Subarachnoid Hemorrhage: Updates in Diagnosis and Management

Emerg Med Clin North Am. 2017 Nov;35(4):803-824. doi: 10.1016/j.emc.2017.07.001. Epub 2017 Aug 24.


Subarachnoid hemorrhage (SAH) is a neurologic emergency due to bleeding into the subarachnoid space. Mortality can reach 50%. The clinical presentation is most often in the form of headache, classically defined as maximal at onset and worst of life. The most common cause is traumatic; approximately 80% of nontraumatic SAH are due to aneurysmal rupture, with the remainder from idiopathic peri-mesencephalic hemorrhage or other less common causes. Noncontrast brain computed tomography (CT) performed within 6 hours of symptom onset has sensitivity approaching 100%. Lumbar puncture may be considered after this period for definitive diagnosis if initial CT is normal.

Keywords: Angiography; Cerebral aneurysm; Computed tomography; Lumbar puncture; Rebleed; Subarachnoid hemorrhage; Vasospasm; Xanthochromia.

Publication types

  • Review

MeSH terms

  • Computed Tomography Angiography
  • Global Health
  • Humans
  • Incidence
  • Neuroimaging / methods*
  • Spinal Puncture / methods*
  • Subarachnoid Hemorrhage* / diagnosis
  • Subarachnoid Hemorrhage* / epidemiology
  • Subarachnoid Hemorrhage* / therapy
  • Survival Rate / trends