From the Guidelines
Cerebral aneurysms are primarily caused by a combination of genetic factors, acquired conditions, and lifestyle factors that weaken blood vessel walls, with hypertension, smoking, and heavy alcohol use being independent risk factors, as supported by the most recent evidence 1. The causes of cerebral aneurysms can be broken down into several key categories, including:
- Genetic factors, such as autosomal dominant polycystic kidney disease (ADPKD), which has an increased prevalence of aneurysms between 10% and 11.5% 1
- Acquired conditions, such as hypertension, atherosclerosis, and traumatic brain injuries
- Lifestyle factors, including smoking, excessive alcohol consumption, and drug abuse, particularly cocaine, which can cause sudden increases in blood pressure that damage vessel walls 1
- Other conditions, such as moyamoya, aortic dissection, bicuspid aortic valve, aortic aneurysm, and coarctation of the aorta, which also increase the risk of cerebral aneurysm 1 It is essential to note that the risk of aneurysm occurrence is higher in families with a history of hypertension, smoking, and female sex, and screening has been shown to be cost-effective in several studies, particularly in patients with ADPKD and a first-degree relative with a history of aneurysm 1. The fundamental mechanism of aneurysm formation involves progressive weakening of the arterial wall, causing it to balloon outward under the pressure of blood flow, creating a risk of rupture and potentially life-threatening bleeding in the brain. Key risk factors for cerebral aneurysms include:
- Hypertension
- Smoking
- Heavy alcohol use
- Family history of aneurysms or subarachnoid hemorrhage
- Certain genetic disorders, such as ADPKD and Ehlers-Danlos syndrome
- Traumatic brain injuries
- Age, with most aneurysms developing in people over 40
- Infections of the arterial wall (mycotic aneurysms)
- Drug abuse, particularly cocaine.
From the Research
Causes of Cerebral Aneurysms
The causes of cerebral aneurysms are multifactorial and can be attributed to various factors, including:
- Chronic inflammation
- Hemodynamic stress
- Vascular wall remodeling
- Reactive oxygen species
- Endothelial dysfunction
- Hypertension
- Genetic predisposition
- Diet-related factors
- Atherosclerotic factors
Risk Factors
Some of the risk factors associated with cerebral aneurysms include:
- Age
- Hypertension 2, 3, 4
- Smoking 5, 4
- Alcohol consumption 6, 5
- Diabetes mellitus 3
- Dyslipidemia 3
- Family history of aneurysms
- Genetic conditions such as Marfan's syndrome, polycystic kidney disease, and neurofibromatosis 5
Genetic Associations
Genetic associations have been found to play a role in the formation and rupture of cerebral aneurysms, with certain genes such as 9p21/CDKN2, EDNRA, and SOX17 being implicated 5.
Diet-Related Factors
Diet-related factors, such as inadequate intake of dietary antioxidants, hyperhomocysteinemia, and high alcohol consumption, may increase the risk of intracranial aneurysms 6.
Atherosclerotic Factors
Atherosclerotic factors, such as hypertension and smoking, may also contribute to the formation of cerebral aneurysms, particularly in certain locations such as the middle cerebral artery 3.
Histopathological Changes
Histopathological studies have shown that mucoid deposits and dystrophic changes in the internal elastic lamina may predispose vessels to structural weakness and aneurysm formation 4.