Objective       To investigate the correlation of seizure frequency with menstrual cycles in women with epilepsy

identify different catamenial epilepsy patterns

and to assess the relationships between seizure and epileptic syndrome.       Methods      Fifty-nine women with epilepsy aged from 16 to 45 admitted in the epilepsy center of our hospital (the second neurosurgery department) from 2012 to 2014 were enrolled in this study. Menstrual and seizure information of these patients were recorded for 3 consecutive cycles. Catamenial epilepsy was classified into 3 patterns

perimenstrual

periovulatory and non-menstrual phase.       Results      In the total obtained 177 menstrual cycles

161 ovulatory and 16 anovulatory cycles were registered in 59 patients. Average seizure frequency was 0.34±0.96 per day during the anovulatory cycles

more than which was 0.17±0.48 per day during the ovulatory cycles. Catamenial epilepsy was observed in 28/59 (47.5%) patients and 75/177 (42.4%) cycles. During ovulatory cycles

catamenial epilepsy was primarily perimenstrual pattern (27/63

42.9%) and periovulatory pattern (28/63

44.4%)

which was non-menstrual pattern (8/12

66.7%) during anovulatory cycles. In 75 catamenial epilepsy

seizure frequency for the ovulatory phase (0.57±0.31 per day) was higher than the other 3 phases

and during anovulatory cycles

seizure frequency for non-menstrual (0.33±0.12 per day) was 3 times more than for menstrual phases (0.11±0.02 per day). Myoclonic seizures were more frequently associated with perimenstrual pattern during vulatory cycles.       Conclusion      Catamenial epilepsy is found in 47.7% premenopausal women. The highest seizure frequency is in ovulatory phase during ovulatory cycles or in non-menstrual phase during vulatory cycles.