A new study found that 14 out of 1,000 Covid-19 patients hospitalized have had a stroke.
A team of researchers from the University of Cambridge’s Stroke Research Group analyzed 61 published studies that included more than 100,000 patients who had been hospitalized with the virus.
The rate of Covid-19 patients who develop a stroke is higher in the elderly, according to analysis published in the International Journal of Stroke.
It’s also higher in patients with severe infection and pre-existing vascular disease, according to the research. Scientists have wondered whether Covid-19 increases the risk of stroke or whether the association is due to the fact that the virus is spread in people who are already more likely to have a stroke.
The study’s lead author, Dr. Stefania Nannoni, of the Cambridge University Institute of Clinical Neuroscience, said, “The picture is complicated. For example, a number of Covid-19 patients are likely already at increased risk of stroke.
“And other factors like the psychological stress of Covid-19 can add to the risk of stroke. On the other hand, we see evidence that Covid-19 can in some cases trigger a stroke or at least be a risk factor for it.
“First, SARS-CoV2 appears to be more associated with stroke than other coronaviruses – and significantly more than seasonal flu. Second, we see a certain stroke pattern in people with Covid-19, which suggests a causal relationship in at least some of the patients. “
Just over 12 out of 1,000 Covid-19 patients admitted to hospital suffered an acute ischemic stroke, in which the blood supply was cut off due to a clot, according to the study.
Professor Hugh Markus, Head of the Stroke Research Group at Cambridge, said: “Although the incidence of stroke among Covid-19 patients is relatively low, the magnitude of the pandemic means that it may affect many thousands of people worldwide.
“Doctors need to watch out for signs and symptoms of stroke, especially in the most vulnerable groups, taking into account that a risk patient’s profile is younger than expected.”
Cerebral haemorrhages were less common, occurring in 1.6 out of 1,000 cases. Most of these patients had been admitted with Covid-19 symptoms and suffered strokes a few days later.
“Given that patients admitted to the hospital with stroke symptoms may have mild respiratory symptoms associated with Covid-19 or are completely asymptomatic, we recommend that all stroke patients be classified as potential Covid by the results of the hospital screening -19 cases to be treated in hospital are negative, “said Dr. Nannoni.
Covid-19 patients who experienced a stroke were on average 4.8 years older than those who did not. On average, they were six years younger than non-Covid-19 stroke patients.
Unsurprisingly, pre-existing medical conditions also increased the risk of stroke. Patients with high blood pressure were more likely to have a stroke than those with normal blood pressure, while both diabetes and coronary artery disease were at increased risk.
People with more severe infections were also more likely to have strokes. Covid-19-associated strokes were also more severe and had high mortality rates.
There was no significant difference between smokers and nonsmokers, nor between the sexes. Researchers say there are several possible mechanisms behind the link between Covid-19 and stroke.