A ruptured distal aneurysm, thought to be a mycotic aneurysm, associated with acute subdural hematoma: case report and review of the literature

A case is described of a ruptured intracranial mycotic aneurysm in the distal middle cerebral artery associated with an acute subdural hematoma. A 55-year-old woman, with a history of tuberculous meningitis at the age of 7, presented left hemiparesis. She was in a state of semi-coma. Computed tomography scan showed a right acute subdural hematoma. Magnetic resonance angiography revealed no cerebral aneurysm. Emergency external decompression was performed and a distal central artery aneurysm was found and was resected during the operation. Numerous areas of hemosiderin pigmentation were recognized around the aneurysm and in the subarachnoid space. Microscopic examination of the aneurysmal sections showed neither elastic lamina nor membranous structures and no infiltration of any inflammatory cells. We think this aneurysm is a pseudoaneurysm. The incidence of ruptured mycotic aneurysms presenting with acute subdural hematoma is extremely low. There have been only four previously reported cases as far as I can ascertain. This case and a review of the literature are discussed.