Subarachnoid haemorrhage

Last reviewed: 5 Nov 2022
Last updated: 01 Dec 2022

Summary

Definition

History and exam

Key diagnostic factors

  • severe sudden-onset headache
  • depressed consciousness/loss of consciousness
  • neck stiffness and muscle aches (meningismus)
  • risk factors
  • eyelid drooping, diplopia with mydriasis, orbital pain
Full details

Other diagnostic factors

  • photophobia
  • nausea/vomiting
  • confusion
  • history of sentinel headaches
  • seizures
  • diplopia
  • visual loss
  • agitation
  • focal neurological deficits
Full details

Risk factors

  • hypertension
  • smoking
  • family history
  • autosomal dominant polycystic kidney disease (ADPKD)
  • alcohol use
  • cocaine use
  • Marfan syndrome
  • Ehlers-Danlos syndrome
  • pseudoxanthoma elasticum
  • neurofibromatosis type I
Full details

Diagnostic investigations

1st investigations to order

  • non-contrast CT head
  • FBC
  • serum electrolytes
  • clotting profile
  • troponin I
  • serum glucose
  • ECG
Full details

Investigations to consider

  • lumbar puncture (LP)
  • computed tomography angiography (CTA)
  • magnetic resonance angiography (MRA)
  • digital subtraction angiography (DSA)
  • electroencephalogram (EEG)
Full details

Treatment algorithm

ACUTE

GCS score ≤8 or falling

GCS score ≥9

ONGOING

with symptomatic vasospasm or DCI

Contributors

Expert advisers

Matthew Jones

Consultant Neurologist

Greater Manchester Neurosciences Centre

Salford Royal Foundation Trust

Honorary Senior Lecturer

University of Manchester

Manchester

UK

Disclosures

MJ is the chair of the Association of British Neurologists Education Committee (unpaid position). MJ is a faculty member of an MRCP revision course.

Rachael Power

Neurology Registrar

Manchester Centre for Clinical Neurosciences

Manchester

UK

Disclosures

RP has been sponsored by Novartis to attend the International Headache Conference.

Acknowledgements

BMJ Best Practice would like to gratefully acknowledge the previous expert contributor, whose work has been retained in parts of the content:

Salah Keyrouz MD, FAHA

Associate Professor

Neurology and Neurosurgery

Washington University School of Medicine

St. Louis

MO

Disclosures

SK is an author of a reference cited in this topic.

Peer reviewers

Tim Harris

Professor of Emergency Medicine

Barts Health NHS Trust

London

UK

Disclosures

Diederik Bulters

Consultant Neurosurgeon

University Hospital Southampton NHS Foundation Trust

Southampton

Hampshire

UK

Disclosures

DB is the chief investigator for the 'SFX-01 after SAH' trial sponsored by Evgen Pharma. He receives no payment from and has no financial interest in Evgen Pharma.

Nicholas Borg

Registrar

University Hospital Southampton NHS Foundation Trust

Southampton

Hampshire

UK

Disclosures

NB declares that he has no competing interests.

Editors

Helena Delgado-Cohen

Section Editor, BMJ Best Practice

Disclosures

HDC declares that she has no competing interests.

Luisa Dillner

Head of Research and Development, BMJ

Disclosures

Tannaz Aliabadi-Oglesby

Lead Section Editor, BMJ Best Practice

Disclosures

TAO declares that she has no competing interests.

Julie Costello

Comorbidities Editor, BMJ Best Practice

Disclosures

JC declares that she has no competing interests.

Adam Mitchell

Drug Editor, BMJ Best Practice

Disclosures

AM declares that he has no competing interests.

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