Middle Cerebral Artery Stroke Causes, Symptoms, and Treatment

A middle cerebral artery (MCA) stroke occurs when blood flow from the largest artery of the brain is suddenly interrupted (ischemia) or altogether stopped (infarction). The loss of blood flow causes tissue death, leading to serious and potentially permanent brain injury.

MCA strokes are most often the result of a blood clot that travels from outside the brain, such as from the heart or carotid artery, and causes a partial or complete blockage of the artery.

While an MCA stroke is serious, people suffering one are more likely to survive than someone with a hemorrhagic stroke, which is caused by a ruptured artery.

This article takes a closer look at the MCA as well as the symptoms and causes of MCA strokes. Is also explains how MCA strokes are diagnosed and treated and what to expect during rehabilitation.

What is the Middle Cerebral Artery?

The arteries in your brain come in symmetrical pairs. Each one has a left and right artery. The MCAs are vital blood vessels that branch off from the internal carotid arteries.

The internal carotid arteries are branches of the common carotid arteries. Those are large blood vessels in your neck.

The MCA is the largest branch of the internal carotid arteries. It can be involved in large strokes.

What Does the MCA Do?

Arteries in the brain carry blood that's rich in oxygen and nutrients to the brain. Each artery supplies a different section of the brain. That section is called the 'territory' of that artery.

The MCAs supply a large territory in the brain that includes the:

• Parietal lobe: Processes sensory information related to touch, taste, and temperature
• Temporal lobe: Processes audio and encodes memory
• Internal capsule: Aids communication between areas of the brain
• A portion of the frontal lobe: Important for movement, expressive language, and the ability to work toward a goal

When blood flow to these areas is impaired, they have a hard time doing their jobs.

MCA Stroke Symptoms

MCA strokes are the most common type. Their symptoms are the ones people usually associate with strokes, such as:

• Weakness and/or numbness on one side
• Facial droop
• Language deficits

An MCA stroke may also cause:

• Sensory deficits
• Visual defects

These affect the opposite side of the body from the artery. So a stroke in the right MCA causes symptoms on the left side of the body.

Causes

The MCA is a large blood vessel. Large-vessel strokes affect more of the brain than strokes in small vessels. If the MCA itself is blocked, the result is a large-vessel stroke that affects its entire territory.

If only a small branch of the MCA is blocked, it causes a small-vessel stroke. This impacts a small section of the MCA's territory and is often less serious.

MCA strokes are generally caused by a blood clot that travels from outside the brain. Typically, it's from the heart or carotid artery. Then the clot gets lodged in the MCA and blocks blood flow.

This is called an embolic stroke. When the clot originates in the arteries of the brain, it's called thrombotic.

Risk factors for MCA strokes include:

• Heart disease
• Carotid artery disease
• General stroke risk factors such as high cholesterol, hypertension, and diabetes

Diagnosis

MCA strokes are among the most easily recognized types of stroke.

Even so, your healthcare provider will likely use multiple labs and tests to confirm the diagnosis. These may include:

• A neurological exam to determine affected brain regions
• Electrocardiogram (EKG) to check electrical conduction of the heart, which may be irregular after a stroke
• Lumbar puncture (spinal tap) to check for hemorrhagic stroke (rupture of a weakened blood vessel)
• Blood tests to look for known risk factors, including clotting disorders, high cholesterol, and diabetes
• Computed tomography (CT) scan to quickly check for a brain bleed
• Magnetic resonance imaging (MRI) to find a blood vessel blockage

Other tests and imaging may be performed depending on your symptoms.

Treatment and Rehabilitation

Urgent treatment may include:

• Tissue plasminogen activator (TPA), a powerful blood thinner
• Other blood thinners
• Careful management of blood pressure, blood sugars, electrolytes, and fluids
• Surgery to remove pressure on vital brain regions

Rehabilitation after a stroke can be intensive and prolonged. It may involve physical, occupational, and speech therapy.

Summary

Blocks or ruptures in the MCA lead to MCA strokes. The resulting loss of blood, oxygen, and nutrients can cause brain damage and impair function in the regions that get blood from the MCA.

MCA strokes are often large unless only a branch of it is blocked, in which case they're smaller and less serious. Symptoms of MCA strokes are the ones most people associate with strokes and have to do with the regions affected.

MCA strokes are often caused by blood clots that travel from the heart or carotid artery. They're diagnosed using a neurological exam, blood tests, and imaging.

Treatment includes blood thinners, surgery to relieve pressure, and management of several vital signs. Recovery may involve multiple types of therapy, depending on the symptoms. Recovery from an MCA stroke may take some time, particularly if the entire MCA was blocked, resulting in a large stroke.

Long-term recovery and rehabilitation may take months or even years. However, a good recovery is possible even from very serious strokes. Most people who have an MCA stroke are able to regain some function.