From the Guidelines
The etiology of a Cerebrovascular Accident (CVA) or Stroke is primarily attributed to ischemic stroke, resulting from atherosclerosis, embolism, or small vessel disease, and hemorrhagic stroke, caused by ruptured blood vessels often due to uncontrolled hypertension, aneurysms, or amyloid angiopathy.
Etiology of Stroke
The etiology of stroke involves multiple factors that disrupt blood flow to the brain. Strokes are primarily caused by either blockage of blood vessels (ischemic stroke) or bleeding in the brain (hemorrhagic stroke).
- Ischemic strokes, accounting for about 87% of cases, result from:
- Atherosclerosis (plaque buildup in arteries) 1
- Embolism (blood clots traveling from elsewhere)
- Small vessel disease
- Hemorrhagic strokes occur due to:
- Ruptured blood vessels, often from uncontrolled hypertension
- Aneurysms
- Arteriovenous malformations
- Amyloid angiopathy
Risk Factors
Major risk factors for stroke include:
- Hypertension
- Diabetes
- Smoking
- Obesity
- High cholesterol
- Atrial fibrillation
- Family history Age is also significant, with risk doubling each decade after 55 1.
Prevention
Prevention focuses on controlling these modifiable risk factors through:
- Medication (antihypertensives, statins, anticoagulants when indicated)
- Lifestyle changes (smoking cessation, healthy diet, regular exercise)
- Treating underlying conditions like diabetes and atrial fibrillation Understanding these causes is crucial for effective prevention strategies and treatment approaches.
From the Research
Etiology of Cerebrovascular Accident (CVA) or Stroke
The etiology of a Cerebrovascular Accident (CVA) or Stroke is multifactorial, involving a combination of genetic, environmental, and vascular risk factors.
- Genetic causes contribute significantly to ischemic stroke genesis, especially in early-onset stroke 2.
- Specific hereditary factors, along with known modifiable determinants such as smoking, obesity, hypertension, cardiac diseases, and diabetes, play a role in the pathogenesis of cerebrovascular accidents 3.
- Ischemic stroke is a complex and multifactorial disease caused by the combination of vascular risk factors, environment, and genetic factors 4.
Risk Factors and Causes
- Hypertension is the most important modifiable risk factor for stroke, although its contribution differs for different subtypes 5.
- Most (85%) strokes are ischemic, predominantly caused by small vessel arteriolosclerosis, cardioembolism, and large artery athero-thromboembolism 5.
- Approximately 15% of strokes worldwide are the result of intracerebral hemorrhage, which can be deep (basal ganglia, brainstem), cerebellar, or lobar 5.
- Ischemic strokes in younger patients can result from a different spectrum of causes such as extracranial dissection 5.
Genetic Contribution
- Genetic risk scores (GRS) and extended polygenic risk scores (PRS) estimate the cumulative contribution of known genetic factors to a specific outcome of stroke 2.
- Polygenic disorders are more frequent, causing about 38% of all ischemic strokes, and their identification is a rapidly developing field of modern stroke genetics 2.
- Monogenic disorders, despite covering only about 7% of stroke etiology, may cause well-known clinical manifestations that include stroke 2.