Subarachnoid hemorrhage overview: Difference between revisions
(Created page with "__NOTOC__ {{Subarachnoid hemorrhage}} {{CMG}}; '''Associate Editor(s)-In-Chief:''' {{CZ}} ==Overview== '''Subarachnoid hemorrhage''' ('''SAH''') is bleeding into the [[sub...") |
No edit summary |
||
| Line 4: | Line 4: | ||
==Overview== | ==Overview== | ||
'''Subarachnoid hemorrhage''' ('''SAH''') is [[bleeding]] into the [[subarachnoid space]] surrounding the brain, i.e., the area between the [[arachnoid (brain)|arachnoid membrane]] and the [[pia mater]]. It may arise due to [[Physical trauma|trauma]] or spontaneously, and is a [[medical emergency]] which can lead to death or severe disability even if recognized and treated in an early stage. Treatment is with close observation, medication and early [[neurosurgery|neurosurgical]] investigations and treatments. Subarachnoid hemorrhage causes 5% of all [[stroke]]s. 10-15% die before arriving in hospital, and average survival is 50%.<ref name=vanGijn>Van Gijn J, Kerr RS, Rinkel GJ. Subarachnoid haemorrhage. ''[[The Lancet|Lancet]]'' 2007;369:306-18. PMID 17258671.</ref> | '''Subarachnoid hemorrhage''' ('''SAH''') is [[bleeding]] into the [[subarachnoid space]] surrounding the brain, i.e., the area between the [[arachnoid (brain)|arachnoid membrane]] and the [[pia mater]]. It may arise due to [[Physical trauma|trauma]] or spontaneously, and is a [[medical emergency]] which can lead to death or severe disability even if recognized and treated in an early stage. Treatment is with close observation, medication and early [[neurosurgery|neurosurgical]] investigations and treatments. Subarachnoid hemorrhage causes 5% of all [[stroke]]s. 10-15% die before arriving in hospital, and average survival is 50%.<ref name=vanGijn>Van Gijn J, Kerr RS, Rinkel GJ. Subarachnoid haemorrhage. ''[[The Lancet|Lancet]]'' 2007;369:306-18. PMID 17258671.</ref> | ||
==Causes== | |||
Spontaneous SAH is most often due to rupture of [[cerebral aneurysm]]s (85%), weaknesses in the wall of the [[artery|arteries]] of the brain that enlarge. While most cases of SAH are due to bleeding from small aneurysms, there is evidence from research that larger aneurysms (which are rarer) are still more likely to rupture. A further 10% of cases is due to ''non-aneurysmal perimesencephalic hemorrhage'', in which the blood is limited to the area of the midbrain. No aneurysms are generally found. The remaining 5% are due to [[vasculitis|vasculitic]] damage to arteries, other disorders affecting the vessels, disorders of the spinal cord blood vessels, and bleeding into various [[tumor]]s. | |||
==Risk Factors== | |||
Risk factors for subarachnoid hemorrhage are [[tobacco smoking|smoking]], [[hypertension]] (high blood pressure) and excessive [[alcoholic beverage|alcohol]] intake; all are associated with a doubled risk for SAH. Some protection of uncertain significance is conferred by Caucasian ethnicity, [[hormone replacement therapy]], a higher than normal [[cholesterol]] and the presence of [[diabetes mellitus]].<ref>{{cite journal |author=Feigin VL, Rinkel GJ, Lawes CM, ''et al'' |title=Risk factors for subarachnoid hemorrhage: an updated systematic review of epidemiological studies |journal=Stroke |volume=36 |issue=12 |pages=2773–80 | year=2005| pmid=16282541| doi=10.1161/01.STR.0000190838.02954.e8}}</ref> | |||
==Diagnosis== | |||
===History and Symptoms=== | |||
The classic symptom of subarachnoid hemorrhage is [[thunderclap headache]] ("most severe ever" headache developing over seconds to minutes). This headache is often described like being "kicked in the head".<ref name="oxford">{{cite book | last = Longmore | first = Murray | coauthors = Ian Wilkinson, Tom Turmezei, Chee Kay Cheung | title = Oxford Handbook of Clinicial Medicine | publisher = Oxford | date = 2007 | pages = 841 | isbn = 0-19-856837-1 }}</ref> 10% of all people with this symptom turn out to have a subarachnoid hemorrhage, and is the only symptom in about a third of all SAH patients. Other presenting features may be [[vomiting]] (non-specific), [[seizure]]s (1 in 14) and [[meningism]]. [[Confusion]], decreased level of consciousness or [[coma]] may be present. Intraocular hemorrhage (bleeding into the eyeball) may occur. Subhyaloid hemorrhages may be visible on fundoscopy (the hyaloid membrane envelopes the [[vitreous body]]). | |||
