Abstracts

Estrogens are generally thought to have a proconvulsant effect.In animals, estrogens activate spike discharges and lower seizure threshold. In humans, catamenial seizure exacerbation at the time of ovulation has been suggested to be due to a peri-ovulatory surge of serum estradiol level (Herzog AG et al, Epilepsia 1997). In the only such study in humans, intravenous administration of conjugated estrogens (premarin) was reported to activate epileptiform discharges and seizures in some women with epilepsy (Logothesis J, et al, Neurol 1959). More recently, oral administration of premarin in perimenopausal women with epilepsy indicated dose-related seizure exacerbation with premarin (Harden C, et al, Epilepsia 2004). The purpose of this study was to determine whether the reported proconvulsant effect of estrogens could be used to activate seizures in women with epilepsy undergoing EEG monitoring for pre-surgical work up., Women of reproductive age with medically refractory localization related epilepsy (LRE) were evaluated. Subjects undergoing in-patient long term video-scalp EEG (LTVEEG) monitoring were injected with 10 mg premarin i.v. at 8 am during the first or second day of monitoring, before AED discontinuation. No changes in AEDs were made for 24 hours after premarin injection. In two subjects, a second injection of 50 mg was given 24 hours after the 10 mg injection. All subjects had been evaluated for presence of catamenial seizure exacerbation using both subjects[apos] subjective impression and previously described criteria (Herzog AG et al., Ann Neurol 2004). Serum levels of estradiol, estrone and progesterone were measured immediately before and 1 and 2 hours after premarin injection. EEG was recorded continuously and stored for manual and automated spike and seizure analysis. EEG was analysed for spike and seizure frequency using 30 minute bins during 12 hours before and 24 hours after the injection., 6 women (age range 23-45) were evaluated. 4 women had subjective impression of catamenial seizure exacerbation, (3 Type I, perimenstrual exacerbation, 1 Type 1 and 2, perimenstrual and periovulatory exacerbation), but this could be confirmed with prospective seizure diary documentation in only 1. 4 subjects had TLE (left, n=2; right, n=1; bitemporal, n=1), 2 had extratemporal LRE.
0/6 women had a seizure during 24 hours after premarin injection with either 10 mg (n=6) or 50 mg (n=2 of the initial 6). There was no change in interictal spike frequency following premarin injection, including absence of spikes for 24 hours after premarin injection in 2 women., Intravenous injection of conjugated estrogens did not activate ictal or interictal epileptiform activity in this small study of women with medically refractory epilepsy. Estrogen injection may not be a useful activating procedure in these patients. A larger study is needed to confirm these preliminary findings.,