Commonest cause of cerebral infarction?

Appeared in: TMC Staff Nurse - 2019

Explanation

Cerebral infarction is tissue death in the brain caused by a lack of oxygen due to interrupted blood supply (ischemia).
The most common cause is an arterial thrombus, which is a blood clot that forms directly within a cerebral artery.
This process, known as thrombosis, is most often a complication of atherosclerosis, where fatty plaques build up in the arteries.
When a plaque ruptures, it triggers the clotting cascade, forming a thrombus that can grow to block the entire vessel, leading to an ischemic stroke.

Option A: While embolism is a major cause of cerebral infarction, it is generally considered the second most common cause after in-situ arterial thrombosis.
Option B: A venous thrombus forms in the brain's venous system (cerebral venous sinus thrombosis), which is a much rarer cause of stroke compared to arterial occlusion.
Option C: An aneurysm is a bulge in an artery wall. Its primary danger is rupture, which causes a hemorrhagic stroke (bleeding into the brain), not a cerebral infarction (which is ischemic).

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Etiology of Cerebral Infarction as background academic context rather than a clinical decision trigger.
Recognizing that arterial thrombosis from atherosclerosis is the leading cause of stroke underscores the importance of primary prevention in nursing.
Nursing interventions focus on patient education and management of modifiable risk factors: hypertension, hyperlipidemia, diabetes, and smoking.
During a stroke alert (Code CVA), nurses must rapidly assess the patient and determine the time of symptom onset, as this is critical for deciding eligibility for thrombolytic therapy (e.g., alteplase), which dissolves clots.

How to Approach the Question

First, understand the term 'cerebral infarction,' which means ischemic stroke or death of brain tissue due to lack of blood.
Next, analyze the options, which are all related to vascular problems. The question asks for the 'commonest' cause.
Differentiate between a 'thrombus' (a clot formed at the site) and an 'embolus' (a clot that travels from elsewhere).
Recall or deduce the underlying pathology. Atherosclerosis is the most common vascular disease, and it leads to local clot formation (thrombosis) in arteries.
Eliminate 'Aneurysm' as it primarily causes hemorrhagic (bleeding) stroke, not ischemic infarction.
Eliminate 'Venous thrombus' as arterial blockages are far more common causes of stroke than venous blockages.

Concept Tested & Keywords

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E6 PATHOLOGY QUICK REVIEWBased on Harsh Mohan Textbook of PATHOLOGY p. 52-54

E6 Pathology-Textbook of PATHOLOGYHarsh Mohan Part 1 (1-214) p. 205-207

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