Occurrence of menstrual cycle related seizure patterns among epileptic women attending the tertiary neurology clinics of the National Hospital of Sri Lanka

Female sex hormones estrogen and progesterone have effects on seizure activity. Patterns of seizure exacerbations associated with the menstrual cycle have been described as catamenial epilepsy. This study was done to investigate the menstrual cycle related seizure occurrence among female epileptics using seizure–menstrual calendars and sex hormonal assays. Frequency and the patterns of seizure occurrence within the menstrual cycles were determined analyzing seizure–menstrual calendars. Luteal phase serum estradiol and progesterone were determined in those with menstrual cycle related seizure patterns to be compared with that of healthy women. Out of 349 epileptics, 6% showed occurrence of perimenstrual, periovulatory or perimenstrual+periovulatory seizure patterns on analysis of seizure–menstrual calendars. These women showed significantly higher luteal serum estradiol concentrations in comparison to age-matched healthy volunteers. There was no significant difference in the luteal serum progesterone concentrations. This study showed menstrual cycle related patterns of seizure occurrence in a minority of Sri Lankan epileptic women, similar to catamenial epilepsy patterns described by previous studies. These seizure patterns may be due to altered hypothalamo-pituitary–gonadal axis function playing a role in the pathophysiology of epilepsy. We suggest the importance of maintaining seizure–menstrual calendars and hormonal studies in all epileptic women to establish the role of hypothalamo-pituitary–gonadal axis in epilepsy and to achieve efficient control of epilepsy in women of childbearing age.