Each year about 500,000 people in the United States suffer a first stroke, and a further 200,000 people have a recurrent stroke. Stroke is the third leading cause of death in the U.S., and also is a major cause of disability and loss of independence and quality of life. Up to 40% of strokes are fatal, but the risks of death from a stroke and the degree of disability can both be significantly reduced by prompt treatment.
Strokes result from impaired oxygen delivery to brain cells via the bloodstream. The oxygen-deprived brain cells die and result in various neurological impairments, depending on the area of the brain that is involved. A stroke is also referred to as a cerebrovascular accident or CVA. The blood supply to the brain can be interrupted both by a blockage in one of the arteries that supply blood to the brain, or a rupture of a blood vessel within the brain. Stroke caused by blockage of an artery is called ischemic stroke, while stroke caused by rupture of an artery is called a hemorrhagic stroke. Ischemic stroke is much more common than hemorrhagic stroke.
The risk factors for stroke include high blood pressure, diabetes, cigarette smoking , a family history of stroke, heart disease, prior history of stroke, alcohol abuse, and increasing age. Learning to recognize the signs and symptoms of a stroke is vital in order to ensure that the victim receives immediate medical attention. According to The U.S. National Institute of Neurological Disorders and Stroke, these are the five major signs of stroke:
- Sudden numbness or weakness of the face, arm or leg, especially on one side of the body. The loss of voluntary movement and/or sensation may be complete or partial. There may also be an associated tingling sensation in the affected area.
- Sudden confusion, trouble speaking or understanding. Sometimes weakness in the muscles of the face can cause drooling.
- Sudden trouble seeing in one or both eyes
- Sudden trouble walking, dizziness, loss of balance or coordination
- Sudden, severe headache with no known cause
Strokes can also cause breathing difficulties and can result in loss of consciousness. Stroke is always a medical emergency. If you believe you or someone else may be having a stroke, call 9-1-1 immediately and seek immediate emergency medical care.
One of the most important treatments of ischemic strokes is immediate infusion of a clot dissolving medication to open blocked arteries. If given within the first three hours after the onset of symptoms, clot dissolving medications can significantly improve the patient's outcome from the stroke over the long term. The sooner it is started, the better the outcome, so time is of the essence.
High blood pressure and atherosclerosis (hardening and narrowing of the arteries) are important risk factors for heart attacks and strokes. Heart attacks and stokes are preventable by life style modifications and medications.
REFERENCE: Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.