title: Bifid median nerve in carpal tunnel syndrome: do we need to know?
abstract: BACKGROUND
  We tested the hypothesis that a bifid median nerve predisposes to development of carpal tunnel syndrome (CTS) and investigated differences in electrophysiological findings and outcome.
  
  
  METHODS
  A total of 259 consecutive patients with clinically defined CTS were included and investigated clinically, electrophysiologically, and ultrasonographically. Fifty-four healthy asymptomatic volunteers were investigated ultrasonographically.
  
  
  RESULTS
  The prevalence of bifid median nerves is equal in patients with CTS and controls. Electrophysiological and ultrasonographic abnormalities are more pronounced in patients with non-bifid median nerves. Some outcome data are better in patients with non-bifid median nerves, but others do not show significant differences.
  
  
  CONCLUSIONS
  A bifid median nerve is not an independent risk factor for development of CTS. Some of our data suggest outcome after surgical decompression to be different, but others do not. The surgical technique in these patients may therefore have to be reevaluated.
authors.affiliation: Department of Neurology, St. Lucas Andreas Hospital, P.O. Box 9243, 1006 AE, Amsterdam, The Netherlands; Department of Neurology and Clinical Neurophysiology, Canisius Wilhelmina Hospital, Nijmegen, The Netherlands.
authors.forename: Kristel M
authors.initials: KM
authors.lastname: Kasius
authors.forename: Franka
authors.initials: F
authors.lastname: Claes
authors.forename: Jan
authors.initials: J
authors.lastname: Meulstee
authors.forename: Wim Im
authors.initials: WI
authors.lastname: Verhagen
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000328:Adult; D000368:Aged; D002349:Carpal Tunnel Syndrome / Q000000981:diagnostic imaging / Q000473:pathology*; D004558:Electric Stimulation; D004576:Electromyography; D005260:Female; D005500:Follow-Up Studies; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008297:Male; D008475:Median Nerve / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology; D017063:Outcome Assessment, Health Care; D012044:Regression Analysis; D014463:Ultrasonography
keywords: bifid median nerve; carpal tunnel syndrome; nerve conduction studies; outcome; ultrasonography