Stroke secondary to carotid stenosis

Injury	Disease	Nutrition	Poison

Symptoms	Surgery	Test	Special Topic

Carotid stenosis, X-ray of the left artery

Carotid stenosis, X-ray of the right artery

Arteries of the brain

Stroke secondary to carotid stenosis

Definition:

Stroke secondary to carotid stenosis is a group of brain disorders involving loss of brain function due to the obstruction of blood flow to the brain. This is usually related to hardening of the arteries (atherosclerosis).

Causes, incidence, and risk factors:

Stroke secondary to carotid stenosis occurs when a major portion of one or both carotid arteries (the arteries in the neck that supply blood to the brain) is narrowed or blocked.

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In atherosclerosis (hardening of the arteries), fatty deposits occur in the inner lining of the arteries, and atherosclerotic plaque (a mass of fatty deposits and blood platelets) develops. The plaque itself may obstruct the artery, or a clot (thrombus) may occur at the site of the plaque and cause obstruction. Blockage of the artery usually develops slowly. However, a piece of atherosclerotic plaque (an embolism) may break off and travel to an artery in the brain, causing obstruction far from the site of the plaque.

Atherosclerotic plaque does not always lead to stroke. There are many small blood vessels around the carotid arteries. If blood flow gradually decreases, these small connections will increase in size and by-pass the obstructed area (collateral circulation). If there is enough collateral circulation, even a totally blocked artery may not cause neurologic deficits.

Stroke secondary to carotid stenosis is most common in older people, and often, there is underlying atherosclerotic heart disease or diabetes mellitus.

Risks are the same as for stroke secondary to atherosclerosis. Radiation therapy to the area may also cause carotid stenosis.