Emergency Central is a collection of disease, drug, and test information including 5-Minute Emergency Medicine Consult, Davis’s Drug, McGraw-Hill Medical’s Diagnosaurus®, Pocket Guide to Diagnostic Tests, and MEDLINE Journals created for emergency medicine professionals. Explore these free sample topics:
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- Bleeding into the subarachnoid space and CSF:
- Most often results from cerebral aneurysm rupture
- Aneurysms that occur are more likely to rupture (>25 mm).
- Represents severe head injury
- Incidence is 6–16 per 100,000 individuals.
- Affects 21,000 in US annually
- Associated mortality in 30–50% of patients
- Uncommon prior to 3rd decade; incidence peaks in 6th decade
- Previous ruptured aneurysm who have other aneurysms
- Family history
- Alcohol abuse
- Sympathomimetic drugs:
- Cocaine, methamphetamine, and ecstasy (MDMA) use
- Gender (female:male 1.6:1)
- 3–7-fold increased risk with 1st-degree relatives with subarachnoid hemorrhage (SAH)
- Strongest genetic association represents only 2% of SAH patients:
- Autosomal dominant polycystic kidney disease, Ehlers–Danlos type IV, familial intracranial aneurysms
- Most often due to arteriovenous malformation in children
- Although rare in children, SAH is a leading cause of pediatric stroke.
- “Congenital,” saccular, or berry aneurysm rupture (80–90%):
- Occur at bifurcations of major arteries
- Incidence increases with age.
- Aneurysms may be multiple in 20–30%.
- Nonaneurysmal perimesencephalic hemorrhage (10%)
- Remaining 5% of causes include:
- Mycotic (septic) aneurysm due to syphilis or endocarditis
- Arteriovenous malformations
- Vertebral or carotid artery dissection
- Intracranial neoplasm
- Pituitary apoplexy
- Severe closed head injury