Subarachnoid hemorrhage (SAH) is a life-threatening condition that refers to bleeding into the subarachnoid space. Most cases are attributed to a ruptured aneurysm. Additionally, there are risk factors such as hypertension, atherosclerosis, smoking, and other conditions as well.
Up to 50% of patients with SAH experience symptoms prior to rupture. The most common feature is a headache, which is frequently accompanied by nausea, emesis, photophobia, and possibly nuchal pain and rigidity. Moreover, the hallmark complaint is "this is the worst headache of my life." Other manifestations include dizziness, visual impairment, diplopia, and orbital pain. Patients may also develop seizures, ptosis, bruits, dysphagia, motor dysfunction, and sensory losses.
The history of the patient often provides a clue regarding the diagnosis. Approximately 60% to 70% of patients report that SAH may be preceded by physical or emotional stress such as head trauma, defecation, or sexual intercourse.
The proposed characteristics which should raise suspicion for SAH are 1) age of patient 40 years or above, 2) pain or stiffness of the neck, 3) loss of consciousness, 4) manifestations induced by physical or emotional exertion, 5) emesis, 6) transportation to the hospital by an ambulance, and 7) diastolic blood pressure of at least 100mm Hg or systolic blood pressure of at least 160mm Hg.
Specific neural deficits will reflect the site of an expanding aneurysm. For example, an affected anterior communicating artery produces paresis of the bilateral lower extremities along with a positive bilateral Babinski sign. An aneurysm in the intracranial vertebral artery results in vertigo among other deficits. Furthermore, a lesion in the MCA leads to paresis of the contralateral face, hand, and vision in addition to left sided aphasia. Finally, an affected ICA or posterior communicating artery causes oculomotor nerve palsy and retro-orbital headaches.
Entire Body System
The recovery process of injured CRTs concurrent with recovery of leg weakness was demonstrated in a patient with SAH using DTT. [ncbi.nlm.nih.gov]
Fatigue will decrease over time as your physical fitness improves. Regular sleep habits and daily naps will reduce your fatigue. Headaches are common after SAH. They tend to improve as time goes by. [mayfieldclinic.com]
All other 147 patients were independent on activities for daily living, but 39 had symptoms including headaches or dizziness (n 7), fatigue (n 7), forgetfulness (n 12), and irritability (n 5). [stroke.ahajournals.org]
Impaired or complete unconsciousness was noted in 34% of patients with SAH compared with 13% of patients without SAH. [aafp.org]
A brief period of unconsciousness immediately after the rupture is common; severe hemorrhage may result in continued unconsciousness, coma, and death. [medical-dictionary.thefreedictionary.com]
"If you put a lot of blood around the brain you will become unconscious." Dr Grabs said Hughes was then taken to surgery where doctors removed some of his skull "to help to allow the brain to expand so it wasn't compressed". [abc.net.au]
After a short time, blood flow increases again as part of a reactive response (reactive hyperaemia ), whereby the patient can re-emerge from the state of unconsciousness. [flexikon.doccheck.com]
- Coarctation of the Aorta
Aneurysm formation is also seen in the setting of mycotic aneurysms, as well as in association with some congenital disorders, including coarctation of the aorta, Marfan's syndrome, Ehlers-Danlos syndrome, fibromuscular dysplasia, and polycystic kidney [casemed.case.edu]
[…] of the aorta fibromuscular dysplasia INVESTIGATIONS Bedside ECG: tall peaked T waves, ST depression, prolonged QT, arrhythmia Echo: neurogenic cardiomyopathy Laboratory hyponatraemia hypovolaemia from SIADH or cerebral salt wasting - worsens vasospasm [lifeinthefastlane.com]
MR Angiography MRA can be used to screen for intracranial aneurysms in asymptomatic patients who have a family history of aneurysms or who have polycystic kidneys, coarctation of the aorta, or collagen vascular disease, putting them at a higher risk for [spinwarp.ucsd.edu]
Connective tissue diseases (autosomal dominant polycystic kidney disease, coarctation of the aorta, Marfan's syndrome, Ehlers-Danlos syndrome type IV, neurofibromatosis type I, alpha-1-antitrypsin deficiency). Anticoagulation (Aspirin or Warfarin). [emed.ie]
