Menstrual migraine

By: Dr Anne MacGregor, specialist in headache and women’s health

It’s an indisputable fact that migraine is affected by hormonal events throughout a woman’s life: the first attack often occurs around puberty; the combined oral contraceptive pill may precipitate attacks during the pill-free week; migraine often improves during pregnancy and worsens during perimenopause, with attacks often linking to menstruation; respite usually follows menopause.

What is menstrual migraine?

Menstrual migraine describes a greater than chance association between menstruation and migraine. Women with menstrual migraine consistently experience migraine attacks with their menstrual periods, often starting a couple of days before the period starts. Menstrual attacks are typically more severe, less responsive to treatment, and last longer than attacks at other times of the menstrual cycle.

Have I got menstrual migraine?

You might think it would be glaringly obvious but I’ve lost count of the number of women who didn’t connect migraine with their menstrual periods until they started to keep a diary and only then noticed a pattern. Diaries are really important – not just to establish a pattern of attacks but also to assess how that pattern changes with treatment. It doesn’t matter if it’s a paper diary, an app, or just making notes on a calendar. If you find that you are consistently experiencing migraine attacks starting within a few days before or after the start of your period, and these attacks are more troublesome than attacks at other times of the month, it is highly likely that you have menstrual migraine.

What causes menstrual attacks?

Lots of research has identified a link between migraine and falling levels of the hormone estrogen. In the case of menstrual migraine, this is the natural drop in estrogen just before a period starts. But it is unlikely to be the only specific trigger for menstrual attacks. For example, women with heavy, painful periods have higher levels of the hormone prostaglandin, which has also been implicated in menstrual attacks of migraine.

How is menstrual migraine treated?

The important point about managing menstrual migraine is to manage the woman with menstrual migraine, not just the attacks. What do I mean by that? There is no single strategy for treating menstrual migraine. Management depends on lots of other factors, including contraceptive needs, pregnancy planning, other menstrual disorders, and menopause symptoms. In some cases, it may simply be a matter of finding effective symptomatic treatment, while other women needing contraception may choose to use a combined contraceptive pill that ‘switches off’ the menstrual migraine trigger.

If you are already taking the combined pill and experience migraine in the pill-free week, the simplest solution is to take the pill continuously without a break. This is perfectly safe to do and has become a standard recommendation for pill-taking in all women. If you have migraine aura, progestogen-only methods are recommended. The desogestrel progestogen-only pill can be effective for some women with menstrual migraine, more usually if it also stops their periods. Unfortunately, unscheduled bleeding is a common problem, often with accompanying migraine.

A few women choose to use preventive medication for a few days around the time of menstruation – so-called ‘perimenstrual prophylaxis’. This involves taking a short course each month of non-steroidal anti-inflammatory drugs such as naproxen or mefenamic acid (which can also help painful periods), estrogen supplements, or triptans. While these can be effective, they depend on your menstrual cycle being regular since they need to be started a few days before the period starts. There is also the problem that they may just delay the menstrual attack rather than prevent it.

Are standard migraine preventives effective for menstrual migraine?

To a certain extent, yes. Standard migraine preventives taken every day can help to reduce the overall frequency and severity of migraine by around 50%. They are often less effective for menstrual migraine than non-menstrual attacks but even if it doesn’t prevent them, menstrual attacks may respond better to symptom treatment than before.

What else can I do to prevent menstrual attacks?

Don’t forget non-hormonal triggers. Triggers combine to reach the migraine ‘threshold’ and whether or not you have an attack depends on if you stay below the threshold or cross it. Even in women with a clear pattern between migraine and menstruation, hormonal triggers are unlikely to be the sole cause. So, if it’s coming up to that time of the month, be extra careful to eat regularly and keep hydrated. Importantly, even when the menstrual trigger is effectively treated, you will still have migraine attacks just by the accumulation of non-hormonal factors. For example, if you are going on a long car journey, you are likely to be stuck in a seat for hours, possibly also skipping a meal and so triggering migraine. This could be prevented by taking some snacks and water with you and stopping for regular breaks.

You can’t avoid every migraine trigger, but you can balance them up!