From the Guidelines
Family members of individuals with brain aneurysms have a significantly higher risk of developing aneurysms themselves, with first-degree relatives having approximately 2-4 times greater risk than the general population, as supported by the guidelines from the American Heart Association/American Stroke Association 1.
Risk Factors and Screening
The risk of aneurysm development in family members is influenced by various factors, including:
- Genetic conditions such as Autosomal Dominant Polycystic Kidney Disease, Ehlers-Danlos syndrome type IV, and Marfan syndrome
- Family history of aneurysms or subarachnoid hemorrhages, particularly if two or more first-degree relatives are affected
- Environmental factors like smoking and hypertension, which can further increase risk in genetically predisposed individuals
Screening Recommendations
Screening with non-invasive imaging such as magnetic resonance angiography (MRA) or CT angiography (CTA) is recommended for patients with two or more family members with intracranial aneurysms (IA) or subarachnoid hemorrhage (SAH), as well as those with a history of autosomal dominant polycystic kidney disease, especially if they have a family history of IA 1. Key points to consider:
- The risk of aneurysm development in family members is significant, and screening can help identify asymptomatic aneurysms
- Lifestyle modifications, such as quitting smoking and managing hypertension, are important for individuals with a family history of aneurysms
- The guidelines from the American Heart Association/American Stroke Association provide recommendations for screening and management of patients with unruptured intracranial aneurysms, including those with a family history of aneurysms 1
From the Research
Correlation of Risk between Family Members and Brain Aneurysms
The correlation of risk between family members and brain aneurysms is a significant concern, with several studies investigating this relationship.
- Individuals with two or more first-degree relatives who have had aneurysmal subarachnoid haemorrhage (aSAH) have an increased risk of aneurysms and aSAH 2.
- The yield of long-term screening for intracranial aneurysms in individuals with a family history of aSAH is substantial, even after more than 10 years of follow-up and two initial negative screens 2.
- Independent predictors of aneurysm detection on MR angiography include female sex, pack-years of cigarette smoking, and duration of hypertension 3.
Risk Factors and Predictors
Several risk factors and predictors have been identified, including:
- Female sex, history of intracranial aneurysms/aneurysmal subarachnoid hemorrhage, and older age 4.
- Smoking history, hypertension, and previous aneurysms 2, 3.
- A family history of aneurysms, with individuals having two or more affected first-degree relatives at higher risk 2, 5.
Screening and Detection
Screening for intracranial aneurysms in individuals with a positive family history is recommended, with the following findings:
- Individuals with ≥2 affected first-degree relatives have a greater prevalence of IA (average 13.1% vs. 3% in the general population) 5.
- Serial screening over time can be cost-effective in persons with only one first-degree relative with IA or aSAH 5.
- The risk of aSAH is also increased in individuals with a family history of aSAH or IA 2, 5.