[…] of the aorta, Marfan syndrome, Ehlers-Danlos syndrome, fibromuscular dysplasia, polycystic kidney disease) Familial cases of AVM are rare, and the problem may result from sporadic abnormalities in embryologic development. [emedicine.com]
Clinical features include headache; nausea; vomiting, nuchal rigidity, variable neurological deficits and reduced mental status. [icd9data.com]
Six days after the surgery, the patient continued to complain of nausea and headache. By 13 days, the patient reported relief from her symptoms. There was no evidence of cerebral aneurysm, or vascular malformation in both cases. [ncbi.nlm.nih.gov]
Lumbar puncture revealed an opening pressure of 360 mmH2O, suggestive of intracranial venous hypertension. Grave disease was diagnosed by endocrinological investigation. [ncbi.nlm.nih.gov]
Given an SAH incidence of 6/100 000 person-years, 9 a prevalence of hypertension approximating 10%, and an RR of hypertension of 3, the incidence of SAH in patients without hypertension is 5/100 000 person-years and that of patients with hypertension [stroke.ahajournals.org]
The tracing, which was normal before SAH, showed sinus tachycardia with frequent ventricular ectopics after 15 seconds, wide QRS tachycardia indicating either transient ventricular tachycardia or sinus tachycardia with intraventricular conduction delay [circ.ahajournals.org]
however, the observed patterns of regional wall-motion abnormalities (RWMAs) of the LV frequently do not match coronary artery distributions. 10 Other mechanisms of injury such as coronary vasospasm and supply-demand mismatch from hypertension and tachycardia [doi.org]
Historically, cardiac dysfunction after SAH has been attributed to coronary thrombosis, epicardial coronary vasospasm, or oxygen supply-demand mismatch in the setting of hypertension and tachycardia, although there is little clinical evidence to support [web.archive.org]
- Neck Pain
A patient with subarachnoid hemorrhage may have a sudden, intense headache, neck pain, and nausea or vomiting. Sometimes this is described as the worst headache of one’s life. [strokecenter.org]
A history of neck pain (LR 4.1; 95% confidence interval [CI] 2.2 to 7.6) and neck stiffness on physical examination (LR 6.6; 95% CI 4.0 to 11.0) were the individual findings most strongly associated with SAH. [doi.org]
After comparing the performance of the three candidate decision rules, the investigators refined the decision tool to combine the six factors that were most predictive of SAH: age 40 or older, neck pain or stiffness, witnessed loss of consciousness, onset [neurologyreviews.com]
A 45-year-old right-handed man was admitted to the hospital with a sudden onset of severe headache associated with nausea, vomiting, and mild photophobia for 6 hours. The patient was fully conscious and totally alert. [ncbi.nlm.nih.gov]
[…] severe headache ("thunderclap headache"), often described as the “worst headache of my life" • Nuchal pain and rigidity • A sudden loss of consciousness (occurs in half of patients at bleeding onset; it is usually transient) • Nausea and/or vomiting • Photophobia [casemed.case.edu]
Snapshot A 45-year-old woman presents to the emergency room with a stiff neck, photophobia, and an extremely severe headache that began while she was enjoying a glass of sweet Alabama southern tea. [step2.medbullets.com]
It is often associated with photophobia and meningism. Focal neurological deficits often present either at the same time as a headache or soon thereafter 2. [radiopaedia.org]
Other symptoms: Decreased consciousness and alertness Eye discomfort in bright light ( photophobia ) Mood and personality changes, including confusion and irritability Muscle aches (especially neck pain and shoulder pain) Nausea and vomiting Numbness [medlineplus.gov]
[…] stiffness or pain, onset of headache on exertion, vomiting, witnessed loss of consciousness, and elevated BP 160/100 Also consider the following signs: stroke‐like symptoms, seizure or 3rd cranial nerve palsy from mass effect, 6th cranial nerve palsy with diplopia [emergencymedicinecases.com]
A headache often is associated with nausea, vomiting, and diplopia. [ncbi.nlm.nih.gov]
[…] poor if happens at onset) Meningism [neck stiffness and photophobia due to meningeal irritation] (prognostically poor) Seizures (only in 7% but highly suggestive) Early seizures predict late seizures and poor outcome New neurology (prognostically poor) Diplopia [oxfordmedicaleducation.com]
