title: Usefulness of assessing repeater F-waves in routine studies.
abstract: BACKGROUND
  Repeater F-waves are sometimes seen in routine studies.
  
  
  METHODS
  We retrospectively reviewed the clinical significance of repeater F-waves in median, ulnar, and fibular nerve recordings in 50 healthy subjects and groups of 50 patients each with diabetic polyneuropathy, amyotrophic lateral sclerosis, carpal tunnel syndrome, ulnar mononeuropathy, and L5 root lesion. The number of identical F-waves and their repetitions in samples of 20 stimuli were estimated.
  
  
  RESULTS
  Repeater F-waves occurred significantly more frequently in all nerves and patient groups than in healthy individuals. Their persistence was negatively correlated with that of non-repeater F-waves.
  
  
  CONCLUSIONS
  Based on the presented material and recording condition it appears that repeater F-waves differentiate between health and disease but not between different types of pathology of motor neurons or their axons. Even in routinely recorded samples of 20 traces, the index of repeater all F-waves could be used as a sign of nerve pathology.
authors.affiliation: Department of Neurology, School of Medicine, University of Patras, Patras, Rion 26504, Greece. echroni@yahoo.com
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Chroni
authors.forename: Isabel Serrano
authors.initials: IS
authors.lastname: Tendero
authors.forename: Anna Rostedt
authors.initials: AR
authors.lastname: Punga
authors.forename: Erik
authors.initials: E
authors.lastname: Stålberg
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000690:Amyotrophic Lateral Sclerosis / Q000503:physiopathology; D002349:Carpal Tunnel Syndrome / Q000175:diagnosis / Q000503:physiopathology; D003627:Data Interpretation, Statistical; D003929:Diabetic Neuropathies / Q000175:diagnosis / Q000503:physiopathology; D004558:Electric Stimulation; D004576:Electromyography; D004594:Electrophysiology / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008475:Median Nerve / Q000503:physiopathology; D008875:Middle Aged; D020422:Mononeuropathies / Q000175:diagnosis / Q000503:physiopathology; D009046:Motor Neurons / Q000502:physiology; D009412:Nerve Fibers / Q000502:physiology; D009422:Nervous System Diseases / Q000503:physiopathology; D009431:Neural Conduction / Q000502:physiology; D009460:Neurologic Examination; D011843:Radiculopathy / Q000175:diagnosis / Q000503:physiopathology; D012016:Reference Values; D014459:Ulnar Nerve / Q000503:physiopathology; D020424:Ulnar Neuropathies / Q000175:diagnosis / Q000503:physiopathology; D055815:Young Adult