About 60% of women with migraine note an increased number of attacks in association with their menstrual period. This is known as menstrually-related migraine.
Pure Menstrual Migraine is diagnosed when attacks occur exclusively around the time of menstruation in at least two out of three menstrual cycles and at no other times during the cycle. Using this definition, about 10% of female migraineurs have pure menstrual migraine. Menstrual attacks tend to be less severe but longer than non-menstrual attacks
The most likely mechanisms responsible for menstrual migraine are:
- Falling levels of oestrogen/ progestogen.
- Entry of prostaglandins (hormone-like, lipid compounds) into the systemic circulation. These levels are at their peak during the first 48 hours of menstruation.
Management of Migraine
A Migraine Diary can be very effective in establishing the link between menses and migraine.
Acute treatment is the same as for other migraine and can include triptans and NSAIDs. Triptans are just as effective for menstrual migraine.
An anticipated menstrual migraine attack may sometimes be prevented by either taking a long acting triptan or some NSAIDs in the hours prior to the attack.
The COC pill is not contraindicated in women who have migraine unless they are affected by migraine with aura. The effects of COC use are quite variable:
- Migraine may improve
- No change in frequency or severity
- Migraine may become more frequent or more severe
- New onset of migraine (particularly if there is a family history)
- Change from Migraine without Aura to Migraine with Aura
- Migraine may occur in the pill-free interval only
If the patterns of migraine change for the worse or if the patient experiences aura for the first time, the oral contraceptive should be discontinued. After discontinuation, about 30-40% of this group will improve but this improvement may not occur for up to one year.
In patients who experience migraine in the pill-free week hormonal prophylaxis may be considered whereby the patient continues on the COC for three months without an interval, thus reducing the number of episodes from twelve a year to four. Note that there is little data to support this practice. An alternative is to consider natural oestrogen supplements during the pill-free week.
Migraine with Aura is a risk factor for ischaemic stroke. This risk is further increased in young women through use of the COC. However, the absolute risk is still very low (c. 30/100,000 in women aged 25-34). Nevertheless, it is advisable that patients with migraine with aura do not use the combined oral contraceptive pill AND reduce their exposure to other risk factors e.g. by stopping smoking before commencing oral contraceptives. Hypertension, family history, obesity and diabetes are other significant risk factors that should be considered.
- Women who have been diagnosed with Status Migrainosus (attacks longer than 72 hours)
- Women who have aura symptoms such as hemiparesis, dyphasia or prolonged focal neurological symptoms
- Use of ergotamine to treat migraine. This class of drugs has widespread vasoconstrictor effects which, combined with COC’s act to increase the risk of stroke
The increased risk of stroke appears to be present only in women who have migraine with aura, so the COC is not contraindicated in women who have migraine without aura, provided there are no other risk factors identifiable.
COCs containing only progesterone do not increase the risk of stroke and can be used as an alternative to the COC if required.
Pregnancy and Migraine
Migraine and Pregnancy: Migraine is likely to improve during pregnancy. 60% experience improvement, particularly during the second and third trimesters. It is thought that the more stable levels of circulating oestrogen and progestogen at this time is responsible for the improvement, but improvement may also be as a result of other changes during pregnancy such as increased endorphin production. Usually, the pre-migraine patterns will return when the pregnancy is over and the patient has begun menstruating again.
However, about 15% of women report worsening or new onset migraine during pregnancy, and as such, there is no definite way to predict how or if migraine will change during pregnancy. However, it has been noted that improvement is most likely in women who have migraine without aura or who have menstrual or menstrual-related migraine. Women who have migraine with aura are more likely to continue having attacks during pregnancy.
Worsening or new-onset migraine does not have an effect on the outcome of the pregnancy and the patient needs to be reassured of this. Most women that experience migraine for the first time during pregnancy will continue to experience migraine thereafter.
Management of Migraine During Pregnancy
Management of migraine during pregnancy must begin by ruling out secondary causes if the headaches are occurring for the first time. Once a diagnosis of migraine has been made, a treatment regime based on the following principles can be considered:
Few drugs have been tested for safety in pregnancy, so acute therapies are limited to the use of paracetamol with or without an anti-emetic. Triptans and prophylactic measures are not advised.
Because most drugs exert their greatest impact on the foetus during the first trimester, medications should be discontinued immediately after pregnancy is confirmed. Prophylactic treatments should also be discontinued if the patient is trying to become pregnant. Feverfew, a common herbal remedy should also be discontinued during pregnancy due to its potential to induce miscarriage.
Patients should be reassured that their migraine is likely to improve during the second and third trimesters, even if attacks become initially worse in the early stages of pregnancy. Patients may also need to be reassured about the safety of the foetus if they have inadvertently taken medication before they discovered they were pregnant.
Non-pharmacologic treatments include:
- Sleep / Rest / Retreat
- Cold therapy
- Light exercise
- Massage /Relaxation therapy
- Trigger avoidance
- Increase water intake or eat a small snack, especially if nausea and vomiting occur early in pregnancy
- Complementary therapies such as acupuncture, reflexology and yoga have no proven efficacy in treating migraine but anecdotally some women find benefit from complementary therapies during pregnancy
Menopause and Migraine
For women whose migraine has been closely linked with their menstrual cycle, the elimination of that trigger with the onset of menopause can result in real improvement, although it is rare for attacks to disappear entirely. In contrast to physiologic menopause, surgical menopause results in worsening of migraine in two thirds of cases.
Getting older is also usually associated with both headaches and associated symptoms becoming less severe so it may not be only menopause, but also aging, which produces headache improvement in many cases.
Perimenopause is sometimes associated with worsening migraine as a result of hormone fluctuations. In addition, irregular menses can make management of the condition less predictable. As menopause progresses, the plasma levels of sex steroids decline and migraine frequently abates.
Even so, in the general population between the ages of 55 and 60, the incidence of migraine in women is still higher than men. This suggests that some factors other than hormones contribute to the predominance of migraine in women, but the reasons for this are not well understood.
Management of perimenopausal migraine
Regular acute and prophylactic measures should be used, bearing in mind that Triptans are indicated only in adults aged 18-65. If attacks linked to irregular menses or other perimenopausal symptoms are apparent, HRT may be considered as an option, provided that there are no contraindications to its use.
Hormone Replacement Therapy
HRT is licensed for the control of menopausal symptoms and the prevention of osteoporosis and has a variable effect on migraine frequency. Research as shown that it is almost a likely to worsen migraine than improve it. It remains virtually impossible to predict what a given woman will experience.
Subcutaneous routes of oestrogen administration are more likely to improve migraine than oral routes.
Lower doses are recommended for migraine, although there may well be some trade off with other menopausal symptoms.
Continuous oestrogen replacement therapy may be preferable to cyclical dosing
For optimal results, oestrogen levels should be kept stable to avoid triggering an attack. The patch forms of oestrogen supplementation release more smoothly than the oral versions.
Note that migraine is not a risk factor for stroke in post-menopausal women and therefore, HRT is not contraindicated for this reason.
Some women may improve when progesterone is eliminated entirely. However, additional progestogen is necessary to prevent endometrial cancer in unhysterectomised women using oestrogen replacement. This may lead to an increase in migraine, especially if administered cyclically, rather than continuously. A transdermal route of administration can help minimise this effect.