Motor unit number estimation.

Since its introduction 30 years ago, MUNE techniques have increasingly been refined and applied to a wide variety of neuromuscular disorders. Differences of opinion remain among MUNE investigators as to which method is best; however, statistical and MPS MUNE are currently the most widely used. Numerous methodologic issues remain, including the development of detailed universal standards for each technique and the implementation of modifications for the enhancement of reproducibility. These issues are the subjects of ongoing investigation. Despite technical variability, the MUNE values obtained using different methods show good agreement in studies of normal subjects and in patients with a variety of neurogenic processes. MUNE has been applied most successfully to patients with amyotrophic lateral sclerosis and to animal models of motor neuron disease, providing significant insight into the pathophysiology of these disorders. These techniques are increasingly being incorporated into clinical therapeutic trials. MUNE offers promise in the study of neuromuscular disease, enabling the collection of novel data in the living patient unobtainable by any other method.