Risk Factors & Causes of Brain Aneurysms

A combination of both genetic and environmental factors can contribute to the development of a brain aneurysm. Certain risk factors can also increase the likelihood of brain aneurysm rupture. Here we provide a comprehensive overview of the known risk factors and causes of brain aneurysms. 

Brain aneurysms form due to a weak point on a blood vessel wall. This can occur due to injury to the blood vessel, inflammation, and wall stress from high blood pressure. The latter is supported by the fact that aneurysms commonly occur at vessel branch points, where blood rushing with each beat of the heart can exert stress on the vessel wall.

Risk factors for the formation and rupture of aneurysms can be categorized as modifiable or non-modifiable. Modifiable risk factors are those that you can change, while non-modifiable are those that you cannot change.

High blood pressure (hypertension) is the main risk factor for brain aneurysms. Excess pressure against the vessel walls causes them to stretch, placing strain on weak spots and leading to the bulges that characterize brain aneurysms. A healthy diet, regular exercise, maintaining a healthy weight, smoking cessation, and limiting alcohol consumption can help to keep your blood pressure under control.

Stress has also been associated with spikes in blood pressure, poor diet, and excessive alcohol consumption, all of which can contribute to aneurysm formation and rupture. Identifying stressors, practicing relaxation techniques, and engaging in enjoyable hobbies and activities can help to manage stress. 

Cigarette smoke contains more than 4,000 different chemicals that can contribute to the development of a wide variety of cardiovascular diseases, including brain aneurysms. Smoking can damage the lining of blood vessels, cause inflammation, and accelerate natural wear and tear. Over time, the damage worsens as cholesterol, fat, and calcium accumulate at the sites of injury, forming plaques.

Excessive alcohol consumption increases your likelihood of developing brain aneurysms and brain aneurysm rupture. Long-term alcohol abuse may injure the liver, which reduces blood clotting ability. Poor blood clotting may contribute to aneurysm rupture. Additionally, large amounts of alcohol intake is also associated with high blood pressure, further contributing to aneurysm formation.

Cocaine and methamphetamine users can develop brain aneurysms 20 years earlier than nonusers. Cocaine increases your risk of developing aneurysms in several ways, primarily by increasing your blood pressure. Cocaine also inflames the lining of your blood vessels, which make them prone to damage. Most cases of brain aneurysms associated with cocaine abuse occur in young people. 

Traumatic brain injuries (TBIs) from a severe physical impact on your head can damage brain tissue and blood vessels. For this reason, TBIs can potentially increase your risk of developing a brain aneurysm, although cases are rare. 

Certain risk factors and conditions present at birth can increase the likelihood of brain aneurysms. These include the following.

• Gender: Approximately 60% more women than men develop brain aneurysms. Researchers have linked the prevalence of brain aneurysms in women to 2 factors: 
  • Blood vessel size: Women have narrower blood vessels than men, which increases the damage caused by hypertension. 
  • Hormone production: Estrogen maintains blood vessel elasticity, but estrogen levels decrease significantly after menopause. 
• Age: Most cases of brain aneurysms are diagnosed in adults 40 to 60 years old. Age is associated with many risk factors for aneurysms, primarily the gradual weakening of blood vessels and the cumulative stress on vessels over time.
• Family History: Brain aneurysms can be associated with certain genetic factors. Having an immediate family member or multiple family members with the condition increases your likelihood of developing one.
• Coarctation of the aorta: The aorta is the body’s main artery. Coarctation of the aorta refers to a congenital heart disease that makes the artery narrower. This condition slightly increases the likelihood of developing aneurysms in the brain and elsewhere in the body.
• Polycystic kidney disease: Individuals with this condition are more prone to developing brain aneurysms.
• Arteriovenous malformation (AVM): AVM refers to an abnormal tangle of blood vessels in the brain. This condition can cause high pressures of blood flow in a certain area, increasing the risk of aneurysm development.
• Klinefelter syndrome: This condition is characterized by the presence of an extra X chromosome in men. In this condition, there is a defect in connective tissue formation, leading to weakness of the artery walls.
• Noonan’s syndrome: This condition is characterized by abnormal growth and development in various body tissue and organs, including the brain and its vascular system. 
• Ehlers–Danlos syndrome: This syndrome is a connective tissue disorder that makes the blood vessels fragile. 
• Fibromuscular dysplasia: This condition affects and damages the medium and large arteries, making them prone to aneurysms. It is most common in middle-aged women. 

Unfortunately, these non-modifiable risk factors of brain aneurysms are not preventable. However, maintaining a healthy lifestyle through a balanced diet, regular exercise, and consistent sleep can help to minimize the risk of developing brain aneurysms, along with many other cardiovascular conditions such as a heart attack and stroke.

To some extent, brain aneurysms are preventable, manageable, and treatable. The best ways to prevent an aneurysm include the following.

• Eat a healthy diet low in calories, sodium, and saturated fats. 
• Exercise regularly to strengthen your body, burn excess fats and cholesterol, and maintain a healthy body weight. 
• Monitor and maintain your blood pressure. 
• Avoid smoking, cocaine, and methamphetamines.
• Limit alcohol intake.
• Reduce and manage your stress and anxiety levels. 
• Get enough sleep and avoid potentially dangerous situations that may result in traumatic brain injuries. 

There is no single trigger that immediately contributes to formation of an aneurysm. It is often a gradual process with many factors involved. Sometimes, aneurysms can occur without the presence of any known risk factor. 

Undergoing regular checkups is particularly crucial if you are at a higher risk of developing brain aneurysms, such as individuals with a family history of aneurysms or certain genetic conditions predisposing them to vascular weaknesses. It is imperative not to overlook any aneurysm and to prioritize seeking neurosurgical advice promptly.

Even small or seemingly stable aneurysms can pose significant risks if left unaddressed, potentially leading to life-threatening complications. Therefore, proactive monitoring and timely intervention can be essential in managing this condition effectively and mitigating potential risks.

• Many of the risk factors associated with cardiovascular diseases in general have also been implicated in the formation of aneurysms.
• Maintaining a healthy lifestyle and managing your other medical conditions is the best way to prevent aneurysm formation.
• If you have multiple family members with brain aneurysms, discuss this with your primary physician to determine if and how regular monitoring should be conducted

• National Institute of Neurological Disorders and Stroke
• American Association of Neurological Surgeons (AANS): Cerebrovascular Disease
• Brain Aneurysm Foundation
• American Association of Neurological Surgeons (AANS): Cerebral Aneurysm
• American Brain Foundation (ABF)