This is a brief review of the potential for cannabinoids to be used to treat migraines. Some recent evidence has pointed to the view that the endocannabinoid system (ECS) is implicated in the perception of pain during migraines. Several of the structures of the brain that are involved in migraines are known to be at least partly mediated by the ECS.
Pain in the meninges and brainstem are ECS mediated in part by the ECS, and the regulatory role of the ECS via the CB1, CB2, and TRPV1 receptors in pain are explored. Millions of people suffer migraines each day but the medications used are only effective for some people, some of the time. The complexity and varied, poorly understood causes of migraines have limited targeted drugs that effectively address the pain of migraine. It is hoped that the endocannabinoid system might offer targets and avenues for effective therapy.
Many of the symptoms of migraine are potentially treatable with cannabinoid therapy. The convulsions that are rarely encountered in migraine are thought to be able to be targeted via the endocannabinoid system, which can be interacted with by the administration of cannabinoids, commonly found in the cannabis plant. Evidence from the successful treatment of epileptic seizures and the tremors in some neurodegenerative disorders suggests that cannabinoid therapy might work.
The well known analgesic effects of cannabinoids are of especial interest. There are few drugs that are both safe and tolerable that can be used for migraine pain in the long-term. Cannabinoids are thought to be generally safe and tolerable, especially non-psychoactive cannabinoids like CBD, which has an excellent safety profile and is an effective analgesic.
Nausea is a very common symptom of migraine. Cannabinoids like THC and CBD are known antiemetics, having been used for some time to treat the nausea that accompanies many forms of cancer chemotherapy. Preliminary data and a wealth of anecdotal evidence suggests that cannabinoids can be used for the nausea from migraine.
Severe forms of migraine are thought to involve an inflammatory element. While this is not well understood at this time, the well established anti-inflammatory effects of many cannabinoids cannot be ignored for the possible treatment of inflammation in migraine.
The authors include discussion of a CECD, which hypothesizes that migraines might be caused by a lower level of CB1 and CB2 receptor expression. There is some evidence that administering cannabinoids can change the levels of endocannabinoids back to healthy levels and therefore treat migraine. This has yet to be conclusively proven.
Endocannabinoid Receptors in Migraine
Endocannabinoid receptors CB1, CB2, and TRPV1 are found in most places that are known to contribute to migraines. They are essential for the regulation of pain and inflammation, and there is substantial evidence that when they are dysregulated, they can contribute to migraines.
However, this complex series of interactions is not clearly modeled and there is substantial work to be done before the holes in knowledge of ECS pain and inflammation mediation are plugged. Until this time, it will be very difficult to target cannabinoids or understand their uses in migraine.
The endocannabinoid system is a very promising target for preventing and treating the effects of migraine, which seem in many cases to be partially the result (or cause of) endocannabinoid system dysregulation. More research is needed.