However, no woman had seizures exclusively connected with her menstrual cycle. In many animal models of epilepsy, estrogens have been found to excite brain activity. An IV infusion of progesterone decreased this type of activity temporarily in 4 of 7 women with partial epilepsy. During the normal menstrual cycle, regular fluctuations in the hormones estrogen and progesterone occur. Research indicates that seizure frequency is maximal when progesterone levels are low compared to estrogen levels.
Seizures are most common when estrogen rises and less common when progesterone levels are highest.
Reproductive disorders Disorders related to hormone regulation during the menstrual cycle appear to occur more frequently in women with epilepsy and also seem to cause increased seizure frequency. Two of these types of disorders are described below. Each affects a phase of the menstrual cycle in which seizures become worse in some women with epilepsy. Anovulatory cycles are menstrual cycles in which ovulation does not occur. This condition is associated with constant estrogen levels which are not balanced during the cycle by progesterone.