RESUMO
PIP: Hormonal contraceptives containing both estrogen and progesterone are commonly used today. They may have any number of undesirable side effects, largely attributable to their estrogen content. A study was undertaken to reveal the effects of hormonal contraceptives on the central nervous system (CNS.) The EEG patterns of 50 oral contraceptive users, 8 non-users, and 5 women with anovulatory cycles were examined. The EEG patterns were divided into 7 categories: normal, atypical, borderline, slightly abnormal, abnormal, markedly abnormal, and grossly abnormal. The EEGs of oral contraceptive users were distributed as follows: 22 normal, 4 atypical, 6 borderline, 17 slightly abnormal, and 1 abnormal. 7 non-users had normal and 1 non-user had abnormal findings. Age and parity were not correlated with atypical or abnormal findings, nor were these findings associated with clinical CNS pathology (headaches, dizziness etc.) Cerebrovascular disorders which have been linked to oral contraceptive use are headaches, migraine, epilepsy, and thromboemboli. It has been demonstrated that anovulatory menstrual cycles are due to disorders of the hypothalamus, so it is postulated that the EEG changes may be observed when anovulatory states are induced by hormonal contraceptive use. The authors have found that most abnormal EEG findings revert to normal within 8 weeks of the time oral contraceptive use is discontinued. The secretions of the hypothalamus are affected by both endogenous and exogenous sex hormones. Impulses probably reach the hypothalamus via the limbic system. The limbic system comprises both the amygdalary and hippocampal sub-systems, which helps to explain hippocampal activity in EEG patterns of oral contraceptive users.^ieng
