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subarachnoid hemorrhage (SAH)

hemorrhage into the subarachnoid space underneath the subarachnoid membrane that results in pressure on the brain or bleeding into the brain. Etiology: 1) arteriovenous malformation - ruptured congenital ('berry') aneurysm (80%) 2) intracranial carotid artery dissection 3) hypertension is risk factor [3] 4) drug abuse a) intravenous drug abuse b) cocaine abuse [3] 5) tobacco abuse [3] 6) polycystic kidney disease [3] 7) amyloid angiopathy, not listed as risk in [3] 8) inflammation, not listed as risk in [3] 9) infection, not listed as risk in [3] Epidemiology: - accounts for 10% of all strokes - age > 40-45 (risk factor) Pathology: - hemorrhage into the subarachnoid space results in pressure on the brain or bleeding into the brain Clinical manifestations: 1) sudden onset of severe 'thunderclap' headache a) many patients do not present with classic 'thunderclap' headache [5] b) because headache is so common, diagnosis is often missed c) sentinal hemorrhage (severe headache during previous 2-3 weeks) [3] 2) obtundation occurs often 3) loss of consciousness 4) vomiting 5) neck pain or stiffness 6) hypertension: BP ? 160/100 mm Hg 7) focal neurologic signs may occur 8) subhyaloid hemorrhage on funduscopy [4] 9) grading with Hunt-Hess clinical grading scale 10) Ottawa SAH rule sensitivity 100% with specificity 14% Laboratory: - serum magnesium - maintain 2.0-2.5 mmol/L (4.8-6.0 mg/dL) if infusing magnesium sulfate [7] Special laboratory: - lumbar puncture (LP) with CSF examination for blood &/or CSF bilirubin if non contrast CT is negative & index of suspicion is high - if > 6 hours has elapsed [15] - neither history & physical examination nor CT can rule out subarachnoid hemorrhage [10] - arteriography for confirmation of diagnosis & opportunity for surgical repair Radiology: 1) computed tomography (CT) without contrast a) blood is subarachnoid space reveals hemorrhage b) sensitivity is 99.5% [12] c) sensitivity 100% within 6 hours [8] - may be used without LP if within 6 hours 2) magnetic resonance imaging is alternative 3) CT angiography a) delineates anatomy of ruptured cerebral aneurysm b) rules out other causes of subarachnoid hemorrhage 1] intracranial arterial dissection 2] mycotic aneurysm c) identification of cerebral vasospasm as a complication [3] Complications: 1) rebleeding within 48 hours 2) ischemia from cerebral vasospasm induced by presence of extravasated blood - occurs 5-10 days after subarachnoid hemorrhage [3] 3) hydrocephalus associated with intracranial hypertension & high mortality - neurosurgical plaacement of external ventricular drain [3] 4) increased intracranial pressure 5) hyponatremia is common 6) seizures early after stroke a) more common with hemorrhagic stroke than ischemic stroke (15% vs 4%) [9] b) more common with cortical stroke than subcortical stroke (19% vs 10%) c) do not predict mortality or function at 6 months [9] 7) rebleeding of intracranial aneurysm is the major cause of morbidity [3] Differential diagnosis: - carotid artery dissection, vertebral artery dissection - venous sinus thrombosis - pituitary apoplexy - reversible cerebral vasoconstriction syndrome - intracranial hemorrhage Management: 1) see general measures under stroke (CVA) 2) surgical clipping of ruptured intracranial aneurysm with 24-72 hours [3] - endovascular coiling with better outcomes than neurosurgical clipping [6] see ISAT 3) craniotomy for intracranial aneurysm 4) blood pressure control - target blood pressure < 140/80 to prevent rebleeding [3] - nicardipine & labetolol preferred agents [3] 5) vasospasm may begin on day 5 a) nimodipine for vasospasm 1] 60 mg PO every 4 hours for 3 weeks 2] start therapy 96 hours after subarachnoid hemorrhage b) hypervolemia for symptomatic vasospasm c) hypertension if aneurysm has been surgically repaired d) angioplasty e) intra-arterial papaverine f) intravenous magnesium sulfate may be of benefit [7] 1] IV bolus of 16 mmol (1920 mg) over 30 minutes followed by 2] continuous infusion of 8 mmol (960 mg) per hour for 10 days or until vasospasm stops 3] monitor serum magnesium (see Laboratory) [7] 6) control bleeding - maintain platelet count of >= 100,000/uL [3] 7) seizure prophylaxis 8) prognosis a) better for those who present with normal mental status b) initial misdiagnosis compromises clinical outcome [5] 9) prevention: a) incidental cerebral aneurysms < 10 mm are followed by MRI b) surgery for cerebral aneurysms > 10 mm c) smoking cessation d) blood pressure control 10) neurorehabilitation

