The Covid-19 pandemic has caused growing concern around the associated neurological risks, including stroke. Researchers set out to understand the short-term risk of stroke among patients hospitalised with the virus.
Ramin Zand and Vida Abedi, researchers from the Geisinger Health System and authors of the paper, told NR Times:
“Since the emergence of the pandemic, several cases of cerebrovascular events were reported among patients with SARS-CoV-2 and highlighted in the news. However, these observations were based on small studies or limited observations and a large multinational study was needed to have a clear answer.”
They collected information on more than 18,00 patients who had been hospitalised for more than 24 hours across the US, Canada, Brazil, Greece, Italy, Finland, Turkey, Lebanon, Iran, India and New Zealand, and found that 0.9 per cent of patients had a stroke.
They used this data to calculate the risk of stroke, which came out at 0.5 per cent among the patients. This, they say, is similar to the risk of stroke in patients with the flu.
Among the 156 stroke patients, 79 per cent had acute ischaemic stroke, with an average age of 69; 17 per cent had intracerebral/subarachnoid haemorrhage, with an average age of 63; and four per cent were diagnosed with cerebral venous or sinus thrombosis, with an average age of 50.
The researchers also boke this risk down by each country and found that the risk of stroke in patients with Covid-19 were 1.2 per cent in the US, O.5 per cent in Europe, 0.3 per cent in Asia and no risk in Oceania.
‘This difference might be due to many factors, including policy variation among different healthcare systems for the hospitalization of SARS-CoV-2 infected patients; some centres had relaxed criteria for admission of positively tested patients, while the others were overwhelmed and adopted strict criteria to hospitalise patients,’ the paper, published in The Lancet, states.
The researchers conclude that being on mechanical ventilation and having a history of heart disease affect the risk of stroke when infected with Covid-19.
“Mechanical ventilation is a surrogate of the disease severity; at the same time, by itself it increases inflammation and hypercoagulability, which are risk factors for stroke. History of heart disease is also a surrogate for vascular complications and share risk factors with stroke,” the researchers say.
While studies have already looked at Covid-19 and stroke risk, the researchers aren’t aware of any other study that has looked at and calculated the risk across multiple countries.
