Abstract

Objectives: Few migraine prophylactic therapies have demonstrated a 50% reduction in headaches. Even when successful, the economic burden of prophylaxis can discourage widespread usage. This article presents a pilot study of a novel, effective, specific, and inexpensive prophylactic strategy for menstrual-associated migraine.

Materials and Methods: Eleven women with menstrual-associated migraine and fewer than 14 days of headache per month were identified from prospective enrollment at a gynecology practice and retrospective chart review at a headache center. Exclusion criteria included current use of prophylactic therapy for migraine.

Methods: Patients received open-label therapy with an oral contraceptive containing 20 μg ethinyl estradiol on days 1 to 21, supplemented with 0.9 mg conjugated equine estrogens on days 22 to 28. Headache intensity and bleeding were recorded in diaries that plotted headache days by oral contraceptive pill days.

Results: All of the patients achieved at least a 50% reduction in number of headache days per cycle (mean 77.9% reduction); 10 of the 11 women achieved at least a 50% reduction in weighted headache score (mean 76.3% reduction).

Conclusions: All currently available estrogen-containing oral contraceptives produce a premenstrual fall in ethinyl estradiol concentration equal to or greater than 20 μg. Estrogen supplementation during the placebo week can reduce the magnitude of this fall to less than 20 μg. When the decline is limited to the equivalent of 10 μg ethinyl estradiol, menstrual-associated migraine is prevented. At an average cost of six dollars per headache-day prevented, this represents an effective and inexpensive strategy for a common migraine trigger.

Key Points

* Menstrual-associated migraine (MAM) is common and is related to the premenstrual decline in estradiol concentration.

* No currently available combined oral contraceptive will benefit MAM if a woman has migraine with her natural cycle (as the lowest-dose pills produce a 20 μg ethinyl estradiol-equivalent decline).

* Reducing the premenstrual decline in estradiol to a 10 μg ethinyl estradiol-equivalent prevents MAM.