A new study sheds light – literally – on a potential means of easing migraine pain.
Inability to endure light
Researchers in Boston exposed 69 migraine patients to different colours of light. They found that while blue light exacerbated headache pain, a narrow spectrum of low-intensity green light significantly reduced light sensitivity.
In some cases, this green light also reduced migraine pain by about 20 percent, the researchers found.
They noted that migraine headache affects nearly 15 percent of people worldwide, and a frequent symptom of migraine is light sensitivity, also known as photophobia.
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"Although photophobia is not usually as incapacitating as headache pain itself, the inability to endure light can be disabling," study author Rami Burstein, of Beth Israel Deaconess Medical Centre in Boston, said in a medical centre news release.
"More than 80 percent of migraine attacks are associated with and exacerbated by light sensitivity, leading many migraine sufferers to seek the comfort of darkness and isolate themselves from work, family and everyday activities," he added. Burstein directs the medical centre's Comprehensive Headache Centre.
Two experts said the treatment may have merit.
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"Certainly Dr Burstein's work suggests that more research should be done, as this is a potentially beneficial new avenue for treatment," said Dr Noah Rosen, who directs Northwell Health's Headache Centre in Great Neck, New York.
He pointed out that "light therapy has been used successfully in other conditions such as certain dermatologic issues and seasonal affective disorder [SAD]".
Dr Gayatri Devi is a neurologist at Lenox Hill Hospital in New York City.
He said the success in some patients with light therapy "implicates the thalamus – a brain 'relay station' between the sensory organs, including the eyes and the cortex of the brain – as the area where migraine-related photophobia is amplified."
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For his part, Burstein said he's now trying to develop an affordable light bulb that emits narrow-band green light at low intensity, as well as sunglasses that block all but the narrow band of green light.
Rosen stressed, however, that more study may still be needed.
"In general, it seems a safe treatment but one that is limited by cost, access and whether its use on a regular basis would decrease disability," he said.
The findings were published in the journal Brain.
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