What screening is recommended for a 50-year-old with a family history of brain aneurysm?

Screening Recommendations for a 50-Year-Old with Family History of Brain Aneurysm

Magnetic resonance angiography (MRA) without contrast using time-of-flight technique is recommended as the primary screening method for a 50-year-old individual with a family history of brain aneurysm. 1, 2

Risk Assessment

• Family history of intracranial aneurysm (IA) increases risk, with prevalence ratios indicating an increased risk between 1.9% and 5.9% 1
• Risk factors that increase likelihood of aneurysm detection in those with familial risk include:
  • Older age (relevant for a 50-year-old patient) 1
  • Female sex 1
  • Cigarette smoking 1
  • History of hypertension 1
  • Higher lipid levels and fasting glucose 1
  • Family history of SAH or aneurysm in ≥2 relatives 1

Screening Recommendations Based on Family History

• For patients with one first-degree relative with history of brain aneurysm:

  • MRA or CTA screening is reasonable, especially with additional risk factors 1
  • First-degree relatives have approximately 4% likelihood of harboring an unruptured intracranial aneurysm (UIA) 1

• For patients with two or more first-degree relatives with history of aneurysmal subarachnoid hemorrhage (aSAH) or UIA:

  • Screening is strongly recommended (Class I; Level of Evidence B) 1
  • Higher yield of detection - up to 11% at first screening 3

Preferred Imaging Modalities

• MRA without contrast is the preferred initial screening method 1, 2

  • Sensitivity rates of 69% to 93% for aneurysms >3-5 mm 1
  • Non-invasive and avoids radiation exposure 1, 4

• CT angiography (CTA) is an acceptable alternative 1

  • May demonstrate aneurysms as small as 2-3 mm with sensitivities of 77% to 97% 1

• Digital subtraction angiography (DSA) remains the gold standard but is more invasive and typically reserved for confirmation of positive findings or when treatment is being considered 1

Follow-up Recommendations

• If initial screening is negative, follow-up screening is recommended at 5-year intervals 3
• Even after two negative screenings, there remains a risk of de-novo aneurysm formation (3% risk) 3
• Long-term serial screening is beneficial as aneurysms can develop over time 3

Important Considerations and Caveats

• Screening should be discussed thoroughly with the patient, including:

  • Implications of detecting intracranial vascular abnormalities (such as eligibility for life insurance) 2, 5
  • Potential anxiety associated with detection 2, 5
  • Understanding that screening does not eliminate the risk of rupture 6, 3

• Modifiable risk factors should be addressed regardless of screening results:

  • Smoking cessation is critical as smoking is a strong risk factor for aneurysm formation and rupture 1, 2
  • Blood pressure control for those with hypertension 1, 2

• If an aneurysm is detected, treatment decisions should consider:

  • Patient age (50 years old is relevant for treatment decisions) 1
  • Aneurysm size, location, and morphology 1
  • Risk factors for rupture 1

The benefit of screening is greatest in populations with higher expected prevalence and higher risk of rupture, which includes individuals with family history of intracranial aneurysms 1.