Abstracts

Catamenial epilepsy includes seizure exacerbation at the time of ovulation and perimenstrually ([quot]Type 2[quot] and [quot]Type 1[quot], respectively). Postulated mechanisms include the proconvulsant effects of high periovulatory serum levels of estrogens and the premenstrual withdrawal of the GABA-ergic anticonvulsant effect of progesterone. During pregnancy, serum levels of both estrogens and progesterone reach very high levels, 20-fold compared to the peak mid-cycle levels and 200-fold compared to the follicular levels. After parturition, levels of both drop 200-fold to early follicular levels within 24-48 hours. I examined the association of high estrogen levels during the last trimester of pregnancy and the post-partum progesterone withdrawal with seizure frequency in order to ascertain the role of estrogen and progesterone in seizure precipitation in a setting of hormonal fluctuation other than the menstrual cycle. 6 women with epilepsy were followed prospectively with monthly visits through a full term pregnancy and for 2 months post-partum. Seizure count was determined with a seizure diary. Serum levels of estradiol, estrone, estriol and progesterone were determined monthly. Seizure frequency was compared during pregnancy months 1,2 and 8,9 and during the first 2 post-partum (PP) months and was correlated with hormone levels.Statistical analysis included Kurskal Wallis test and multivariate logistic regression analysis. Statistical significance was set at p[lt]0.05. Total of 29 seizures occurred during months 1,2,8 and 9 of pregnancy and PP months 1 and 2. Seizures were most common during months 1 and 2 (n=13, mean 1.1 seizure/woman/month), least common during months 8 and 9 (n=6, mean 0.5 sz/w/mo) and intermediate during the PP months (n=10, 0.8 sz/w/mo), but the difference was not statistically significant.7/10 of the seizures during the post-partum period occurred within 11 days of delivery, making the PP month the most likely month for seizure occurrence (1.2 sz/w/mo). Mean serum estradiol levels were 437, 11957, and 35 pg/ml for months 1/2, 8/9 and for PP months 1/2, respectively. The mean serum progesterone levels for the same periods were 28, 158 and [lt]1 ng/ml. There was no correlation between seizure frequency and serum estradiol levels or between serum estradiol/progesterone level ratios.There was a statistically non-significant suggestion of an inverse correlation between progesterone levels and seizures. (1)Very high serum estrogen levels during pregnancy are not associated with seizure exacerbation. Therefore, high serum estrogen levels alone are not sufficient to cause seizure exacerbation. (2) By contrast, high progesterone levels may mitigate against seizures during pregnancy and progesterone withdrawal during post -partum period may facilitate seizures.