Complications of arteriovenous malformations rupture and medical management of hemorrhage

Arteriovenous malformations (AVMs) are responsible for only 1-2% of all strokes and 4% of primary intracerebral hemorrhages. However, patients with intracranial hemorrhage from an AVM are usually younger than most stroke victims and AVMs are responsible for one-third of intracranial hemorrhages in young adults [1]. The incidence of hemorrhage as a presenting symptom of an intracranial AVM varies among different series in relation to the time period considered (before or after the widespread availability of non-invasive imaging studies) and the type of setting: Population-based study versus series of patients referred for tertiary specialized care. In a small retrospective but population-based study conducted between 1965 and 1992 in Olmsted County, 65% of patients with AVMs presented with hemorrhage [2]. With advances in imaging techniques and widespread availability of non-invasive imaging studies, the relative percentage of patients with AVMs presenting with hemorrhage is decreasing. In a prospective population-based study conducted in Scotland, 114 of 229 adults (50%) diagnosed with an intracranial parenchymal AVM between 1999 and 2003 suffered an intracranial hemorrhage as a presenting symptom [3]. Parenchymal hemorrhage is the most common mode of hemorrhagic presentation. In the Scottish Intracranial Vascular Malformations Study [4], 50% of the hemorrhages were strictly limited to the brain parenchyma and intraventricular hemorrhage (IVH) was present in 34%. Similarly in the study conducted in Olmsted County, intracerebral hemorrhage (ICH) was present in 41% of patients, subarachnoid hemorrhage (SAH) in 24%, IVH in 12%, and a combination of the different types in 23% [2]. In the Scottish study, location of the hematoma was lobar in 73%, deep in 11%, and infratentorial in 16% [1]. The median volume in 90 patients with ICH was 16 cm³ [5], and IVH was present in 34%.