The cause of light sensitivity in migraine has remained murky in research, but a new study gives us some exciting leads. Light (and sound) sensitivity may be due to heightened connectivity in certain areas of the brain, according to an article published in the March 10 issue of the journal Neurology. The study found that people who have migraine “have heightened regional connectivity between networks involved in processing upstream sensory information and those that represent the salience of such stimuli” compared to those without migraine. Simply put, sensitivity to light and sound in people with migraine appears to be linked to brain anatomy.

The study included 15 participants who have migraine without aura and 15 participants who do not have migraine. Using fMRI, researchers compared the connectivity in areas of the brain between the two groups. The participants with migraine had imaging done at least three days before or after a migraine attack, not during one. Participants with migraine had higher levels of connectivity than those without migraine in several areas. In case you’re curious about the specifics, the areas are: between the primary visual and auditory cortices and the right dorsal insulae, between the dorsal pons and bilateral anterior insulae, and between the right and left ventral insulae.

It’s unlikely that medications will be developed to specifically target this region of the brain, but it could lead to better migraine diagnosis. Researchers believe this increased connectivity could be a biomarker—a measurable sign—for migraine. If that’s the case, then brain imaging could help doctors make a definitive diagnosis of migraine. Right now, the only reason people with migraine get brain imaging is to rule out another cause of symptoms, like a brain tumor or aneurysm. Migraine is considered a diagnosis of exclusion, but there are no ways to test for migraine. If future research supports the findings of this study, doctors could test for migraine by looking at these specific regions of the brain.

Even if this research doesn’t lead directly to treatment, finding possible biomarkers is an exciting advancement in migraine research that could ultimately improve diagnosis and treatment.

References

Anderson, P. (2015). Light and Sound Sensitivity in Migraine Explained? Medscape. Published online March 19, 2015. Accessed March 23, 2015.

Tso, A. R., Trujillo, A., Guo, C. C., Goadsby, P. J., & Seeley, W. W. (2015). The anterior insula shows heightened interictal intrinsic connectivity in migraine without aura. Neurology, 84(10), 1043-1050.