title: Motor unit number index (MUNIX).
abstract: The surface-recorded compound muscle action potential (CMAP) and electromyographic (EMG) interference pattern is used to compute the motor unit number index (MUNIX). The MUNIX demonstrated all known changes in the number of motor units in normal subjects, and in patients with amyotrophic lateral sclerosis (ALS). In normal subjects MUNIX decreased slightly with age and showed excellent reproducibility. In many ALS patients MUNIX was reduced even when the CMAP was normal. Lower MUNIX values were seen in weaker muscles. This is a noninvasive method that requires minimal electrical stimulation. It is performed in less than 5 min. This makes it suitable for serial EMG investigations.
authors.affiliation: Oxford Instruments, 12 Skyline Drive, Hawthorne, NY 10532, USA. sanjeev@casaengineering.com
authors.forename: Sanjeev D
authors.initials: SD
authors.lastname: Nandedkar
authors.forename: Desh S
authors.initials: DS
authors.lastname: Nandedkar
authors.forename: Paul E
authors.initials: PE
authors.lastname: Barkhaus
authors.forename: Erik V
authors.initials: EV
authors.lastname: Stalberg
mesh_terms: D000200:Action Potentials; D000328:Adult; D000368:Aged; D000465:Algorithms; D000690:Amyotrophic Lateral Sclerosis / Q000175:diagnosis* / Q000503:physiopathology; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D004576:Electromyography / Q000379:methods*; D006801:Humans; D008875:Middle Aged; D009046:Motor Neurons; D018485:Muscle Fibers, Skeletal; D018482:Muscle, Skeletal / Q000503:physiopathology*