GENERAL BACKGROUND: This is a continuation of a topic I started in February. Here I highlight and critique a review article, or a summary of the current science in the field. You can read the abstract here on PubMed. This article is relevant to you if you are a woman with migraines or if you are the mother of a daughter with migraines. I have been following Dr. Calhoun’s papers for some time now and I am a big fan of her work on the very important and under-studied topic of hormones and migraine. One of the biggest reasons I find her work interesting is that I have found, anecdotally, that women can experience great relief from menstrual migraines (MM) through the use of hormones to either stop their menstrual cycles, or decrease the hormone fluctuations associated with them. While this area is yet to be studied extensively, there are studies out there showing this to be true.
DISCUSSION: This particular article addresses the confusion that exists in the medical and scientific community about the use of combined hormonal contraceptives (CHC’s) in females who have migraine with aura (MwA), especially in the context of preventing MM. The main problem lies with widespread concern that MwA has been associated with an increased risk of ischemic stroke. CHC’s have also been associated with an increased risk of ischemic stroke, and there are historic concerns that this increased risk is worse for patients with migraine. Because of the concern over stroke risk, both the American College of Obstetrics and Gynecology and the Centers for Disease Control have published guidelines limiting the use of CHC’s in patients with migraine, especially those with MwA and in those with “focal neurological signs”.
Dr. Calhoun explains that these concerns are left over from a time when CHCs were much higher doses and that proper use of the current low dose formulations have the potential to decrease aura frequency, and thus potentially decrease migraine and stroke risk.
There are formulations of CHCs available today with ethinyl estradiol (EE) concentrations as low as 10ug, and almost all current formulations are lower than 50 ug EE, far below those originally released and studied. Often studies don’t differentiate between doses and types of estrogen in their work. This leads to difficulty when studies are carried out with women on different formulations.
When Dr. Calhoun dissects the data in published studies she shows that most the risk to migraine patients is from taking high dose CHC’s, and that there is even some evidence that very low dose CHC’s may decrease the stroke risk in patients with MwA. Data has shown that higher frequency of migraine aura is an issue for risk of cardiovascular disease including stroke. The risk of stroke rises four-fold when aura frequency is more than once a week. Also, interestingly, it has been found that higher estrogen levels are achieved during the menstrual cycles of women who have MwA.
To summarize, when Dr. Calhoun looks more closely at these studies, it seems that many studies do not include patients on these lower dose formulations at all.
It appears that most evidence against the use of CHC’s in patients with migraine was in patients taking what today are considered high-dose CHC’s, instead of low-dose CHC’s. In her words, this is like comparing tigers to cats.
MY TWO CENTS: I think this article is long overdue and I am so happy she has written it. I am thrilled there is a research group out there so interested in this area. Two thumbs up!!