Estrogen withdrawal confirmed as migraine trigger
Last Updated: 2007-01-11 14:18:26 -0400 (Reuters Health)
By Michelle Rizzo
NEW YORK (Reuters Health) - There is a relationship between fluctuations in estrogen levels during the menstrual cycle and the incidence of migraine, according to a new report, which supports the "estrogen withdrawal" hypothesis. The researchers also found that, if timed correctly, transdermal estrogen therapy may prevent these migraines.
Dr. Anne MacGregor from the City of London Migraine Clinic and UK colleagues studied 38 women (average age 43 years) with menstrual migraine and regular menstrual cycles.
The participants kept a daily migraine diary and provided the study team with an early morning urine sample each day.
Over three menstrual cycles, the incidence of migraine peaked on the first full day of bleeding and on the preceding day, which correlated with a drop in estrogen levels. As estrogen levels began to rise, migraine incidence began to decline, the investigators found.
"Although we were not surprised to confirm the hypothesis of estrogen withdrawal as a trigger for migraine," MacGregor said, "we were surprised to find that rising levels of estrogen appeared to offer some protection."
In a second study with the same group of women, MacGregor's team confirmed that treatment with estrogen supplements, around the time the menstrual cycle begins, can reduce the severity and duration of menstrual migraine attacks.
During six menstrual cycles, the women began treatment with an estrogen gel or placebo 10 days after day 1 of peak fertility and continued daily through the second full day of bleeding.
Estrogen gel was associated with a 22-percent reduction in migraine days, the team reports. Migraine attacks were also less severe and less likely to be associated with nausea.
However, in the 5 days after estradiol was discontinued, migraine incidence increased by 40 percent, consistent with a delayed estrogen withdrawal.
"As a result of the study, we've learnt that estrogen supplements are effective and if we continue them for several days into the next cycle, we can avoid the problem of deferring attacks," MacGregor told Reuters Health. "We now routinely recommend this as a strategy for our patients with menstrual migraine."
SOURCE: Neurology, December 26, 2006.
