Coronavirus patients are at increased risk of experiencing a stroke compared with those of similar age who have not contracted the illness, a major international study has found.
In many cases, the patients did not present typical symptoms of COVID-19, and were not known to have any pre-existing risk factor.
The findings based on the research in 132 centers from 36 countries were published in the medical journal Stroke, with the contribution of 89 authors from around the world, including Lebanon and Iran.
Researchers considered data from patients who were identified as virus carriers after being hospitalized as a consequence of a stroke or other serious brain event.
Seventy-one medical centers in 17 countries had at least one patient whose clinical situation met the criteria for the study, which surveyed 432 subjects.
“Surprisingly, many patients that we identified as having both corona and a stroke did not present the typical clinical symptoms of coronavirus,” said Hebrew University Prof. Ronen Leker, who participated in the study. “Some 40% of them had no fever, shortness of breath, abdominal pain, diarrhea and so on. But since all patients who were admitted to the hospital were tested, we were able to identify them as virus carriers.”
The data also showed that coronavirus patients under 55 were more likely to suffer from strokes related to large vessel occlusion – which tends to lead to poorer outcomes – as opposed to small vessel occlusion, while the opposite is true in the non-corona affected population.
Leker said the findings showed that the strokes were likely caused or influenced by the virus.
“Many patients, especially the younger ones, did not present any traditional risk factor for strokes, such as high blood pressure, high cholesterol, diabetes, heart problems and so on,” he said. “Basically, individuals younger than 55 had no risk factors other than COVID.”
Leker said that there are many possible connections between the virus and brain events.
“The brain is one of the organs that the coronavirus targets, as well as blood vessels in the brain,” he said. “We believe that the disease might lead to local thrombosis. In addition, COVID affects the heart – can cause an irregular heart rhythm – which can clot the organ, migrate to the brain, and produce a stroke.”
He said that these phenomena and the study’s findings have nothing to do with the coronavirus vaccines.
“If anything, the vaccine can reduce the risks, and this study was conducted way before the vaccine was available,” Leker stressed.
While the study showed that strokes represent a possible complication of COVID, he said that the occurrence is rare.
Leker expressed hope that further research would shed more light on the connection between the coronavirus and strokes, which would ensure better treatment.