2020 年 48 巻 4 号 p. 254-258
Acute subdural hematoma without a history of trauma may be due to a ruptured aneurysm. We experienced a case of a ruptured aneurysm at the internal carotid artery-posterior communicating artery bifurcation that led to bilateral acute subdural hematoma without any accompanying subarachnoid hemorrhage. A 73-year-old woman suddenly developed severe headache while singing at karaoke. She also suffered from disorientation of consciousness accompanied by upper limb tension. There was no clear history of head injury. Upon arriving at the hospital, her consciousness disorder had improved. There were no pupil inconsistencies or neurological deficit symptoms. Computed tomography (CT) showed acute subdural hematoma on both sides of the dura and around the cerebral scalp and cerebellum tent. Her state of consciousness suddenly worsened, and her right pupil dilated. Three-dimensional CT showed an aneurysm projecting forward from the outside of the right internal carotid artery-posterior communicating artery bifurcation. CT further showed that the right-sided hematoma had increased in size, and midline shift was present. She underwent emergency aneurysm neck clipping and right craniotomy removal of hematoma with right external decompression. The intraoperative findings showed no traumatic changes or subarachnoid hemorrhage. Acute subdural hematoma without a history of trauma may be caused by a ruptured aneurysm, irrespective of its laterality.
