Last reviewed: 16 Mar 2025
Last updated: 14 Jul 2023
Summary
Definition
History and exam
Other diagnostic factors
- seizures
- nuchal rigidity
- decreased level of consciousness
- focal neurologic deficit
Risk factors
- smoking
- moderate- to high-level alcohol consumption
- family history of subarachnoid hemorrhage
- previous subarachnoid hemorrhage
- heritable connective tissue disease
- hypertension
- head trauma
- intracranial infection
- tumor
- arteriovenous malformations or fistulas
- drug abuse
Diagnostic tests
1st tests to order
- CT head scan
- conventional catheter-based angiogram
- CT angiography
- magnetic resonance angiography (MRA)
Treatment algorithm
Contributors
Authors
Brendan Eby, MD
Assistant Professor
Departments of Neurology, Neurosurgery, and Radiology
Washington University School of Medicine
St. Louis
MO
Disclosures
BE has been a paid speaker at a national neurointervention fellows course sponsored by Penumbra Inc; the talk was unrelated to the sponsor's products or services.
Acknowledgements
Dr Eby would like to gratefully acknowledge Dr Grasso and Dr Michael Chen, the previous contributors to this topic.
Disclosures
MC is an author of a reference cited in this topic.
Peer reviewers
David Altschul, MD
Chief of Neurovascular Surgery
Montefiore Medical Center
New York
NY
Disclosures
DA declares that he has no competing interests.
Peter Martin, MA, BM BCh, MD, FRCP
Consultant Neurologist
Addenbrookes Hospital
Cambridge
UK
Disclosures
PM declares that he has no competing interests.
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