My daughter has epilepsy. She seems to have more seizures around the time of her menstrual period. What causes this?

Answers from Jerry W. Swanson, M.D.

An estimated one-third to one-half of women who have epilepsy experience an increase in seizures right before their menstrual periods. When seizures occur predominantly around the time of menstruation, the condition is referred to as catamenial epilepsy. Such seizures are most likely caused by the hormonal changes associated with the menstrual cycle. These hormonal changes can alter the activity of nerve cells (neurons) in the brain.

If your daughter has catamenial epilepsy, discuss treatment options with her neurologist. The doctor may suggest increasing the dose of anti-seizure medications or taking an additional anti-seizure drug during the week before menstruation. Although preliminary evidence suggests that the addition of progesterone — one of the hormones that regulates menstruation — to anti-seizure medications improves catamenial epilepsy, more research is needed to establish the safety and effectiveness of this treatment.

Aug. 08, 2008