Most migraine and post-traumatic headache sufferers find their headaches get worse in light, leading them to quit their most fundamental daily tasks and seek the comfort of darkness. A new study from Harvard Medical School reveals that exposing these headache sufferers to pure-wavelength green light significantly reduces their photophobia, or sensitivity to light, and can even reduce the severity of their headaches. The results have been published in Brain.
Photophobia, associated with more than 80% of migraine attacks, gives migraine sufferers little choice but to isolate themselves in dark rooms, unable to work, care for their family, or pursue everyday activities.
Although hotophobia is not as incapacitating as the pain of the headache itself to migraine sufferers, "it is their inability to endure light that most often disables them," says Rami Burstein, Professor of Anesthesia at Beth Israel Deaconess Medical Center (BIDMC) and Harvard Medical School, and lead author of the study.
The new study shows that a narrow band of green light exacerbates migraine significantly less than all other colors of light and that at low intensities it can even reduce the headache itself.
Burstein and his colleagues devised a way to study the effects of different colors of light on headache in patients without visual impairment, after discovering that only blue light hurts blind migraine patients
They asked patients undergoing acute migraine attacks to report any change in headache when exposed to different intensities of blue, green, amber and red light. At high intensity of light (as in a well-lit office) nearly 80% of the patients reported intensification of headache - in all colours but green. Burstein and his colleagues found, unexpectedly, that green light actually reduced their pain by about 20%.