===Laboratory Findings=== | |||
[[lumbar puncture]] (removal of [[cerebrospinal fluid]]/CSF with a needle from the lumbar sac under [[local anesthetic]]) will identify another 3% of the cases by demonstrating ''xanthochromia'' (yellow appearance of centrifugated fluid) or [[bilirubin]] (a breakdown product of [[hemoglobin]]) in the CSF. | |||
==References== | ==References== | ||
{{Reflist|2}} | {{Reflist|2}} | ||
Revision as of 20:38, 1 February 2013
|
Subarachnoid Hemorrhage Microchapters |
|
Diagnosis |
|---|
|
Treatment |
|
AHA/ASA Guidelines for the Management of Aneurysmal Subarachnoid Hemorrhage (2012)
|
|
Case Studies |
|
Subarachnoid hemorrhage overview On the Web |
|
American Roentgen Ray Society Images of Subarachnoid hemorrhage overview |
|
Risk calculators and risk factors for Subarachnoid hemorrhage overview |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-In-Chief: Cafer Zorkun, M.D., Ph.D. [2]
Overview
Subarachnoid hemorrhage (SAH) is bleeding into the subarachnoid space surrounding the brain, i.e., the area between the arachnoid membrane and the pia mater. It may arise due to trauma or spontaneously, and is a medical emergency which can lead to death or severe disability even if recognized and treated in an early stage. Treatment is with close observation, medication and early neurosurgical investigations and treatments. Subarachnoid hemorrhage causes 5% of all strokes. 10-15% die before arriving in hospital, and average survival is 50%.[1]
Causes
Spontaneous SAH is most often due to rupture of cerebral aneurysms (85%), weaknesses in the wall of the arteries of the brain that enlarge. While most cases of SAH are due to bleeding from small aneurysms, there is evidence from research that larger aneurysms (which are rarer) are still more likely to rupture. A further 10% of cases is due to non-aneurysmal perimesencephalic hemorrhage, in which the blood is limited to the area of the midbrain. No aneurysms are generally found. The remaining 5% are due to vasculitic damage to arteries, other disorders affecting the vessels, disorders of the spinal cord blood vessels, and bleeding into various tumors.
Risk Factors
Risk factors for subarachnoid hemorrhage are smoking, hypertension (high blood pressure) and excessive alcohol intake; all are associated with a doubled risk for SAH. Some protection of uncertain significance is conferred by Caucasian ethnicity, hormone replacement therapy, a higher than normal cholesterol and the presence of diabetes mellitus.[2]
Diagnosis
History and Symptoms
The classic symptom of subarachnoid hemorrhage is thunderclap headache ("most severe ever" headache developing over seconds to minutes). This headache is often described like being "kicked in the head".[3] 10% of all people with this symptom turn out to have a subarachnoid hemorrhage, and is the only symptom in about a third of all SAH patients. Other presenting features may be vomiting (non-specific), seizures (1 in 14) and meningism. Confusion, decreased level of consciousness or coma may be present. Intraocular hemorrhage (bleeding into the eyeball) may occur. Subhyaloid hemorrhages may be visible on fundoscopy (the hyaloid membrane envelopes the vitreous body).
Laboratory Findings
lumbar puncture (removal of cerebrospinal fluid/CSF with a needle from the lumbar sac under local anesthetic) will identify another 3% of the cases by demonstrating xanthochromia (yellow appearance of centrifugated fluid) or bilirubin (a breakdown product of hemoglobin) in the CSF.
References
- ↑ Van Gijn J, Kerr RS, Rinkel GJ. Subarachnoid haemorrhage. Lancet 2007;369:306-18. PMID 17258671.
- ↑ Feigin VL, Rinkel GJ, Lawes CM; et al. (2005). "Risk factors for subarachnoid hemorrhage: an updated systematic review of epidemiological studies". Stroke. 36 (12): 2773–80. doi:10.1161/01.STR.0000190838.02954.e8. PMID 16282541.
- ↑ Longmore, Murray (2007). Oxford Handbook of Clinicial Medicine. Oxford. p. 841. ISBN 0-19-856837-1. Unknown parameter
|coauthors=ignored (help)