In a case report published in April 2020 in The New England Journal of Medicine, the authors outline five cases of a large-vessel stroke in individuals under age 50 who had been diagnosed with SARS-CoV-2, the infection caused by the coronavirus. It’s rare for someone under 50 years old to have a stroke, says Robert Stevens, MD, an intensive care physician and the associate director of the Johns Hopkins Neurocritical Care Precision Medicine Center of Excellence in Baltimore, who was not involved in this paper. About 1 out of every 7 strokes occur in people ages 15 to 49 years old, according to the Centers for Disease Control and Prevention. And the average number of people under age 50 treated for this type of stroke in any two-week period last year was 0.73 patients, meaning the incidence of stroke was 7 times higher than normal during the two-week period detailed in the paper, the authors write. Although no robust conclusion can be drawn from the small case report, Dr. Stevens says it is good for people to be aware of the possibility of strokes occurring in younger populations. “It does increase our level of vigilance and alert clinicians to have a very low threshold to investigate the possibility of a stroke,” says Stevens. “It’s a good thing for people to be aware of this possibility.” “The exact mechanism of stroke in those patients is not fully understood yet,” says Hazem Shoirah, MD, the director of thrombectomy services at Mount Sinai Queens and an assistant professor of neurosurgery at the Icahn School of Medicine at Mount Sinai in New York City and one of the authors of the case study. “We believe that hypercoagulability is playing a role, as clots are seen with increased frequency in other organ systems as well,” says Dr. Shoirah. “There is also some evidence that there may be inflammation in the endothelium, which lines the vessels.” The endothelium is thought to play an important role in a variety of conditions including peripheral vascular disease, venous thrombosis, and severe viral infectious diseases, according to a review published in the International Journal of Biological Sciences. More mechanisms may be discovered as we learn more about the virus, adds Shoirah. RELATED: Tips for Stroke Treatment and Rehabilitation

More Research Is Needed to Determine if COVID-19 Increases the Risk of Stroke

“When you see a paper like this, there’s a tendency for people to think, Oh, this must be a consequence of COVID-19. But we should keep in mind the possibility of coexistence rather than consequence, meaning that since COVID-19 is extremely prevalent, COVID-19 and stroke might occur simultaneously without there being a causal relationship,” says Stevens. “It’s not evident from this data or other published data that I’ve seen that the risk of having a stroke is any higher in COVID-19 patients than it is in patients without COVID-19,” says Stevens, adding that a lot more research is needed to understand whether that’s the case. “I’m not convinced, either, that there is a higher propensity for stroke in younger individuals with COVID-19,” says Stevens. “This paper doesn’t provide any epidemiological or mechanistic clues as to whether younger people are at higher risk. It’s nicely reporting observations made in the five individuals, and it’s suggesting a lot of things that need to be substantiated in future studies.” Those studies would need to look at a much larger group and be much more detailed in terms of the kind of data collected, he adds. The authors of the case study have also seen more strokes in older adults, according to Shoirah. “However, the observation of strokes of this type in younger adults was what led us to believe that COVID-19 may be driving the risk higher than expected,” he says. Validation of the findings in other groups of people will help confirm the phenomenon, says Shoirah. “We then need to understand the exact mechanism better, so that we can target our treatment,” he says. For example, because an increased likelihood of clotting in cerebral vasculature and other organs has been observed, new protocols have been started that call for prophylactic anticoagulation in certain people, according to Shoirah. Prophylactic anticoagulation is the practice of giving a high-risk patient (in this case, individuals with COVID-19) drugs to reduce the risk of clotting before it occurs.

Seek Care Immediately if You Are Having Symptoms of a Stroke

“There appears to be a decrease in [the] incidence of acute hospitalization for stroke or heart attacks, and some people have speculated that could be because people who are presenting with symptoms are reluctant or afraid to come to the hospital because they’re afraid they might get COVID-19 in the hospital,” says Stevens. Although that is a legitimate concern, people should know that healthcare systems across the country have put in very robust measures to minimize the risk of getting the coronavirus when you arrive at the hospital, he says. “I’m not aware of widespread transmission of COVID-19 occurring in hospital systems,” he adds. “It is extremely important to be vigilant to the signs and symptoms of stroke, which include one-sided weakness of the face, arm, or leg, as well as numbness, speech disturbance, vision changes, or change in balance,” says Shoirah. “Hospital-anxiety related to COVID-19 should not prevent people from seeking medical attention if those symptoms are encountered. Time is of critical importance when it comes to stroke treatment,” says Shoirah.