title: Normal values for single fiber EMG parameters of frontalis muscle in healthy subjects older than 70 years.
abstract: OBJECTIVE
  Single fiber EMG (SFEMG) is a potent electrophysiological method to evaluate impaired neuromuscular transmission, and allows sensitive diagnosis of neuromuscular transmission abnormalities such as myasthenia gravis. The jitter and fiber density values are different for various muscles and age groups and the reference values increase with age. In this study, we evaluated the reference values of jitter and fiber density of frontalis muscle in healthy subjects older than 70 years.
  
  
  METHODS
  We evaluated the jitter and fiber density of frontalis muscle in 32 healthy subjects. Twenty-two of them were between 70 and 79 years old (mean +/- SD, 73.9 +/- 1.7), and 10 of them were older than 80 years (mean +/- SD, 82.2 +/- 1.2).
  
  
  RESULTS
  Normal limit of jitter (95% confidence limit) was calculated as 40.4 micros for healthy subjects between 70 and 79 years old and 43.7 micros for healthy subjects older than 80 years and normal limit of fiber density (95% confidence limit) were calculated as 1.90 for subjects between 70 and 79 years old and 2.14 for subjects older than 80 years.
  
  
  CONCLUSIONS
  We designated the reference values of jitter and fiber density for frontalis muscle in healthy subjects older than 70 years. Our reference values may have value to diagnose neuromuscular transmission abnormalities in elderly patients.
  
  
  CONCLUSIONS
  SFEMG is sensitive for neuromuscular transmission abnormalities and it is important to know the reference values of frontalis muscle in healthy subjects older than 70 years.
authors.affiliation: School of Medicine, Neurology Department, Trakya University, Edirne 22030, Turkey. kemalbalci@yahoo.com
authors.forename: Kemal
authors.initials: K
authors.lastname: Balci
authors.forename: Nilda
authors.initials: N
authors.lastname: Turgut
authors.forename: Gülay
authors.initials: G
authors.lastname: Nurlu
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001369:Axons / Q000502:physiology; D004576:Electromyography / Q000379:methods / Q000592:standards*; D005152:Facial Muscles / Q000294:innervation / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009046:Motor Neurons / Q000502:physiology; D009119:Muscle Contraction / Q000502:physiology*; D018485:Muscle Fibers, Skeletal / Q000502:physiology*; D009469:Neuromuscular Junction / Q000502:physiology*; D020511:Neuromuscular Junction Diseases / Q000175:diagnosis / Q000503:physiopathology; D012016:Reference Values; D009435:Synaptic Transmission / Q000502:physiology