Abstract
There are not many reports of a spontaneous acute subdural hematoma (ASDH) without the presence of a subarachnoid hemorrhage as a result of a ruptured aneurysm. A 66-year-old woman presented with acute subdural hematoma secondary to a ruptured intracranial aneurysm. She was admitted with an acute onset of bursting headache and nausea. There was no past history of head trauma. The CT scan demonstrated a left subdural hematoma with extension along the tentorium in the absence of subarachnoid or intraparenchymal hemorrhage. CT angiography revealed an aneurysm of the left posterior communicating aneurysm, which was directed posterolaterally. Uneventful clipping was performed without any neurological deficits. The possibility of aneurysmal subdural hemorrhage should be considered in all cases of ASDH that present with a sudden bursting headache without any history of trauma. Therefore, CT angiography can be an indispensable tool for detecting the aneurysm that has an unusual pattern of subdural hematoma.