The Link Between Coronavirus and Stroke

Stroke is one of the uncommon—and very serious—complications of a COVID-19 infection. When a stroke occurs due to COVID-19, it generally happens several weeks after the infection has started producing other symptoms throughout the body. A stroke is rarely the first sign of a COVID-19 infection. 

A stroke can cause weakness, slurred speech, confusion, and a variety of other problems, and rehabilitation is usually a necessary component of recovery. 

Causes of COVID-19-Related Stroke 

Most people who have strokes associated with the COVID-19 virus have pre-existing hypertension, heart disease, diabetes, or cerebrovascular disease. But there have been some reports of previously healthy people having strokes attributed to COVID-19 infection as well.

The strokes linked to COVID-19 infection are mostly ischemic strokes, which are caused by blood clots. They also tend to be large vessel strokes, meaning they are caused by blockage of the large arteries in the brain and can lead to significant damage.

Blood Clots

According to a study looking at 3,556 hospitalized patients with a diagnosis of COVID-19 in New York City, 32 of them—or 0.9%—had confirmed ischemic stroke. Compared to stroke patients without a COVID-19 diagnosis, they were more likely to have higher levels of the D-dimer protein in their blood—10,000 vs. 525—which can mean significant blood clotting.

While blood clots related to COVID-19 are more likely to manifest as deep vein thrombosis (DVT) in the legs, microvascular clotting in the toes, or a pulmonary embolism (PE) in the lungs, it is possible for a blood clot to cause a stroke if it forms in an artery in the brain. A blood clot in the heart may travel to the brain and cause a stroke. 

Hypercoagulability

Hypercoagulability, or too much clotting of the blood, raises the chances of a dangerous blood clot and an ischemic stroke. A number of COVID-19 complications can lead to hypercoagulability:

• Sepsis: A major inflammatory reaction due to an infection
• Cytokine storm: Severe response to an infection leading to excess production of inflammatory proteins
• Disseminated intravascular coagulation (DIC): A reaction that can be triggered by a severe infection and lead to blood clots throughout the body

While it's normal for blood to coagulate, or clot, to heal a wound like a cut, hypercoagulability causes dangerous blood clots that block the healthy flow of blood to your organs and tissues.

Signs and Symptoms 

Strokes associated with COVID-19 typically affect people who have become very sick from the infection and who are in the hospital due to other complications from the illness.

Signs of a stroke can include:

• Slurred speech 
• Weakness on one side of the body 
• Altered sensation on the face, arm, or leg on one side of the body
• Facial weakness and/or a droopy eyelid in one side of the face 
• Trouble understanding speech or finding the right words to say
• Loss of vision on the left or right side of both eyes 
• Confusion or decreased level of consciousness

These symptoms may happen suddenly and can rapidly worsen.

Diagnosis 

A stroke is diagnosed based on a physical examination and/or imaging studies of the brain. The medical team will assess the patient's neurological function on a regular basis, and they may be able to detect a stroke at a very early stage—even before symptoms occur.

Imaging Tests

A brain computerized tomography (CT) or magnetic resonance imaging (MRI) scan may show changes caused by a lack of blood flow in the brain. Some people who are at risk of having a COVID-19-associated stroke may have more than one stroke as a result of the infection. Other strokes can be detected on a brain imaging study as well.

Blood Tests

If you have a stroke due to COVID-19, your doctors may order blood tests to determine whether you have alterations in your blood clotting factors.

Blood tests may include:

• PT/PTT and INR
• D-dimer
• Lupus anticoagulant
• Antiphospholipid antibody
• Antithrombin

These values can deviate from normal ranges due to your infection and the results may help guide your treatment.

Treatment and Prevention 

The medical community is gathering information about COVID-19 and formulating the best treatment approaches. For example, while mechanical thrombectomy is often indicated within 24 hours of an ischemic stroke to remove blood clots, the complexities of performing invasive procedures on COVID-19 patients means decisions must be made on a case-by-case basis.

When it comes to prevention, blood thinning medications are among the established ways of preventing a stroke. Your medical team may consider this approach if you are at risk or if you have already had a blood clot, such as a DVT, PE, or heart attack.

However, blood thinners can increase the risk of bleeding, which could be a dangerous problem as well. They have to be used with caution and might not be safe for everyone. Your medical team will balance your immediate stroke prevention strategy by weighing your individual risks and benefits.

Rehabilitation 

If you've had a stroke due to COVID-19 infection, you may need to have physical therapy, speech therapy, or another type of stroke-specific rehabilitation as you recover. Rehabilitation can help you improve the functions impaired by a stroke. 

Because COVID-19 is highly contagious, there are many safety issues to consider. Decisions regarding inpatient or outpatient rehabilitation have to be weighed with these factors in mind. 

A Word From Verywell 

While it is unlikely that you would have a stroke due to COVID-19, it unfortunately does happen. Stroke recovery takes time, but you are likely to regain at least some of your function again, especially if you haven’t had a stroke in the past. 

If you develop a COVID-19 infection that requires hospitalization, you'll be closely monitored to reduce your chances of developing a complication like stroke. 

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.