Other manifestations include dizziness, visual impairment, diplopia, and orbital pain. Patients may also develop seizures, ptosis, bruits, dysphagia, motor dysfunction, and sensory losses. [symptoma.com]
- Pupillary Abnormality
Urgent salvage procedures to evacuate parenchymal haematomas (before DSA investigation) is reserved for states of acute intracranial decompensation and pupillary abnormalities (fig 1B). [jnnp.bmj.com]
Face, Head & Neck
- Facial Pain
These symptoms, which can occur minutes to weeks before a rupture, include: Severe headache Facial pain Double vision, droopy eyelid or other vision problems If these symptoms are present, they should always be brought to a doctor’s attention quickly [ufhealth.org]
pain; photophobia; and stiff or painful neck; deterioration of neurological status Discharge and home healthcare guidelines Prepare the patient and family for the possible need for rehabilitation after the acute care phase of hospitalization. [medical-dictionary.thefreedictionary.com]
Childhood ischemic stroke is attributed to vasculopathy with moyamoya syndrome. Hemorrhagic stroke is commonly attributed to aneurysms accompanying HbSS cerebral vasculopathy in SCD. [ncbi.nlm.nih.gov]
Stroke. 2005;36:2773-2780 Published online before print November 10, 2005, doi: 10.1161/01.STR.0000190838.02954.e8 ( Stroke. 2005;36:2773.) 2005 American Heart Association, Inc. [web.archive.org]
Stroke. 2003 ; 34 : 1771–1776. Link Google Scholar [stroke.ahajournals.org]
Abstract Headache is the presenting complaint in roughly 2% of ED visits. 1 Of all those with headache, about 1% will have Subarachnoid Hemorrhage (SAH), 2-4 meaning 99% of ED headache patients do not have SAH. [web.archive.org]
Conclusions Less than one in 10 headache patients concerning for SAH are ultimately diagnosed with SAH in recent studies. [doi.org]
The headache preceding an intracranial aneurysm rupture is called a sentinel headache (SH), and it is characterized by a sudden, intense, and persistent headache. [ncbi.nlm.nih.gov]
[…] such as migraine or tension headache more likely. [jama.ama-assn.org]
None of the patients with epilepsy after discharge had electrographic seizures while hospitalized. [ncbi.nlm.nih.gov]
Preventing a seizure may prevent rebleeding, 3 although in multivariate models seizures and rebleeding are not associated. 8 Benefit from prophylaxis, however, assumes that seizures are harmful and PHT is harmless. [dx.doi.org]
Seizures During Hospitalization Twenty-seven (5%) patients had seizures in the hospital. Clinical variables associated with in-hospital seizures are listed in Table 2. [web.archive.org]
Tuberculosis in the central nervous system may present as tuberculoma and tuberculous meningitis. Vasculitis secondary to tuberculous meningitis can cause infarcts, and, rarely, aneurysm formation. [ncbi.nlm.nih.gov]
Conclusion: SAH in meningitis could be explained by vasculitis or undetected ruptured mycotic aneurysm induced by acute inflammation from meningitis. [n.neurology.org]
Applies To Middle meningeal hemorrhage following injury ICD-9-CM Volume 2 Index entries containing back-references to 852.0 : ICD-9-CM codes are used in medical billing and coding to describe diseases, injuries, symptoms and conditions. [icd9data.com]
The aneurysm was coiled with balloon protection, and later, on the fifth day of ictus, the patient became acutely confused and developed memory disturbances. [ncbi.nlm.nih.gov]
Some people remain in a coma, but most often patients wake up feeling confused and sleepy. Within a few minutes or few hours, the patient may again begin to feel confused and sleepy. [ufhealth.org]
Symptoms of SAH include a severe headache with a rapid onset ("thunderclap headache"), vomiting, confusion or a lowered level of consciousness, and sometimes seizures. [urmc.rochester.edu]
Common symptoms of a subarachnoid hemorrhage include: Loss of consciousness Double vision Nausea or vomiting Severe headache — the worst headache pain you've ever had that feels different from other headaches Trouble speaking Drooping eyelid Confusion [hopkinsmedicine.org]
Patients with characteristic symptoms should raise suspicion for SAH as they warrant immediate medical evaluation and management. The workup includes a thorough history, a complete exam with a neural assessment, and the appropriate workup.
