Women and epilepsy (part 1): hormones, periods and contraception

The female body can create some additional hurdles in the management of epilepsy. Fortunately, there is a wealth of knowledge and research that allows specialists, such as Professor Matthew Walker, to work with women’s hormones, menstrual cycles and contraception to manage the condition. In this article, Professor Walker explains all you need to know.

Cluster seizures during menstruation

It’s been well recognised that certain hormones can have a big impact on the likelihood of having epileptic seizures. Around 40-50 per cent of women with epilepsy find that the frequency and/or likelihood of seizures vary with their cycle. Seizures triggered by a women’s menstrual cycle are medically referred to as catamenial epilepsy.

Two important hormones in the human body that fluctuate during women’s menstrual cycles are oestrogen and progestogen. Oestrogens tend to have a pro-seizure effect on the brain, making seizures more likely to occur. Progestogens, on the other hand, tend to have an anti-seizure effect and lower the possibility of seizures.

For example, a women’s chance of seizures is increased during ovulation (mid-cycle) due to high oestrogen levels. It is then increased again during menstruation due to a withdrawal of progestogen. Because of this, catamenial epilepsy is most often experienced within a day or so of menstruation, but also during ovulation.

Medication and hormones

For women who have their seizures tightly correlated with their cycle, we can give them medication within particular windows (most commonly menstruation and ovulation) to stop seizures happening. The person may be on medication anyway, but we can add another drug just for the three or four days of their cycle to stop seizures occurring.

Contraception and hormones

The progestogen-only pill stops the natural cycle and keeps the progestogen level high. As a result, many women stop having seizures. However, results are often quite mixed. Sometimes it can create the issue of seizures occurring sporadically in the month rather than clustering at one time. Therefore, while some women may become seizure-free, others can lose the ability to predict when seizures happen.
While the progestogen-only pill can be helpful, often the combined pill has no particular effect. This is because the combined pill is a combination of oestrogen (pro-seizure) and progestogen (anti-seizure). Because it increases and decreases both hormones, the effect balances out in the end.

Medication and contraception effectiveness

It’s important for any women to make sure medication doesn’t interact with their contraceptive pill. Quite a lot of drugs for epilepsy increase the breakdown of the contraceptive pill, particularly the breakdown of oestrogen within the pill. As a consequence, many contraceptive pills can become less effective. This lack of effectiveness can be evident via breakthrough bleeding, which is when a woman has blood or spotting outside her normal bleed.

Alternative forms of contraception that don’t contain oestrogen are:

• The progestogen-only pill.
• An intrauterine device (IUD), often referred to as the coil. Mirena and Jaydess being two popular brands in the UK.
• A higher dose of a pill with oestrogen.

Another thing to recognise is that some anti-epileptic drugs themselves can drop in their levels when a woman also takes the contraceptive pill. Something to be wary of for women with controlled epilepsy is that starting a new pill can induce seizures for a while until once again controlled.

Click here for part 2 – Women and epilepsy: pregnancy, breastfeeding and safety

Professor Matthew Walker is a leading specialist in the field of epilepsy who has contributed greatly to research. Learn more and book a consultation by visiting his profile.