Does the menstrual cycle affect the rate of seizures in women with epilepsy?

Yes. Approximately half the women of childbearing age who have epilepsy report an increase in seizures around the time of their monthly menstrual period. Seizures that occur around the menstrual cycle are called catamenial epilepsy. Studies show that changes in seizures are most often in the middle of the cycle around ovulation and about a week before menstrual bleeding.

What causes seizures to be seen during hormonal changes with menses?

The hormonal changes during the menstrual cycle are the most likely cause of changes in seizure frequency. The brain contains many nerve cells that are directly affected by estrogen and progesterone, the main sex hormones in women. Studies in animals have shown that high doses of estrogen can cause or worsen seizures. Yet progesterone can protect against seizures. It’s thought that seizures may occur in women with epilepsy because they don’t have enough progesterone at certain times of their cycle or there’s an imbalance between estrogen and progesterone. Other hormones are being looked at as possible triggers of seizures during menses and at times of other hormonal changes in women.

What strategies can be used to reduce seizures associated with the menstrual cycle? 

  • Adjusting the dose of a seizure medication before the time of increased seizures. (Note: This applies only to women with regular cycles.) Changes in seizure medicines should only be made with advice of your health care provider. 
  • Reducing the water retention that occurs in the premenstrual period.
  • Taking an additional seizure medication such as lorazepam (Ativan) for several days around the menstrual cycle.
  • Using hormonal agents such as progesterone or birth control pills for women with catamenial epilepsy may help.  While small studies have shown benefits for some women using progesterone to help control seizures. A randomized controlled study published in 2012 found no significant difference in women taking progesterone during parts of their cycle compared to women taking a placebo or non-active drug. Certain groups of women were found to benefit from progesterone treatment however.
  • All women should track when their menses is due and look at other possible triggers at that time. Women sensitive to hormone changes can make sure they sleep well, don’t miss medicines, avoid other triggers or adjust their lifestyle to lessen the risk of seizures during their menses.


Authored By: 
Steven C. Schachter, MD
Patty Obsorne Shafer RN, MN
Joseph I. Sirven MD
Authored Date: 
Reviewed By: 
Joseph I. Sirven MD
Patty Obsorne Shafer RN, MN
Wednesday, March 19, 2014