CT scan without contrast demonstrates a sensitivity greater than 90% with excellent detection if performed within 6 hours of onset of the clinical picture. MRI is also sensitive but its availability may be limited. Cerebral angiography and CT angiography are alternative tests if other modalities are inconclusive.
If the CT fails to detect SAH, then a lumbar puncture is the next step unless the patient has elevated ICP, in which case the procedure can exacerbate the bleeding. Evaluation of the cerebrospinal fluid (CSF) yields findings such as the presence of red blood cells (RBCs), although this may result from trauma. Other typical features include xanthochromia and elevated pressure.
In addition to the critical imaging studies, comprehensive laboratory tests should be obtained in order to understand the overall clinical picture. These include a complete blood count (CBC) to rule out infection, a coagulation panel for the exclusion of bleeding disorders, cardiac enzymes to evaluate myocardial infarction, and a metabolic panel. Additionally, blood typing and screening are very important in the event that a transfusion is required.
These patients should also have an electrocardiogram (ECG) done, which may reveal ST changes, abnormalities such as QRS or QT prolongation, or T wave peaking or inversion.
Traditional teaching is that a positive tap is Xanthochromia or blood in the CSF What exactly is Xanthochromia? The word xanthochromia is simply Greek for “yellow color.” It refers to the yellow color that CSF can take in certain situations. [tamingthesru.com]
[…] and visual xanthochromia seems to be most sensitive. [bmj.com]
Key Words: subarachnoid hemorrhage, aneurysm, thunderclap headache, sentinel headache, lumbar puncture, xanthochromia, emergency department, head CT, CTA, angiography, MRI, nimodipine, risk factors, prehospital care, diagnosis, management, analgesia, [web.archive.org]
True xanthochromia is pathognomonic for SAH. [westjem.com]
We assess the sensitivity and specificity of xanthochromia as adjudicated by visual inspection and spectrophotometry at predicting the presence of cerebral aneurysm in patients with suspected subarachnoid hemorrhage who have a normal computed tomography [ncbi.nlm.nih.gov]
Pooled data [ 26, 27 ] demonstrated lower incidences of hyponatremia (Na serum 2 c). [doi.org]
Hyponatremia Hyponatremia is the most common clinically significant electrolyte derangement associated with SAH. [intechopen.com]
RESULTS: The rate of complications in the NPM-SAH group was higher than in the PM-SAH group, including early hydrocephalus, delayed cerebral ischemia, clinical vasospasm, pneumonia, and hyponatremia. [ncbi.nlm.nih.gov]
It is the most common cause of hyponatremia in these patients and may respond to fludorcortisone [Stroke 20: 1156, 1989; Clin Neurol Neurosurg 90: 209, 1988]. [openanesthesia.org]
- T Wave Inversion
ECG Electrocardiographic manifestations are non-specific, but commonly include: deep, symmetric T wave inversions 12 often referred to as "cerebral T waves" prolongation of the QT interval sinus bradycardia Three distinct patterns of subarachnoid hemorrhage [radiopaedia.org]
ECG changes in 50‐100% of patients due to neurogenic myocardial stunning and coronary vasospasm: deep, wide precordial T‐wave inversion, bradycardia, and prolonged QT – beware of anticoagulating these patients on the assumption of acute coronary syndrome [emergencymedicinecases.com]
‡Q wave, QTc prolongation ( 0.4 ms), T-wave inversion, or ST-T–segment abnormality. §Available in 230 patients; in 50 patients, the day 14 or discharge mRS score was used. [circ.ahajournals.org]
ECG may show Tall T waves, ST depression, Giant T wave inversions secondary to raised ICP, QT prolongation and arrhythmias. [emdidactic.blogspot.com]
Since this is a life-threatening condition, patients should be promptly stabilized and admitted to the ICU or stroke center. In order to prevent complications, the medical team should immediately manage the cardiovascular, respiratory, and neurologic manifestations.
