How many times have we or the people we know found our Migraines worsened by light? Countless times! Researchers at Beth Israel Deaconess Medical Center in Boston have determined why this happens. This exciting research how visual and pain pathways converge in the brain, causing light to exacerbate the pain of a Migraine.
In an interview, researcher Burstein commented:
"We had no clue in the world where in the world light and pain talk to each other in the brain. They have completely different pathways in the brain...
We identified a new pathway in the brain that originates in the eye and goes to the brain areas where neurons are found that are active during migraine attacks. The light can increase the electrical activity in neurons that are active to begin with."4
- Researchers documented the prevalence of Migraine-associated photophobia in 20 (15 female, five male) blind study participants.
- The demographics of these participants was similar to Migraineurs with normal eyesight for their ages, their age when they experienced their first Migraine attack, frequency of their Migraines, and incidence of visual aura (35% of participants).
- Six of the participants (group 1) had no light perception because of bilateral enucleation (removal of the eye) or damage to the optic nerves.
- The remaining 14 participants (group 2) were legally blind, but capable of detecting light.
- Participants in the first group experience no exacerbation of Migraine pain when exposed to light.
- Group 2 did experience exacerbation in their Migraine pain when exposed to light, particularly blue or gray wavelenghts.
- With the findings from these two groups of participants, researchers turned to laboratory animals. They injected dye into the eye and traced the pathway of light sensitive retinal cells through the optic nerve to the brain. There, they found a group of neurons that become electrically active during a Migraine.
- In the animal model, those neurons remained activated even when the light was removed.