title: Ultrasonography of median nerve and electrophysiologic severity in carpal tunnel syndrome.
abstract: OBJECTIVE
  To investigate the correlation of the ultrasonographic wrist-to-forearm median nerve area ratio (WFR) and cross sectional area of median nerve at the wrist (CSA-W) to the electrophysiologic severity in patients with carpal tunnel syndrome (CTS).
  
  
  METHODS
  One hundred and ten wrists electrophysiologically graded as mild, moderate, and severe CTS and 38 healthy controls underwent ultrasonography of median nerve at the distal wrist crease and mid-forearm. WFR and CSA-W were analyzed according to the severity of CTS.
  
  
  RESULTS
  WFR was 1.12±0.14, 1.91±0.33, 2.27±0.47 and 3.02±0.97 and the CSAs-W was 7.23±1.67 mm(2), 13.51±3.72 mm(2), 14.67±2.93 mm(2), and 18.74±6.01 mm(2) in controls, mild (n=28), moderate (n=46), and severe (n=36) CTS, respectively. CSA-W displayed significant differences between the control and the mild CTS, moderate CTS and severe CTS groups. However, there was no significant difference between mild CTS and moderate CTS groups. WFR revealed significant difference between all groups. The sensitivity and specificity of the WFR in grading the severity of CTS were higher than those of the CSA-W.
  
  
  CONCLUSIONS
  Ultrasonography is a useful complementary tool for the evaluation of CTS. Both WFR and CSA-W are highly correlated with severity grade of CTS. However, WFR is superior to CSA-W for diagnosis and grading of the severity of CTS.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Gangwon-do Rehabilitation Hospital, Chuncheon 200-853, Korea.
authors.forename: Seok
authors.initials: S
authors.lastname: Kang
authors.forename: Hee Kyu
authors.initials: HK
authors.lastname: Kwon
authors.forename: Ki Hoon
authors.initials: KH
authors.lastname: Kim
authors.forename: Hyung Seok
authors.initials: HS
authors.lastname: Yun