Abstract: ObjectiveTo compare the clinical significance of motor unit number estimates (MUNE) and conventional electromyogram (EMG) in the evaluation of neuromuscular disorders. MethodsUnder the model of MUNE or quantity of motor unit potential (QMUP), 53 patients with various neurogenic disorders were tested with EMG at extensor digitorum brevis, thenar, or hypothenar eminence. ResultsFor 8 patients with amyotrophic lateralizing sclerosis, large and long-duration polyphasic potentials were detected in needle electrode EMG tests, and the motor unit numbers reduced. For 45 patients with peripheral neuropathies, few distinctive features could not be detected by needle electrode EMG, but motor unit numbers reduced in 2 patients; spontaneous activities were the only abnormality in the other 2 patients, and there were no obviously abnormal changes in the configuration and size of motor unit potentials and in motor unit numbers; EMG tests revealed neurogenic features and motor unit numbers significantly reduced in the remaining 41 patients. ConclusionConventional EMG and MUNE can work for the diagnosis of neuromuscular disorders, and do better in combination.

Key words: motor unit number estimates (MUNE), motor unit potential, neuromuscular disorder, electromyogram, diagnosis