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Childhood Stroke: Cerebral Sinovenous Thrombosis (CSVT)

What is a stroke?

Arteries and veins are called blood vessels. They carry blood, oxygen, and nutrients to all the tissues in the body, including the brain. Blood is pushed through the blood vessels by your heartbeat.

A stroke is a sudden blockage or damage in the blood vessels in part of the brain. This stops blood from flowing to that part of the brain, and as a result, less oxygen and other nutrients can get to that part of the brain. This can cause some permanent damage and stop it from working properly.

This page explains some of the possible causes of stroke in children, what test may be used when a stroke is suspected, and available treatment options. The warning signs of stroke are also discussed.

A stroke can happen to anyone at any age. Strokes happen in babies, children, and teenagers as well as in adults and seniors. There are many reasons why a child might have a stroke that may be different from why adults have stroke.

Finding the cause of the stroke is important, for these reasons:

  • It helps decide what kind of treatment is best.
  • It may help prevent more damage.
  • It may stop your child from having another stroke in the future.

Even after many tests, sometimes it is not possible to find out the exact cause of a stroke.

A blood clot is the most common cause of stroke in children

A blood clot or clotting occurs when blood changes from liquid to solid form. A certain amount of blood clotting in the body is normal. However, a blood clot that gets stuck in veins or the brain is not normal. If this happens in the brain, it can cause a stroke.

A stroke caused by a blood clot is called an ischemic (say: iss-KEE-mik) stroke.

Blood vessels

Arteries and veins are both blood vessels in the body.

  • An artery carries blood from the heart to the body’s tissues, including the brain.
  • A vein carries blood from the body’s tissues back to the heart.

Because there are two kinds of blood vessels, there are 2 kinds of ischemic strokes:

  • A stroke caused by a blood clot in an artery is called arterial ischemic stroke (AIS). Detailed information on AIS is available in another brochure.
  • A stroke or brain swelling caused by a blood clot in a vein is called cerebral sinovenous thrombosis (CSVT).

Cerebral sinovenous thrombosis (CSVT)

CSVT is a stroke caused by a blood clot in a vein.

Cerebral Sinovenous Thrombosis (CSVT)
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CSVT is when a blood clot is found in the sinovenous system of the brain.
Some of the warning signs of CSVT

Children, teenagers, and young adults who are having a stroke due to CSVT may gradually or suddenly show one or more of the following signs:

  • They slur their speech, cannot speak at all, or have trouble speaking and understanding simple statements.
  • They cannot see clearly in one or both eyes.
  • They experience confusion or become less conscious.
  • They have a new, severe headache, with or without vomiting (throwing up).
  • They find that their face, arm, or leg feels weak or numb, usually on one side of the body.

Babies who are having a stroke due to CSVT may only show the following signs:

  • They have seizures without a clear reason. Seizures may look like twitching of the face, arms or legs, or starring spells
  • They have extreme trouble staying awake and alert during the day outside of their normal sleeping time.

Possible causes of CSVT

Sometimes, CSVT occurs in otherwise healthy children. For other children, CSVT may be caused by another condition the child already has. Possible causes of CSVT include the following:

  • dehydration or not having enough fluid in the body
  • worsening head and neck infections
  • leukaemia and medicines that are used to treat leukaemia
  • blood clotting disorders
  • head trauma
  • iron deficiency anemia
  • taking birth control pills that contain estrogen, which are believed to increase the risk of stroke
  • other childhood diseases

Treating CSVT

The main goals in the treatment of CSVT are as follows:

  • Decrease the brain damage that the CSVT can cause.
  • Prevent the blood clot from getting bigger

Treatments may include medicines called blood thinners (anticoagulants).  These help stop the blood from forming more clots. Your child may receive one or more of the following blood thinners:

  • warfarin​ (Coumadin), given by mouth
  • heparin, given by intravenous
  • low molecular weight heparin (LMWH), given by injection under the skin

CSVT can happen again

The chance that a stroke will happen again depends on the following:

  • the cause of the stroke
  • treatment options
  • how well the treatment works

Common tests for childhood stroke

The doctor may order some or all of the following tests when a child has CSVT.

Some of these are routine tests. This means they are done on many children in the hospital for different reasons other than stroke. If you want to learn more about a certain test your child is having, ask your health care teamfor more detailed information.

Most of these tests will be done several different times, to see how well your child is doing over time.

Physical exam (neurological exam)

A neurological exam looks at how well your child’s brain is working. For example, how well the brain is sending messages to the body.


Blood tests help doctors better understand why your child had a stroke. If your child is taking blood thinners, tests will be done to find out how well they are working. Tests may show that the dose needs to be changed.

Computed tomography (CT) scan

Cerebral Sinovenous Thrombosis
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CT scan showing a venous clot at the back of the brain.
A CT scan takes detailed pictures of the area in the brain where that the stroke affected. This test may show whether or not a stroke has occurred. It may also show what kind of stroke happened, and which tissues it affected.

A CT venogram (CTV) will take a detailed look at the veins inside the brain.

Magnetic resonance imaging (MRI)

An MRI can show if a stroke occurred or not. It can also show when the stroke occurred and how serious it is. 

A magnetic resonance venogram (MRV) will take a closer look at the veins in the brain.

Lumbar puncture

This test looks for signs of infection or inflammation in your child’s nervous system. These conditions may have caused the stroke. A lumbar puncture is also called a spinal tap.

For more information

If you have any questions, please write them down so that your doctor or nurse can answer them for you:

Key points

  • Stroke can occur in people of all ages, including babies and children.
  • Stroke can happen for many different reasons.
  • Trying to find out the cause of stroke is important. It may help decide the best treatment.
  • Treatment of stroke may include blood thinners. Treatment focuses on decreasing damage and stopping further strokes.

For more information about different types of stroke in children or babies, see "Stroke in Newborns" and "Childhood Stroke: Arterial Ischemic Stroke."

Ivanna Yau, RN, MN, ACNP

Gabrielle deVeber, MD, FRCPC