Catamenial epilepsy describes a menstrual cycle seizure disorder. It is a term that is used to describe seizures that occur or increase during certain phases throughout a woman’s menstrual cycle. This particular seizure diagnosis is given to approximately 70% of all women who suffer from seizure activity, affecting over 1 million women in the U.S. alone. Levels of ovarian hormones (particularly progesterone and estrogen) 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. Recently, studies and investigations are confirming the existence of three different patterns within the catamenial seizure catagory. The first pattern is seen to occur just prior to the onset of menstruation, and is called perimenstrual. The second pattern is frequently seen at ovulation (or right before it), during the ovulatory period of the menstrual cycle. Thirdly, women can experience seizure activity at any point during the luteal phase (the time between when you ovulate and when you get your period).
Through careful assessment of menstrual cycles in conjunction with documented seizure activity, it is believed that the changes in the ovarian hormone levels, particularly estrogen levels throughout a woman’s cycle, is a contributing factor to seizure activity. Because it has been found that estrogens are excitatory hormones, or pro-convulsant, the level of estrogen that is unopposed by progesterone, identified as an anti-convulsant hormone, is many times a determining factor in the development of catamenial epilepsy. Seizures have been proven to be influenced by variations in the secretions of both estrogen and progesterone, and their opposing affects on the seizure threshold throughout the menstrual cycle.
Those women who are on anti-epileptic drugs (AED’s) throughout their menstrual cycle have experienced an increased susceptibility to seizure activity as their hormone levels fluctuate as well, due to the concentrations of those AED’s.
What Treatments Are Available For Catamenial Epilepsy?
Quite a bit of research is being done as of late regarding the best approach for the treatment of catamenial epilepsy. By demonstrating in animals as well as humans that progesterone has anti-convulsant properties, it is quickly becoming a more studied treatment, placing it as one of the commonplace treatments to be considered alongside the typical, traditional treatment methods for treating the diagnosis of catamenial epilepsy, including AED’s, acetazolamide or benzodiazepines. Of course, larger trials and further investigation can still be warranted to identify the most effective treatment of the seizure disorder.
Recent studies have, however, provided an improved understanding of the pathophysiology of catamenial epilepsy. The progesterone metabolite allopregnanolone has been identified as a neurosteroid produced within the body that has powerful antiseizure activity. In animal studies, when progesterone and allopregnanolone levels in brain decrease, it has been shown to increase seizure susceptibility. Natural progesterone therapy has proven to be effective in women with epilepsy.
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