Objective: Local corticosteroid (CS) injection has been widely used to treat carpal tunnel syndrome, but its invasiveness can cause several complications. In this study, the authors tested the efficacy of a new treatment method, extracorporeal shock wave therapy (ESWT), compared with CS injection.
Design: The authors carried out a randomized controlled trial comparing one session of ESWT (1000 shots at the maximal tolerable intensity) with one session of CS injection in 36 patients with carpal tunnel syndrome. Outcome measures including nerve conduction studies, a visual analog scale, and the Levine Self-assessment Questionnaire were performed at baseline and at 1 and 3 mos after treatment.
Results: At baseline, there were no significant differences between the groups with respect to the outcome parameters. Both groups showed a significant reduction in the visual analog scale at 1 and 3 mos after treatment compared with baseline. For the symptom severity score on the Levine Self-assessment Questionnaire, the ESWT group showed a significant reduction at 1 and 3 mos after treatment, whereas the CS injection group showed a significant reduction at 3 mos after treatment. For the nerve conduction parameters, there were mild but no significant improvements in the ESWT group, whereas the sensory nerve conduction velocity, the sensory nerve action potential amplitude, and the distal sensory and motor latencies of the median nerve were significantly improved in the CS injection group.
Conclusions: ESWT can be as useful as CS injection for relieving symptoms of carpal tunnel syndrome. Furthermore, in contrast to CS injection, it has the merit of being noninvasive.