Stroke is one of the top causes of death in the United States and a leading cause of major disability. Approximately 800,000 people have a stroke each year — about one every four seconds, with one person dying every four minutes as a result.
A stroke occurs when the blood supply to a part of the brain is interrupted or severely reduced, depriving brain tissue of oxygen and nutrients. When blood flow does not reach the brain, brain cells begin to die, which results in brain damage. The brain functions that are affected depend on where the stroke occurs and how much damage has occurred.
There are three types of stroke:
• Ischemic strokes are the most common and are due to lack of blood flow when an artery in the brain is blocked. The two types of ischemic stroke are thrombotic and embolic. In a thrombotic stroke, a blood clot forms in an artery that supplies blood to the brain. In an embolic stroke, a blood clot or other substance, such as plaque, travels through the bloodstream to an artery in the brain.
• Hemorrhagic strokes occur if an artery in the brain leaks blood or ruptures. The pressure causes swelling of the brain, and increased pressure in the skull can damage tissue and brain cells.
• Mini-strokes or transient ischemic attacks occur when the blood supply to the brain is briefly interrupted. Symptoms of a TIA last less than 24 hours and, generally, no permanent damage occurs. However, they can be a serious warning sign of stroke.
Strokes can occur at any age. The chance of having a stroke increases depending on certain risk factors. Some risk factors cannot be controlled, such as age and family history. Conditions that increase risk of stroke include a previous TIA or stroke, high blood pressure, high blood cholesterol, diabetes, obesity, tobacco use, heart disease and atrial fibrillation.
Risk of stroke can be reduced by managing risk factors, eating a healthy diet rich in fruits and vegetables, limiting saturated fats, salt and alcohol and being active daily.
The most common signs of stroke are sudden and may last more than a few minutes. They may start, briefly go away, then return. It is important to learn the warning signs:
• Numbness or weakness of face, arm or leg (mainly on one side).
• Trouble seeing in one or both eyes.
• Trouble walking, dizziness or loss of balance.
• Confusion or trouble talking or understanding speech.
• Bad headache with no known cause.
Strokes need to be diagnosed and treated as quickly as possible in order to minimize brain damage and preserve brain function. Treatment depends on the type of stroke. Ischemic strokes can be treated with medications and medical procedures. Hemorrhagic strokes can be treated with surgery to repair blood vessel weaknesses.
Remember, a stroke is a medical emergency. Every minute counts, and it is vital to act FAST:
F-Face: Is it numb? Ask the person to smile; does one side of the face droop?
A-Arms: Is one arm weak or numb? Ask the person to raise both arms; does one arm drift downward?
S-Speech: Is the speech slurred? Ask the person to repeat a simple phrase. Are any words wrong or difficult to understand?
T-Time: If you observe any of these signs, call 911 immediately. Also note the time symptoms first appeared.
(Melissa Ulberg is a family nurse practitioner at CHI St. Alexius Health Neurology Clinic and the Stroke Clinic coordinator. She received her master’s degree in nursing and family nurse practitioner from the University of Mary.)