Photo of stroke survivor Sebastian and his brother.

About childhood and perinatal stroke

The term ‘childhood stroke’ covers stroke occurring from 29 days old up to the age of 18.

The term ‘perinatal stroke’ covers stroke from week 20 of pregnancy until 28 days after birth.

Several hundred children a year have stroke in the UK.

Causes and effects of stroke in babies and children

The causes and the effects of a stroke are likely to be different depending on how old the child is.

The causes of stroke in children are very different from those in adults. These webpages explain the causes, treatment and impact of stroke on children and families, and list sources of help and support.

It's important to know that for some children there may not be a clear cause of stroke, or it may take a long time to be determined.

On these pages, you can find information about the different types of childhood stroke and their causes. You can also find out about common symptoms of stroke in children and babies.

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A stroke happens when the blood supply to part of the brain is cut off, killing brain cells. Damage to the brain can affect how the body works. It can also change how you think and feel.

There are two main types of stroke. Ischaemic strokes are due to a blocked blood vessel in the brain. Haemorrhagic strokes are due to bleeding in or around the brain. In children, both types of stroke are rare and they occur in similar numbers.

Children can also have transient ischaemic attacks (also known as TIA or mini-stroke). A TIA is the same as a stroke, except that the symptoms last for a short amount of time. In a TIA, a blood vessel in the brain gets blocked, but the blockage clears by itself. TIA is a major warning sign for stroke and should always be taken seriously.

Although it's very rare, babies can have a stroke in the womb or just after birth. Find out more about perinatal stroke, which is the name for stroke in a baby from week 20 of pregnancy until 28 days after birth.

Ischaemic strokes are caused by a blockage in the blood supply to the brain. Strokes can happen for different reasons in children than they do in adults. For children, stroke due to a clot can happen for a number of reasons.

Strokes in children from 29 days to 18 years old are often associated with existing conditions, most commonly congenital heart disease and sickle cell disease. Other risk factors include infectious diseases, trauma to the head or neck, vascular problems and blood disorders. See the ‘Risk Factors’ section below for more information.

Strokes can also affect previously healthy children and in around 1 in 10 cases, there is no identified cause.

There are several different conditions that can make children more likely to have an ischaemic stroke. These fall mainly into four categories:

  • Heart disorders.
  • Blood disorders.
  • Infections.
  • Vascular disorders.

Heart Disorders

Heart disorders increase the risk of ischaemic strokes in children. Some children are born with a heart problem, known as congenital heart disease, and heart problems that develop in childhood are known as acquired heart disease. Sometimes a heart disorder is only diagnosed after a stroke.

Heart Surgery and Stroke

If a child has surgery for a heart condition, this can raise the risk of a stroke. But the outcome of any serious operation depends on the individual child and their unique health needs. If your child needs heart surgery, the doctor should explain the likely risks and benefits of the operation. If your child had a stroke after heart surgery, your medical team can help you understand why this happened. They can also support you and your child with recovery.

Blood Disorders

Sickle Cell Disease (SCD)

Sickle cell disease is an inherited condition affecting red blood cells. These are the blood cells that carry oxygen around your body. In sickle cell disease, some red blood cells change shape from round to a narrow sickle (half-moon) shape. The damaged cells are less able to carry oxygen around the body. They can also block blood vessels and cause clots in the brain. SCD can also lead to a bleed in the brain, but this is rare in children under 18 years old.

'Silent' strokes can also affect children with SCD. This sort of stroke may not have obvious physical signs but can be picked up on an MRI sign. Silent stroke can cause cognitive problems such as with thinking and learning, and an increased risk of another stroke.

SCD is most common among Black Caribbean, Black African, and Black British people, but cases can also occur in people with heritage from the Middle East, parts of India, the eastern Mediterranean, and South and Central America. It affects boys and girls alike.

Blood Clotting Disorders

Some types of rare blood clotting disorders make it more likely for clots to form, raising the risk of a stroke. Sometimes known as 'sticky blood' disorders, they may be diagnosed after a stroke.

Infections

Chickenpox is linked to an increased risk of childhood stroke for around six months after the infection. Although chickenpox is a very common childhood illness in the UK, stroke is an extremely rare complication. Other serious infections affecting the brain and other organs may cause a stroke, such as bacterial meningitis, encephalitis, and sepsis.

Vascular Disorders

Vascular disorders are problems with blood vessels in the body that can affect blood flow. In children, vascular problems can be caused by injury, inflammation, or the blood vessels developing abnormally (malformation). The type of vascular problems leading to stroke in adults tends to be changes due to age and fatty deposits accumulating in the arteries, which do not affect children in the same way.

Arterial Dissection

A cervical arterial dissection happens when a tear develops in the lining of one of the large arteries in the neck. A clot can form and block the artery, which can cause a stroke.

It can happen after an injury or an activity like sport. It can also be related to an infection or a health condition such as Ehlers-Danlos syndrome and Marfan syndrome. A spontaneous dissection can have no apparent cause.

