Migraine Study: Light Does More Than Just Make The Headache Worse

(r. nial bradshaw/Flickr)
(r. nial bradshaw/Flickr)

If you're one of the estimated 36 million Americans who suffer from migraines, chances are you retreat to a darkened room when the headache hits. I do.

With my last migraine, I was out on the street when the weird, visual disturbances of my pre-migraine aura began, and I stumbled home as quickly as I could — not very quickly because there were sparkling holes in my vision — to raid the medicine cabinet and lower all the shades in my bedroom.

To those of us who instinctively know to avoid light while the migraine attacks, a study just out in the journal PNAS offers some fascinating new insights into the migraine-light connection.

First, a close examination of migraine patients found that it's not just that light makes the headache pain worse — it triggers other physical and even emotional reactions: "They were telling us that light made them anxious, angry, irritable, agitated, nervous, hopeless, needy, sad, scared, upset, depressed, worried, panicky," says Dr. Rami Burstein of Beth Israel Deaconess Medical Center and Harvard Medical School, the paper's senior author.

And physically, the patients reported that light gave them feelings of tightness in the chest or throat, it made them breathe faster, gave them dry mouth, dizziness, nausea — all responses controlled by the autonomic nervous system. All in all, dramatic effects that go a lot further than the usual understanding of just "light makes your migraine worse."

Another novel finding: the researchers report that the color of the light makes a difference. Specifically, they found that green light is much less problematic for migraine patients than other colors.

Burstein says work is under way now by several companies to turn these findings into products that could help patients within a year or two — lenses and light-boxes that could let people get mainly the green wavelength that doesn't worsen the migraine. If they pan out, they could help the multitudes who are disabled by migraine in part because they have to avoid light during an attack.

Already, the study may herald a significant shift, from thinking that aversion to light is just one more symptom of migraine to seeing light as a possible contributing factor.

Working with rats, the researchers traced the pathway from the retina in the eye, through a major control center in the brain, the hypothalamus, and out to the nervous system, where symptoms like nausea or fast heart-rate appear.

Until now, Dr. Burstein says, we thought aversion to light was just part of how the brain changes during a migraine attack. "Now we are bringing a new concept here," he says, "suggesting that many of the symptoms, like nausea and vomiting and stuffy sinuses — many of those can actually be exacerbated or attributed to the fact that migraine patients are spending much of their time in the light."

That new understanding may eventually lead to better treatments — perhaps a way to block the contribution that light makes to a migraine attack. For now, Burstein says there are some much closer prospects of good news for people who get migraines: a promising new family of migraine drugs that's expected to come to market next year. They're known as humanized monoclonal antibodies against a peptide called CGRP,  he says, and four companies have just completed clinical trials on them.

"The results are outstanding for about 50 percent of the patients, who can see 75 to 90 to 100 percent response rate," Burstein says, "whereas in about 40 to 50 percent of patients, the benefit is way, way, way smaller."

There are already anti-migraine drugs on the market, but for people who don't respond to them, or don't respond well enough, it sounds like there will soon be new options. "There is definitely a reason for high hope for many of these patients," Burstein says.

And meanwhile, what do these new findings about light mean for migraine patients? Will doctors be recommending that patients avoid light preemptively?

That's just not realistic, Burstein says; patients have to live their lives. My own takeaway:
Next time the aura hits, I may try to skedaddle even a bit faster to my dark bedroom...

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Carey Goldberg Editor, CommonHealth
Carey Goldberg is the editor of WBUR's CommonHealth section.



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