It is understandable to feel concerned about your own health after a parent has experienced a brain aneurysm, given the known link between family history and this condition. An intracranial aneurysm (IA), often called a brain aneurysm, is a localized dilation or bulging of a blood vessel in the brain due to a weakness in the artery wall. These aneurysms are present in an estimated 1% to 5% of the general adult population, though most remain small and never rupture. The presence of an IA often goes unnoticed until it is discovered incidentally during medical imaging for another reason.
Understanding Familial Risk
Your personal risk of developing a brain aneurysm is higher than the general population’s because your mother is a first-degree relative (parent, sibling, or child) who was affected. Studies show that having one first-degree relative with an IA or aneurysmal subarachnoid hemorrhage (aSAH, or ruptured aneurysm) generally increases your risk by two to four times compared to someone with no family history.
The likelihood of developing an IA increases further if multiple family members are affected. If two or more first-degree relatives have had an IA, the risk can be significantly higher, sometimes reaching 20% in certain families. Researchers believe this increased familial risk is due to inheriting a predisposition, meaning a genetic tendency toward vessel wall weakness, rather than inheriting the aneurysm itself. This tendency is thought to be driven by a combination of multiple genes, not a single inherited mutation.
Familial aneurysms tend to rupture at a younger average age and sometimes at a smaller size than those that occur in people with no family history. Recognizing this pattern is important, as having an affected parent signals the need for a proactive approach to monitoring your health.
Other Significant Risk Factors
While family history is a major factor, the formation and rupture of brain aneurysms are also significantly influenced by other factors that are not directly inherited. Cigarette smoking is considered the single most modifiable risk factor for IA formation and rupture, as it weakens blood vessel walls.
Uncontrolled hypertension, or high blood pressure, is another contributing factor that damages and weakens artery walls over time. Managing blood pressure is important for reducing the risk of both aneurysm formation and rupture. The risk of developing an IA also increases with age, typically after 40, and is slightly higher in women than in men, particularly after menopause.
Certain underlying medical conditions may also increase your risk by affecting the integrity of connective tissues throughout the body. These conditions include Autosomal Dominant Polycystic Kidney Disease (ADPKD) and connective tissue disorders like Ehlers-Danlos syndrome. These factors combine with any inherited predisposition to determine an individual’s overall likelihood of developing an IA.
When Should Screening Be Considered
Consulting with a neurosurgeon or neurologist to discuss screening is the logical next step due to your familial link. Screening is generally recommended for individuals who have at least one first-degree relative who experienced an aneurysmal subarachnoid hemorrhage. The strongest consensus for screening is typically for individuals with two or more affected first-degree relatives.
Screening aims to detect an unruptured aneurysm before it becomes symptomatic, allowing for risk modification or preventative treatment. The most common non-invasive screening methods are Magnetic Resonance Angiography (MRA) and Computed Tomography Angiography (CTA). MRA is often preferred for serial screening because it avoids ionizing radiation, which is beneficial for repeated tests.
If your initial scan is clear, your physician will recommend serial screening, which means periodic repeat imaging. For those with one first-degree relative, a baseline scan followed by repeat screening every five to ten years may be suggested. If you have multiple affected relatives, screening may be recommended more frequently, such as every five years, usually starting between the ages of 20 and 30. An initial negative screen does not guarantee that an aneurysm will not develop later, as aneurysms can form de novo, or new, over time, making long-term monitoring important.