Ruptured distal anterior cerebral artery aneurysm presenting as subdural hemorrhage

We report on a 64-year-old man with no history of trauma who went into a deep coma after aneurysmal rupture. The brain computed tomography (CT) scan showed interhemisphere and convexity subdural hemorrhage (SDH) without detectable subarachnoid hemorrhage. The CT angiography confirmed a rare condition of pericallosal aneurysmal rupture. We emphasize that when a patient with an unclear history of head trauma presented with acute convexity and interhemispheric SDH, the possibility of distal pericallosal artery aneurysmal rupture should be considered. We also recommend CT angiography must be performed as soon as possible to determine the cause of bleeding.