuromuscular disorders was analysed. Concentric needle electromyography was performed in 29 cases of spinal muscular atrophy (SMA), 25 cases of amyotrophic lateral sclerosis (ALS), 30 cases of Duchenne muscular dystrophy (DMD) and in 20 healthy controls. The DD were recorded only in the patients with neurogenic lesion, mainly in the ALS group. The diagnostic yield of DD in early detection of neurogenic lesion is discussed.