Bright-Light Treatment Shows Promise for Fibromyalgia

https://www.medscape.com/viewarticle/881527

BOSTON — Morning bright-light treatment may be an effective adjunctive treatment for fibromyalgia, improving function and easing pain sensitivity, perhaps by shifting sleep patterns in a way that appears to help fibromyalgia, results of a pilot study suggest.

Helen J. Burgess, PhD, director, Biological Rhythms Research Laboratory and professor, Department of Behavioral Sciences, Rush University Medical Center in Chicago, Illinois, presented the study here at SLEEP 2017: 31st Annual Meeting of the Associated Professional Sleep Societies.

Morning light treatment has been shown to reduce depression. Moreover,  improved mood can lead to diminished pain and improvement in people’s ability to cope and function with pain.

Dr Burgess and colleagues tested the effect of bright-light treatment on function and pain sensitivity in 10 women meeting American College of Rheumatology 2010 criteria for fibromyalgia.

The women slept at home, keeping their usual sleep schedule for 1 week, followed by an overnight session in the sleep lab. During the overnight session, the researchers assessed baseline function (Fibromyalgia Impact Questionnaire [FIQ]), pain sensitivity (heat threshold and tolerance), and circadian timing (dim-light melatonin onset). 

The following morning, the women were randomly assigned to 6 days of a self-administered home morning (n = 6) or evening (n = 4) light treatment, using light boxes 1 hour per day. Afterward, function, pain sensitivity, and circadian timing were reassessed.

On average, the women completed 84% of the scheduled light treatments. No side effects were reported.

Both morning and evening light treatments led to improvements in function and pain sensitivity, but only morning light treatment led to a clinically meaningful improvement in function (>14% reduction in FIQ) and heat pain threshold (P < .05).

Dr Burgess noted that the improvement was about equal to that seen after cognitive-behavioral therapy and about half of that seen after weeks of intense exercise therapy. 

The study also found that phase advances in circadian timing were associated with an increase in pain tolerance (r = 0.67; P < .05).

Dr Burgess cautioned that more study is needed before light treatment can be used to manage chronic pain. “Our study sample was very small, and the results simply suggest that we keep investigating light treatment as a possible treatment to reduce pain and improve function,” she told Medscape Medical News.

“Noteworthy” Study

Approached for comment, Shelby Harris, PsyD, director, Behavioral Sleep Medicine, Sleep-Wake Disorders Center, Montefiore Health System, New York City, said this is a “very noteworthy and novel study since, in terms of helping sleep and fibromyalgia, the researched sleep treatments in this population — that we currently have on hand — are cognitive-behavior therapy for insomnia and medication interventions.”

“This study utilized a simple, quick method (light therapy) to help patients shift sleep patterns in a way that appears to help their fibromyalgia symptoms,” Dr Harris told Medscape Medical News.

“Patients with fibromyalgia typically suffer from difficulties falling asleep and staying asleep,” she said, “and this study noted that early-morning light exposure helped to advance their sleep timing, helping them to fall asleep earlier.”

“It is very possible that earlier sleep times, with less tossing and turning in bed throughout the night, can lead to more alertness in the morning, pain tolerance, helping to decrease pain and increase overall functioning. However, this was a small study and one that needs more research behind it,” added Dr Harris.

She also noted that some patients are “not ideal candidates for light boxes due to eye problems, and it would be interesting to see whether similar results would be found using natural outdoor light. This is worth studying further because a simple technique may make a big impact on the lives of those with chronic pain problems. More research is needed in this area,” said Dr Harris.

Kevin Fleming, MD, medical director of the Fibromyalgia and Chronic Fatigue Clinic at Mayo Clinic in Rochester, Minnesota, also thinks the study is noteworthy.

“Although a small study (just 10 patients) and only 1 week long, it is very suggestive of being useful because it fits with at least one physiology issue known to contribute to FM [fibromyalgia] — bad sleep. Light therapy may address that portion,” he told Medscape Medical News.

“Impaired sleep is known to be common in FM and likely contributes to pain (sleep deprivation makes people have widespread discomfort like FM),” Dr Fleming explained. “Why this is so is unclear; what sleep does for our muscles and brain is uncertain. But lacking good sleep contributes to pain, so it is reasonable to focus on sleep in treating FM.”

“The sleep clock (circadian rhythm) is set at least in part by your exposure to bright light, such as sunlight. Exposure to bright light or light therapy can remedy that part of the sleep disorder,” he noted.

Dr Fleming said light therapy for fibromyalgia is worth continued study. 

“There’d be no way to do a randomized trial I can think of, but size could be increased and compared to usual FM care for 12 months,” he said.

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