Migraine is twice as prevalent in women than in men.1 Oestrogen is a predisposing factor with decreasing levels associated with increased frequency of migraine episodes. The associations between oestrogen and migraine and why changing oestrogen levels are linked to migraine episodes were explored by Patricia Pozo-Rosich, University of Barcelona, Spain, in an online presentation for live EAN 2020.
Why is migraine more common in women?
Menstruation is a risk factor for migraine without aura5
Among 40,000 people who participated in the 2003 National Health Interview Survey in the US the prevalence of migraine was 9% in males and 18% in females,1 said Dr Pozo-Rosich. It is highest in women between puberty and the menopause,2 reaching a peak of 25% among women in their thirties and forties.3
Changing oestrogen levels are linked to migraine episodes
Changing oestrogen levels associated with menarche, oral contraceptive (OC) use, pregnancy, lactation, and menopause are frequently accompanied by changes in the patterns and frequency of migraine:4
- decreasing oestrogen levels at the onset of menses, during the pill-free interval with OC use, and postpartum are associated with increased frequency of migraine episodes4
- increasing or stable oestrogen levels during pregnancy, while taking OC, and after the menopause are associated with decreased frequency of migraine episodes4
Perimenstrual migraine episodes are less responsive to treatment than non-menstrual episodes5
Furthermore, menstruation is a risk factor for migraine without aura attacks, said Dr Pozo-Rosich, and can be the only or primary trigger in up to 14% of patients.5
Perimenstrual migraine episodes are longer and less responsive to treatment than non-menstrual episodes.6
Why can oestrogens cause migraine?
Oestrogens cause changes in the circulation, nociception, and the brain7-10
Oestrogens appear to cause migraine through a variety of mechanisms including:
- vasodilatation due to increased endothelial nitric oxide synthase7
- genetic modulation of serotonin levels involved in nociception8
- endometrial synthesis of prostaglandin, which sensitises nociceptors and promotes inflammation9
- cortical excitability10
ICHD-3 criteria for diagnosing migraine related to menstruation
For better characterization of migraine associated with menstruation the Appendix of International Classification of Headache Disorders 3rd edition (ICHD-3) offers criteria for diagnosing pure menstrual migraine without aura and with aura, menstrually-related migraine without aura and with aura, and non-menstrual migraine without aura and with aura.11