Carpal tunnel syndrome is a chronic condition resulting from inflammation of the tissues surrounding the median nerve inside the wrist. The inflammation causes pressure on the median nerve that produces pain and numbness in the hand and fingers. Laser treatment is sometimes used in an attempt to alleviate the pain.
Carpal Tunnel Syndrome
Carpal tunnel syndrome is a result of chronic median nerve compression inside the wrist. The compression occurs because tissues adjacent to the median nerve inside the confines of the carpal tunnel become inflamed. This causes them to swell and apply pressure on the adjacent median nerve. The pressure registers as unpleasant sensations in the brain, usually felt as pain, numbness, tingling or burning in the hand and fingers. In the most severe cases, surgery may be indicated to alleviate pressure on the median nerve. However, some nonsurgical therapies work well in alleviating the symptoms of carpal tunnel syndrome. One nonsurgical therapy is known as low level laser therapy, or LLLT. While used by many therapists, its effectiveness in alleviating carpal tunnel syndrome is not yet scientifically established.
How LLLT Works
It should be noted that LLLT has not proved any more effective than placebo for pain relief in carpal tunnel syndrome. Due to insufficient evidence for effectiveness, studies are being carried out to determine its scientific validity. LLLT uses what are known as cold lasers, or non-thermal lasers. LLLT lasers have a power of 5-500 milliwatts, which is about a thousand times less powerful than surgical cutting lasers. The power is so low that it is barely felt on the skin. However, due to the wavelength, the skin absorbs very little of the laser light, which means it penetrates deep into the tissues. It is theorized that this light produces a photostimulatory effect to relieve pain. The mechanism by which pain might be alleviated is not well understood, but photostimulation may facilitate the body's ability to repair damaged cells and stimulate blood and lymphatic flow.
LLLT Procedure
Wearing eye protection is required before starting the therapy to avoid accidental retinal damage from the laser light. A technician then uses a hand-held laser and moves the laser light over the lower forearm and wrist. This is a dry contact procedure since no conductive gels are necessary. This continues for 5 to 15 minutes, depending on the severity of the condition. No posttreatment bandaging is required. Some patients may experience pain relief immediately and some after several hours. Depending on the severity of symptoms, therapy is recommended several times per week for up to three weeks.
Advantages
LLLT for carpal tunnel syndrome has a number of advantages with few disadvantages. It is a noninvasive therapy that's also nontoxic. It is easy to perform with minimal training. There are no known side effects, the procedure is not expensive, and it can be used with other therapies and in children. The results are at least as good as placebo treatment for carpal tunnel syndrome.
Disadvantages
While the disadvantages of LLLT are few, the major one concerns effectiveness. Studies are inconclusive as to the efficacy of LLLT in treating carpal tunnel syndrome. Clinical trials have shown that it may have only a marginal effect, with pain relief and strength results that are not much better than placebo therapy. Another disadvantage is that eye protection is required, because laser light causes retinal damage if the eyes are not protected. The treatment cannot be used over cancerous or suspicious lesions, or on pregnant women.
References
- Regence: Medical Policy: Medicine Section---Low Level Laser Treatment
- "Photomedicine and Laser Surgery"; Laser therapy in the treatment of carpal tunnel syndrome; D. Evcik, et al.; February 2007
- Cigna Medical Coverage Policy: Low Level Laser Therapy
- "Laser Therapy Clinical Practice and Scientific Background"; J. Turner and L. Hode; 2002
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