The most common type of stroke, an acute ischemic stroke, which is caused by a clot in an artery of the brain, represents a significant impact to the health of the global population. Each year there are approximately 800,000 strokes occurring in the United States, making strokes the 5th leading cause of death, and the leading cause of long term disability in the United States. As stroke clinicians, one of our goals is to maximize the long term functional outcomes after a stroke occurs by restoring blood flow to the brain quickly.
The first line treatment, and the traditional method to achieve restored blood flow, is through the use of a drug called tissue plasminogen activator or tPA, which is given intravenously and helps to dissolve the clot. There is a more novel approach which has been found to be highly successful in the most severe strokes, referred to as endovascular reperfusion. This procedure is used in very large strokes, after a catheter is inserted into an artery, a trained physician uses devices designed specifically for this to access the clot and manually remove it from the artery that is blocked. This results in immediate restoration of blood flow to the brain and has been shown to significantly reduce long term disability in the most critical patients. Endovascular therapy requires a skilled team of highly trained nurses, technologists, and physicians to perform effectively and is only available in select hospitals.
Both IV tPA and endovascular therapy are time sensitive. Studies have shown that as many as 2 million neurons are lost every minute that an artery is blocked, and the likelihood of a good outcome decreases as time goes by without restored blood flow. Furthermore, the longer an area of the brain goes without blood flow, the greater the risk of complication associated with restoring blood flow. Based on this IV tPA is only recommended within 4.5 hours of symptom onset and endovascular therapy, within 6 hours of symptom onset, although endovascular therapy can be done beyond 6 hours in selected patients.
Recognizing the Symptoms
This time sensitivity highlights the importance of recognizing stroke symptoms and seeking medical treatment urgently. Symptoms of a stroke include weakness on one side of the face, weakness on one side in an arm or leg, difficulty speaking or slurred speech, visual loss, double vision, blurry vision, and loss of balance. Unfortunately, the number one reason patients do not receive an acute treatment is delays in presentation to the hospital. Only approximately 25% of stroke patients arrive to the hospital within the time window for treatment with IV tPA. Any time that a symptom listed above is seen, emergency medical systems should be immediately activated for transport to a stroke center that can provide diagnosis and treatment of a stroke.
The Risk Factors
Those at risk for stroke include anyone with high blood pressure, high cholesterol, diabetes, obesity, buildup of plaque in a carotid artery, cardiac conditions such as atrial fibrillation, or smokers. Anyone with these conditions should speak to their primary care physician, and may need to be referred to a stroke specialist, about their risk of stroke and the strategies to manage this. Many preventative measures are simple changes, such as diet and exercise modifications that can reduce the risk of having a stroke. For other patients, it may be appropriate to have their blood pressure modified or take certain medications to reduce the risk of stroke; this should be done with direction from a medical provider.
In summary, strokes are a very serious disease process that can result in death or the inability to function without assistance. Strokes are urgent and time sensitive, patients with signs and symptoms of a stroke should immediately be taken to a hospital where life saving treatment can be administered. Strokes are preventable and knowing your risk factors, paired with taking preventative steps can reduce the risk and prevent future strokes from occurring.
Please visit www.upmc.com/services/stroke-institute for more information.
For how to identify the signs of a stroke FAST and the various types of strokes, you can read our article “Can You Spot the Signs of a Stroke?”
This article was written by Benjamin Morrow of UPMC Stroke Institute, 2017