Epilepsy in women

Epilepsy and hormones

Epilepsy is a chronic neurological disease characterized by recurrent seizures and associated with multiple comorbidities.¹ The term comorbidity refers to the presence of medical conditions that occur during the course of an illness.²

There is an important correlation between epilepsy and hormones, in that they can influence each other reciprocally.³ For example, it has been found that female sex hormones can affect the excitability of neurons: oestrogen tends to favour seizures, while progesterone tends to limit them.³

There are three main forms of oestrogen:³

• oestradiol, present mostly in fertile women
• oestriol, present mostly in pregnant women
• oestrone, present mostly in postmenopausal women

Testosterone, on the other hand, plays a variable role in relation to epilepsy, as it can be transformed into 17β-oestradiol, which generally promotes seizures, or into androstenediol and dihydrotestosterone, which exert antiepileptic effects.³

Conversely, epilepsy may have an impact on hormones: dysfunction in the reproductive sphere and disorders of the endocrine system, i.e., the glands that release hormones, have been reported in both men and women with epilepsy.³ For example, the rate of infertility is twice as high in women with epilepsy as in other women.¹ A possible explanation may be that women with epilepsy are more likely to develop polycystic ovary syndrome, which in turn could be due to the interplay between epilepsy/antiepileptic drugs and the endocrine system.¹

Puberty and menopause mark the beginning and end of a woman's reproductive cycle, and they represent two stages of major transformation in women.⁴

Epilepsy in women of childbearing age and pregnant women

Worldwide, epilepsy affects about 50 million people, of whom about 15 million are women of childbearing age.⁵ Puberty begins in late childhood with hormonal changes that allow physical growth, sexual maturation, and the possibility of having a reproductive life.⁴ Menarche, i.e., the beginning of the menstrual cycle, occurs near the end of puberty.⁴

Normally, a woman's menstrual cycle lasts about 28 days and can be divided into two phases: the follicular phase (from the first day of menstruation until ovulation) and the luteal phase (from the day of ovulation until the next menstruation).⁶

During this cycle, oestrogen and progesterone undergo fluctuations that, in some women with epilepsy, can promote so-called catamenial seizures.⁶ Catamenial seizures are associated with a rapid decrease in progesterone levels immediately before, during and after menstruation.⁷ Catamenial epilepsy involves about one-third of women with epilepsy and is considered a drug-resistant form of epilepsy.⁶

Pregnancy is also a time of great changes for a woman; pregnancy in women with epilepsy can alter the course of the disease but also the response to antiseizure medications.⁸

Epilepsy in women during menopause

Menopause is the phase of a woman's life when the menstrual cycle ceases; the approximately 4-5 years prior to this time define a period called perimenopause, during which the hormonal and biological changes that will lead to menopause begin to occur.⁴ These hormonal changes during the transition to menopause appear to have an effect on seizure susceptibility.⁷ Women with catamenial epilepsy may experience an increase in seizure frequency during perimenopause and a decrease after menopause, which is consistent with the elevated oestrogen levels during perimenopause and the low levels of this hormone during postmenopause.⁷ However, this does not occur in all women with epilepsy: for some, the frequency and severity of seizures during premenopause are similar to those observed during peri- and postmenopause.⁷

Postmenopausal women with epilepsy deserve extra attention because of a possible increase in osteoporosis due not only to the natural decrease in oestrogen but also to the intake of certain antiseizure medications that may accelerate the vitamin D metabolism.⁷

In conclusion, if you are a girl or a woman diagnosed with epilepsy, or a parent or guardian of a girl diagnosed with epilepsy, it is important to obtain accurate information about:

• screening and treatment of possible reproductive disorders, such as polycystic ovary syndrome¹
• handling of information that can fuel fears, such as fear of transmitting epilepsy to offspring or causing defects in offspring due to antiseizure medications, or fear of being inadequate as parents⁹
• proper medical counselling on contraception and pregnancy planning in order to optimize treatment and limit complications⁵