Patterns of Recurrence of Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) accounts for approximately 10% of strokes. Its causes include hypertension and cerebral amyloid angiopathy in the middle-aged and elderly, respectively, while vascular malformations predominate in the younger than 45 years old population. Recurrence of ICH is not as low as it was traditionally thought, and overall it is about 4.5% for an aggregate of several studies with different lengths of follow-up. Most of these recurrences occur over a 1-2 year period after the initial episode of ICH, but late recurrence (over several years) is not uncommon, leading to cumulative frequencies of recurrence of up to 25-55% after 7-8 years of follow-up in some series. The main risk factors for recurrence are age, poorly controlled hypertension, lobar location (probably due to cerebral amyloid angiopathy), presence of asymptomatic microhemorrhages, and carrying the ϵ2 and ϵ4 alleles of the apolipoprotein E gene. The initial location of ICH (ganglionic vs. lobar) is generally predictive of the same topography for the recurrent event. Recurrent ICH is associated with high mortality, in the order of 70%.