Abstracts

RATIONALE: Clinical impression suggests that menarche may be a time of increased susceptibility to seizure development. Only a few studies have addressed this issue and have indicated that 20-33% of women with epilepsy may have seizure onset or exacerbation at the time of menarche (Roscizewska D et al 1985; Morrell MJ et al 1998). Only one study has specifically examined seizure onset as opposed to seizure exacerbation during menarche, and that study was a mailed questionnaire survey. The goal of the present study is to determine whether there is an increased risk of onset of epilepsy at the time of menarche. This is done by comparing seizure onset during menarche/perimenarche to seizure onset during other childhood periods.
METHODS: 76 consecutively evaluated, cognitively normal women with seizure onset between 0.5-18 years (63 with localization related epilepsy, LRE, 13 with primary generalized epilepsy, PGE; age range 16-55 years) underwent reproductive endocrine history interviews. Questions included age of seizure onset, age of onset of menarche, and the nature of menstrual cycles after menarche. Women older than 55 years were excluded in order to maximize accuracy of recall of reproductive history. Women with seizure onset before 6 months of age were also excluded. 69/76 women were interviewed on 2 separate occasions at least 1 month apart. Data were analyzed using [chi] square and Fisher[ssquote]s exact test.
RESULTS: Reproducible information concerning age of menarche and seizure onset was obtained in 67/76 women. Mean age of seizure onset was 10.8 (median 12, range 0.5-18). Mean age of menarche was 12.2 (median 12, range 8-17). Temporal distribution of seizure onset in relation to menarche showed clustering of seizure onset around the year of menarche. Seizures began during the year of menarche in 13 (17%) patients, within 1 year of menarche in 18 (24%) and within 2 years of menarche in 25 (33%) patients, excluding two patients with seizure onset following acute CNS injury within one year of menarche. Seizures were more likely to start within two years of menarche than during any other childhood time intervals ([chi]²p=0.02). There was no difference in seizure onset during the year of menarche between women with PGE (2/13) and LRE (11/63). In addition, 6/46 (13%) patients with premenarcheal seizure onset experienced seizure exacerbation during the year of menarche.
CONCLUSIONS: Girls have an increased risk of developing epilepsy at the time of menarche compared to other childhood periods. This may be due to hormonal changes associated with menarche.
Support: No current funding support.