Women whose epilepsy started when they were children very often find that when they reach puberty the nature of their epilepsy changes. About two-thirds of women experience some sort of change. Usually there is an increase in seizure frequency, or a new type of seizure develops. But in about a third of cases the change is positive; seizure frequency decreases and seizures may even stop altogether. As a general rule, absence seizures tend to become less frequent or to stop. The chances of a woman’s epilepsy getting worse at puberty are greater if she reaches puberty later than average, or if her epilepsy started early in childhood, or if she has an abnormal EEG and has previously had a great many generalized tonic clonic seizures.
MENSTRUATION AND EPILEPSY
Does epilepsy affect periods:
It is very unusual for a woman’s periods to be affected if she develops epilepsy. However, a few women have seizures which affect the part of the brain that regulates the menstrual cycle, and in this case they may be more likely than other women to have menstrual problems such as irregular periods. In addition, some anti-epileptic drugs, particularly sodium valproate (Epilim) affect the menstrual cycle.
Do periods affect epilepsy?
Nearly everyone who has epilepsy discovers that the frequency of their seizures varies. There will be times when you seem to have more seizures than at others. So it is not surprising that quite often a woman notices that she seems to have more seizures around the time of her period. However, if you keep a seizure diary you will probably find that this does not happen every month. Seizures are nearly always more irregular and unpredictable than this.
A few women (probably less than 10 per cent of all women with epilepsy) do have what is called catamenial epilepsy — a type of epilepsy in which every month there is a regular and definite increase in seizure frequency around menstruation. Often they start to have regular, recurrent ‘bad patches’ of seizures just before they reach puberty. When their periods start it is clear that they have catamenial epilepsy.
Catamenial epilepsy is probably somehow related to the relative levels of the hormones oestrogen and progesterone which are produced during the menstrual cycle, though it is difficult to find a clear relationship. The normal pattern is that during the first half of the menstrual cycle, oestrogen is the main hormone produced. During the second half of the cycle both oestrogen and progesterone are produced. Oestrogen is known to have a seizure-provoking effect, while progesterone is an anticonvulsant and tends to protect against seizures.
But even if hormones play a part, they cannot provide a complete explanation, because there does not seem to be any noticeable difference in the hormonal changes between women who have catamenial epilepsy and those whose epilepsy is no worse at the time of their periods. Another explanation is that pre-menstrual tension may play a part, and that women with catamenial epilepsy are more likely to suffer PMT. Stress and anxiety are known to precipitate seizures and the mood changes of PMT may have something to do with their seizure increase at that time. At the moment, however, this is only a theory.
EPILEPSY AND FERTILITY
Another worry many women have is that epilepsy may affect their ability to conceive. Fertility rates are slightly reduced in both men and women with epilepsy. Women may find it more difficult to become pregnant if seizures affect the part of the brain that regulates the menstrual cycle and they experience irregular periods, or if they are taking anticonvulsants which affect the menstrual cycle. Yet although you may take a little longer to become pregnant, these factors will not stop you conceiving. If after a year of trying you are still not pregnant, talk to your doctor. Modern methods of fertility treatment should solve the problem.
EPILEPSY AND CONTRACEPTION
Hormonal contraception (‘The Pill’)
Hormonal contraception is a safe and very effective form of birth control. It can be taken orally, in the form of the combined pill (which contains two hormones, oestrogen and progesterone) or the progesterone-only ‘mini-pill’. It can also be given as a slowly absorbed (depot) injection or an implant under the skin. These two methods have the advantages that the implant or injection lasts several weeks, and you do not have to remember to take a pill every day.
Because it is so effective, hormonal contraception, usually in the form of the Pill, is the method of first choice for many women. However, if you have epilepsy, you need to discuss its pros and cons with your doctor before you decide it is the right method for you.
If you are taking sodium valproate, vigabatrin, lamotrigine, gabapentin, clobazam, clonazepam or ethosuximide, there is no problem and you can take the oral contraceptives, or use contraceptive injections or implants, in the normal way. However, a few widely-used anticonvulsants (phenytoin, phenobarbitone, carbamazepine, and primidone) make the liver break down the hormones in these contraceptive preparations more rapidly, reducing their effectiveness. The sign that the contraceptive effect of the pill has failed is that you get ‘breakthrough’ bleeding.
You are not prevented from using hormonal contraception if you are taking any of these latter drugs, but for them to be effective you may need to take a higher than usual dose of the oral contraceptive, or receive more frequent injections or implants. The dose of the Pill, for example, may need to be increased two or three times until you have a cycle with no breakthrough bleeding. Until you have a cycle without breakthrough bleeding you will need to use a condom or some other form of contraception.
The larger dose of the contraceptive will not have any more side-effects than the normal one, because the excess hormone is being broken down and disposed of by the liver.
A few women with epilepsy find that the Pill makes their epilepsy worse. But it is more likely that going on the Pill will reduce your seizure frequency by helping to reduce pre-menstrual seizures. Some women therefore decide to take the pill continually on a 28 day cycle without the usual seven days’ break.
If it is to be effective, the pill has to be taken regularly, every day and at the same time every day. Remembering to take it may be a problem if you have frequent seizures. If you want a hormonal method of contraception, but do not feel that you can rely on your memory to take the Pill regularly, contraceptive injections or implants may be a better solution. These are hormones with a long-term effect and are either given by injection or implanted beneath the skin. This must be done by a doctor or specially-trained family planning nurse.
Emergency contraception used to be known as the ‘morning after’ pill, but in fact it need not be taken the morning after unprotected intercourse. Ideally, it should be taken within 3 days (72 hours) of having sex. However, it may even work if taken within five days; sperm can survive for a couple of days, and so it is always possible that you may have ovulated and conceived two days after having sex. The pill consists of two hormonal pills taken immediately, and another two taken 12 hours later. You can use emergency contraception if you are taking anticonvulsant medication, but, depending on the drug you are taking, you may need a slightly larger dose. If you tell the doctor who gives it to you that you have epilepsy, and what drugs you are on, your anticonvulsant medication can be taken into account.
The menopause is often another time of seizure change though, as ever, epilepsy is so unpredictable that it is difficult to say which direction the change will take. Seizures may increase or decrease in frequency, go into remission, recur if they have been in remission or there may be no change at all. And a few women who have never had seizures before in their lives may start to have them at the menopause, though no one knows the reason for this.
If your seizures have always been related to your periods they will probably improve during the menopause. You can also feel optimistic about improvement if your seizures began late in life and have always been infrequent. However, there is some evidence that in women who have an earlier than average menopause seizure frequency tends to remain unchanged, or to increase.
One of the inevitable results of old age is that bones grow less dense and more brittle (a condition called osteoporosis). Until women reach the menopause, oestrogen gives some protection against thinning of the bones, and many doctors advise women to have hormone replacement therapy (HRT) to prevent osteoporosis. This is especially important for women who have a family history of osteoporosis. It is also very important for women with epilepsy, because anticonvulsant drugs, particularly phenytoin, tend to cause calcium deficiency and increase the risk of brittle bones.
HRT contains the same hormones as the contraceptive pill, and so you may need to take a higher dose than normal to be effective if you are taking phenytoin, phenobarbitone, carbamazepine, or primidone. In a few women HRT increases seizure frequency, though if you have this problem it may be possible for you to find a different form of HRT which does not have this effect.