Stroke Health Article

Definition

A stroke, also called a cerebral infarction, is a life-threatening condition marked by a sudden disruption in the blood supply to the brain.

Description

A disruption in the blood supply to the brain starves the brain of oxygen-rich blood and causes the nerve cells in that area to become damaged and die within minutes. The body parts controlled by those damaged brain cells lose their ability to function.

Depending on the area of the brain that is affected, a stroke can alter many aspects of a child's functioning such as speech, movement, behavior and learning. A stroke also may cause weakness or paralysis on one side of the body. The loss of function may be mild or severe, temporary or permanent.

If medical treatment begins within hours after symptoms are recognized, brain damage can be limited and the risk of permanent medical effects can be decreased.

Types of stroke

An ischemic stroke—the most common form of stroke in children under age 15—is caused by a blocked or narrowed artery. In children, blockages may be caused by a blood clot, injury to the artery, or rarely in children, atherosclerosis (build-up of fatty deposits on the blood vessel walls). A cerebral thrombosis is a blood clot that develops at the clogged part of the blood vessel. A cerebral embolism is a blood clot that travels to the clogged blood vessel from another location in the circulatory system.

A hemorrhagic stroke—the more common form of stroke in infants and children under age two—occurs when a weakened blood vessel leaks or bursts, causing bleeding in the brain tissue or near the surface of the brain.

Two types of weakened blood vessels usually cause hemorrhagic stroke, including:

• aneurysm: ballooning of a weakened area of a blood vessel
• arteriovenous malformations: cluster of abnormal blood vessels

A transient ischemic attack (TIA), also called a "mini stroke," is characterized by a short-term blood vessel obstruction or clot that tends to resolve itself quickly, usually within 10–20 minutes, or up to 24 hours. A TIA usually does not require intervention. However, a TIA is a strong indicator of an ischemic stroke and should be evaluated in the same way as a stroke to prevent a more serious attack.

In children, strokes can be categorized as:

• prenatal stroke: occurring before birth
• neonatal or perinatal stroke: occurring in infants less than 30 days old
• pediatric or childhood stroke: occurring in children aged 15 and under

Demographics

Childhood stroke is relatively rare, occurring in about two to three of every 100,000 children aged one to 14 per year. In comparison, stroke occurs in about 100 of every 100,000 adults per year. The rate of ischemic stroke and hemorrhagic stroke is similar among children aged one to 14.

Stroke occurs more frequently in children under age two, and peaks in the perinatal period. In the National Hospital Discharge Survey from 1980-1998, the rate of stroke for infants less than 30 days old (per 100,000 live births per year) was 26.4, with rates of 6.7 for hemorrhagic stroke and 17.8 for ischemic stroke.

More fatal strokes occur in African-American children than white children, mirroring the racial differences of stroke in adults. Compared to the stroke risk of white children, African-American children have an increased relative risk of 2.12, Hispanics a decreased relative risk of 0.76 and Asians have a similar risk. Boys have a 1.28-fold higher risk of stroke than girls and have a higher case-fatality rate for ischemic stroke than girls. The increased risk among African Americans is not explained by the presence of sickle cell disease, nor is the excess risk among boys explained by trauma.

Research conducted by the National Institute of Neurological Diseases and Stroke (NINDS) indicates a "stroke belt," or geographical area where fatal strokes are more predominant. This stroke belt includes Alabama, Arkansas, Georgia, Indiana, Kentucky, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, and Virginia. Researchers examined death certificates over a 19-year period and found a 21 percent higher risk of death from stroke in people under age 20 in the stroke belt states had compared with the same age group in other states. During the same period, people over age 25 in the stroke belt region had a 20 percent higher risk of death from stroke. Because the overall rate of stroke in children is low, researchers warn parents in these states not to be too alarmed. However, the findings indicate further investigation is needed.