According to current recommendations, intravenous nicardipine is administered if the mean arterial pressure (MAP) is above 130mm Hg. The blood pressure should be maintained in a particular range so as to not exacerbate or produce complications. Another essential component in the management of these patients is vasospasm prophylaxis with nimodipine for 21 days.
To decrease the likelihood of rebleeding, the aneurysm should be occluded through clipping or coiling within the first 24 hours of rupture. The goal is to create a bypass of the blood flow. Clipping is an option for accessible masses or in cases wth hematomas that can be evacuated.
If the rupture occurred more than 24 hours ago, the neurosurgeons may choose to operate after 10 days to reduce the probability of angry brain complications although the risk for rebleeding and fatality is increased.
Furthermore, acute hydrocephalus may warrant drainage and shunt placement. Other sequelae may also require surgery.
Important measures that should be implemented in patients with SAH include bed rest, headache relief.
Anticoagulants and antiplatelet drugs should be avoided in these patients.
The prognosis of SAH due to a ruptured aneurysm tends to be poor even with prompt intervention. Specifically, SAH is deadly in as much as 50% of patients , with the majority dying after the initial rupture and others meeting a fatal outcome from a further rupture a few weeks later. SAH is also associated with severe neurological and cognitive disabilities .
Note that the dynamic nature of aneurysm formation increases the likelihood for development of new aneurysms and expansion of previous ones . Therefore, these patients are at increased risk for future episodes of rupture and hemorrhage.
SAH is caused by a ruptured aneurysm in nearly 80% of cases. Structural defects in the walls of the cerebral vessels contribute to aneurysm formation   especially in the context of hypertension, smoking, and excessive alcohol consumption .
About 20% of SAH cases are the result of nonaneurysmal conditions such as peri mesencephalic hemorrhage, cerebral arteriovenous malformations, arterial dissection, rare diseases, as well as anticoagulant treatment .
There are risk factors for the formation of an aneurysm, which include hypertension, cerebral atherosclerosis, abnormalities in the circle of Willis, chronic use of analgesic drugs, hypertensive diseases in pregnancy, positive family history for stroke, and persistent headaches. Certain genetic disorders may predispose affected individuals to the development of this defect as well. Marfan syndrome, Ehlers-Danlos syndrome, and adult polycystic kidney disease are among the examples.
Predictors of rupture include an aneurysm that measures 3mm or less in diameter as well as a positive family history of the cerebrovascular disease .
The annual incidence of SAH in the U.S. is 6 to 8 individuals per population of 100,000  with a higher occurrence in Hispanics . Furthermore, there is a greater prevalence in Finland and Japan .
With regards to the patient demographics, this SAH manifests at an average age that ranges between 50 to 55 . There is a predilection for women, who exhibit a rate that is 1.6 times that of men . Additionally, the incidence in black individuals is double that of white people .
SAH refers to bleeding into the subarachnoid space, which most commonly stems from a ruptured aneurysm. Specifically, saccular aneurysms (also known as berry aneurysms) are found in the terminal segment of the internal carotid artery (ICA) and the anterior arteries of the circle of Willis. Intracranial arteries are susceptible to developing aneurysms since these vessels have a thin adventitia layer, absent external elastic lamina, and no support in the subarachnoid space.
The growth of these lesions is influenced by the hemodynamics and structure of the large cerebral arteries, which are under significant hydrostatic pressure due to the turbulent and rapid changes in blood flow. Moreover, the arterial wall stress is highest at bifurcation points. The likelihood of rupture is determined by the La Place's law, which explains that the radius and transmural pressure of an aneurysm determine the amount of tension in the wall.
