Stroke in children (Paediatric stroke) ~ Causes ~

(If you missed last week's post, you can find it here.)

Stroke can happen at any point in a person’s lifetime, from infancy and childhood to adulthood. A stroke is caused by the interruption of normal flow of blood to the brain, either by a blockage or a rupture in the blood vessels. When a part of the brain doesn't receive its regular flow of blood that carries vital nutrients and oxygen, brain cells die, causing a loss of brain function.

The age of the child at the time of stroke makes a difference in how doctors identify and treat the problem. Stroke can occur in these three different age groups: 

• The prenatal phase, or in the womb
• The first 28 days of life, or newborn phase
• The infant years up to 18 years of age 

Stroke is relatively more common in the first two age groups, occurring in up to one in every 4,000 live births. In the third age group, stroke is more rare, only affecting about five out of every 100,000 children each year in Canada.

The location in the brain the stroke takes place will determine the extent of the damage and the after-effects, if any.

Children may experience two types of stroke: hemorrhagic stroke (rupturing of blood vessels), or ischemic stroke (blockage caused by a blood clot).  

 ~The causes of stroke in children ~

The reasons why stroke occurs in children are varied and include malformations of the blood vessels and rare diseases. Here are the most common causes:

Hemorrhagic stroke occurs when a blood vessel ruptures in the brain. In children, it may be due to a weakened or malformed artery. If an artery wall is weak, blood can collect in the wall causing it to balloon (aneurysm). If the pressure builds, the aneurysm can rupture. When this happens, two problems arise. One is that blood flows into areas of the brain where it doesn’t belong, and second, blood fails to reach its destination, depriving that part of the brain of oxygen and nutrients.

The causes of hemorrhagic stroke in children include: 

• an artery malformation or disorder
• a brain tumour
• drug or alcohol abuse by the mother (rare)

Ischemic stroke is usually caused by a blood clot in the brain. The leading risk factors for ischemic stroke in children include:  

• Heart disease When children are born with a heart defect (congenital heart disease), their risk of having a stroke is increased. Heart disease, such as rheumatic heart disease, can also be acquired later in childhood. Stroke is not usually the first sign of heart disease. Often heart disease has been diagnosed before the child has a stroke. 
• Blood-clotting disorders Blood-clotting disorders, also known as prothrombotic disorders, cause the blood to thicken and clot faster. These disorders can be present at birth or acquired later on. A child can be born with a genetic mutation that makes the blood clot faster. Stroke is often the first sign of a blood-clotting disorder. Some illnesses, such as meningitis, sepsis, diarrhea, dehydration or an iron deficiency, can also lead to a blood clotting disorder.  
• Irregular arteries A child can have a stroke because the arteries in the brain are irregular or narrowed. This is called arteriopathy. Often, children are born with this problem, but it often goes undetected. In these cases, stroke is the first sign of an irregular artery problem. Children with irregular arteries need to be monitored very closely by their stroke clinic team because 25% of them will experience another stroke. 
• Viruses Stroke can also be indirectly caused by a virus. One of the culprits is the chicken pox virus. Once a child is infected, the virus can lie dormant in the body. When the virus is triggered, it can attack an artery in the brain.  
• Other risk factors Children are also at higher risk of having a stroke if they have any of the following risk factors: 
  • heart or brain surgery
  • moyamoya disease
  • sickle cell disease
  • autoimmune disease that attacks arteries in the brain
  • trauma to the brain or neck
  • leukemia
  • migraine headaches with aura
  • metabolic illness

Up to 20% of paediatric stroke cases have no known cause. This is an area of active medical research.

Over several Wednesdays I will offer information on the following - 

• Anatomy of the Brain, √  Anatomy of the Brain, part 2 √
• Ischemic Stroke √ 
• Transient Ischemic Attack (TIA or mini-stroke) - part 1 √  Transient Ischemic Attack (TIA or mini-stroke) - part 2 √
• Hemorragic Stroke √
• Stroke in children (Paediatric stroke) - Causes √ 
• Stroke in children (Paediatric stroke) - Diagnosis, Treatment and Rehabilitation
• Effects of a stroke

 All information contained in this post was obtained, with permission, from the Heart and Stroke Foundation  website. Please visit their site for more information.

Monica

Disclaimer

The material provided on this site is designed for information and educational purposes only. The materials are not intended to be a self diagnostic and/or self treatment tool. I encourage you to use this information as a tool for discussing your condition with your health practitioner.