Mechanisms of intracranial hemorrhage in infective endocarditis.

Analysis of 17 patients with infective endocarditis and intracranial hemorrhage yielded several different mechanisms of bleeding. Nine of 15 (60%) symptomatic intracranial hemorrhages occurred within 48 hours of admission and 3 more (20%) after hospital discharge. In 7 patients with Staphylococcus aureus endocarditis, symptomatic intracranial hemorrhage occurred within 48 hours of admission and resulted from septic arteritis in all 3 examined pathologically. Secondary hemorrhagic transformation (hemorrhagic infarction) was asymptomatic in 2 nonanticoagulated patients but was associated with clinical worsening in 2 anticoagulated patients. Anticoagulation potentially contributed to intracranial hemorrhage in 4 of the 17 patients (24%). Proven mycotic aneurysms were present in only 2 patients (12%), 1 of whom presented with massive, fatal intracranial hemorrhage. Mycotic aneurysms amenable to surgery are uncommon and underlie only a fraction of intracranial hemorrhages in infective endocarditis.