Have you ever heard the lie that the brain can’t feel pain? Try telling that to someone with chronic migraines. Okay… well… it is only kind of a lie. It is true that the actual tissue of the brain cannot sense pain (i.e. it has no nociception), but the blood vessels of the brain can indeed sense pain and are not afraid to activate those pain receptors (nociceptors) at the first sign of blood vessel expansion (vasodilation).
Migraines are defined as recurring one-sided headaches accompanied by vomiting and sensitivity to light and sound. These pains in the head are due largely to vasodilation and inflammatory responses of the blood vessels that supply the brain with blood. This vasodilation can be caused by the parasympathetic nervous system (the “rest and digest” part of the nervous system) and some of the chemicals it releases including NO, VIP and ACh. Another nerve called the trigeminal nerve also plays a huge role in migraines. It can release CGRP which is a chemical highly linked to vasodilation and inflammation and the induction of migraines.
While there is still much we do not know about migraines, anyone who has ever had one can tell you that more research should be done to find treatments for these excruciating events. As of yet, there are three main treatments for migraines: triptans, which activate serotonin receptors to constrict the vessels; gepants, which block CGRP receptors to counter vasodilation; and glutamate antagonists, which inhibit glutamate receptors. Also, botox can be used as a treatment for migraines.
Migraines are a complex and individualized disease with many possible processes of origin and a vast array of symptoms and recurrence. They are a hard neurological disorder to peg down and need to be researched much more in depth before treatments and even prevention can become as effective as possible.
Who knew vasodilation could be such a pain?
