Premenstrual seizure increase: influence of age, duration of disease, seizure frequency, previous complaint of perimenstrual accentuation, EEG and CT scan findings.

Unlabelled: We selected prospectively 80 mentally healthy women at menacme age, with chronic epilepsy and at least one seizure in the month preceding this study. They underwent four EEGs weekly. CT scan of the skull was done in 57 patients (71.25%). Seven patients were excluded because they had no seizures or menses. We registered 5630 seizures during 579 regular menstrual cycles over a 30 month period.

Results: there was a higher incidence of seizures in the premenstrual period (p less than 0.001); age did not influence the distribution of seizures during the menstrual cycle in the group studied; patients with 11 or more years of disease showed more accentuation of premenstrual seizures than patients with 10 or less years of disease; there was no relation between the patients frequency of seizures and the occurrence of premenstrual seizures; the patients impression of the incidence of seizures not related to menstruation was not confirmed; patients with abnormal skull CT scans had more accentuation of premenstrual seizures than patients with normal exams; patients with abnormal EEGs had more premenstrual seizures than patients with normal exams. Our findings suggest that the female sexual hormones alter cerebral excitability when there is an underlying structural pathology shown by CT scan or an electrical cerebral dysfunction revealed by EEG.