Among more than 1,900 patients with COVID-19, 1.6% suffered a stroke, versus 0.2% of nearly 1,500 patients seriously ill with flu, researchers found.
“Doctors and practitioners taking care of patients with COVID-19 infection should remain vigilant for signs and symptoms of stroke, because prompt diagnosis may permit effective stroke treatment,” said researcher Dr. Neal Parikh, an assistant professor of neurology and neuroscience at Weill Cornell Medicine in New York City.
“Fundamentally, our results support the notion that COVID-19 infection is more severe than influenza infection,” Parikh added.
For the study, Parikh and colleagues compared the incidence of stroke among COVID patients and flu patients in two New York City hospitals. Patients with coronavirus were assessed March 4 through May 2, while researchers analyzed flu data from Jan. 1, 2016, through May 31, 2018.
Two neurologists who reviewed the findings weren’t surprised that COVID was linked with stroke.
“Infections and other inflammatory conditions are established risk factors for stroke, so it is not surprising that patients with COVID-19 disease might have stroke as a complication of the infection,” said Dr. Larry Goldstein, professor and chairman of neurology at the University of Kentucky.
COVID-19 disease has also been associated with blood clots that could increase stroke risk, he said.
Dr. Salman Azhar is director of stroke at Lenox Hill Hospital in New York City. He said, “This virus has a predilection to cause some level of clotting, and we think that maybe it’s because of increases in inflammation in the body.”
Azhar explained that COVID-19 attacks the cells that line blood vessels, which is one reason for the increased risk for blood clots leading to stroke. Also, the virus increases the production of clotting factors, he said.
Antibodies also play a role in the development of stroke, Azhar said.
“There are antibodies that we’ve known for a long time, nothing to do with this virus, but we know increase people’s risk to have strokes and other blood vessel clots, and we are seeing them in a higher incidence in patients with COVID-19,” Azhar said.