Epilepsy, sex hormones, and antiepileptic drugs

Many factors associated with hormone function have an impact on the course of epilepsy. Patients with epilepsy may have disturbances in sexual function such as anovulatory cycles in women and decreased libido and potency in men. Data indicate seizures, especially those arising in the limbic system, may influence the hypothalamic pituitary axis. Antiepileptic drugs also influence sexual function through direct brain effects as well as through induced changes in pharmacokinetics of the sex steroid hormones. Pregnancy has been reported to be a time of increased seizures; however, this has often been associated with low drug levels, for reasons that include inadequate drug dose, possible changes in pharmacokinetics, and noncompliance. Some evidence suggests that hormones affect seizure frequency. Changes in seizures during the menstrual cycle (catamenial epilepsy) have been found in some women: seizures were fewer during the luteal phase but increased when progesterone levels declined. Some improvement in seizure frequency has been shown in pilot studies using medroxyprogesterone acetate, a synthetic progesterone. Current concepts of the interrelationship among epilepsy, sex hormones, and antiepileptic drugs are discussed.