Pure Subdural Hemorrhage Caused by Internal Carotid Artery Dorsal Wall Aneurysm Rupture.

A 37-year-old woman was admitted to our hospital with altered mentality. The patient was diagnosed an internal carotid artery (ICA) dorsal wall aneurysm leading to acute subdural hemorrhage (SDH) without occurring subarachnoid hemorrhage and/or internal parenchymal hemorrhage. An aneurysmal neck clipping and hematoma evacuation were performed at once. A pure SDH by ruptured aneurysm is unusual, but it is important to consider it if a SDH patient has no other medical history.