John Jacono

Date of Award


Degree Type


Degree Name

Doctor of Philosophy


More males than females are affected by epilepsy. This is so for all ages, with the exception of puberty. During the pubertal years, incidence rates of epilepsy are higher in females than in males.;Factors suspected of causing epilepsy are numerous, however the role of the female sex hormone estrogen is thought to be highly significant to epilepsy of puberty.;This study was designed to provide information about the role of estrogen and ionized calcium in seizures during the menstrual cycle of gynaecologically mature female epileptics. The study sample comprised 16 female epileptics ages 18 to 40 years resident in southwestern Ontario. Each subject donated a blood sample on alternate days for the duration of one menstrual cycle. In addition, seizures occurring were entered on a seizure diary.;Results were analyzed using linear regression techniques adjusted for repeated measurements and measures of association adjusted for clustering effect.;It was found that high levels of estrogen encountered during the middle of the cycle severely decreased levels of ionized calcium at that time.;Further, most of the seizures exhibited by the subjects occurred before and after the estrogen peak, when ionized calcium levels were relatively stable. Thus low ionized calcium levels appear to have a salutary effect on estrogen and may reduce seizures expected at this time.;No causal inferences are generated from these results. Rather, an expansion of previously promoted models of epileptogenesis is proposed. Increased hypothalamic work rate to stimulate production/reduction of hormones governing the menstrual cycle, the presence of fluctuating levels of estrogen and concomitant alteration in the ionic micro-environment could lead to the spread of intense burst firing activity. This model is applicable to both pubertal as well as mature females.



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