eMedicine Specialties > Neurology > Neurological Emergencies

Subarachnoid Hemorrhage: Differential Diagnoses & Workup

Author: George I Jallo, MD, Associate Professor of Neurosurgery, Pediatrics and Oncology, Director, Clinical Pediatric Neurosurgery, Department of Neurosurgery, Johns Hopkins University School of Medicine
Coauthor(s): Tibor Becske, MD, Assistant Professor, Department of Neurology, New York University Medical Center
Contributor Information and Disclosures

Updated: Dec 4, 2008

Differential Diagnoses

Acute Stroke Management
Extraocular Muscles, Actions
Anisocoria
Extraocular Muscles, Anatomy
Aphasia
First Seizure in Adulthood: Diagnosis and Treatment
Arteriovenous Malformations
Frontal Lobe Syndromes
Aseptic Meningitis
Hydrocephalus
Basilar Artery Thrombosis
Intracranial Hemorrhage
Cerebellar Hemorrhage
Lumbar Puncture (CSF Examination)
Cerebral Aneurysms
Magnetic Resonance Imaging in Acute Stroke
Cerebral Venous Thrombosis
Meningococcal Meningitis
Epidural Hematoma
Migraine Headache

Other Problems to Be Considered

Arterial supply, orbit
Back pain
Diplopia
Computed tomography (CT) in neurovascular diseases

Workup

Laboratory Studies

Laboratory studies for subarachnoid hemorrhage should include the following:

  • Serum chemistry panel
  • CBC count
  • Prothrombin time (PT) and activated partial thromboplastin time (aPTT) tests
  • Blood typing/screening tests

Imaging Studies

  • CT without contrast
    • CT is the most sensitive imaging study in subarachnoid hemorrhage (see Media files 1-3).
    • Findings may be negative in 10-15% of patients with SAH.
    • Maximum sensitivity is within 24 hours after the event; sensitivity is 80% at 3 days, 50% at 1 week.
    • Look for evidence of hydrocephalus (trapped temporal horns and "Mickey Mouse" appearance of ventricular system).
    • Look for intraparenchymal clot, intraventricular hematoma, and interhemispheric hematoma.
    • Degree and location of SAH are significant prognostic factors. The Fisher grading system is used to classify SAH, as follows:
      • Grade I - No subarachnoid blood seen on CT scan
      • Grade II - Diffuse or vertical layers of SAH less than 1 mm thick
      • Grade III - Diffuse clot and/or vertical layer greater than 1 mm thick
      • Grade IV - Intracerebral or intraventricular clot with diffuse or no subarachnoid blood
  • Cerebral angiography - To assess the following:
    • Vascular anatomy (see Media files 4-7)
    • Site of bleed (location of aneurysm that bled this time)
    • Presence of other aneurysms (about 20% have multiple aneurysms)
    • Operative planning
    • Negative angiographic findings do not rule out aneurysm. Approximately 10-20% of patients with clinically diagnosed SAH (CT and/or lumbar puncture [LP]) have negative angiographic findings. A repeat angiogram is usually required in 10-21 days.
  • MRI is inferior to CT in an acute setting to detect SAH.
  • MR angiography (MRA) is less sensitive than cerebral angiography to detect small aneurysms.
  • CT angiography is beneficial in very unstable patients who cannot undergo angiography or in emergent settings prior to operative intervention for clot evacuation.

Other Tests

  • ECG
    • Nonspecific ST and T changes, prolongation of QRS segments or QT intervals, deeply inverted T waves, and U waves sometimes are seen in subarachnoid hemorrhage.
    • Patients with SAH can have myocardial ischemia due to the increased level of circulating catecholamines or to autonomic stimulation from the brain.

Procedures

  • Lumbar puncture
    • If the CT scan shows no subarachnoid hemorrhage, an LP needs to be performed to evaluate the cerebrospinal fluid (CSF) for the presence of RBCs and xanthochromia.
    • LP is most sensitive 12 hours after onset of symptoms.
    • LP findings can be negative in approximately 10-15% of patients with SAH.
    • Patients with negative CT and LP findings have a favorable prognosis.

More on Subarachnoid Hemorrhage

Overview: Subarachnoid Hemorrhage
Differential Diagnoses & Workup: Subarachnoid Hemorrhage
Treatment & Medication: Subarachnoid Hemorrhage
Follow-up: Subarachnoid Hemorrhage
Multimedia: Subarachnoid Hemorrhage
References
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References

  1. Caplan LR. Subarachnoid hemorrhage. In: Stroke: A Clinical Approach. Boston: Butterworth-Heinemann; 1993:389-423.

  2. Greenberg MS. SAH and aneurysms. In: Handbook of Neurosurgery. New York: Thieme Medical Publishers; 1999:711-52.

  3. Jayaraman MV, Mayo-Smith WW, Tung GA, et al. Detection of intracranial aneurysms: multi-detector row CT angiography compared with DSA. Radiology. Feb 2004;230(2):510-8. [Medline].

  4. Langer DJ, Zager EL, Flamm ES. Parasurgical management of aneurysmal subarachnoid hemorrhage. Neurologic and Neurosurgical Emergencies.

