Mycotic intracranial aneurysms rupture presenting as pure acute subdural hematoma in infectious endocarditis. Report of 2 cases and review of the literature

Acute subdural hematoma (ASDH) revealing mycotic aneurysm (MA) is an exceptional occurrence. We report 2 cases of MA-related pure ASDH in the course of infective endocarditis (IE) without history of head trauma, hypertension or coagulopathy. Case 1: A 54-year-old man presented with a 10-day history of headache, fever. At admission neurologic examination and Brain-CT were normal. Blood cultures showed Streptococcus bovis. MRI 5 days later revealed ischemic spots and minime ASDH over the right convexity. Cerebral angiography, revealed a 3 mm saccular aneurysm at the bifurcation of a distal branch of the right posterior cerebral artery (PCA). Case 2: A 42-year-old man presented with a 8-day history of fever, and worsening headache. Mitral regurgitation was evidenced. A methicillin-sensitive staphylococcus aureus left-sided IE was diagnosed. Pre- and post-contrast Brain-CT were normal. He presented 15 days later a secondarily generalized status epilepticus. Brain CT showed an ASDH over the convexity with falco-tentorial extension, midline shift and temporal herniation. It was removed in emergency. Cerebral angiography revealed a MA of a peripheral branch of the left PCA. The 2 patients were successfully treated by endovascular glue embolization and recovered without complications. Even rare, ruptured MA should be considered as a cause of pure ASDH of unknown origin. As MA can be missed on CT- and MR-Angiography because of mass effect, cerebral angiography may be mandatory.