An arterial dissection does not always have symptoms. However, it can cause headaches, pain in the face or neck, and also stroke symptoms if it leads to a stroke. It’s important to get immediate medical help if you suspect a dissection or a stroke.

Moyamoya Syndrome

In Moyamoya syndrome, the main arteries in the brain become narrowed. To compensate for the reduced blood flow in the main vessels, a network of small blood vessels grows inside the brain. Moyamoya means ‘puff of smoke’ in Japanese, referring to the appearance of the abnormal blood vessels in the brain scan image.

It does not always have symptoms, but it can cause headaches, slurred speech, and weakness on one side of the body. It can lead to strokes and TIA in some children. Moyamoya syndrome has been found in children with sickle cell disease, Down syndrome, and neurofibromatosis. It sometimes occurs in otherwise healthy children when it is known as Moyamoya disease.

It is very rare, with around one in a million people in the UK affected. It is more common among people from Japan and some other East Asian countries, and there are certain genes associated with predisposition towards Moyamoya.

Vasculitis

Vasculitis is a rare condition in which the blood vessels inside the brain become inflamed (known as central nervous system vasculitis), which can lead to a stroke or TIA in children.

Cerebral Venous Thrombosis (CVST)

Large veins drain the blood away from the brain through spaces under the brain known as the venous sinuses. If a clot (thrombosis) develops in this space, it can cause symptoms such as headaches, seizures, and blurred vision. It is known as a cerebral venous sinus thrombosis (CVST). It can be due to conditions including blood-clotting disorders, infections, and congenital heart disease.

Inherited Metabolic Disorders

Some inherited metabolic disorders have been linked to an increased risk of ischaemic stroke and also metabolic stroke. In metabolic stroke, a child may experience stroke-like episodes but without a clot or bleed in the brain.

Up to 50% of strokes in children are hemorrhagic. They can be due to problems with the blood vessels in the brain and other conditions.

Arteriovenous Malformation (AVM)

In an AVM, the blood vessels carrying blood to and from the brain grow together in a cluster, often in the brain or spine. An AVM can reduce the blood flow in the brain, and compress the surrounding brain tissue. The blood flow can be diverted from arteries into veins, damaging the veins and sometimes causing bleeding.

Aneurysm

An aneurysm is a weakness in an artery wall which can sometimes burst, causing bleeding in the brain. In children, this can happen for several reasons including head injury, connective tissue disorders, and heart conditions. Sometimes it may not be possible to find a cause.

Cavernous Malformation or Cavernoma

A cavernous malformation is a small cluster of abnormal blood vessels in the brain, often said to look like a raspberry. It is made up of a series of connected ‘bubbles’, or caverns, filled with blood. Often these do not cause any symptoms unless the structure is pressing on the surrounding brain tissues. But if the walls of the caverns are weak, blood can leak out or a large bleed can happen. Symptoms of a cavernoma or a bleed can include seizures, headaches, and slurred speech. Those with multiple cavernous malformations may have an underlying genetic predisposition, so other family members may need to be screened.

Other Disorders

Some of the disorders that have already been mentioned - including Moyamoya syndrome, some types of vasculitis, sickle cell disease, and clotting disorders - are also known risk factors for hemorrhagic stroke in children. Deficiency of Adenosine Deaminase 2 (DADA2), an extremely rare genetic disorder, has also been linked to an increased risk of hemorrhagic and ischemic stroke.

It's important to remember that stroke symptoms that last a short amount of time can be a transient ischaemic attack (TIA or mini-stroke). In a TIA, a blood vessel in the brain gets blocked, but the blockage clears by itself. A TIA is a major warning sign of a stroke, and you should call 999.

It is important to know the warning signs of another stroke. The FAST test can be used to help identify strokes in children.

  • Face: Can the young person smile? Has their face fallen on one side?
  • Arms: Can they raise both arms and keep them there?
  • Speech: Can they speak clearly and understand what you say? Is their speech slurred?
  • Time: If you see any one of these three signs, it’s time to call 999.

However, children and young people may have other stroke symptoms, including:

  • Sudden, severe headache.
  • Seizures (fits).
  • New and sudden vertigo, dizziness, or confusion.
  • Problems with walking or balance.
  • Nausea/vomiting, drowsiness, or loss of consciousness.
  • Sudden blurred vision or loss of sight in both eyes.
  • Weakness or numbness on one side of the body.
  • Changes in sensation, like pins and needles in arms or legs.

For information on signs of stroke in babies up to 28 days old, see our Perinatal Stroke webpage.

It is important to remember that stroke symptoms that last a short amount of time can be a transient ischaemic attack (TIA or mini-stroke). A TIA is a major warning sign of a stroke, and you should call 999.

Find out more

For more information, please visit these pages:

Diagnosing and treating childhood stroke
How will my child recover?
Returning to school after stroke
Useful tips for you and your family