Unruptured aneurysms can also cause brain injury since the compressive force of the lesion damages tissue and limits perfusion.
There are numerous complications that can arise from SAH such as rebleeding, which is a very serious risk that likely occurs due to the instability of the thrombus. About 20% of patients experience rebleeding episodes within 2 weeks. Risk factors for this sequel are anxiety , as well as hypertension and seizures.
A predominant cause of morbidity and mortality in patients with SAH is delayed cerebral ischemia, which results from vasospasm . The most common vessels involved are the ICA and the proximal segments of the anterior cerebral artery (ACA) and middle cerebral artery (MCA).
Aneurysms of the ACA, ICA, and other vessels can rupture and induce intracranial hemorrhage. Additionally, intraventricular hemorrhage (IVH) can emerge from ruptured aneurysms in the brain vasculature.
Hydrocephalus can develop, especially in older individuals and/or those with vasospasms, subdural hematoma, intraventricular bleeding, and systolic heart failure. Consequently, acute hydrocephalus can increase the ICP, which leads to loss of consciousness and possibly even coma.
Universal recommendations advocate for a healthy lifestyle that helps prevent cerebrovascular disease. For example, all individuals are advised modify risk factors through strict blood pressure control, smoking cessation, alcohol restriction, weight management, and proper diet.
Prevention of rupture
There are challenges that present with regards to management of patients with incidental findings. Since the probability of rupture does increase with age, the medical team and the patient should discuss the risks of rupture and complications of surgery in order to make the best decision. Note that the screening of first-degree family members of affected individuals does not give promising results.
Subarachnoid hemorrhage (SAH) is the extravasation of blood into the space between the arachnoid membrane and pia mater. The majority of nontraumatic cases of SAH are attributed to a ruptured cerebral aneurysm , while a head injury is implicated in traumatic cases. Moreover, SAH accounts for up to 7% of stroke cases , and thus shares risk factors such as hypertension, atherosclerosis, and alcohol abuse.
The characteristic features of SAH are a severe "a thunderclap headache," nausea, emesis, altered mental status, and other neurologic manifestations . Due to elevated intracranial pressure (ICP) and damage to the brain tissue and vasculature, SAH can also result in serious complications such as episodes of rebleeding, vasospasm, hydrocephalus, intraventricular hemorrhage, intracerebral hemorrhage, and seizures.
Patients suspected to have SAH should be evaluated and treated urgently. The clinical assessment includes patient and family history, identification of all risk factors, a detailed physical exam with neurologic focus, and the appropriate studies. The latter consists of computed tomography (CT) scan, and a lumbar puncture if the former is negative for SAH. Furthermore, various blood tests should be obtained to rule out other causes of the clinical picture.
Emergency treatment is crucial since SAH is associated with high rates of morbidity and mortality. Initial management is composed of stabilization, maintenance of blood pressure within a therapeutic range, and emergent surgical intervention to prevent rebleeding and other complications. Procedures such as clipping or coiling of an aneurysm are usually performed immediately.
What is Subarachnoid hemorrhage?
Subarachnoid hemorrhage (SAH) refers to bleeding in an area known as the subarachnoid space. This space is the protective cushion between the brain and the tissue that surrounds it.
What causes it?
There are numerous causes but the most common one is a ruptured aneurysm. An aneurysm is a bulge that forms in the large arteries of the brain in some people. When it bursts, the blood spills into the arachnoid space. Other causes include abnormalities in the structure of arteries, rare genetic diseases, the use of anticoagulant medications, and head injuries.
The factors that increase the risk for the formation of aneurysms are:
- Alcohol abuse
- Certain genetic diseases such as Marfan syndrome
- Certain abnormalities in the vessels of the brain
What are the signs and symptoms?
SAH more commonly occurs between the ages of 50 and 55 although it can develop at any age. The following are the signs and symptoms:
- Severe headache
- Sensitivity to light
- Pain and stiffness in the neck
- Double vision
- Loss of vision
- Difficulty swallowing
- Trouble with motor
- Loss of sensation
- Loss of consciousness
How is it diagnosed?
