Most people are surprised to hear that children can have strokes. They can, at any age, from before birth through the teenage years. This page explains what paediatric stroke is, what the underlying causes can be (including a particular condition called moyamoya), how it is diagnosed, and what the treatment can do. Your child's neurology and neurosurgery team will discuss what applies specifically to your child.
A stroke happens when part of the brain suddenly loses its blood supply. There are two main ways this can happen. An ischaemic stroke is when an artery to the brain is blocked, usually by a clot, and the brain tissue beyond the block does not receive enough oxygen. A haemorrhagic stroke is when a blood vessel in the brain bursts and bleeds into the surrounding tissue. Both can cause sudden, dramatic symptoms.
Paediatric stroke is not just "adult stroke in a smaller body". The causes are very different. The most common reasons for a child to have a stroke include congenital heart disease, sickle cell disease, narrowing of brain arteries (such as moyamoya, described below), abnormal blood vessels in the brain (such as arteriovenous malformations or cavernous malformations), trauma to the neck arteries, infections, or inherited problems with blood clotting. In some children, no clear cause is ever found, even after thorough investigation.
Moyamoya deserves a particular mention because it is a condition in which neurosurgery can directly prevent future strokes. In moyamoya, the large arteries at the base of the brain become slowly and progressively narrower. As they narrow, tiny new vessels grow to try to compensate. On a particular imaging study, these new vessels look like a puff of smoke, and "moyamoya" is the Japanese phrase for a puff of smoke. Children with moyamoya often have repeated mini-strokes (called transient ischaemic attacks, or TIAs) before a larger stroke. Moyamoya can occur on its own or together with another condition (most commonly sickle cell disease, neurofibromatosis type 1, Down syndrome, or after radiation to the head).
Arteriovenous malformations (AVMs) are another important cause, tangles of abnormal blood vessels that can bleed and cause a haemorrhagic stroke. Cavernous malformations and aneurysms are rarer but possible. Your child's team will tell you which of these applies to your child.
The most important thing parents and caregivers can know is how to recognise a stroke, because every minute matters. The simple word "FAST" is used worldwide as a memory aid for the main signs - Face (sudden drooping on one side), Arm (sudden weakness in one arm or leg), Speech (sudden difficulty speaking, slurred speech, or difficulty understanding), Time (call for emergency help right away). In children, you may also see specific patterns:
Paediatric stroke is a medical emergency. In the emergency department, the first task is to find out which type of stroke it is and what is causing it. A CT-scan is often the first test because it is fast and can show bleeding clearly. An MRI of the brain is then performed, sometimes immediately, sometimes after the child is stable, because the MRI shows the stroke itself far better than CT.
Once a stroke is confirmed, attention turns to the blood vessels. An MR angiogram (MRA) uses MRI to show the brain's arteries. Sometimes a CT angiogram (CTA) is used instead. For more detailed views, particularly when moyamoya, an AVM, or an aneurysm is suspected, a conventional cerebral angiogram is performed. This involves passing a thin tube (catheter) into an artery, usually through the groin, and taking detailed pictures of every vessel feeding the brain. It is the most detailed test of all and gives the surgical team the information needed to plan treatment.
Other tests look for the cause. An echocardiogram (an ultrasound of the heart) checks for heart problems that can throw clots up to the brain. Blood tests look for clotting disorders, sickle cell disease, and certain infections. A neck ultrasound or scan may be performed to assess for injury to the neck arteries. Depending on the picture, genetic testing or other specialist studies may also be performed.
A neurological examination is repeated frequently in the early days because the picture can change quickly. The team uses standard scales to measure the impact of the stroke on your child.
Treatment of paediatric stroke has two parts, the care of the brain in the acute phase, and the treatment of the underlying cause to prevent another stroke. The right plan depends entirely on the type of stroke and the cause.
For children with moyamoya, day-to-day precautions also matter, avoiding dehydration, avoiding situations that cause fast deep breathing (such as blowing up balloons, or crying for long periods where this can be prevented), and seeking quick medical attention for any new neurological symptoms. The team will give you a specific plan for your child.
Recovery from a paediatric stroke depends very much on the size and the location of the stroke, on how quickly treatment was started, and on the underlying cause. The first few weeks in hospital focus on protecting the brain, treating the cause, and beginning rehabilitation. Many children show small but real improvements in the first days, others take weeks or months to begin to recover.
The brains of children have a remarkable ability to adapt, the medical word for it is plasticity. Functions affected by a stroke can sometimes be taken over by other parts of the brain, particularly in younger children. This is the reason that recoveries from paediatric stroke are often better than adult recoveries from a similar injury. The plasticity is not unlimited, however, large strokes or strokes in critical areas leave lasting differences, and the recovery is usually a slow process.
Specialists you and your child may work with over the coming months and years include paediatric neurology, neurosurgery, haematology (for sickle cell or clotting disorders), cardiology (for heart-related causes), physiotherapy, occupational therapy, speech-language therapy, neuropsychology, ophthalmology, and orthopaedics. A coordinator or a case manager often helps make sense of all the appointments.
School matters a great deal. Many children return to mainstream school with adjustments, extra time, support for one-sided weakness, breaks for fatigue, or specific learning support. A formal neuropsychological assessment is often performed some months after the stroke to map out exactly which abilities have been affected and to plan school support around them.
For children with moyamoya who have undergone revascularisation surgery, follow-up usually includes regular clinical reviews and imaging (MRI/MRA, and sometimes a repeat angiogram) to confirm that the new blood supply is functioning. Most children with a successful revascularisation go on to live full lives with very low risk of further strokes.
The emotional toll on the family is real and is not separate from the medical care. Family support groups, mental health support, and connection with other families who have travelled this path are part of the picture, not extras.
After a stroke or after stroke surgery, certain signs can mean that another stroke is happening, that a TIA is occurring, or that a complication has developed. Do not wait, call the emergency services or go to the nearest emergency department right away if you notice any of the following:
If your child is unconscious, is having a seizure, or is having difficulty breathing, this is an emergency, call the emergency services immediately. For any stroke symptom, time matters, the faster the team sees your child, the more they can do.