Cerebral Circulation in Men and Women.

Despite several advancements in stroke care, disparities continue to exist with regard to sex differences in cerebrovascular disease. These sex differences are due to a combination of several factors, many of which are unique to the female sex. Some of these unique factors, such as pregnancy and menopause, are related to hormonal changes seen throughout the female life cycle. Hormonal fluctuations, which impact the protective effects of the female sex hormones, can be induced by the use of hormonal contraception. Other risk factors, although present in both sexes, have a higher prevalence in elderly females, such as atrial fibrillation leading to cardioembolic strokes. Similarly, differences in premorbid modified Rankin Scale have an impact on the differences in stroke outcome between the two sexes. Clinical research aimed toward highlighting potential causes of these disparities has shown important differences in the calibers of blood vessels in the cerebral circulation between the two sexes, whereas basic science research has shown differences in circulating endothelial progenitor cell pools between males and females, with higher levels being more protective. With the increasing awareness of these sex differences, future research is being geared toward gender-specific modes of therapy, focusing on the molecular level, as well as the individual patient.