Though usually considered an adult disease, strokes do strike children. While there are many causes of pediatric stroke, they all result in brain damage due either to bleeding or blockage of the blood vessels. Bleeding strokes are known as hemorrhagic strokes, while strokes due to blockage of the blood vessels are known as ischemic strokes. Both hemorrhagic and ischemic strokes have multiple causes.
Neonatal Strokes
Neonatal strokes occur either in the womb or around the time of birth. Neonatal ischemic strokes can be caused by blood clots in the placenta that travel into the fetus's blood vessels, and then travel into the brain to block blood flow. Infants with genetic predispositions towards blood clots, are at higher risk for ischemic strokes. A special type of hemorrhagic stroke, known as periventricular hemorrhage, is more common in premature infants.
Heart Disease
Heart disease can cause pediatric strokes. Abnormalities of the heart muscle, its valves, or its blood vessels can lead to clot formation in the heart. These clots then travel into the brain, where they block the blood vessels and cause an ischemic stroke. Nelson's Textbook of Pediatrics lists many heart conditions that place children at higher risk for ischemic stroke such as ventricular septal defects, endocarditis, cardiomyopathies, rheumatic fever and aortic stenosis.
Infections
Infections are another cause of pediatric strokes. Meningitis, which is an infection of the lining of the brain, and encephalitis, which is an infection of the brain itself, can cause clotting inside the blood vessels of the brain. Endocarditis, which is an infection inside the heart, can lead to small particles known as emboli traveling from the heart into the brain. Once these emboli lodge in the blood vessels of the brain, they block blood flow and cause an ischemic stroke.
Blood Clotting Disorders
According to Nelson's Textbook of Pediatrics, more than 50 percent of children with strokes due to blood clots have some type of coagulation, or blood clotting, disorder. These disorders include factor V Leiden mutations, protein C and protein S deficiencies and antiphospholipid antibodies. Each of these diseases makes the blood more hypercoagulable, meaning it is more likely to clot. When these clots occur in the brain, they cause ischemic strokes. Many children who suffer strokes need testing to determine if they suffer from one of these coagulation disorders.
Blood Vessel Malformations
Blood vessel malformations, technically called arteriovenous malformations, or AVMs, can cause hemorrhagic strokes. These abnormal vessels are more prone to rupture, leading to bleeding inside the brain. Aneurysms, or ballooning of a blood vessel, are a more rare cause of hemorrhagic strokes in children. They are associated with polycystic kidney disease and coarctation of the aorta.
References
- Johnston MV and Comi A, "Acute Stroke Syndromes" in Kliegman: Nelson Textbook of Pediatrics, 18th ed. 2007.
- Causes of Childhood Stroke
