title: Avoiding false-negative nerve conduction study in ulnar neuropathy at the elbow.
abstract: BACKGROUND
  Ulnar nerve displacement at the elbow causes overestimation of nerve conduction velocity. We hypothesized that this overestimation may cause false-negative results when the American Association of Neuromuscular and Electrodiagnostic Medicine (AANEM) diagnostic criteria are used.
  
  
  METHODS
  We investigated 9 cases of ulnar neuropathy at the elbow, all having ulnar nerve displacement confirmed by ultrasonography and meeting none or just one of the AANEM criteria with distance measurement by anatomic landmarks. First, the distance across the elbow segment was measured by anatomic landmarks, and then it was re-estimated by ultrasonography.
  
  
  RESULTS
  Overestimated ulnar conduction velocity was corrected by 7.9 m/s. Three cases met none of the AANEM criteria before correction. After correction of overestimation, all cases met two of the AANEM criteria.
  
  
  CONCLUSIONS
  This study highlights the importance of using ultrasonography to confirm the possibility of ulnar nerve displacement, especially when electrodiagnostic findings do not meet AANEM criteria in patients with suspected UNE.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Korea University College of Medicine, Guro Dong, Seoul, South Korea.
authors.forename: Sun Jae
authors.initials: SJ
authors.lastname: Won
authors.forename: Joon Shik
authors.initials: JS
authors.lastname: Yoon
authors.forename: Jun Yeon
authors.initials: JY
authors.lastname: Kim
authors.forename: Sei Joo
authors.initials: SJ
authors.lastname: Kim
authors.forename: Jin Seok
authors.initials: JS
authors.lastname: Jeong
mesh_terms: D004550:Elbow / Q000000981:diagnostic imaging / Q000294:innervation* / Q000503:physiopathology; D004558:Electric Stimulation / Q000379:methods; D004568:Electrodiagnosis / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology*; D009460:Neurologic Examination; D020424:Ulnar Neuropathies / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000503:physiopathology*; D014463:Ultrasonography / Q000379:methods