A randomised clinical trial of oral steroids in the treatment of carpal tunnel syndrome: a long term follow up.

OBJECTIVES To determine the efficacy of a two week and a four week course of oral steroids in the conservative treatment of carpal tunnel syndrome. METHODS 109 patients with carpal tunnel syndrome were randomly divided into two treatment groups: (1) two weeks of prednisolone 20 mg daily followed by two weeks of prednisolone 10 mg daily (n = 53); (2) two weeks of prednisolone 20 mg daily and two weeks of placebo (n = 56). A symptom questionnaire was used to rate the five major symptoms of carpal tunnel syndrome (numbness, pain, weakness/clumsiness, tingling, and nocturnal awakening) on a scale of 0 (nil) to 10 (severe); the resulting global symptom score was used to evaluate the efficacy of treatment. Assessments were made at baseline and at one, three, six, nine, and 12 months. Electrodiagnosis was repeated at the end of the study to validate improvement. RESULTS In an intention to treat analysis at the end of the study, improvement in the four week treatment group was achieved in 66.0% of the patients after one month and in 49.0% at the end of the study; in the two week treatment group, the respective values were 48.2% and 35.7%. In the four week treatment group, 51% were considered treatment failures (including those lost to follow up, receiving surgery, or with mild or no improvement), compared with 64.3% for the two week group. Though the percentage improvement was higher in the four week group, the difference did not reach a statistical significance. Persistence of improvement was 74.2% in the four week group v 74.1% in the two week group, suggesting no difference in the long term effect. Efficacy analysis showed no significant difference in global symptom score reduction between the two groups. Follow up electrodiagnosis showed significant improvement in all measured variables except for the amplitude of compound muscle action potentials. CONCLUSIONS Short term low dose oral steroid are effective treatment for carpal tunnel syndrome. The dose of steroids and the duration treatment are not key determinants of efficacy.