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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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