What is a Thrombotic Stroke?

Illustration of the cause of a transient ischemic attack
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A thrombotic stroke, a type of ischemic stroke, occurs when a blood clot, also called a thrombus, forms in an artery supplying blood to the brain. The blood clot blocks the flow of oxygen-rich blood to a portion of the brain.

A thrombotic stroke may also be called a cerebral thrombosis or a cerebral infarction.

Thrombotic strokes are further divided into two categories that correlate to the area of the blockage within the brain – large-vessel thrombosis and small-vessel thrombosis.

Causes of a Thrombotic Stroke

There are several causes of thrombotic stroke

  • Atherosclerosis or narrowing of the blood vessels

A thrombotic stroke is most commonly caused by the narrowing or disease of the arteries in the head or neck. Most often caused by atherosclerosis, the arteries become narrowed and irregular, resulting in the collection of cholesterol, fat, debris and blood cells which form a blood clot. Atherosclerosis and narrowing of the blood vessels in the brain is often referred to as cerebrovascular disease.

  • High blood pressure

Persistently high blood pressure, also called hypertension, may cause disease and narrowing of the blood vessels, predisposing to thrombotic strokes. Hypertension and atherosclerosis are often conditions that occur together, which causes even further damage to the blood vessels.

  • Recreational drugs

Certain drugs, such as cocaine, methamphetamine and performance enhancing drugs can cause the slow development of cerebrovascular disease.

These drugs may also cause sudden narrowing and or 'spasm' of the blood vessels, abruptly closing off blood flow to an area of the brain for a brief period of time.

  • Trauma to the blood vessels of the neck 
  • Blood clotting disorders

Risk Factors for a Thrombotic Stroke

An ischemic stroke is the most common type of stroke.

People with high cholesterol levels and atherosclerosis are at high risk for developing a thrombotic stroke. Other conditions that may place you at a higher risk for stroke include hypertension, heart disease, smoking, diabetes, a previous stroke or “mini-stroke” .

A thrombotic stroke may be preceded by a series of one or more transient ischemic attacks, also known as “mini-strokes” or TIAs. A TIA may last for a few minutes or hours and is often a sign of an impending stroke. The symptoms of a TIA are similar to those of a stroke.

Types of Thrombotic Stroke

There are two types of blood clots that cause a thrombotic stroke. They include large vessel disease and small vessel disease.               

Large Vessel Thrombosis

Large vessel thrombosis is the most common cause of thrombotic stroke and occurs in the larger blood-supplying arteries of the brain, such as the carotid artery or middle cerebral artery. Most large vessel thrombosis are caused by long-term atherosclerosis combined with the formation of blood clots. Smoking and high cholesterol are among the major risk factors for large vessel disease.

Small Vessel Thrombosis

This type of thrombotic stroke occurs when blood flow is blocked to a smaller, yet deeper penetrating arterial vessel.

This type of stroke, also known as a lacunar stroke, most often occurs as a result of smoking and/or hypertension.

Symptoms of a Thrombotic Stroke

It is important for you to be able to recognize the symptoms of a stroke or a TIA. A simple way to learn the symptoms of a stroke can be summarized by the phrase "Think FAST”

  • Face Can you smile? Does one side of your face droop?
  • Arms –Can you raise both arms? Does one of your arms drift downward or are you unable to raise either one of you arms?
  • Speech – Are you able to speak? Is your speech slurred? This test also applies if you think someone else could be having a stroke.
  • Time –Seek immediate medical attention if you observe any of these signs.

Don’t wait for the symptoms to disappear. The sooner a stroke is treated, the less the complications of brain damage and disability result.

More symptoms of a thrombotic stroke include:

  • Trouble understanding or speaking
  • Numbness of the arm, face or leg
  • Blurred or blackened vision in one or both eyes
  • Double vision
  • Sudden, severe headache
  • Vomiting
  • Dizziness
  • Difficulty walking
  • Loss of balance or coordination

A Word From Verywell

While certain risk factors as age, gender, heredity and ethnicity are uncontrollable, if you have risk factors for a stroke, you can reduce your risk of stroke by beginning treatment that controls your risk factors and adjusts your lifestyle choices.

Ways to control risk factors for a stroke include:

  • Quitting smoking
  • Losing weight
  • Increasing physical activity
  • Reducing alcohol intake
  • Eliminating illegal drug usage


Acute Cerebral Venous Thrombosis: Three-Dimensional Visualization and Quantification of Hemodynamic Alterations Using 4-Dimensional Flow Magnetic Resonance Imaging, Schuchardt F, Hennemuth A, Schroeder L, Meckel S, Markl M, Wehrum T Harloff A, Stroke. 2017 Feb 8