TY - CHAP M1 - Book, Section TI - Subarachnoid Hemorrhage A1 - Hemphill, III, J. Claude A1 - Smith, Wade S. A1 - Gress, Daryl R. A2 - Loscalzo, Joseph A2 - Fauci, Anthony A2 - Kasper, Dennis A2 - Hauser, Stephen A2 - Longo, Dan A2 - Jameson, J. Larry PY - 2022 T2 - Harrison's Principles of Internal Medicine, 21e AB - Subarachnoid hemorrhage (SAH) renders the brain critically ill from both primary and secondary brain insults. Excluding head trauma, the most common cause of SAH is rupture of a saccular aneurysm. Other causes include bleeding from a vascular malformation (arteriovenous malformation or dural arteriovenous fistula) and extension into the subarachnoid space from a primary intracerebral hemorrhage. Some idiopathic SAHs are localized to the perimesencephalic cisterns and are benign; they probably have a venous or capillary source, and angiography is unrevealing. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/11/12 UR - accessmedicine.mhmedical.com/content.aspx?aid=1201833124 ER -