A randomized clinical trial on the changing of median nerve cross-sectional area and pain after extracorporeal shock wave and low-level laser therapy added to conventional physical therapy in patients with mild-to-moderate carpal tunnel syndrome

Background

Carpal tunnel syndrome (CTS) is the most common mononeuropathy in the upper limb. It remains uncertain whether adding extracorporeal shockwave therapy (ESWT) or low-level laser therapy (LLLT) to conventional treatment benefits CTS patients.

Purpose

This study aimed to compare the effectiveness of ESWT and LLLT in conjunction with conventional treatments (including carpal mobilization, transcutaneous electrical nerve stimulation, and ultrasound) on the cross-sectional area (CSA) of the median nerve and pain in mild-to-moderate CTS patients.

Study Design

This was a single-blinded randomized clinical trial with registration number IRCT20220504054734N1.

Methods

Thirty-six patients were randomly assigned using block balanced randomization to receive either four sessions of ESWT or 10 sessions of LLLT in addition to 10 sessions of conventional treatments over 2 weeks. Patients received numbered closed envelopes indicating their treatment group. CSA (primary) and pain (secondary) in 18 patients who completed the treatment were assessed at baseline and after 2 weeks by a blinded assessor. Paired and independent sample t-tests were used for analyses due to the normal distribution of data was checked by Kolmogorov-Smirnoff. Cohen's d effect size was used to assess the intervention's magnitude.

Results

Both ESWT and LLLT groups showed significant improvements in CSA (p = 0.002) and pain (p < 0.001) from baseline to posttreatment. CSA improvement was moderate for ESWT (mean difference: 1.2, 95% CI 0.51-1.9) and mild for LLLT (mean difference: 0.76, 95% CI 0.4-1.14). Conversely, pain improvement was substantial in both groups (ESWT: mean difference 4.4, 95% CI 3.6-5.3; LLLT: mean difference 4.4, 95% CI 3.7-5.2). No substantial differences between ESWT and LLLT were observed, highlighting their comparable efficacy.

Conclusion

The addition of either LLLT or ESWT to conventional treatment effectively reduced pain and median nerve CSA in mild-to-moderate CTS. The absence of significant differences between ESWT and LLLT indicates their comparable efficacy in pain relief and CSA reduction.