Researchers at the University of Michigan in Ann Arbor have used PET scans of the brain to show that dopamine falls and fluctuates at different times during a migraine headache, which could help scientists better understand dopamine-based therapies for migraine sufferers.
Alex DaSilva, assistant professor at the U-M School of Dentistry and Center for Human Growth and Development, and his team used PET scans and 3D imaging to measure various amounts of brain activity and dopamine levels of eight migraine sufferers. They then compared study participants to each other with and without headaches, and also migraine patients to healthy ones.
“This dopamine reduction and fluctuation during the migraine attack is your brain telling you that something is not going well internally, and that you need time to heal by forcing you to slow down, go to a dark room, and avoid any kind of stimulation,” DaSilva says.
Though he admits the connection between dopamine and migraines is generally a “poorly understood therapeutic and research area,” emergency room doctors often give migraine patients dopamine antagonists drugs that block overactive dopamine receptors to level off wild dopamine fluctuation and provide some relief.
DaSilva’s study indicated that when migraine patients were between headaches, their dopamine levels were stable and as even as healthy patients, but during an attack, dopamine levels fell significantly.
“Dopamine is one of the main neurotransmitters controlling sensory sensitivity,” says Kenneth Casey, a study co-author and U-M professor emeritus of neurology. “Therefore, a drop in dopamine could produce increased sensory sensitivity so that normally painless or imperceptible sensory signals from skin, muscle, and blood vessels could become painful.”
The findings support the hypothesis held by some researchers that migraines are a periodic disorder characterized by sensory hypersensitivity during which light, sound, and odors may become abnormally tense. The study will be published in the March issue of Neurology, the medical journal of the American Academy of Neurology.