Hormones and seizures.

The opposing effects of estrogen (proconvulsant) and progesterone (anticonvulsant) on seizure threshold have been noted in animal and human studies. Levels of these hormones fluctuate throughout the menstrual cycle, and, in some women with epilepsy, these fluctuations may be related to the occurrence of seizures around the time of menses or an increase in seizures in relation to the menstrual cycle, also known as catamenial epilepsy. Variations in concentrations of antiepileptic drugs across the menstrual cycle may also contribute to increased seizure susceptibility. Diagnosis of catamenial epilepsy requires careful assessment of menstrual and seizure diaries and characterization of cycle duration and type. While there are several approaches to the treatment of catamenial epilepsy, each is based on small, unblinded studies or anecdotal reports. It is important for the physician to work closely with the patient to determine whether her seizures are indeed catamenial and to design an appropriate treatment plan.