Laser therapy and carpal tunnel syndrome

By Dava Stewart

As is the case with a number of musculoskeletal conditions, researchers don’t fully understand the underlying causes of carpal tunnel syndrome (CTS). Patients who suffer the condition, however, understand the pain and limited function it causes all too well. Scientists are currently studying the effectiveness of low level laser therapy (LLLT) to treat patients with carpal tunnel syndrome.

According to the National Institute of Neurological Disorders and Stroke, carpal tunnel is:

“Carpal tunnel syndrome occurs when the median nerve, which runs from the forearm into the palm of the hand, becomes pressed or squeezed at the wrist. The median nerve controls sensations to the palm side of the thumb and fingers (although not the little finger), as well as impulses to some small muscles in the hand that allow the fingers and thumb to move. The carpal tunnel—a narrow, rigid passageway of ligament and bones at the base of the hand—houses the median nerve and tendons. Sometimes, thickening from irritated tendons or other swelling narrows the tunnel and causes the median nerve to be compressed. The result may be pain, weakness, or numbness in the hand and wrist, radiating up the arm. Although painful sensations may indicate other conditions, carpal tunnel syndrome is the most common and widely known of the entrapment neuropathies in which the body’s peripheral nerves are compressed or traumatized.”

LLLT has been shown to have two properties that could be useful in treating carpal tunnel: anti-inflammatory and analgesic.^1-2 Since carpal tunnel syndrome involves thickening and swelling of soft tissues, it makes sense to study whether or not LLLT could help reduce the inflammation and therefore ease some of the pain.

Research, however, has so far been inconclusive—most likely due to the fact that studies have been fairly small and because the power density, length of treatments, and number of treatments, along with other factors, play a critical role in whether LLLT is an effective treatment for any condition.

A study completed in 2008 concluded, “Laser therapy as a new conservative treatment is effective in treating CTS paresthesia and numbness and improves the subjects’ power of hand grip and electrophysiological parameters.”³

Another study from the same year, carried out by a different group of researchers, concluded, “LLLT was effective in alleviating pain and symptoms, and in improving functional ability and finger and hand strength for mild and moderate CTS patients with no side effects.”⁴

Taken together, the available studies seem to indicate that LLLT shows great promise in providing pain relief for patients with carpal tunnel syndrome and may promote healing in the condition. As further research progresses, smart DCs will be well prepared to explain how LLLT can be an effective part of a conservative carpal tunnel treatment plan.

References:

¹Civi OG, Kucuk, BB, Oral K, Seluck NA, Toklu T. The anti-inflammatory effect of low-level laser therapy on experimentally induced inflammation of rabbit temporomandibular joint retrodiscal tissues. J Orafac Pain. 2010:24(3);293-297.

²Barbosa DG, Cury Y, Ferreira DM, et al. Analgesic effect of He-Ne (632.8 nm) low-level laser therapy on acute inflammatory pain. Photomed Laser Surg. 2005:23(2);177-181.

³Amanollahi AH, Badiee V, Grami MT, et al. The effects of low level laser in clinical outcome and neurophysiological results of carpal tunnel syndrome. Electromyogr Clin Neurophysiol. 2008:48(5);229-231.

⁴Chang WD, Jiang JA, Tsai CT, Wu JH, Yeh CY. Carpal tunnel syndrome treated with a diode laser: a controlled treatment of the transverse carpal ligament. Photomed Laser Surg. 2008:26(6);551-557.