A recent research has shown that dopamine levels fall during the migraine attacks.

Using PET scans of the brain, the University of Michigan researchers showed that dopamine falls and fluctuates at different times during a migraine headache. This could help scientists better understand dopamine-based therapies for migraines as well as a patient's behaviour during an attack.

The connection between dopamine and migraines has long been a poorly understood therapeutic and research area, said researcher Alex DaSilva. Dopamine, sometimes called the brain's feel-good neurotransmitter, helps regulate emotion, motivation and sensory perception.

Physicians and emergency rooms often give migraine patients dopamine antagonists, drugs that block overactive dopamine receptors, to level off wild dopamine fluctuations and ease migraine attacks. DaSilva and colleagues took various measurements of brain activity and dopamine levels of eight migraine sufferers and eight healthy patients during migraine attacks and between headaches. They compared study participants to each other with and without headaches, and also migraineurs to healthy patients.

When migraine patients were between headaches, their dopamine levels were as stable and even as the healthy patients, DaSilva said. But during an attack, the migraine patients' dopamine levels fell significantly. "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," he said.

The study appears in the journal Neurology.