Menarche, like other changes in reproductive hormonal status, may affect the clinical manifestation of seizures.21 It may be associated with the resolution of some forms of partial seizures and the exacerbation of others.
The seizures that tend to resolve are "primary" partial seizures, such as benign rolandic epilepsy of childhood and benign occipital epilepsy of childhood,22,23 which resolve spontaneously in both sexes in the midteens, almost invariably by 16 years of age. The explanation for this phenomenon has not been investigated. It may involve changes in both the reproductive hormones and adrenal steroid hormones associated with puberty and adrenarche.
Secondary partial seizures (idiopathic or lesional) may be exacerbated around the time of menarche. A number of investigators have observed that late childhood and adolescence are peak periods for the first manifestation of epilepsy.21 Up to two-thirds of women with catamenial epilepsy may experience the onset of seizures within 3 years of menarche.24,25 Preexisting complex partial seizures in young women may increase in frequency at the time of menarche.26 The finding that oophorectomy in rats before their sexual maturation decreases their susceptibility to seizures in adulthood suggests that increased neuronal excitability associated with the elevation of estrogens at the time of menarche may explain this observation.27
In one study, no effect of menarche on seizures was found.28 One explanation may be that the effect of menarche is difficult to distinguish from the effect of adrenarche.
Adapted from: Klein P and Herzog AG. Endocrine aspects of partial seizures. In: Schachter SC, Schomer DL, eds. The comprehensive evaluation and treatment of epilepsy. San Diego, CA: Academic Press; 1997. p. 207-232.
With permission from Elsevier (www.elsevier.com).