title: Usefulness of ultrasonography to predict response to injection therapy in carpal tunnel syndrome.
abstract: OBJECTIVE
  To verify the feasibility of initial parameters of ultrasonography or electromyography for the prediction of effect after steroid injection therapy in a carpal tunnel syndrome (CTS) patient.
  
  
  METHODS
  We recruited individuals with clinical and electrodiagnostic evidence of CTS. Results from the Boston self-assessment questionnaire, median motor and sensory nerve conduction studies, and median nerve ultrasonography were evaluated at baseline, 1 month, and 6 months after injection. Evaluation of median nerve ultrasonography parameters included measurements taken at the maximal swelling point (MS), 2 cm proximal from MS (2MS), and 12 cm proximal from MS (12MS), and its ratio (MS/12MS, 2MS/12MS) was calculated. The correlation between improvement of the symptom score after treatment and baseline parameters was estimated.
  
  
  RESULTS
  Fourteen individuals (14 women, mean age 53.8 years) with 22 affected wrists were enrolled. After steroid injection therapy, clinical and electromyographic parameters showed significant improvements at 1 month or 6 months after injection, and ultrasonographic parameters showed significant changes in maximal area and area ratio (MS/12MS) of the median nerve. Symptom score improvement showed a positive correlation in the initial 2MS and ratio of 2MS/12MS after 6 months (p<0.05).
  
  
  CONCLUSIONS
  Most of the improvements occurred during the first month after injection and lasted up to 6 months. The initial median nerve swelling and its ratio may be a useful predictor of response after steroid injection.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Korea University College of Medicine, Seoul 152-703, Korea.
authors.forename: Jin Seok
authors.initials: JS
authors.lastname: Jeong
authors.forename: Joon Shik
authors.initials: JS
authors.lastname: Yoon
authors.forename: Sei Joo
authors.initials: SJ
authors.lastname: Kim
authors.forename: Byung Kyu
authors.initials: BK
authors.lastname: Park
authors.forename: Sun Jae
authors.initials: SJ
authors.lastname: Won
authors.forename: Jung Mo
authors.initials: JM
authors.lastname: Cho
authors.forename: Chan Woo
authors.initials: CW
authors.lastname: Byun