title: Motor unit number estimation: a technology and literature review.
abstract: BACKGROUND
  Numerous methods for motor unit number estimation (MUNE) have been developed. The objective of this article is to summarize and compare the major methods and the available data regarding their reproducibility, validity, application, refinement, and utility.
  
  
  METHODS
  Using specified search criteria, a systematic review of the literature was performed. Reproducibility, normative data, application to specific diseases and conditions, technical refinements, and practicality were compiled into a comprehensive database and analyzed.
  
  
  RESULTS
  The most commonly reported MUNE methods are the incremental, multiple-point stimulation, spike-triggered averaging, and statistical methods. All have established normative data sets and high reproducibility. MUNE provides quantitative assessments of motor neuron loss and has been applied successfully to the study of many clinical conditions, including amyotrophic lateral sclerosis and normal aging.
  
  
  CONCLUSIONS
  MUNE is an important research technique in human subjects, providing important data regarding motor unit populations and motor unit loss over time.
authors.affiliation: Department of Neurology, University of South Florida, Tampa, Florida, USA.
authors.forename: Clifton L
authors.initials: CL
authors.lastname: Gooch
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Doherty
authors.forename: K Ming
authors.initials: KM
authors.lastname: Chan
authors.forename: Mark B
authors.initials: MB
authors.lastname: Bromberg
authors.forename: Richard A
authors.initials: RA
authors.lastname: Lewis
authors.forename: Dan W
authors.initials: DW
authors.lastname: Stashuk
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Berger
authors.forename: Michael T
authors.initials: MT
authors.lastname: Andary
authors.forename: Jasper R
authors.initials: JR
authors.lastname: Daube
mesh_terms: D000200:Action Potentials / Q000502:physiology; D035843:Biomedical Research / Q000379:methods*; D002452:Cell Count / Q000379:methods*; D004558:Electric Stimulation; D004594:Electrophysiology / Q000379:methods*; D006801:Humans; D009046:Motor Neurons / Q000166:cytology* / Q000502:physiology; D009431:Neural Conduction / Q000502:physiology; D015203:Reproducibility of Results
keywords: aging; amyotrophic lateral sclerosis; compound muscle action potential; motor unit; motor unit number estimation