title: Ultrasonographic findings of the normal ulnar nerve in adults.
abstract: OBJECTIVE
  To provide a detailed description of the ultrasonographic findings along the entire length of the normative ulnar nerve.
  
  
  METHODS
  Volunteers were recruited to undergo ultrasonography of both upper extremities. Age, sex, height, weight, body mass index, arm length, and hand length were recorded, and cross-sectional measurements of the ulnar nerve were obtained at 7 predetermined sites.
  
  
  METHODS
  The diagnostic neurology laboratory of a referral medical center.
  
  
  METHODS
  Thirty volunteers (60 arms) were recruited. Volunteers were screened by history and physical examination, and those with evidence of peripheral nervous system disease were excluded.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  The average cross-sectional area (CSA) of the ulnar nerve at 7 predetermined sites along the entire course of the nerve.
  
  
  RESULTS
  The following average ulnar nerve CSAs were obtained: distal wrist crease, 5.9 mm2; arterial split, 6.3 mm2; 2 cm distal to tip of the medial epicondyle, 6.4 mm2; tip of the medial epicondyle, 6.5 mm2; 2cm proximal to tip of the medial epicondyle, 6.7 mm2; mid-humerus, 6.1 mm2; and axilla, 6.2 mm2. There was no statistical difference in nerve size when dominant and nondominant arms were compared, but women did have smaller nerves than men. Of all the variables measured, nerve size correlated most closely with weight, with a correlation coefficient of .59.
  
  
  CONCLUSIONS
  The ulnar nerve was easily visualized and measured along its entire course, and the CSA of the nerve was consistent at multiple sites. The reference values obtained in this study will facilitate the analysis of abnormal nerve conditions, and the information on side-to-side variation and sex-specific differences should be particularly helpful.
authors.affiliation: Department of Neurology, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA. mcartwri@wfubmc.edu
authors.forename: Michael S
authors.initials: MS
authors.lastname: Cartwright
authors.forename: Hae W
authors.initials: HW
authors.lastname: Shin
authors.forename: Leah V
authors.initials: LV
authors.lastname: Passmore
authors.forename: Francis O
authors.initials: FO
authors.lastname: Walker
mesh_terms: D000328:Adult; D019412:Anatomy, Cross-Sectional; D001835:Body Weight; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012727:Sex Characteristics; D014459:Ulnar Nerve / Q000000981:diagnostic imaging*; D014463:Ultrasonography