Local corticosteroid injection for carpal tunnel syndrome.

BACKGROUND: Carpal tunnel syndrome is a clinical syndrome manifested by signs and symptoms of irritation of the median nerve at the level of the carpal tunnel in the wrist. Local corticosteroid injection for carpal tunnel syndrome has been studied but its effectiveness and duration of benefit of local corticosteroid injection for Carpal tunnel syndrome remain unknown.
OBJECTIVES: To evaluate the effectiveness of local steroid injection for carpal tunnel syndrome versus placebo injection or other non-surgical interventions in improving clinical outcome and to determine the length of symptom relief. SEARCH STRATEGY: We searched the Cochrane Neuromuscular Disease Group register (searched June 2002), MEDLINE (searched January 1966 to May 2002), EMBASE (searched January 1980 to May 2002)and CINAHL(searched January 1982 to May 2002). SELECTION CRITERIA: We included randomized or quasi-randomized studies of participants with carpal tunnel syndrome treated with local corticosteroid injection. The primary outcome measure was clinical improvement. DATA COLLECTION AND ANALYSIS: Three reviewers independently selected the trials to be included rated for their overall quality. Relative risks and 95% confidence intervals were calculated for each trial and summary relative risks and 95% confidence intervals were also calculated. MAIN
RESULTS: We identified nine randomized controlled trials. Four were excluded. One trial demonstrated clinical improvement of carpal tunnel syndrome at one month following local corticosteroid compared to placebo injection (Relative risk 3.83 (95% confidence intervals 1.82 to 8.05)). One trial compared local corticosteroid injection to oral steroid and at three months after treatment there was a significant improvement in the injection group (mean difference -7.00 (95% confidence intervals -11.58 to -2.42)). In one trial the rate of improvement after one month was greater after local than systemic corticosteroid injection (Relative risk 3.17(95% confidence intervals 1.02 to 9.87)). In one trial symptoms did not improve significantly for the injection group at eight weeks after injection compared to treatment with anti-inflammatory medication and splinting (mean difference 0.10 (95% confidence intervals -0.33 to 0.53)). Although local steroid injection did provide benefit compared to Helium-Neon Laser treatment at two weeks after onset of treatment (Relative risk 0.27 (95% CI 0.09 to 0.83), this effect did not hold at six months follow-up (Relative risk 0.76 (95% confidence intervals 0.48 to 1.21). REVIEWER'S
CONCLUSIONS: Local corticosteroid injection for carpal tunnel syndrome provides greater clinical improvement in symptoms one month after injection compared to placebo. Symptom relief beyond one month compared to placebo has not been demonstrated. Local corticosteroid injection provides significantly greater clinical improvement compared to oral steroid up to three months after treatment. Local corticosteroid injection does not provide improved clinical outcome compared to either anti-inflammatory treatment and splinting after eight weeks or Helium -Neon laser treatment after six months.