Monday, November 16, 2009
Low-Level Lasers Effective in Chronic Neck Pain
I have used Low-level laser therapy or Cold laser therapy in my NYC practice for close to 7 years, I have found it to be extremely effective in reducing pain and dysfunction.
Cold laser therapy NYC
By John Gever, Senior Editor, MedPage Today
Published: November 13, 2009
Reviewed by Zalman S. Agus, MD; Emeritus Professor
University of Pennsylvania School of Medicine and
Dorothy Caputo, MA, RN, BC-ADM, CDE, Nurse Planner
Although no one is sure how it works, low-intensity laser therapy appeared to be effective in relieving chronic neck pain, researchers found in a meta-analysis.
Pooled data from 16 randomized, controlled trials indicated that most patients reported both short- and medium-term pain relief with the noninvasive treatment, according to Roberta T. Chow, MBBS, PhD, of the University of Sydney in Australia, and colleagues.
"The results of low-level laser therapy in this review compare favorably with other widely used therapies, and especially with pharmacological interventions, for which evidence is sparse and side effects are common," the researchers wrote online in The Lancet
The procedure involves shining low-intensity laser beams -- too weak to generate biologically significant heat -- usually at the back or side of the neck, targeting muscles, and vertebral joints. Wavelengths of 780, 810 to 830, or 904 nm are typically used. These beams are able to penetrate several centimeters of tissue.
Several possible mechanisms of action have been proposed. The radiation may have anti-inflammatory effects by inhibiting prostaglandins and/or cytokines. Alternatively, it may reduce oxidative stress and muscle fatigue, with support from some animal studies and clinical experiments.
A third possibility is that the laser light alters nerve signalling at the neuromuscular junction or elicits overt nerve blockade.
Whatever the mechanism, however, the randomized, controlled studies included in the review showed a clear clinical benefit for the treatment.
None of the individual trials were very large -- the biggest (led by Chow herself) had 90 patients. In total, 820 patients participated in the 16 studies.
Five of the studies, with 122 patients, included the presence of global improvement, relative to sham treatment, as an outcome.
The relative likelihood of improvement with the laser treatment was 4.05 (95% CI 2.74 to 5.98), Chow and colleagues found.
In 11 trials with 333 patients, the weighted mean change in pain severity -- as reported by patients on a 100-mm analogue scale -- was 19.86 mm relative to controls (95% CI 10.04 to 29.68).
In four studies that measured pain severity 10 to 22 weeks after treatment ended, with a total of 86 patients, there was a weighted mean improvement from baseline of 23.44 mm at the end of follow-up (95% CI 17.11 to 29.77).
Overall, the researchers said, the trials "show moderate statistical evidence for efficacy of low-level laser therapy" for neck pain.
Limitations to the available evidence include the differences in laser treatments -- schedules and doses as well as wavelengths -- and in the varieties of neck pain with which patients had presented.
Current diagnostic terms "suggest distinct clinical entities; however, there is strong evidence that a definitive diagnosis of the causes of neck pain is not possible in a clinical setting," the researchers wrote.
They said adverse effects from treatment were minimal. Several studies reported increased tiredness.
The primary safety concern with the treatment is the possibility of inadvertently directing the laser into patients' eyes, Chow and colleagues said. Safety glasses would be required in all studies.
In an accompanying commentary, Jaime Guzman, MD, of the University of British Columbia in Vancouver, B.C., said the existing evidence on low-level laser therapy still leaves many questions unanswered, especially on the mechanism of action.
Nevertheless, he said, "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 nonspecific neck pain," Guzman wrote.
External funding for the study was not reported.
Chow and some co-authors reported relationships with the World Association for Laser Therapy and healthcare professional societies. No authors reported relationships with manufacturers of laser therapy devices.
Guzman declared he had no conflicts of interest.
Primary source: The Lancet
Chow R, et al "Efficacy of low-level laser therapy in the management of neck pain: a systematic review and meta-analysis of randomised placebo or active-treatment controlled trials" Lancet 2009; DOI: 10.1016/S0140-6736(09)61522-1.
Additional source: The Lancet
Guzman J "Neck pain and low-level laser: Does it work and how?" Lancet 2009; DOI: 10.1016/S0140-6736(09)61837-7.
Cold Laser therapy, Low-level laser therapy NYC