Primary Intracerebral Hemorrhage: Natural History, Prognosis, and Outcomes

Intracerebral hemorrhage (ICH) has an incidence of 10-20/100,000. Its most important risk factors are age, gender, race (more common in African-American, Hispanic, and Asian populations), hypertension, excessive alcohol use, and smoking. The latter two underline the importance of prevention via modification of behavior, while the value of treatment of hypertension is highlighted by clinical trial data (Perindopril Protection Against Recurrent Stroke Study [PROGRESS]) indicative of substantial risk reduction (50% relative risk reduction) by relatively modest lowering of blood pressure (by 9/4 mmHg). The importance of genetic factors for ICH has been recently documented, with endoglin gene insertions and Factor XIII polymorphisms being associated with a significant increase in the risk of ICH. The prognosis of ICH is dependent on age, level of consciousness, hematoma volume, and intraventricular extension of hemorrhage, which are all predictors of mortality. The risk of ICH recurrence is about 2%/year overall, but with an increase to 4-5%/year if the localization is lobar. Predictors of ICH recurrence include age > 65, carrying the ϵ2 and ϵ4 alleles of the apolipoprotein E gene, the presence of asymptomatic microhemorrhages and leukoaraiosis. The functional outcome of ICH is poor, with only 12% of survivors being independent at 30 days.