Photobiomodulation of Pain in Carpal Tunnel Syndrome: Review of Seven Laser Therapy Studies

Abstract

In this review, seven studies using photoradiation to treat carpal tunnel syndrome (CTS) are discussed: two controlled studies that observed real laser to have a better effect than sham laser, to treat CTS; three openprotocol studies that observed real laser to have a beneficial effect to treat CTS; and two studies that did not observe real laser to have a better effect than a control condition, to treat CTS. In the five studies that observed beneficial effect from real laser, higher laser dosages (9 Joules, 12-30 Joules, 32 J/cm 2 , 225 J/cm 2 ) were used at the primary treatment sites (median nerve at the wrist, or cervical neck area), than dosages in the two studies where real laser was not observed to have a better effect than a control condition (1.8 Joules or 6 J/cm 2 ). The average success rate across the first five studies was 84% (SD, 8.9; total hands = 171). The average pain duration prior to successful photoradiation was 2 years. Photoradiation is a promising new, conservative treatment for mild/moderate CTS cases (motor latency < 7 msec; needle EMG, normal). It is cost-effective compared to current treatments.

Low-level Laser Treatment Relieves Pain and Neurological Symptoms in Patients with Carpal Tunnel Syndrome

“…The VAS of the moderate CTS patients was decreased to 3.76 ± 1.81. The results of our study were similar to the previous researches 3,5) and confirmed immediate pain alleviation of LLLT. We also found that LLLT could not maintain this effect for the next five weeks, and thus further research with longer follow-up periods were required.…”

“…The analgesic effect of LLLT is still controversial, but the clinical effect is confirmed 4,8) . 5,7,8,12) , and enhance the respiration metabolism of the cells 13) . Those metabolisms reduce the wastes from the inflammation including leukotrienes and metabolite which could improve the healing process.…”

“…Many studies [3][4][5] have already reported the effectiveness of low-level laser treatment (LLLT) for CTS since Anderson's study involving 100 employees of the General Motors Company 2) . Some studies have suggested that conservative treatments for the initial onset of CTS are safer than surgery 3,4) .…”

“…Some studies have suggested that conservative treatments for the initial onset of CTS are safer than surgery 3,4) . LLLT is one of the choices of conservative treatments for CTS 5) . The efficacy of LLLT in treating CTS is controversial.…”

“…The beam energy of LLLT was more than 9 J in studies [6][7][8] which found the treatment to be effective, while the energy was less than 6 J in a study which found it ineffective 9) . Besides, regarding pain, there are several reports of the effectiveness of LLLT on physiological factors and it has been shown to be an effective treatment by meta-analysis 3,5) . Recently, some researchers used LLLT to treat CTS and irradiated the transverse carpal ligament of the wrist 8) .…”