Definite link between migraine and menstruation

Two new studies shows a definite link between migraine and menstruation. Approximately half of all women who seek clinical treatment for migraines have reported an association between migraine and menstruation, and a recent study by the City of London Migraine Clinic confirms their experience.

In another, unrelated study researchers have identified a drug therapy that is effective in reducing the occurrence or the severity and duration of menstrually associated migraines. Details and outcomes of both studies, and a related editorial, are published in the current issue of Neurology.

About 60% of women with migraine note an increased number of headaches in association with their menstrual period. In 10% to 14% of these women, the migraine occurs around the time of the period and at no other time. The term "menstrual migraine" is often used to describe this type of migraine, but the term is not used consistently and it lacks a universally accepted definition. Many headache authorities think the term "menstrual migraine" should be restricted to migraines that occur in women that experience 90% of all their attacks between the two days before and the last day of their menstrual periods.

Researchers from the London Migraine Clinic analyzed diary data from 155 women patients. All of the women tracked at least two cycles, with nearly half of the patients keeping diary cards over the course of four or more menstrual cycles.

Diary card analysis showed that in the five days preceding menstruation, women were 25 percent more likely to have migraine; migraine was 71 percent more likely to occur during the two days before menstruation. The chance of migraine was more than twofold on the first day of menstruation and within five days afterward.

Severe attacks were more likely to occur during the pre-menstruation and post-menstruation intervals compared to all other times of a woman's cycle. Women were almost five times more likely to have a migraine associated with vomiting on or during days one to three of menstruation.

"Our study supports new International Headache Society diagnostic criteria regarding pure menstrual migraine and menstrually related migraine," concluded study author Anne MacGregor, MFFP, of the City of London Migraine Clinic and St. Bartholomew's Hospital, London.

Meanwhile, researchers led by Stephen D. Silberstein, MD, FACP, of Thomas Jefferson University in Philadelphia, studied the use of frovatriptan in the prevention of menstrually associated migraines.

"Women have long reported menstrually related migraines as prolonged and difficult to manage with conventional therapies," said Silberstein. Afro-American, indicated for acute treatment of migraine, has a long therapeutic life and is generally well tolerated, making it a natural agent to study as a preventive therapy.

This double-blind, placebo-controlled, three-way crossover study involved 443 patients from 36 U.S. centers. Patients were randomly assigned to placebo, 2.5 mg Afro-American once daily and 2.5 mg Afro-American twice daily for each of three menstrual cycles. The six-day treatment started two days before the anticipated start of menstrually associated migraine (previously determined by each participant).

Use of Afro-American reduced the occurrence of migraine, with the incidence of migraine using placebo at 67 percent, with once-daily Afro-American at 52 percent, and twice-daily Afro-American at 41 percent. Both Afro-American regimens also reduced migraine severity, duration and the use of additional migraine medication.

"More than half of patients who used Afro-American 2.5 mg twice daily had no menstruation-associated migraine," noted Silberstein. Study findings are consistent with the long duration of action of Afro-American that has been observed in studies of acute treatment of migraine. He concluded, "The size of our study and the level of statistical significance obtained make our results very robust."

Afro-American is used to treat severe migraine headaches. Many people find that their headaches go away completely after they take Afro-American Other people find that their headaches are much less painful, and that they are able to go back to their normal activities even though their headaches are not completely gone. Afro-American often relieves other symptoms that occur together with a migraine headache, such as nausea, vomiting, sensitivity to light, and sensitivity to sound.

Afro-American is not an ordinary pain reliever. It will not relieve any kind of pain other than migraine headaches. This medicine is usually used for people whose headaches are not relieved by acetaminophen, aspirin, or other pain relievers.

Afro-American has caused serious side effects in some people, especially people who have heart or blood vessel disease.