The influence of estrogen on migraine: a systematic review.

CONTEXT

Menstrual migraine affects approximately 50% to 60% of female migraineurs, but knowledge regarding the role of hormones, especially estrogen, appears incomplete.

OBJECTIVE

To conduct a systematic review to determine the role of hormones on menstrual migraine.

EVIDENCE ACQUISITION

MEDLINE (January 1966 through September 1, 2005) and EMBASE Drugs and Pharmacology (January 1991 through September 1, 2005) were searched for articles published in the English language using the keywords migraine, estrogen, menstrual migraine, pure menstrual migraine, true menstrual migraine, menstrually-associated migraine, menstrually-related migraine, pregnancy, breast-feeding, perimenopause, menopause, nitric oxide, and estrogen receptors. A total of 643 unique articles were reviewed for relevance, scientific rigor, and generalizability. For each relevant citation, the bibliography was reviewed to identify additional sources of pertinent data.

EVIDENCE SYNTHESIS

The influence of estrogen on migraine is evident by a 3-fold greater prevalence among women compared with men, and by significant changes in migraine incidence with changes in female reproductive status. Menstrual migraines are usually more resistant to treatment, generally not associated with aura, of longer duration, and associated with more functional disability compared with attacks at other times of the month. Biochemical and genetic evidence suggest central and peripheral roles for estrogen in the pathophysiology of menstrual migraine, with potential interactions with excitatory circuits, including serotonergic components. Although evidence for estrogen as a preventive treatment for menstrual migraine is inconsistent, serotonin receptor agonists (triptans) provide acute relief and also may have a role in prevention.

CONCLUSIONS

Epidemiological, pathophysiological, and clinical evidence link estrogen to migraine headaches. Triptans appear to provide acute relief and also may be useful for headache prevention. Clear, focused, and evidence-based treatment algorithms are needed to support primary care physicians, neurologists, and gynecologists in the treatment of this common condition.