CV

Cerebral Aneurysm

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Cerebral Aneurysm, Intracranial Aneurysm, Berry Aneurysm

  • See Also
  1. Neurovascular Anatomy
  2. Subarachnoid Hemorrhage
  1. Incidental finding in 6% of U.S. population
  2. Family History of Cerebral Aneurysm (RR 3.6)
    1. One first degree relative: 4% higher risk (up to 10% overall risk)
    2. Two or more first degree relatives: 8 to 10% higher risk (up to 16% overall risk)
  • Risk Factors
  1. General risk factors
    1. Age over 50 years
    2. More common in postmenopausal women
    3. Tobacco Abuse
    4. Cocaine Abuse
    5. Head Trauma
    6. Intracranial neoplasm
    7. Hypertension
    8. Alcohol use
    9. Oral Contraceptive
    10. Hyperlipidemia
  2. Inherited and Other Non-modifiable Conditions
    1. No relationship to Marfan's Syndrome
    2. Autosomal Dominant Polycystic Kidney Disease (10-15% have aneurysms)
    3. Type IV Ehlers-Danlos Syndrome
    4. Pseudoxanthoma elasticum
    5. Hereditary Hemorrhagic Telangiectasia
    6. Neurofibromatosis Type I
    7. Alpha-1-Antitrypsin Deficiency
    8. Klinefelter's Syndrome
    9. Tuberous sclerosis
    10. Noonan's Syndrome
    11. Alpha-glucosidase deficiency
    12. Hypertensive conditions (e.g. Pheochromocytoma)
    13. Moyamoya Disease
    14. Loeys-Dietz Syndrome
    15. Sickle Cell Anemia
    16. Japanese Descent
    17. Finnish Descent
    18. Aortic disorders
      1. Aortic aneurysm
      2. Bicuspid aortic valve
      3. Aortic Coarctation
  • Types
  1. Most common sites of aneurysm
    1. Anterior Communicating Artery (35%)
    2. Posterior Communicating Artery (35%)
      1. Highest risk of rupture
    3. Middle Cerebral Artery (20%)
  2. Saccular Aneurysm (Berry Aneurysm)
    1. Most common Cerebral Aneurysm (90%)
    2. Defect in artery tunica muscularis
    3. Usually occurs at vessel bifurcation
  3. Fusiform Aneurysm
    1. Originates in tortuous arteries
    2. More commonly occurs in vertebrobasilar vessels
  4. Dissecting Aneurysm
    1. Result of cystic medial necrosis or Trauma
    2. Blood follows false lumen
  • Symptoms
  1. Asymptomatic until rupture in most patients
  2. See Subarachnoid Hemorrhage
  3. Headache
  4. Vision changes or Oculomotor Nerve dysfunction
  5. Seizures
  6. Ischemic changes in specific anatomic distribution
    1. Anterior Cerebral Artery CVA
    2. Middle Cerebral Artery CVA
    3. Vertebro-Basilar CVA
    4. Posterior Cerebral Artery CVA
    5. Posterior Inferior Cerebellar Artery CVA
  • Imaging
  1. Intra-arterial digital subtraction angiography
    1. Gold Standard
    2. Permanent neurologic complications in 0.5% cases
  2. MR angiography
  3. CT angiography
  4. Transcranial Doppler Ultrasound
  1. Mortality: 50% for ruptured aneurysm
  2. Risk of rupture
    1. Aneurysm >9 mm: 1% annual risk
    2. Aneurysm <10 mm
      1. Prior Subarachnoid Hemorrhage: 0.5% annual risk
      2. No prior Subarachnoid Hemorrhage: 0.05% annual risk
        1. Study suggests 0.1% annual risk if <7 mm
        2. (2003) Lancet 362:103-10 [PubMed]
  • Management
  • Observation
  1. Periodic imaging with MR Angiogram or CT Angiogram
  2. Indicated when lesions do not meet criteria for neurosurgery
    1. Lesion <3 mm
    2. Lesion 3-7 mm and no high risk criteria (e.g. Posterior Circulation)
    3. Age over 70 years old
  3. Approach
    1. Observed small aneurysms should NOT be considered "time bombs" (rupture risk is low)
    2. Most patients may participate in regular vigorous Exercise without restriction
  • Management
  • Neurosurgery
  1. Indications
    1. Anterior Circulation aneurysm 7 mm or larger (typically if under age 70 years)
    2. Posterior Circulation aneurysm 3-7 mm or larger (higher risk of rupture)
  2. Open repair via craniotomy
    1. Mortality: 2.6%
    2. Morbidity: 10.9% (decreased neurologic function)
  3. Endovascular treatment (Guglielmi detachable coil)
    1. New procedure with unclear efficacy (ISAT Trial did not evaluate unruptured aneurysm)
    2. Coiling has become the predominant procedure (based on ISAT Trial)
  • Prevention
  1. Screening asymptomatic patients is not recommended
  2. Screening patients with significant risk factors (Head CTA or MRA)
    1. Avoid screening children (delay screening until adult)
    2. Indications
      1. One or more first degree relatives with Cerebral Aneurysm
      2. See Inherited and Non-modifiable Risk Factors above (e.g. Connective Tissue Disorders)
  • References
  1. (1998) N Engl J Med 339:1725-33 [PubMed]
  2. Kane (2023) Am Fam Physician 108(4): 386-95 [PubMed]
  3. Raaymakers (1998) Stroke 29:1531-8 [PubMed]
  4. Vega (2002) Am Fam Physician 66(4):601-8 [PubMed]
  5. Wardlaw (2000) Brain 123:205-21 [PubMed]