Researchers Find Link Between Light Exposure and Migraine Intensity

Image credit: Nano Anderson / CC BY 2.0Although it is common knowledge that migraine sufferers are sensitive to light, researchers at Harvard Medical School and Beth Israel Deaconess Medical Center have determined an actual link between the two. The research was published online in Proceedings of the National Academy of Sciences.

The researchers discovered the link between light-sensitive nerve cells in the eye and regions of the brain that manage mood and other physical factors such as shortness of breath, fatigue, heart rate, nausea and congestion, which may explain the physical and emotional symptoms that typically accompany a migraine.

“While studying the effects of color on headache intensity, we found that some patients reported finding light uncomfortable even when it didn’t make their headaches worse,” said lead author Rami Burstein, the HMS John Hedley-Whyte Professor of Anaesthesia and vice chair of research in the Department of Anesthesia, Critical Care and Pain Medicine at Beth Israel Deaconess. “We found that exposure to different colors of light could make patients experiencing a migraine feel irritable, angry, nervous, depressed and anxious. These patients also reported feeling physical discomfort, including tightness in the chest or throat, shortness of breath, light-headedness and nausea.”

As part of the study, researchers exposed 81 migraine sufferers and 17 people who never experienced a migraine to an assortment of colored lights. Documenting what the participants experienced, researchers found that exposure to almost all colored lights resulted in negative physiological and emotional responses from migraine sufferers. Conversely, people who had not ever experienced a migraine only reported experiencing pleasant emotions when exposed to each color of light.

“These findings explained accounts from earlier work from blind migraine sufferers in a previous study,” said Burstein. “We had noticed that light exacerbated headache intensity in participants who perceive light but have no sight as a result of loss of rods and cones, but not in those who lack light perception because of optic nerve degeneration. This suggested the nerves relaying signals from the eye to the brain played a critical role in the discomfort associated with migraine.”

“We now have a physical explanation of why migraine patients have negative reactions to light,” said Burstein. “And now we are working on ways to use this information in hopes that soon migraine sufferers will be able to avoid not only the pain but also the negative emotions and physical discomfort that light creates for them.”