title: Toward the validation of a new method (MUNIX) for motor unit number assessment.
abstract: BACKGROUND
  This prospectively designed study analyzed the correlation of a new, non-invasive neurophysiological method (Motor Unit Number Index - MUNIX) with two established Motor Unit Number Estimation (MUNE) methods.
  
  
  METHODS
  MUNIX and incremental stimulation MUNE (IS-MUNE) were done in the abductor digiti minimi muscle (ADM), while MUNIX and spike-triggered averaging MUNE (STA-MUNE) were tested in the trapezius muscle. Twenty healthy subjects and 17 patients with amyotrophic lateral sclerosis (ALS) were examined.
  
  
  RESULTS
  MUNIX and MUNE values correlated significantly (ADM: n=108; Spearman-Rho; r=0.88; p<0.01; trapezius muscle: n=49; Spearman-Rho; r=0.46; p<0.01).
  
  
  CONCLUSIONS
  MUNIX indeed reflects the number of motor units in a muscle, and may sensibly be recorded from the trapezius muscle. With MUNIX being both much more patient friendly and much more rapid to assess than MUNE, the results support the use of MUNIX when motor unit number assessment is desired.
authors.affiliation: Department of Neurology, University Hospital Regensburg, Regensburg, Germany.
authors.forename: Franziska
authors.initials: F
authors.lastname: Stein
authors.affiliation: Department of Neurology, University Hospital Regensburg, Regensburg, Germany.
authors.forename: Ines
authors.initials: I
authors.lastname: Kobor
authors.affiliation: Department of Neurology, University Hospital Regensburg, Regensburg, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Bogdahn
authors.affiliation: Department of Neurology, University Hospital Regensburg, Regensburg, Germany. Electronic address: wilhelm.schulte-mattler@klinik.uni-regensburg.de.
authors.forename: Wilhelm J
authors.initials: WJ
authors.lastname: Schulte-Mattler
mesh_terms: D000010:Abducens Nerve / Q000502:physiology; D000200:Action Potentials / Q000502:physiology; D000328:Adult; D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000175:diagnosis* / Q000503:physiopathology*; D004576:Electromyography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009046:Motor Neurons / Q000502:physiology*; D011446:Prospective Studies; D011999:Recruitment, Neurophysiological / Q000502:physiology*; D064171:Superficial Back Muscles / Q000502:physiology; D055815:Young Adult
keywords: Amyotrophic lateral sclerosis; Incremental stimulation motor unit number estimation; Motor unit number estimation; Motor unit number index; Spike-triggered averaging motor unit number estimation