What Is A Stroke?


According to the National Stroke Association, stroke is the third leading cause of death in the United States. Fortunately, 80 percent of strokes are preventable with lifestyle changes and proper medical care. Stroke occurs when a blood vessel bursts or when a blood clot blocks an artery. This disrupts the flow of blood to the brain, causing the death of brain cells. The death of brain cells causes a loss of function in the affected area. Cell damage in the area of the brain that controls speech, for example, will result in difficulty speaking or an inability to speak. Stroke is responsible for the deaths of approximately 137,000 Americans each year.


Types of Stroke

Embolic stroke occurs when a blood clot travels into the brain via the bloodstream. The clot travels into a tiny blood vessel and blocks the blood flow through the vessel. This blockage causes a stroke. Thrombotic stroke occurs when a blockage forms in one of the arteries leading to the brain. This disrupts the flow of blood to the brain. Another cause of thrombotic stroke is the buildup of arterial plaque, which consists of cholesterol and fatty deposits. The human body sees these deposits as signs of an injury, so it forms clots around the deposits in an attempt to heal the blood vessels. These clots block blood from flowing to the brain normally.

The third major type of stroke is a hemorrhagic stroke. This type occurs when a blood vessel bursts or breaks. Risk factors for hemorrhagic stroke include cerebral aneurysm and uncontrolled high blood pressure. Subarachnoid hemorrhage occurs when a large artery bursts on or near the membrane that surrounds the brain. Intracerebral hemorrhage occurs when one of the vessels within the brain starts bleeding. High blood pressure is the most common cause of this type of hemorrhage. Transient ischemic attack (TIA), also called a mini stroke, occurs when something briefly blocks the flow of blood to the brain. While this is not considered a true stroke, it is a warning sign that a stroke may occur. The National Institute of Neurological Disorders and Stroke estimates that one-third of those who experience a TIA will go on to have a full stroke in the future.


Signs and Symptoms

The signs and symptoms of a stroke occur very suddenly. Sudden confusion, dizziness, numbness or weakness, severe headache, loss of balance, difficulty walking, loss of coordination, trouble speaking, trouble seeing, and trouble understanding others may indicate that a stroke has occurred. Anyone who experiences these signs and symptoms should seek emergency medical attention immediately.


Risk Factors

There are a number of factors that increase a person’s risk for having a stroke. Some of these are controllable, but others are not. Potential stroke victims cannot control their race, gender, age, family history of stroke, or the presence of fibromuscular dysplasia or a hole in the heart. Anyone over the age of 55 has an increased risk of stroke. Men have a higher risk of stroke than women, and African Americans have a higher risk of stroke than people of other races. Other risk factors for stroke are controllable with lifestyle changes and medical treatment. These risk factors include diabetes, high blood pressure, smoking, alcohol use, tobacco use, obesity, lack of physical activity, atherosclerosis, and problems with blood circulation.


Diagnosis

Timely diagnosis of a stroke is very important, as quick delivery of the right medications may mean the difference between irreversible brain damage and a partial or full recovery from the stroke. Physicians use several tests and exams to diagnose stroke, specifically to determine if someone is having an ischemic stroke or hemorrhagic stroke. This is important because medications used to treat ischemic stroke are dangerous if used on someone who is having a hemorrhagic stroke. A CT scan of the brain can help medical professionals identify bleeding in the brain. Magnetic resonance imaging (MRI) helps to determine the amount of damage to the brain so physicians can predict how a person will recover.

Laboratory tests help identify any problems with the kidneys and liver, while an electrocardiogram helps diagnose heart problems that could have contributed to the stroke. Doppler scanning of the carotid artery may help detect arterial narrowing that can block blood flow to the brain. After immediate stroke treatment, many physicians also assess their patients for heart disease risk factors. This is because those who have had a stroke may also have coronary artery disease.


Prevention and Treatment

In people who have had thrombotic strokes, drugs called thrombolytics help restore blood flow to the brain by dissolving blood clots. Time is of the essence when administering a thrombolytic. Another possible treatment for thrombotic stroke is administration of tPA, an enzyme that helps dissolve blood clots. This treatment must be given within three hours of experiencing stroke symptoms, so getting immediate medical treatment is essential. For patients who do not respond to tPA or those who are not eligible to receive tPA, a device called the MERCI Retriever can remove blood clots and restore the flow of blood to the brain. The Penumbra System allows physicians to repair damaged blood vessels following an ischemic stroke. The suction from the system also helps remove blood clots from the brain. This system is usually effective if used within eight hours of stroke symptom onset.

Several lifestyle changes can reduce the risk of having a stroke. Reducing the amount of sodium in the diet, getting plenty of exercise, and taking medication as prescribed can lower blood pressure and reduce the workload of the heart and blood vessels. Diabetics should carefully monitor their blood sugar levels and take all medications as prescribed. Following a diabetic diet and getting enough exercise can keep blood sugar levels in check, preventing the blood vessel damage that occurs in cases of uncontrolled diabetes. Eliminating the use of tobacco in all forms can prevent damage to the blood vessels and reduce the risk of stroke, heart attack, high blood pressure, and other serious medical problems. A medical professional can provide tips and advice on quitting and remaining tobacco-free.

Scientists do not know exactly how alcohol use increases the risk for stroke, but there is a possible link between alcohol consumption and stroke risk. Limiting alcohol use to just one drink per day may reduce this risk. One drink is 12 oz. of beer, 5 oz. of wine, or one shot of liquor. Obesity is an accumulation of excess fat on the body. This condition increases the risk for stroke, diabetes, high blood pressure, joint problems, heart attack, and other serious conditions. Eating fruits, vegetables, lean meats, and whole-grain foods instead of fried foods, baked goods, and processed foods can help reduce weight associated with excess calorie consumption. Regular exercise burns calories and helps the body process food more efficiently. As muscle mass increases, the metabolism speeds up, which burns more calories. Prescription medications may help control appetite or remove fat from the digestive system before the body has a chance to absorb it. In very severe cases, gastric bypass or other forms of weight loss surgery may be used to reduce weight and reduce the risk of life-threatening diseases.

Those without severe mobility problems can easily increase their activity levels. Small changes, such as taking the stairs instead of the elevator, can increase the amount of physical activity someone gets each day. Participating in fun activities like tennis, swimming, and intramural sports can help people get more activity without having to walk miles on a treadmill or spend hours at the gym every day.