The effects of estrogen, progesterone, and ionized calcium on seizures during the menstrual cycle of epileptic women.

Previous research suggested a positive relationship between levels of serum estrogen and seizures, a negative relationship between levels of serum Ca++ and seizures, and a negative relationship between serum levels of estrogen and Ca++. This study sought a relationship between levels of serum estrogen, ionized calcium, progesterone, and its possible effect on seizures during the menstrual cycle of epileptic women. The negative relationship between serum estrogen and Ca++ was confirmed. However, a study of 15 institutionalized epileptic women, all with a diagnosis of primary generalized epilepsy, demonstrated that fewer seizures occurred in midcycle (when estrogen levels were elevated and Ca++ levels were decreased) than at other stages of the menstrual cycle. This is suggestive of a protective (anticonvulsant) aspect of the hypothalamo-hypophyseal negative feedback system, previously unreported.