II. Epidemiology: Incidence
- Incidental finding in 6% of U.S. population
-
Family History of Cerebral Aneurysm (RR 3.6)
- One first degree relative: 4% higher risk (up to 10% overall risk)
- Two or more first degree relatives: 8 to 10% higher risk (up to 16% overall risk)
III. Risk Factors
-
General risk factors
- Age over 50 years
- More common in postmenopausal women
- Tobacco Abuse
- Cocaine Abuse
- Head Trauma
- Intracranial neoplasm
- Hypertension
- Alcohol use
- Oral Contraceptive
- Hyperlipidemia
- Inherited and Other Non-modifiable Conditions
- No relationship to Marfan's Syndrome
- Autosomal Dominant Polycystic Kidney Disease (10-15% have aneurysms)
- Type IV Ehlers-Danlos Syndrome
- Pseudoxanthoma elasticum
- Hereditary Hemorrhagic Telangiectasia
- Neurofibromatosis Type I
- Alpha-1-Antitrypsin Deficiency
- Klinefelter's Syndrome
- Tuberous sclerosis
- Noonan's Syndrome
- Alpha-glucosidase deficiency
- Hypertensive conditions (e.g. Pheochromocytoma)
- Moyamoya Disease
- Loeys-Dietz Syndrome
- Sickle Cell Anemia
- Japanese Descent
- Finnish Descent
- Aortic disorders
- Aortic aneurysm
- Bicuspid aortic valve
- Aortic Coarctation
IV. Types
- Most common sites of aneurysm
- Anterior Communicating Artery (35%)
- Posterior Communicating Artery (35%)
- Highest risk of rupture
- Middle Cerebral Artery (20%)
- Saccular Aneurysm (Berry Aneurysm)
- Most common Cerebral Aneurysm (90%)
- Defect in artery tunica muscularis
- Usually occurs at vessel bifurcation, especially in the Circle of Willis
- Fusiform Aneurysm
- Originates in tortuous arteries
- More commonly occurs in vertebrobasilar vessels
- Dissecting Aneurysm
- Result of cystic medial necrosis or Trauma
- Blood follows false lumen
V. Symptoms
- Asymptomatic until rupture in most patients
- See Subarachnoid Hemorrhage
- Headache
- Vision changes or Oculomotor Nerve dysfunction
- Seizures
- Ischemic changes in specific anatomic distribution
VI. Imaging
- Intra-arterial digital subtraction angiography
- Gold Standard
- Permanent neurologic complications in 0.5% cases
- MR angiography
- CT angiography
- Transcranial Doppler Ultrasound
VII. Complications: Subarachnoid Hemorrhage
- Mortality: 50% for ruptured aneurysm
- Risk of rupture
- Aneurysm >9 mm: 1% annual risk
- Aneurysm <10 mm
- Prior Subarachnoid Hemorrhage: 0.5% annual risk
- No prior Subarachnoid Hemorrhage: 0.05% annual risk
- Study suggests 0.1% annual risk if <7 mm
- (2003) Lancet 362:103-10 [PubMed]
VIII. Management: Observation
- Periodic imaging with MR Angiogram or CT Angiogram
- Indicated when lesions do not meet criteria for neurosurgery
- Lesion <3 mm
- Lesion 3-7 mm and no high risk criteria (e.g. Posterior Circulation)
- Age over 70 years old
- Approach
- Observed small aneurysms should NOT be considered "time bombs" (rupture risk is low)
- Most patients may participate in regular vigorous Exercise without restriction
IX. Management: Neurosurgery
- Indications
- Anterior Circulation aneurysm 7 mm or larger (typically if under age 70 years)
- Posterior Circulation aneurysm 3-7 mm or larger (higher risk of rupture)
- Open repair via craniotomy
- Mortality: 2.6%
- Morbidity: 10.9% (decreased neurologic function)
- Endovascular treatment (Guglielmi detachable coil)
- New procedure with unclear efficacy (ISAT Trial did not evaluate unruptured aneurysm)
- Coiling has become the predominant procedure (based on ISAT Trial)
X. Prevention
- Screening asymptomatic patients is not recommended
- Screening patients with significant risk factors (Head CTA or MRA)
- Avoid screening children (delay screening until adult)
- Indications
- One or more first degree relatives with Cerebral Aneurysm
- See Inherited and Non-modifiable Risk Factors above (e.g. Connective Tissue Disorders)
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Related Studies
Concepts | Disease or Syndrome (T047) , Anatomical Abnormality (T190) |
MSH | D002532 |
SnomedCT | 125236003, 277196008 |
English | Aneurysms, Berry, Berry Aneurysms, Aneurysm, Berry, berry aneurysms, berry aneurysm, Berry aneurysm, Berry aneurysm (disorder), Berry aneurysm (morphologic abnormality), Berry aneurysm - disorder, Berry Aneurysm |
German | Beerenaneurysma, Berry-Aneurysma, Aneurysma sacciforme, Beerenförmiges Aneurysma, Sackförmiges Aneurysma |
Italian | Aneurisma sacciforme, Aneurisma di Berry |
Portuguese | Aneurisma cerebral sacular, Aneurisma em Amora |
