Embolic Stroke

What causes an embolic stroke?

An embolism is a clot or clump of blood that forms inside one of your arteries (the main artery supplying oxygenated blood to all parts of your body). An embolism can form anywhere in the body. The most common location for an embolism is in the carotid artery, which supplies blood to your brain. Other locations include:

The aorta, which carries blood through your heart and lungs;

Your veins, where it enters the bloodstream; and/or

Other organs such as kidneys.

When the blood supply to any part of your body is interrupted, the clotting process slows down. When this happens, a clot forms within your vessel and blocks the flow of blood to other areas of your body. This blockage results in swelling and pain, usually in one or more vital organs. A small amount of blood still flows into these organs but they cannot function properly because their normal functions have been impaired.

How is an embolism diagnosed?

The symptoms of most embolism are related to the part of the body being deprived of oxygen or being in pain. Arterial emboli cause a rapidly spreading loss of functioning of various organs, while the symptoms of several deep-vein blood clots in the legs may include pain in the hip or knee and a swollen leg, usually on just one side.

Your doctor diagnoses embolism by taking your medical history and doing a physical examination. If you do not have the symptoms mentioned above, your doctor may still be suspicious that you are suffering from an embolism. In this case your doctor may order tests such as:

A chest x-ray or CT scan to check for clots in the lung arteries;

An echocardiogram to look at your heart; and/or

Magnetic resonance angiography (MRA), a test that uses magnetic waves to make detailed images of the inside of the body, typically the blood vessels.

What are the risk factors for embolic stroke?

Risk factors for embolic stroke are similar to those for heart attacks and other kinds of arterial disease. The most common risk factor is a history of atrial fibrillation (a kind of irregular heartbeat). Other risk factors include:

Smoking;

High blood pressure;

High cholesterol levels; and

Diabetes mellitus.

What are the symptoms of an embolic stroke?

The following are the most common symptoms of embolic strokes:

Sudden numbness or weakness of face, arm, or leg, especially on one side of the body;

Trouble speaking or understanding speech;

Trouble seeing in one or both eyes; and

Dizziness, loss of balance, fall.

Less common symptoms of an embolic stroke are:

Sudden confusion; and

Severe headache.

How is an embolic stroke treated?

Treatment of embolic strokes depends on the specific location and size of the clots. In some cases, anticoagulants such as heparin may be used to dissolve the clots over time. Carotid endarterectomy can be a surgical procedure to remove the clot if it is in an accessible area (usually in the neck or head).

What is the outcome for embolic stroke patients?

The outcome for embolic strokes is usually good if the patient receives rapid treatment. It is not uncommon for people who have had a stroke to have some permanent weakness or paralysis. They may also have a permanent speech difficulty or other long-term mild problems. This kind of damage is more likely the longer the period of interruption of blood to the brain, and the older the patient is.

Sources & references used in this article:

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Recombinant tissue plasminogen activator in acute thrombotic and embolic stroke by GJ Del Zoppo, K Poeck, MS Pessin… – Annals of …, 1992 – Wiley Online Library

Recent heavy drinking of alcohol and embolic stroke by M Hillbom, H Numminen, S Juvela – Stroke, 1999 – Am Heart Assoc

Rivaroxaban for stroke prevention after embolic stroke of undetermined source by RG Hart, M Sharma, H Mundl, SE Kasner… – … England Journal of …, 2018 – Mass Medical Soc

Aortogenic embolic stroke: a transesophageal echocardiographic approach. by K Toyoda, M Yasaka, S Nagata, T Yamaguchi – Stroke, 1992 – Am Heart Assoc

Thrombolytic therapy in experimental embolic stroke. by K Overgaard – Cerebrovascular and Brain Metabolism Reviews, 1994 – europepmc.org

Dabigatran for prevention of stroke after embolic stroke of undetermined source by HC Diener, RL Sacco, JD Easton… – … England Journal of …, 2019 – Mass Medical Soc