title: Concentric needle jitter on stimulated Orbicularis Oculi in 50 healthy subjects.
abstract: OBJECTIVE
  The aim of this study was to estimate the jitter parameters in healthy controls in stimulated Orbicularis Oculi (OOc) muscle using concentric needle electrode (CNE).
  
  
  METHODS
  Fifty healthy subjects, 13 males and 37 females (21-56 years, mean age of 38±9.2 years) were studied. The zygomatic branch of facial nerve was stimulated with a bar electrode. Jitter was expressed as the mean consecutive difference (MCD). Filter settings 1000 Hz-10 kHz.
  
  
  RESULTS
  The mean MCD from individual studies (n=50, Gaussian distribution) was 21.5±1.99 μs (median=21 μs), ranging from 17.8 to 26 μs (upper limit, 97.5%, 25.5 μs). The mean and median MCD from all potentials (n=1500, non-Gaussian distribution) were 21.6 and 21 μs, ranging from 7.1 to 39 μs (upper limit, 97.5%, 33.4 μs).
  
  
  CONCLUSIONS
  Suggested practical limits in the OOc for mean MCD was 26 μs and for outliers 34 μs.
  
  
  CONCLUSIONS
  Stimulation jitter recordings with CNE could be used in practice but borderline findings should be judged with great caution until larger database obtained with uniform setting available.
authors: Faculdade de Medicina de São José do Rio Preto (FAMERP), Laboratório de Investigação Neuromuscular, São Paulo, Brazil. Electronic address: jaris@terra.com.br.
authors: João Aris
authors: JA
authors: Kouyoumdjian
authors: Department of Clinical Neurophysiology, Institute of Neurosciences, Uppsala University, Uppsala, Sweden.
authors: Erik V
authors: EV
authors: Stålberg
mesh_terms: D000328:Adult; D001767:Blinking / Q000502:physiology*; D003627:Data Interpretation, Statistical; D004558:Electric Stimulation; D004566:Electrodes; D004576:Electromyography; D005154:Facial Nerve / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009339:Needles; D016011:Normal Distribution; D012016:Reference Values; D055815:Young Adult