A cerebral aneurysm is an abnormal widening of an artery in the brain caused by a weakness in the blood vessel wall. This increases the risk of rupture, potentially leading to a life-threatening hemorrhage. The prevalence of cerebral aneurysms is estimated to be between 1.5% and 8%, although most do not show symptoms until they become large or rupture.
Intracranial aneurysm
Intracranial aneurysms are relatively common and most do not cause health problems or symptoms. Therefore, many are never diagnosed and can be detected during tests performed for other conditions.
Their exact causes are unknown, but significant risk factors that may contribute to their development have been identified. These include:
- Advanced age.
- Smoking.
- Hypertension.
- Drug abuse.
- Excessive alcohol consumption.
- Sex, being more common in women.
- Head trauma.
- Certain infections by microorganisms.
Additionally, although much less frequently, aneurysms can be related to certain conditions such as connective tissue disorders (e.g., Ehlers-Danlos syndrome), polycystic kidney disease, or congenital arteriovenous malformations.
Symptoms
In most cases, intracranial aneurysms are asymptomatic, especially when they are small. However, when they are large, they can put pressure on the tissues, potentially causing pain, dilated pupil, changes in vision, or numbness on one side of the face.
Occasionally, intracranial aneurysms can rupture, causing more severe symptoms that may include:
- Sudden and very intense headache.
- Nausea and vomiting.
- Neck stiffness.
- Blurred vision and sensitivity to light.
- Seizures.
- Pale skin.
- Loss of consciousness.
In these cases, immediate medical treatment is required.
Prevention
The prevention of intracranial aneurysms involves controlling risk factors, especially in older people and those with a family history of the disease. Among them, special care should be taken with cardiovascular risk factors and diseases that can weaken blood vessels, such as diabetes, hypercholesterolemia, and atherosclerosis. Additionally, a healthy lifestyle should be maintained, avoiding stress and the consumption of tobacco and alcohol.
Number of observed variants
13.5 million variants
Number of risk loci
16 loci
Genes analyzed
Bibliography
Bakker MK, van der Spek RAA, van Rheenen W, et al. Genome-wide association study of intracranial aneurysms identifies 17 risk loci and genetic overlap with clinical risk factors. Nature Genetics. 2020 Dec;52(12):1303-1313.
UK National Health Service (NHS) [March 2022]
Tawk RG, Hasan TF, D'Souza CE, Peel JB, Freeman WD. Diagnosis and Treatment of Unruptured Intracranial Aneurysms and Aneurysmal Subarachnoid Hemorrhage. Mayo Clin Proc. 2021 Jul;96(7):1970-2000.