Effect of high-intensity laser therapy and mirror therapy on complex regional pain syndrome type I in the hand area: A randomized controlled trial.

Background: Complex regional pain syndrome type I (CRPS-I) is a painful condition with peripheral and central nervous system dysfunction, disproportionate inflammation, and the resultant muscle atrophy and restriction of motion. The use of high-intensity laser therapy (HILT) is being considered to reduce inflammation and neural and musculoskeletal pain. As maladaptive neuroplasticity occurs, peripheral treatment may not be enough and a combination of peripheral and centrally-focused interventions may be required.

Purpose: To explore the impact of HILT combined with mirror therapy (MT) on pain intensity, swelling, functional ability, range of motion (ROM), and electromyography (EMG) activity in CRPS-I.

Study design: Randomized, sham-controlled, single-blind clinical trial.

Methods: Twenty-four CRPS-I patients were randomly assigned to two groups of HILT at 5 watts with an energy density of 20 J/cm², combined with MT and sham HILT and MT for six sessions. Pain was assessed by the Visual Analog Scale (VAS) before, the third session, and after the treatment. Hand swelling, function, and ROM were measured by a motion analysis system, and EMG of the hand muscles was also evaluated.

Results: Pain significantly decreased in the HILT group. Compared to before treatment, the VAS mean difference in the third session was -2 ± 0.8 in the HILT group versus -0.4 ± 0.5 in the sham group (p < 0.001, ηp2 = 0.57). The VAS mean difference for before-after treatment was -4.2 ± 1.2 in the HILT group versus -1.4 ± 0.6 in the sham group (p < 0.001, ηp2 = 0.69). The other outcomes, like function, effusion, ROM, and EMG activity, were also in favor of the HILT group (p < 0.05).

Conclusions: Our study results offer conclusive evidence of pain reduction, a highly debilitating symptom in CRPS-I, even after the third HILT treatment session. Additionally, HILT effectively reduced swelling, improved performance, and enhanced muscle activity in CRPS-I.