What Is the Link?
At first, COVID-19 was seen as a respiratory illness. Now, it is known as the disease that can cause long-lasting neurological symptoms and stroke.
A stroke happens when blood flow to the brain is cut off. Several factors increase the risk of a stroke. These include obesity, physical inactivity, poor nutrition, smoking, high blood pressure, high cholesterol and diabetes.
There are two types of stroke: hemorrhagic and ischemic. In a hemorrhagic stroke, a weakened blood vessel bursts and bleeds into or around the brain. In an ischemic stroke, a blood clot blocks blood flow to the brain. Studies show a link between COVID-19 and ischemic strokes.
How COVID-19 Can Lead to a Stroke
Studies are ongoing and more research is needed to fully understand how COVID-19 can lead to stroke.
The conditions may be connected for several possible reasons. Risk factors may set the body up for a stroke, and then a sudden event can act as a trigger to cause the actual stroke. Infections, like COVID-19, are well-known triggers.
Scientists also believe inflammation may be partly to blame. Inflammation occurs due to the body's normal response to fighting an infection. Inflammation is also a risk factor for a stroke. The more inflammation you have, the higher your stroke risk.
In addition, COVID-19 can attach to cells that line the blood vessels, which can cause blood clots throughout the body. If one of these blood clots forms in the brain and blocks blood flow, a stroke occurs.
"Having COVID-19 increases your risk for stroke, especially when you have traditional risk factors for stroke, such as high blood pressure, obesity and diabetes. Age doesn't matter, although older adults and those with more severe, uncontrolled risk factors have a higher risk," explains Ayush Batra, MD, Northwestern Medicine Neuro-critical Care physician.
COVID-19 and Stroke: A Two-Way Street
Not only does having COVID-19 increase your chance of a stroke, but having a history of a stroke may also cause a more serious COVID-19 infection. Certain medical conditions, including stroke, are linked with a higher risk of severe illness from COVID-19.
For patients who have been placed on a ventilator due to COVID-19, Dr. Batra and other neuroscientists use transcranial doppler ultrasonography to help gauge stroke risk. This test measures blood flow characteristics to the brain to detect cerebral microemboli, which can predict a possible stroke. The test is important because patients who are critically ill are unable to communicate and describe their symptoms. Dr. Batra has proposed a 3-year study to evaluate the risk of stroke in COVID-19 patients.
Do Not Delay Medical Care
During a stroke, the sooner you get medical help, the better your chance of survival. Still, many people with stroke symptoms have delayed seeking medical care due to COVID-19.
"There were reports that the number of stroke cases decreased in the year 2020. However, this is not true," explains Dr. Batra. "People with stroke symptoms were potentially delaying medical care or not seeking it at all because they were fearful of getting infected with COVID-19."
"If you have any symptoms, it is in your best interest to seek immediate medical assistance to reduce neurological injury," he says. "The less time we have to treat the symptoms, the less we can do to reduce long-term disability."
Reduce Your Chance of a Stroke
Having healthy habits can lower your risk of having a stroke:
- Eat a healthy diet high in fiber and filled with a variety of fruits and vegetables. Limit foods high in sodium (salt), trans fats, saturated fats and cholesterol.
- Get regular exercise. Aim for five, 30-minute sessions of moderate-intensity physical activity each week. Try brisk walking, biking or dancing.
- Reach and keep a healthy weight. Lose weight if you are overweight.
- Do not smoke. If you smoke, get help to quit.
- Limit alcohol. Men should have no more than two alcoholic drinks per day. Women should have no more than one.
If you have a history of stroke or heart disease, follow your care plan as directed by your healthcare provider.
Dr. Batra also emphasizes continuing to take action to reduce your risk of COVID-19. Wear masks in public, maintain physical distancing and get a COVID-19 vaccine when it is your turn. "These are the best steps to minimize risk of getting infected in the first place," he says.While there is a connection between COVID-19 and stroke, most people with COVID-19 recover and do not have a stroke. If you are concerned about your risk, talk to your healthcare provider.