Sex Differences in Incidence, Pathophysiology, and Outcome of Primary Intracerebral Hemorrhage

Primary intracerebral hemorrhage (ICH) is a common, yet devastating, stroke subtype. Although ethnicity and age can predispose individuals to ICH and affect outcome, little investigation has been made into investigating sex differences in incidence, pathophysiology, or outcome after ICH. In order to understand fundamental mechanisms, improve preclinical research models, and develop effective treatment options for patients with ICH, assessing the effects of sex in ICH is imperative. Thus, the purpose of this review is to gather available information on incidence, pathophysiology, outcome, and preclinical study to provide basis for further investigations.Comprehensive literature search of Medline and National Library of Medicine (PubMed) publications was performed (last accessed December 1, 2013) using ICH, gender, sex, gender difference, sex difference, race, stroke, mortality, preclinical model, animal model, and neuroprotection as keywords. Articles in English were fully reviewed and included if clear definition of primary ICH and available sex data were reported. Primary ICH was defined as intraparenchymal hemorrhage not because of trauma or underlying structural lesion, for example, aneurysm, tumor, and so on. A total of 73 articles were included: (1) epidemiological studies assessing incidence and outcome (47 articles); (2) hospital-based studies assessing hematoma characteristics, treatment response, ICH-related complications or goals of care (14 articles); and (3) preclinical studies assessing gonadal hormones effects on ICH outcomes (12 articles).Published data are reported in chronological and geographical manner. Significant P values, relative risk (RR), odds ratios (OR), and confidence intervals (CI) are noted when available. Notably, epidemiological stroke studies generally treat ICH as a stroke subtype. Further, African and Indian population studies were absent from the literature.Over the last few decades, incidence of primary ICH in developed countries is unchanged or, perhaps, decreasing.4–8 Decreasing incidence may be attributable to greater public awareness of preventive measures, such as healthy lifestyle …