  5. Le Roux PD, Winn HR. Management of the ruptured aneurysm. Neurosurg Clin N Am. Jul 1998;9(3):525-40. [Medline].

  6. Liebenberg WA, Worth R, Firth GB, et al. Aneurysmal subarachnoid haemorrhage: guidance in making the correct diagnosis. Postgrad Med J. Jul 2005;81(957):470-3. [Medline].

  7. Lin CL, Dumont AS, Lieu AS, et al. Characterization of perioperative seizures and epilepsy following aneurysmal subarachnoid hemorrhage. J Neurosurg. Dec 2003;99(6):978-85. [Medline].

  8. Marden FA, Roy SS. Endovascular management of intracerebral and subarachnoid hemorrhage. Curr Treat Options Cardiovasc Med. Jul 2005;7(3):197-209. [Medline].

  9. Molyneux A, Kerr R, Stratton I, et al. International Subarachnoid Aneurysm Trial (ISAT) of neurosurgical clipping versus endovascular coiling in 2143 patients with ruptured intracranial aneurysms: a randomised trial. Lancet. Oct 26 2002;360(9342):1267-74. [Medline].

  10. Morris PG, Wilson JT, Dunn L. Anxiety and depression after spontaneous subarachnoid hemorrhage. Neurosurgery. Jan 2004;54(1):47-52; discussion 52-4. [Medline].

  11. Ratcheson RA, Wirth FP. Ruptured cerebral aneurysms: perioperative management. In: Concepts in Neurosurgery. Baltimore: Williams & Wilkins; 1994.

  12. Schievink WI. Intracranial aneurysms. N Engl J Med. Jan 2 1997;336(1):28-40. [Medline].

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Further Reading

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Keywords

subarachnoid hemorrhage, stroke, blood into the subarachnoid space, aneurysm rupture, arteriovenous malformations, berry aneurysm, mycotic aneurysm, ruptured aneurysm, saccular aneurysm, thunderclap headache, SAH, fibromuscular dysplasia, polycystic kidney disease, aortic coarctation, cerebral arteriovenous malformation, AVM, persistent carotid-basilar anastomosis, systemic lupus erythematosus, SLE, moyamoya disease, granulomatous angiitis, Marfan syndrome, Ehlers-Danlos syndrome, Osler-Weber-Rendu syndrome, pseudoxanthoma elasticum, Klippel-Trenaunay-Weber syndrome, atrial myxoma, choriocarcinoma

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Contributor Information and Disclosures

Author

George I Jallo, MD, Associate Professor of Neurosurgery, Pediatrics and Oncology, Director, Clinical Pediatric Neurosurgery, Department of Neurosurgery, Johns Hopkins University School of Medicine
George I Jallo, MD is a member of the following medical societies: American Association of Neurological Surgeons, American College of Surgeons, American Medical Association, and American Society of Pediatric Neurosurgeons
Disclosure: Nothing to disclose.

Coauthor(s)

Tibor Becske, MD, Assistant Professor, Department of Neurology, New York University Medical Center
Tibor Becske, MD is a member of the following medical societies: American Association of Neurological Surgeons
Disclosure: Nothing to disclose.

Medical Editor

Stephen A Berman, MD, PhD, Professor, Department of Internal Medicine, Section of Neurology, Dartmouth Medical School; Chief, Neurology Service, White River Junction Veterans Medical Center
Stephen A Berman, MD, PhD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Neurology, and Phi Beta Kappa
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: Nothing to disclose.

Managing Editor

Howard S Kirshner, MD, Professor of Neurology, Psychiatry and Hearing and Speech Sciences, Vice Chairman, Department of Neurology, Vanderbilt University School of Medicine; Director, Vanderbilt Stroke Center; Program Director, Stroke Service, Vanderbilt Stallworth Rehabilitation Hospital; Consulting Staff, Department of Neurology, Nashville Veterans Affairs Medical Center
Howard S Kirshner, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Neurology, American Heart Association, American Medical Association, American Neurological Association, American Society of Neurorehabilitation, National Stroke Association, Phi Beta Kappa, and Tennessee Medical Association
Disclosure: Boehringer Ingelheim Honoraria Speaking and teaching; BMS/Sanofi Honoraria Speaking and teaching; Pfizer Honoraria Speaking and teaching; Novartis Consulting fee Review panel membership

CME Editor

Selim R Benbadis, MD, Professor, Director of Comprehensive Epilepsy Program, Departments of Neurology and Neurosurgery, University of South Florida School of Medicine, Tampa General Hospital
Selim R Benbadis, MD is a member of the following medical societies: American Academy of Neurology, American Academy of Sleep Medicine, American Clinical Neurophysiology Society, American Epilepsy Society, and American Medical Association
Disclosure: Nothing to disclose.

Chief Editor

Helmi L Lutsep, MD, Professor, Department of Neurology, Oregon Health and Science University; Associate Director, Oregon Stroke Center
Helmi L Lutsep, MD is a member of the following medical societies: American Academy of Neurology and American Stroke Association
Disclosure: Co-Axia Consulting fee Review panel membership; Talecris Consulting fee Review panel membership; AGA Medical Consulting fee Review panel membership; Boehringer Ingelheim Honoraria Speaking and teaching; Boston Scientific Honoraria Speaking and teaching; Concentric Medical None Review panel membership; Northstar Neuroscience  Review panel membership; ev3 Consulting fee Review panel membership

 
 
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