Spanish | Aneurisma en frambuesa, Aneurisma Sacciforme, aneurisma en frambuesa (anomalía morfológica), aneurisma en frambuesa (trastorno), aneurisma en frambuesa |
Japanese | 小嚢状動脈瘤, ショウノウジョウドウミャクリュウ |
Czech | Vakovité aneurysma |
French | Anévrisme en forme de baie, Anévrysme en forme de baie, Anévrisme ampullaire, Anévrysme ampullaire |
Hungarian | Bogyó aneurysma |
Norwegian | Berry aneurysm |
Dutch | Aneurysma sacciforme, Berry-aneurysma |
Ontology: Intracranial Aneurysm (C0007766)
Definition (NCI) | A congenital or acquired aneurysm within the cranium. |
Definition (MSH) | Abnormal outpouching in the wall of intracranial blood vessels. Most common are the saccular (berry) aneurysms located at branch points in CIRCLE OF WILLIS at the base of the brain. Vessel rupture results in SUBARACHNOID HEMORRHAGE or INTRACRANIAL HEMORRHAGES. Giant aneurysms (>2.5 cm in diameter) may compress adjacent structures, including the OCULOMOTOR NERVE. (From Adams et al., Principles of Neurology, 6th ed, p841) |
Concepts | Disease or Syndrome (T047) |
MSH | D002532 |
SnomedCT | 128609009, 42994005 |
English | Aneurysms, Intracranial, Intracranial Aneurysm, Intracranial Aneurysms, Aneurysm, Intracranial, Aneurysm intracranial, Intracranial Aneurysm [Disease/Finding], intracranial aneurysm, aneurysms intracranial, cranial aneurysm, intracranial aneurysms, Intracranial aneurysms, Intracranial aneurysm, Intracranial aneurysm (disorder), Intracranial aneurysm, NOS |
German | Aneurysma intrakraniell, intrakranielles Aneurysma, Aneurysma, intrakranielles, Intrakranielles Aneurysma |
Portuguese | Aneurisma intracraniano, Aneurismo intra-craniano, Aneurisma Intracraniano |
Swedish | Hjärnaneurysm |
Czech | intrakraniální aneurysma, Aneurysma intrakraniální, Intrakraniální aneurysma |
Finnish | Kallonsisäinen aneurysma |
Russian | ARTERIOVENOZNAIA ANEVRIZMA GOLOVNOGO MOZGA, VNUTRICHEREPNYKH SOSUDOV ANEVRIZMA, TSEREBRAL'NAIA ANEVRIZMA, VNUTRICHEREPNAIA ANEVRIZMA, ANEVRIZMA SOSUDOV GOLOVNOGO MOZGA, BERRY ANEVRIZMA, BERRY АНЕВРИЗМА, АНЕВРИЗМА СОСУДОВ ГОЛОВНОГО МОЗГА, АРТЕРИОВЕНОЗНАЯ АНЕВРИЗМА ГОЛОВНОГО МОЗГА, ВНУТРИЧЕРЕПНАЯ АНЕВРИЗМА, ВНУТРИЧЕРЕПНЫХ СОСУДОВ АНЕВРИЗМА, ЦЕРЕБРАЛЬНАЯ АНЕВРИЗМА |
Japanese | 頭蓋内動脈瘤, 動脈瘤-脳, 巨大脳動脈瘤, 真菌性動脈瘤-頭蓋内, 脳動脈瘤-真菌性, 動脈瘤-頭蓋内, 真菌性脳動脈瘤, 頭蓋内真菌性動脈瘤, 脳動脈動脈瘤, 巨大頭蓋内動脈瘤, 脳動脈瘤, トウガイナイドウミャクリュウ |
French | Anévrisme d'une artère intracrânienne, Anévrysme d'une artère intracrânienne, Anévrysme intracrânien, Anévrisme intracrânien, Anévrisme intra-crânien, Anévrysme intra-crânien |
Croatian | INTRAKRANIJSKA ANEURIZMA |
Polish | Tętniak śródczaszkowy, Tętniak wewnątrzczaszkowy |
Hungarian | Intracranialis aneurysma |
Norwegian | Intrakranialt aneurisme, Aneurisme, intrakranialt |
Spanish | aneurisma intracraneal (trastorno), aneurisma intracraneal, Aneurisma intracraneal, Aneurisma Intracraneal |
Dutch | intracraniaal aneurysma, Aneurysma, intracranieel, Intracranieel, aneurysma |
Italian | Aneurisma intracranico |
Ontology: Cerebral Aneurysm (C0917996)
Definition (NCI) | A balloon type pouch or bulge in the wall of a cerebral blood vessel. |
Definition (CSP) | congenital or acquired abnormal outpouching of an intracranial blood vessel wall; saccular (berry) aneurysms are the most common variant, and tend to form at arterial branch points near the base of the brain; rupture results in subarachnoid hemorrhage or intracranial hemorrhages; giant aneurysms (>2.5 cm in diameter) may compress adjacent structures, including the oculomotor nerve. |
Concepts | Disease or Syndrome (T047) |
MSH | D002532 |
ICD10 | I67.1 |
SnomedCT | 266316009, 155409000, 128609009 |
English | Aneurysm, Cerebral, Aneurysms, Cerebral, Cerebral Aneurysms, Aneurysm cerebral, Cerebral aneurysm NOS, aneurysms cerebral, cerebral aneurysm, aneurysm cerebral, cerebral aneurysms, Aneurysm-cer.non rupt., Cerebral aneurysm-non ruptured, Cerebral aneurysm, Cerebral Aneurysm |
Dutch | cerebraal aneurysma, Aneurysma, cerebraal, Cerebraal aneurysma |
German | Aneurysma zerebral, Zerebrales Aneurysma, Aneurysma, zerebrales |
Portuguese | Aneurisma cerebral, Aneurisma Cerebral |
Spanish | Aneurisma cerebral, Aneurisma Cerebral, aneurisma cerebral |
Japanese | 脳動脈瘤, ノウドウミャクリュウ |
French | Anévrysme cérébral, Anévrismes cérébraux, Anévrysmes cérébraux, Anévrisme cérébral |
Czech | Mozkové aneurysma, cerebrální aneurysma |
Hungarian | Agyi aneurysma |
Italian | Aneurisma cerebrale |
Norwegian | Cerebralt aneurisme |