Any patient with the above signs and symptoms should be evaluated immediately. The clinician will ask important questions about the history, perform a full physical exam including a detailed neurologic exam, and order the following tests:
- CT scan without contrast
- MRI if needed
- Cerebral angiography and CT angiography if CT scan is negative
- If CT is negative, the patient should have a lumbar puncture
- Laboratory tests: complete blood count, coagulation panel, cardiac tests metabolic tests, and blood typing and screening
How is it treated?
This life-threatening condition must me treated immediately. Patients should be admitted to the ICU or stroke center. The treatment includes the following:
- Very high blood pressure is treated carefully
- Spasm of cerebral vessels should be prevented with specific medications such as calcium channel blockers
- Surgery: neurosurgeons block blood flow of the affected artery since the risk of recurrent bleeding is usually high. They can clip or place coils in the vessel.
- The patient should be placed on bed rest to prevent more bleeding
- Treatment with medications that prevent constipation (so that the patient does not strain and exert pressure)
- Headache relief
What is the prognosis?
This is a life-threatening condition and should be treated urgently. Survivors may experience further episodes of aneurysm formation and rupture in the future. Also, patients who survive SAH may develop neurologic disabilities.
- Suarez JI, Tarr RW, Selman WR. Aneurysmal subarachnoid hemorrhage. New England Journal of Medicine. 2006;354(4):387-396.
- Feigin VL, Rinkel GJ, Lawes CM et al. Risk factors for subarachnoid hemorrhage: an updated systematic review of epidemiological studies. Stroke. 2005; 36 (12): 2773–80.
- van Gijn J, Kerr RS, Rinkel GJ. Subarachnoid haemorrhage. Lancet. 2007; 369 (9558): 306–18.
- Brisman JL, Song JK, Newell DW. Cerebral aneurysms. New England Journal of Medicine. 2006; 355(9):928-939.
- Wiebers DO, Piepgras DG, Meyer FB, et al. Pathogenesis, natural history, and treatment of unruptured intracranial aneurysms. Mayo Clinic Proceedings. 2004;79(12):1572-1583.
- van Gijn J, Rinkel GJ. Subarachnoid haemorrhage: diagnosis, causes and management. Brain. 2001;124 (Pt 2):249-278.
- You SH, Kong DS, Kim JS, et al; Characteristic features of unruptured intracranial aneurysms: predictive risk. Journal of Neurology, Neurosurgery, and Psychiatry. 2010 May;81(5):479-84.
- Linn FH, Rinkel GJ, Algra A, et al. Incidence of subarachnoid hemorrhage: role of region, year, and rate of computed tomography: a meta-analysis. Stroke. 1996;27(4):625-629.
- Bruno A, Qualls C. Risk factors for intracerebral and subarachnoid hemorrhage among Hispanics and non-Hispanic whites in a New Mexico community. Neuroepidemiology. 2000;19(4):227-232.
- Broderick JP, Brott T, Tomsick T, et al. The risk of subarachnoid and intracerebral hemorrhages in blacks as compared with whites. New England Journal of Medicine. 1992;326(11):733-736.
- Morris PG, Wilson JT, Dunn L. Anxiety and depression after spontaneous subarachnoid hemorrhage. Neurosurgery. 2004; 54(1):47-52; discussion 52-4.
- Jaeger M, Soehle M, Schuhmann MU, Meixensberger J. Clinical Significance of Impaired Cerebrovascular Autoregulation After Severe Aneurysmal Subarachnoid Hemorrhage. Stroke. 2012;43(8):2097-101.
- van der Velden LB, Otterspoor LC, Schultze Kool LJ, Biessels GJ, Verheugt FW. Acute myocardial infarction complicating subarachnoid haemorrhage. Netherlands Heart Journal. 2009; 17(7-8):284-7.
- Wermer MJ, van der Schaaf IC, Velthuis BK, et al. Follow-up screening after subarachnoid haemorrhage: frequency and determinants of new aneurysms and enlargement of existing aneurysms. Brain. 2005;128 (Pt 10):2421-2429.