Low-level laser therapy (LLLT) reduces pain after treatment for non-specific neck pain, concludes an Article published Online First (www.thelancet.com) and in an upcoming edition of the Lancet. The Article is written by Dr Roberta Chow, Nerve Research Foundation, Brain and Mind Research Institute, University of Sydney, Australia, and colleagues.
Chronic pain is predicted to reach epidemic proportions in developed countries with ageing populations in the next 30 years. Chronic neck pain is a highly prevalent condition, affecting 10-24% of the population. LLLT uses laser irradiation to aid tissue repair, relieve pain, and stimulate acupuncture points. LLLT is non-invasive, painless, and can be easily administered in primary-care settings. Incidence of adverse effects is low and similar to that of placebo, with no reports of serious events. In this study, the authors did a systematic review and meta-analysis of randomised controlled trials to assess the efficacy of LLLT in neck pain. They used a 100-point scale to determine difference in pain experienced.
The team identified 16 randomised controlled trials including a total of 820 patients. For acute neck pain, evidence was limited to two trials with mixed results, showing that patients were around 70% more likely to experience reduced pain following LLLT compared with placebo. Five trials of chronic neck pain showed patients given LLLT were around four times more likely to have reduced pain compared with placebo. Patients in 11 trials reported reductions of chronic pain of around 20 points on the 100 point scale. Seven of these trials provided follow-up data for 1-22 weeks after completion of treatment, with short-term pain relief persisting in the medium term with a reduction of 22 points on the scale. Side-effects from LLLT were mild and not different from those of placebo.
The authors say that the mechanisms for LLLT-mediated pain relief are not fully understood, but could involve reducing inflammation, nerve conduction of painful stimuli, and muscle fatigue. They say*: "Which of these mechanisms are most important cannot be determined, because all of the trials irradiated several points overlying joints, nerves, and muscles."
They add: "Whatever the mechanism of action, clinical benefits of LLLT occur both when LLLT is used as monotherapy and in the context of a regular exercise and stretching programme. In clinical settings, combination with an exercise programme is probably preferable. The results of LLLT in this review compare favourably with other widely used therapies, and especially with pharmacological interventions, for which evidence is sparse and side-effects are common."
They conclude: "[This study] shows that LLLT reduces pain immediately after treatment in acute neck pain and up to 22 weeks after completion of treatment in patients with chronic neck pain."
In an accompanying Comment, Dr Jaime Guzman, University of British Columbia, Vancouver, BC, Canada, says: "Today's findings of low-level laser therapy indicate that this non-invasive treatment provides pain relief in the short and medium term for people with neck pain. This evidence is more solid than that for many current interventions. Although mechanisms of action and effects on function and occupational outcomes are not clearly understood and warrant further impartial study, low-level laser therapy is an option worthy of consideration for management of non-specific neck pain."
Professor Jan M. Bjordal, Institute of Physiotherapy, Bergen University College, Norway. T) +47 55 585663 (office) +47 91 77 98 32 (cell phone) E) jmb@hib.no
Dr Jaime Guzman, University of British Columbia, Vancouver, BC, Canada. T) +1 778 328 8026 E) jaime@ohsah.bc.ca
For full Article and Comment, see: http://press.thelancet.com/neckfinal.pdf
Note to editors: *quote direct from Prof Bjordal and cannot be found in text of Article
Journal
The Lancet