Double-blind randomized controlled trial of low-level laser therapy in carpal tunnel syndrome.

Several studies have suggested that low-level laser therapy (LLLT) is effective in patients with carpal tunnel syndrome (CTS). In a double-blind randomized controlled trial of LLLT, 15 CTS patients, 34 to 67 years of age, were randomly assigned to either the control group (n = 8) or treatment group (n =7). Both groups were treated three times per week for 5 weeks. Those in the treatment group received 860 nm galium/aluminum/arsenide laser at a dosage of 6 J/cm2 over the carpal tunnel, whereas those in the control group were treated with sham laser. The primary outcome measure was the Levine Carpal Tunnel Syndrome Questionnaire, and the secondary outcome measures were electrophysiological data and the Purdue pegboard test. All patients completed the study without adverse effects. There was a significant symptomatic improvement in both the control (P = 0.034) and treatment (P =0.043) groups. However, there was no significant difference in any of the outcome measures between the two groups. Thus, LLLT is no more effective in the reduction of symptoms of CTS than is sham treatment.