Risk factors and genetics
Aneurysm formation and rupture are multifactorial. The same patient can have risk factors for developing an aneurysm and separate risk factors that influence rupture.
Modifiable risk factors
- Smoking (formation, growth, and rupture risk)
- Hypertension (formation and rupture risk; treat aggressively)
- Stimulant drugs (e.g., cocaine/amphetamines) — increase acute rupture risk
- Heavy alcohol patterns — associated with hemorrhagic stroke risk
For many patients with an unruptured aneurysm under observation, the most impactful “treatment” is stop smoking and control blood pressure.
Non‑modifiable or partially modifiable
- Age (risk increases with age)
- Sex (higher prevalence in women in many studies)
- Family history of aneurysm/aSAH
- Prior aneurysmal SAH (increases future rupture risk for other aneurysms)
- Aneurysm features: size, location (posterior circulation higher), shape/irregularity, growth on follow‑up
Genetic associations and syndromes
Most aneurysms are sporadic. However, the likelihood rises in certain inherited conditions and in strong familial clustering.
| Condition / pattern | Why it matters | Typical clinical note |
|---|---|---|
| Familial intracranial aneurysm | Higher prevalence and risk vs general population | Consider screening when ≥2 first‑degree relatives affected |
| ADPKD | Well‑recognized association with intracranial aneurysms | Screening may be advised depending on family history, occupation, and prior symptoms |
| Connective tissue disorders (e.g., Ehlers‑Danlos vascular type) | Arterial fragility; different procedural risk profile | Management in specialized centers; procedure choice may differ |
| Other associations | Some evidence links aneurysms with Marfan syndrome and other arteriopathies, but risk varies | Discuss individualized screening with genetics/cardiovascular specialists |
Note: Genetic associations are an evolving area. Some “associations” are stronger than others, and recommendations differ by guideline and clinical scenario.
Practical questions to bring to clinic
- Is the aneurysm saccular vs fusiform, and what is its exact size and location?
- Does it have irregular shape or a daughter sac?
- Is there evidence of growth compared with prior imaging?
- What are my key modifiable risks (BP, smoking) and what targets should I aim for?
- Should my close relatives be screened?
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