eMedicine Specialties > Neurology > Neurological Emergencies
Subarachnoid Hemorrhage: Differential Diagnoses & Workup
Updated: Dec 21, 2009
- Overview
- Differential Diagnoses & Workup
- Treatment & Medication
- Follow-up
- Multimedia
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 images below).
CT scan reveals subarachnoid hemorrhage in the right sylvian fissure; no evidence of hydrocephalus is apparent.
CT scan reveals subarachnoid hemorrhage in the sylvian fissure, right more than left.
A 47-year-old woman presented with headache and vomiting; her CT scan in the emergency department revealed subarachnoid hemorrhage.
- 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
- CT is the most sensitive imaging study in subarachnoid hemorrhage (see images below).
- Cerebral angiography - To assess the following:
- Vascular anatomy (see images below)
Cerebral angiogram reveals a middle cerebral artery aneurysm.
Cerebral angiogram reveals a middle cerebral artery aneurysm.
Cerebral angiogram (lateral view) reveals a large aneurysm arising from the left anterior choroidal artery.
Cerebral angiogram (anteroposterior view) reveals a large aneurysm arising from the left anterior choroidal artery.
- 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) have negative angiographic findings. A repeat angiogram is usually required in 10-21 days.
- Vascular anatomy (see images below)
- 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 angiography2 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
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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].
Marden FA, Roy SS. Endovascular management of intracerebral and subarachnoid hemorrhage. Curr Treat Options Cardiovasc Med. Jul 2005;7(3):197-209. [Medline].
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].
O'Kelly CJ, Kulkarni AV, Austin PC, Wallace MC, Urbach D. The impact of therapeutic modality on outcomes following repair of ruptured intracranial aneurysms: an administrative data analysis. J Neurosurg. Oct 23 2009;[Medline].
Koffijberg H, Rinkel GJ, Buskens E. Aneurysm Occlusion in Elderly Patients with Aneurysmal Subarachnoid Hemorrhage: A Cost-Utility Analysis. J Neurol Neurosurg Psychiatry. Dec 3 2009;[Medline].
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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].
van der Velden LB, Otterspoor LC, Schultze Kool LJ, Biessels GJ, Verheugt FW. Acute myocardial infarction complicating subarachnoid haemorrhage. Neth Heart J. Aug 2009;17(7-8):284-7. [Medline].
Becker H. Consequences of a Nonrecognized Subarachnoid Hemorrhage. Klin Neuroradiol. Nov 20 2009;[Medline].
Caplan LR. Subarachnoid hemorrhage. In: Stroke: A Clinical Approach. Boston: Butterworth-Heinemann; 1993:389-423.
Greenberg MS. SAH and aneurysms. In: Handbook of Neurosurgery. New York: Thieme Medical Publishers; 1999:711-52.
Langer DJ, Zager EL, Flamm ES. Parasurgical management of aneurysmal subarachnoid hemorrhage. Neurologic and Neurosurgical Emergencies.
Le Roux PD, Winn HR. Management of the ruptured aneurysm. Neurosurg Clin N Am. Jul 1998;9(3):525-40. [Medline].
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].
Ratcheson RA, Wirth FP. Ruptured cerebral aneurysms: perioperative management. In: Concepts in Neurosurgery. Baltimore: Williams & Wilkins; 1994.
Schievink WI. Intracranial aneurysms. N Engl J Med. Jan 2 1997;336(1):28-40. [Medline].
Further Reading
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