Related

hemorrhagic stroke increased intracranial pressure (ICP) subarachnoid space

Specific

Terson syndrome

General

cerebrovascular hemorrhage

References

  1. Harrison's Principles of Internal Medicine, 14th ed. Fauci et al (eds), McGraw-Hill Inc. NY, 1998
  2. Saunders Manual of Medical Practice, Rakel (ed), WB Saunders, Philadelphia, 1996, pg 1019-20
  3. Medical Knowledge Self Assessment Program (MKSAP) 11, 14, 16, 17, 18, 19. American College of Physicians, Philadelphia 1998, 2006, 2012, 2015, 2018, 2021. - Medical Knowledge Self Assessment Program (MKSAP) 19 Board Basics. An Enhancement to MKSAP19. American College of Physicians, Philadelphia 2022
  4. Geriatrics Review Syllabus, American Geriatrics Society, 5th edition, 2002-2004; 7th edition 2010
  5. Journal Watch 24(6):48-49, 2004 Kowalski RG et al, JAMA 291:866, 2004 PMID: 14970066
  6. Molyneux AJ, Kerr RS, Yu LM, Clarke M, Sneade M, Yarnold JA, Sandercock P; International Subarachnoid Aneurysm Trial (ISAT) Collaborative Group. International subarachnoid aneurysm trial (ISAT) of neurosurgical clipping versus endovascular coiling in 2143 patients with ruptured intracranial aneurysms: a randomised comparison of effects on survival, dependency, seizures, rebleeding, subgroups, and aneurysm occlusion. Lancet. 2005 Sep 3-9;366(9488):809-17. PMID: 16139655 - Britz GW. ISAT trial: coiling or clipping for intracranial aneurysms? Lancet. 2005 Sep 3-9;366(9488):783-5. No abstract available. PMID: 16139637
  7. Westermaier T et al. Prophylactic intravenous magnesium sulfate for treatment of aneurysmal subarachnoid hemorrhage: A randomized placebo- controlled, clinical study. Crit Care Med 2010 May; 38:1284. PMID: 20228677 - Taccone FS. Vasodilation and neuroprotection: The magnesium saga in subarachnoid hemorrhage. Crit Care Med 2010 May; 38:1382. PMID: 20404634
  8. Perry JJ et al. Sensitivity of computed tomography performed within six hours of onset of headache for diagnosis of subarachnoid haemorrhage: Prospective cohort study. BMJ 2011 Jul 18; 343:d4277 PMID: 21768192
  9. Beghi E et al. Incidence and predictors of acute symptomatic seizures after stroke. Neurology 2011 Nov 15; 77:1785 PMID: 21975208 - De Herdt V et al. Early seizures in intracerebral hemorrhage: Incidence, associated factors, and outcome. Neurology 2011 Nov 15; 77:1794. PMID: 21975203
  10. Mark DG et al. Nontraumatic subarachnoid hemorrhage in the setting of negative cranial computed tomography results: External validation of a clinical and imaging prediction rule. Ann Emerg Med 2012 Oct 1; PMID: 23026788
  11. Slichter SJ. Evidence-based platelet transfusion guidelines. Hematology Am Soc Hematol Educ Program. 2007:172-8. PMID: 18024626
  12. The NNT: Risk Assessment: High-Risk Headache in the Emergency Department. http://www.thennt.com/risk/high-risk-headache-in-the-emergency-department/ - Perry JJ et al. Clinical decision rules to rule out subarachnoid hemorrhage for acute headache. JAMA 2013 Sep 25; 310:1248 PMID: 24065011 - Perry JJ, Spacek A, Forbes M et al Is the combination of negative computed tomography result and negative lumbar puncture result sufficient to rule out subarachnoid hemorrhage? Ann Emerg Med. 2008 Jun;51(6):707-13 PMID: 1819129
  13. van Gijn J, Kerr RS, Rinkel GJ. Subarachnoid haemorrhage. Lancet. 2007 Jan 27;369(9558):306-18. PMID: 17258671
  14. Connolly ES Jr, Rabinstein AA, Carhuapoma JR et al Guidelines for the management of aneurysmal subarachnoid hemorrhage: a guideline for healthcare professionals from the American Heart Association/american Stroke Association. Stroke. 2012 Jun;43(6):1711-37 PMID: 22556195
  15. Carpenter CR et al. Spontaneous subarachnoid hemorrhage: A systematic review and meta-analysis describing the diagnostic accuracy of history, physical exam, imaging, and lumbar puncture with an exploration of test thresholds. Acad Emerg Med 2016 Jun 16 PMID: 27306497
  16. Lawton MT, Vates GE Subarachnoid Hemorrhage. N Engl J Med 2017; 377:257-266. July 20, 2017 PMID: 28723321 http://www.nejm.org/doi/full/10.1056/NEJMcp1605827
  17. Rothaus C Subarachnoid Hemorrhage NEJM Resident 360. July 19, 2017 https://resident360.nejm.org/content_items/subarachnoid-hemorrhage/
  18. Perry JJ, Sivilotti MLA, Sutherland J et al. Validation of the Ottawa Subarachnoid Hemorrhage Rule in patients with acute headache. CMAJ 2017 Nov 13; 189:E1379 PMID: 29133539
  19. Fernando SM, Perry JJ. Subarachnoid hemorrhage. CMAJ. 2017 Nov 20;189(46):E1421. PMID: 29158456
  20. Connolly ES Jr, Rabinstein AA, Carhuapoma JR et al. Guidelines for the management of aneurysmal subarachnoid hemorrhage: a guideline for healthcare professionals from the American Heart Association/American Stroke Association. Stroke. 2012;43(6):1711-1737 PMID: 22556195 https://www.ahajournals.org/doi/10.1161/STR.0b013e3182587839

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