Seizures more frequent during anovulatory menstrual cycles

Women are more likely to suffer seizures during menstrual cycles when ovulation doesn’t occur and progesterone therefore doesn’t increase, according to a study that was published online July 14 in Epilepsia.

To investigate whether lack of increase in progesterone during anovulatory cycles is linked to an increase in seizures, the study examined data on 92 women who had both anovulatory and ovulatory menstrual cycles during the 3-month baseline phase of a multicenter trial of progesterone therapy for intractable focal onset seizures. Ovulatory cycles were defined by midluteal progesterone levels of 5 ng/mL or greater. Average daily seizure frequency was 29.5% greater during anovulatory cycles than ovulatory cycles for secondary generalized tonic-clonic seizures (2°GTCS) but didn’t differ for simple or complex partial seizures or all seizures combined. The researchers found a significant correlation between proportional increases in 2°GTCS during anovulatory cycles and proportional increases in estradiol-progesterone serum level ratios.

“These findings support a possible role for reproductive steroids in 2°GTCS occurrence,” they conclude, adding, “if hormones play a role in seizure occurrence, there may also be a role for hormones in seizure therapy.”

The researchers observe that “the finding of an association between increased 2°GTCS frequency and anovulatory cycles and the existence of a greater frequency of anovulatory cycles among women with epilepsy suggest that greater attention be devoted to the ovulatory status of women with epilepsy, not only with regard to general reproductive health and fertility but also for comprehensive seizure management.”