What is an arterial ischemic stroke?
An arterial ischemic stroke (AIS) is an injury to the brain or spinal cord caused by a lack of oxygen to the area affected. Usually AIS results from obstruction of blood flow by blood clots, narrowed or damaged arteries or both.
Children commonly recover from strokes more quickly and completely than adults, thanks to their young, healthy blood vessels and the ability of young brains to adapt following injury. Some strokes will have minimal or no long-term effect. Others, however, can cause problems, depending on the severity of the stroke, the part of the brain affected and how quickly it is treated. Complications can include weakness, sensory loss, visual difficulties and cognitive or language impairment.
What are the symptoms of an arterial ischemic stroke?
Symptoms of an arterial ischemic stroke typically start suddenly, and may affect just one side of the body. Newborns may show no noticeable symptoms, but some infants may have seizures or unusual irritability.
In older children, symptoms include:
- seizures, especially affecting one side of the body
- feeling weak or numb in the limbs, usually on one side the body or the face
- trouble walking because of weakness
- trouble speaking or understanding what others are saying
- severe headache, especially one accompanied by sleepiness, double vision or vomiting
- dizziness, loss of balance or falling
- vision problems in one or both eyes
If your child has any of these symptoms, don't wait - go directly to an emergency room.
What causes an arterial ischemic stroke?
Children's arteries can become obstructed for a number of reasons, which fall in two main groups.
Blood clots caused by:
- blood diseases, such as sickle cell anemia and clotting disorders
- congenital heart disease, leading to clots that travel to the brain
- serious infections
- metabolic disorders
- hypercoagulability, or abnormal blood clotting, around the time of birth (in newborns)
Damage to or abnormalities of the arteries, caused by:
- accidents causing trauma to the head and neck
- arterial dissection, a tear along the lining of an artery caused by trauma or medical conditions that weaken the artery's walls
- moyamoya disease
- cerebral arteritis or vasculitis
How we care for arterial ischemic stroke
Children who experience an arterial ischemic stroke should receive care from a multidisciplinary team of specialists, starting in the emergency room. At Boston Children's Hospital, our Stroke and Cerebrovascular Center team comes to the emergency department and quickly deliver clot-dissolving drugs to your child if appropriate. In some cases, we use tiny, catheter-based devices to break up or extract the clot physically. Our Cerebrovascular Surgery and Interventions Center has pioneered the use of these techniques in children. If the stroke was caused by injury or disease of the arteries themselves, we may be able to use a surgical or neurointerventional procedure to correct the condition. If the stroke is related to inflammation of the arteries in the brain, medical treatment to resolve vascular inflammation may be appropriate.
Once the immediate danger is past, our specialists provide long-term care, creating a comprehensive rehabilitation plan to help each child regain the best quality of life possible.
Arterial Ischemic Stroke | Diagnosis & Treatments
How is an arterial ischemic stroke diagnosed?
Evaluation of an arterial ischemic stroke usually begins in the emergency room. A team of specialists will conduct a rapid physical examination and will work to quickly confirm and locate the cause of the stroke through imaging tests. These can include:
All of these tests are painless and noninvasive, although some might require placement of an intravenous (IV) line to deliver agents needed for certain types of imaging. Since MRI requires a child to hold still inside a scanner, very young children may need sedation.
In addition to imaging, the care team may collect blood samples to look for a medical condition that may increase risk for blood clotting.
How is arterial ischemic stroke treated?
An arterial ischemic stroke is a medical emergency, and treatment usually starts in the emergency department. There, the care team will quickly determine whether clot-dissolving drugs such as tissue plasminogen activator (tPA) should be administered or thrombectomy performed.
In cases when drugs alone cannot successfully restore blood flow and the child faces potentially severe neurologic problems, physicians may use tiny, catheter-based devices to remove the clot mechanically. Guided by neuroimaging, these devices are specially designed to extract or suction out the clot from the inside.
Based on the results of blood testing, your child may require additional treatment for a clotting disorder or blood disease. For example, if the stroke was caused by arterial dissection (a tear along the lining of an artery), the team may begin anticoagulation therapy to prevent further thrombus formation at the site of the arterial dissection. Rarely, placement of a stent inside the vessel or performance of bypass surgery to reroute blood flow around the dissection may be advised. If the stroke was caused by moyamoya disease, which leads to thickened, narrowed vessels, an operation called pial synangiosis can decrease the risk of future strokes by providing a new blood supply to the oxygen-starved parts of the brain.
Stroke specialists will oversee your child's long-term care and provide referrals to physical or occupational therapists and speech/language therapists to improve functioning and quality of life.