Fluctuations in dopamine worsens migraine symptoms
Dopamine levels fall during migraines, as shown by brain scans generated from a new study published in the journal Neurology.
Brain scans done by a team of researchers from the University of Michigan show a fall in dopamine levels during migraine attacks. The happiness molecule fluctuates in concentration as the headache persists, worsening the symptoms.
Dopamine is often referred to as the feel-good brain substance because, as a neurotransmitter, it regulates emotion as well as reward-motivated behaviour. It also plays a role in sensory perception, and thus in pain sensations. Dopamine and migraines seem to be linked, as suggested by previous research, but what is the exact interaction about? According to study author, Alex DaSilva, little information has hitherto been gleaned about this connection. On the other hand, dopamine-based therapies have been developed to help relieve migraine patients: for instance, drugs blocking dopamine receptors are given to them to control the dopamine fluctuations with the aim of easing migraine attacks. Given the lack of literature on this matter, the new insights are hoped to assist scientists to gain a better understanding of these therapies, and to have a deeper knowledge of patients’ behaviours during such attacks.
DaSilva and his team enlisted the participation of 8 migraine and 8 healthy patients, and measured their brain activity during migraine attacks, and in between the headaches. The results show that migraine patients had stable dopamine levels in between headaches, comparable to the healthy patients. However, during migraine attacks, the dopamine levels of the former decreased significantly.
Co-author Kenneth Casey explains that since dopamine controls sensory perception, a drop of it could increase sensory sensitivity such that sensory signals, that are otherwise painless or simply unnoticeable, become painful. These signals could originate in the skin, in muscles, or in blood vessels. Casey says that this interpretation supports a common theory put forward by other researchers who argue that migraines constitute a periodic disorder that is linked with sensory hypersensitivity, a condition whereby stimuli like light, sound, and odours are sensed on a deeper level.
Another finding is that patients resting during the attacks had a small sudden dopamine level rise accompanied by worse symptoms when warmth was applied onto their foreheads—this condition is known as allodynia, characterised by pain resulting from a stimulus that does not normally cause pain. DaSilva explains that the spike in dopamine might be an aversive response to a stimulus from one’s environment. According to him, the suffering went from bad to worse at this small increase in the molecule because its receptors had already reached a high level of sensitivity—then, even a small recovery would come with unpleasant effects like more nausea, and similar migraine symptoms.
Another aspect of the new findings: the dopamine level fall might explain the behaviour of migraine patients who sometimes feel like withdrawing and isolating themselves: the dopamine decrease and fluctuation during an attack is tantamount to the brain informing the patient of something going wrong inside of him, prompting him to take the time to heal by going into a dark room away from environmental stimulation.
View a 3D representation of the migraine brain in the video below: