Preventing stroke—strokes affect infants and children as well as adults

What is a stroke and what causes it?

Stroke is a cardiovascular disease that occurs when the blood supply to the brain is disrupted and the functions of a particular part of the brain are impaired or stop. The blood circulation to the brain can be disrupted in two main ways, either because an artery is blocked or if a damaged artery ruptures and causes bleeding in the brain.  In adults most strokes result from a combination of high blood pressure and atherosclerosis.  Atherosclerosis is the progressive silent accumulation of cholesterol in the walls of arteries that form a plaque that thickens arterial walls.  The resultant loss of flexibility, scaring and narrowing of the lumen of the artery cuts down on or even blocks the ability of the vessel to carry blood.

According to the American Stroke Association, most strokes in children are caused by risk factors that are much different than those for adults. The commonest risk factors are sickle cell disease and congenital or acquired heart disease.

Other risk factors for stroke in infants and children include:

• Head and neck infections;
• Systemic conditions, such as inflammatory bowel disease and autoimmune disorders
• Head trauma;
• Dehydration;
• Maternal infection in the fluid surrounding an unborn baby (chorioamnionitis);
• Premature rupture of membranes during pregnancy;
• Maternal preeclampsia (pregnancy-related high blood pressure).

Among adolescents, young adults, and older adults, risk of all cardiovascular diseases including stroke is related to improper diet, high blood cholesterol, smoking, diabetes, obesity, alcohol consumption, stress, lack of exercise, and injuries but especially to high blood pressure, or hypertension. 

High blood pressure defined as a systolic over diastolic reading of 140/90 mm Hg (millimeters of mercury) or higher, is a very common risk to health for Americans.  An estimated 78 million Americans have high blood pressure.  Hypertension creates a major risk for stroke, heart attack, vision loss, brain damage and kidney failure.  Two-thirds of those with a first heart attack and three-quarters of those with a first stroke have hypertension.  Smoking is also a major factor in causation of heart attack and stroke.  It increases the risk of a stroke by 2 to 4 times.

About 2 percent of all strokes but possibly up to 25 percent of those in young and middle aged people are caused by a dissection (tear) in an artery that may be spontaneous or caused by falls when surfing, skiing or participating in other sports, yoga moves, or chiropractic manipulations.

Risk of stroke is also increased among people who have migraine headaches, especially among those who have associated symptoms (called an aura) such as blurry vision.   With increased abuse of cocaine, methamphetamines and marijuana more strokes are occurring among young people.   Especially synthetic marijuana may accelerate heart rate, increase blood pressure, and cause agitation, seizures, hallucinations, strokes, and even death.  There is also concern about the use of energy, weight-loss, and a variety of other dietary supplements, some of which contain substances that mimic amphetamines.  These common health food store products are not beneficial for health and may cause harmful effects on heart rate, blood pressure and blood clotting.

How common are strokes and what are the health effects of a stroke?

Stroke is both a leading cause of disability and the fourth most frequent cause of death.   According to the CDC and the American Stroke Association:

• Stroke kills almost 130,000 Americans each year—1 out of every 19 deaths.
• Every year, more than 795,000 people in the United States have a stroke.
• About 185,000 strokes—nearly one of four—are in people who have had a previous stroke.
• The risk of stroke from birth through age 19 is nearly 5 per 100,000 children per year.
• Stroke is one of the top 10 causes of death for children between the ages of one and 19
• The risk of stroke in children is greatest in the first year of life, and peaks during the perinatal period (roughly the weeks before and immediately after birth).
• Between 20% and 40% of children die after a stroke.
• About 3,000 children and young adults had a stroke in the United States in 2004.
• About 87% of all strokes are ischemic strokes, when blood flow to the brain is blocked.
• Stroke is a leading cause of serious long-term disability.
• According to the American Stroke Association, Americans paid about $73.7 billion in 2010 for stroke-related medical costs and disability.

Of children surviving stroke, about 60% will have permanent neurological deficits, most commonly hemiparesis or hemiplegia. Hemiplegia/hemiparesis (total or partial paralysis on one side of the body) is the most common form of cerebral palsy in children born at term, and stroke is its leading cause.  Other long-term disabilities caused by a stroke occurring around the time of birth include cognitive and sensory impairments, epilepsy, speech or communication disorders, visual disturbances, poor attention, behavioral problems, and poor quality of life.

For infants and children, and youth the disabilities caused by a stroke can be devastating.  In general, a stroke can cause one or several of five types of disabilities: paralysis or problems controlling movement; sensory disturbances including pain; problems using or understanding language; problems with thinking and memory; and emotional disturbances.  

Combating Hypertension and Other Approaches to Reducing the Risk of Stroke

For infants and children it is essential to avoid and/or treat the risk factors, such as sickle cell disease and heart disease that can lead to stroke and to obtain medical care to minimize their impact if these risks are present.  It is increasingly recognized that even when high blood pressure does not lead to a major stroke it can eventually lead to cognitive decline—a precursor to dementia.  Even a slightly elevated systolic blood pressure seems to put people at risk for brain damage. 

Young people and adults can decrease their risk of stroke by adopting a healthy lifestyle to avoid the risks of atherosclerosis and high blood pressure.  Elevated blood pressure, elevated blood cholesterol levels and cigarette smoking are the most important risk factors for heart attack and stroke.  A healthy diet, not being overweight or obese, and regular physical activity are also important for preservation of cardiovascular health and preventing stroke.

Since there is no single condition that is associated with all of the increased risk of stroke and cardiovascular disease, the best strategy is to simultaneously address multiple risk factors.  Those that can be modified so as to decrease risk include, smoking, use of psychoactive drugs such as marijuana, use of dietary supplements such as energy drinks, improper diet, high blood cholesterol, high blood pressure, smoking, diabetes, obesity, alcohol consumption, stress, and lack of exercise.  All of these factors are important.  The subjects of proper nutrition, smoking, marijuana, and physical activity are discussed in other Catalyst for Children Timely Topics. 

Preventive measures to avoid an arterial dissection include use of proper protective gear when participating in sports and to the extent possible avoiding falls when participating in sports, caution with yoga moves, and avoidance of chiropractic manipulations.

People who have frequent headaches, or migraine headaches, especially those who have aura, should have their headaches evaluated by their health provider and avoid use of estrogen containing oral contraceptives and any other drug that might increase the propensity for blood clots.

Avoiding abuse of cocaine, methamphetamines, synthetic marijuana, marijuana and use of energy, weight-loss, and a variety of other dietary supplements is a crucial step to decrease the risk of stroke.

Among the several interventions to decrease the risk of stroke, controlling blood pressure is critical.  In general, the lower blood pressure is the healthier ones cardiovascular system is, and the lower the risk of stroke and heart attack is.   Although a blood pressure of 120/80 mm Hg or lower is considered a normal blood pressure, cardiovascular risk increases at any level of blood pressure above of 110/70 mm Hg.  About 30 percent of Americans have a systolic blood pressure between 121 and 139 or a diastolic blood pressure between 81 and 89, a condition that is considered prehypertension, and has a high risk of evolving to hypertension.  Systolic blood pressures of 140 mm Hg or higher and diastolic pressures of 90 mm Hg or higher are considered hypertension.

Blood pressure fluctuates throughout the day and is regulated by the interplay between how hard your heart beats, for example during exercise compared to at rest or during sleep, how elastic your blood vessels are—atherosclerosis makes them stiffer, and how well your kidneys function to regulate sodium in the body—more sodium means greater blood volume and higher blood pressure.  Blood pressure is also regulated by hormones and by the nervous system. 

Almost all hypertension, 90 to 95 percent, is related to lifestyle and is called essential hypertension.  The most important factor that causes high blood pressure among Americans is our typical diet that is high in salt (sodium), high in fat and cholesterol, and low in fruits and vegetables—and therefore low in potassium.  Other lifestyle factors that make important contributions to hypertension are physical inactivity, overweight and obesity.  Other factors, over which an individual has no control, such as genetics and race, also influence the risk of getting hypertension.  A family history of hypertension is a risk and African Americans are more susceptible to hypertension than whites.

The 5 to 10 percent of hypertension that is caused by a disease condition or drug is called secondary hypertension.  Kidney disease, a narrowing of the arteries that supply blood to the kidneys, a variety of adrenal gland tumors and other hormone disorders, sleep apnea and certain drugs can all cause medically treatable forms of secondary hypertension.

The good news about essential hypertension and prevention of stroke is that high blood pressure usually can be controlled with lifestyle interventions, and if that fails, with drugs.  Among lifestyle interventions to prevent and treat hypertension, the most effective is the optimal nutrition that limits sodium (salt) in the diet.

The average of 3,500-4,000 mg of salt a day in the typical American’s diet far exceeds recommended levels. The American Heart Association recommends a 2,400 mg, or even better a 1,500 mg of sodium per day limit for everyone including children.   Reducing daily sodium intake to less than 1,500 mg per day is particularly important for persons who are 51 and older and those of any age who are African American or have hypertension, diabetes, or chronic kidney disease. The 1,500 mg recommendation applies to about half of the U.S. population, including children, and the majority of adults.

A very low fat, whole-food plant-based diet can reduce the risk of all forms of cardiovascular disease including stroke. Mediterranean, mixed, and balanced diets are also major improvements over the typical American’s diet. These diets are described in more detail in the Catalyst for Children Timely Topic: The role of diet in preventing cardiovascular disease.

 Among the mixed and balanced diets, the Dietary Approaches to Stop Hypertension (DASH) diet that emphasizes reducing the intake of salt, saturated fat and cholesterol and increased consumption of fruits, vegetables and whole grains has been shown to lower blood pressure and decrease other forms of cardiovascular disease.  A DASH diet is even more effective in lowering blood pressure when it is combined with other measures to increase fitness through appropriate levels of physical activity , attain and maintain a healthy weight, and manage stress.    Alcohol and cigarettes also contribute to hypertension.  More than one drink of alcohol a day can raise blood pressure, and the chemicals in cigarette smoke raise blood pressure and damage blood vessels.
 
The average American consumes 4,000 mg of sodium daily. Because salt is added to so many processed foods including canned foods, bakery goods, soups, snack foods and fast foods, it is difficult to limit intake of sodium to the UDSA’s recommended daily limit of 2,300 mg of sodium for those with normal blood pressure.  It is even more difficult to attain the 1,500 mg per day limit the USDA recommends for those age 51 or older, those who are black, and those who already have high blood pressure.  The American Heart Association recommends the 1,500 mg of sodium per day limit for everyone including children.

If lifestyle measures including elimination of added salt, increasing physical activity and weight loss are not effective in lowering blood pressure, a variety of effective medications to lower blood pressure are available through a prescription from a health care provider.  Fortunately most antihypertensive drugs are effective and have few side effects.

References and Links