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How does atherosclerosis in cerebral arteries lead to stroke?
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cardiovascular disease
This micrograph shows a cross section of a coronary artery narrowed by an atherosclerotic plaque (purplish matter inside the artery). Most heart attacks are caused by the rupture of an atherosclerotic plaque, which triggers the formation of a clot that abruptly blocks blood flow to part of the heart muscle.
Atherosclerosis leads to a stroke through two primary mechanisms involving the obstruction of blood flow to the brain:
- Chronic Occlusion: Over time, the accumulation of fatty plaquesâcomposed of cholesterol, cells, and debrisâgradually narrows the arterial lumen. When this narrowing becomes severe, it restricts the necessary blood supply to the brain, potentially leading to ischemia.12
- Acute Thrombotic Occlusion: This is a common cause of sudden, life-threatening strokes. It occurs when an existing atherosclerotic plaque ruptures. This rupture releases "proclotting" chemicals, such as tissue factor, which trigger the rapid formation of a blood clot (thrombus) directly at the site. Because this blockage happens suddenly, the body cannot compensate, resulting in irreversible tissue damage and loss of brain function.12
Additionally, mechanical instability in larger arteries can lead to the formation of clots that break off and travel downstream to occlude smaller cerebral vessels, further contributing to the risk of stroke.1