Middle Cerebral Artery Stroke

A stroke is brain damage that occurs as a result of an interruption in blood supply to a portion of the brain. This happens because of either blockage of a blood vessel or bleeding of a blood vessel in the brain. A stroke is usually labeled either by the injured part of the brain or by the blocked blood vessel. A middle cerebral artery (MCA) stroke is one of the most widely recognized large vessel strokes.

Where are the Middle Cerebral Arteries?

There are two middle cerebral arteries- the right middle cerebral artery and the left middle cerebral artery. The right and left middle cerebral arteries are two vital blood vessels that branch off from the right and left internal carotid artery.

Each internal carotid artery is a branch of either the right or left common carotid artery, large blood vessels located on each side of the neck. The right and left common carotid arteries are normally mirror images of each other, and each common carotid artery divides into an external carotid artery and an internal carotid artery. Then, within the skill, the internal carotid artery further divides into several arteries that supply blood to the brain, the largest of which is the middle cerebral artery.

The left and right middle cerebral arteries each supply a significant portion of the brain with oxygen-rich and nutrient rich blood.

What does the Middle Cerebral Artery do?

Arteries in the brain carry blood to deliver oxygen and nutrients to the brain. The different arteries are structured like pipelines that travel to different regions of the brain. Each artery supplies a different section of the brain. A section of the brain that receives blood from a particular artery it is referred to as the 'territory' of that artery.

The middle cerebral arteries supply a large territory in the brain which includes the temporal lobe, the parietal lobe, the internal capsule, the thalamus and a portion of the frontal lobe. Therefore, if blood flow in the middle cerebral artery is impaired, the jobs that are normally carried out by these areas of the brain become compromised.

What is a Middle Cerebral Artery Stroke?

A middle cerebral artery stroke is an interruption of blood flow to the areas of the brain that receive blood through the middle cerebral artery. These regions include the parietal lobe, the temporal lobe and the internal capsule and thalamus.

If the whole entire middle cerebral artery is blocked, then that is a large vessel stroke that affects the whole entire middle cerebral artery territory- which is every region of the brain that receives blood through the middle cerebral artery. A middle cerebral artery stroke causes a language deficit, weakness on the opposite side of the body, a sensory deficit on the opposite side of the body and vision defects.

If a small branch of the middle cerebral artery is blocked, then a small vessel stroke results, impacting a small section of the middle cerebral artery territory.

This is often less serious.

Why Does a Middle Cerebral Artery Stroke Occur?

A middle cerebral artery is a large vessel stroke. Large vessel strokes are generally embolic as opposed to thrombotic. This means that usually a middle cerebral artery stroke is caused by a blood clot that traveled from elsewhere in the body, typically from the heart or from the carotid artery, and lodged in the middle cerebral artery, blocking blood flow.


Because a middle cerebral artery stroke is usually a large stroke, the short-term situation must be handled with the utmost care. Long-term recovery and rehabilitation may take months or even years.

However, even very serious strokes can result in good recovery.


Right-side propensity of cardiogenic emboli in acute ischemic stroke with atrial fibrillation, Park KY, Kim YB, Chung PW, Moon HS, Suh BC, Yoon KJ, Lee YT, Scandanavian Cardiovascular Journal, December 2014

Mechanisms of acute cerebral infarctions in patients with middle cerebral artery stenosis: a diffusion-weighted imaging and microemboli monitoring study, Wong KS, Gao S, Chan YL, Hansberg T, Lam WW, Droste DW, Kay R, Ringelstein EB, Annals of Neurology, July 2002

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