Nonlobar Intracerebral Hemorrhage Research Articles

Genetic and Environmental Risk Factors for Intracerebral Hemorrhage

Background and Purpose — Intracerebral hemorrhage (ICH) has a 30-day mortality rate of 40% to 50% and lacks a proven treatment. We report a preplanned, midpoint analysis of the first population-based, case-control study that examines both genetic and environmental risk factors of ICH. Methods — We prospectively identified cases of hemorrhagic stroke at all 16 hospitals in the Greater Cincinnati/Northern Kentucky region. All cases underwent medical record and neuroimaging review. Cases enrolled in the direct interview and genetic sampling arm of the study were matched to population-based control subjects by age, race, and sex. Multivariable logistic regression was performed to identify significant independent risk factors. Results — We enrolled 188 cases of ICH (67 lobar, 121 nonlobar) and 366 control subjects in the direct interview arm of the study. Significant independent risk factors for lobar ICH included the presence of an apolipoprotein E2 or E4 allele, frequent alcohol use, prior stroke, and first-degree relative with ICH. Significant independent risk factors for nonlobar ICH were hypertension, prior stroke, and first-degree relative with ICH. An increasing level of education was associated with a decreased risk of nonlobar ICH. The attributable risk of apolipoprotein E2 or E4 for lobar ICH was 29%, and the attributable risk of hypertension for nonlobar ICH was 54%. Conclusions — There is significant epidemiological evidence that the pathophysiology of ICH varies by location. We estimate that a third of all cases of lobar ICH are attributable to possession of an apolipoprotein E4 or E2 allele and that half of all cases of nonlobar ICH are attributable to hypertension.

Genetic and Environmental Risk Factors for Intracerebral Hemorrhage

27 Introduction: We report a planned midpoint analysis of a prospective, population-based, case-control study of the genetic and environmental risk factors of spontaneous, non-traumatic, intracerebral hemorrhage (ICH). Methods: Cases were matched to two controls by age, race and gender. Data was obtained by direct interview and review of all available medical and neuroimaging data. Apolipoprotein E (Apo E)genotype was determined by polymerase chain reaction. Multivariable analyses were performed using logistic regression modeling. Results: Between 6/97 and 2/00, 189 cases of ICH (150 white/39 black; 68 lobar/121 non-lobar) and 368 controls were enrolled into the study. Independent risk factors for multivariable analysis are listed in the table. Only prior stroke was an independent risk factor for both lobar and non-lobar ICH. Conclusions: The importance of individual genetic and environmental risk factors for ICH vary substantially by location of ICH. A history of a first-degree relative with ICH was associated with an increased risk of lobar ICH, independent of Apo E genotype. This finding indicates that other genetic risk factors may be important in the development of ICH.