We all know that COVID-19 can cause long-term fatigue and brain fog. However, one of the toughest tests to date on the long-term cognitive effects of severe infection has yielded very disturbing results.
In a study comparing 46 severe COVID-19 patients with 460 adequate controls, the researchers found that after six months, the psychological effects of severe COVID-19 could be equivalent to 20 years of old age – 50 to 70 years – or a loss of 10 IQ points. .
Mental changes, in particular, were different from those observed in early dementia or general old age.
“Cognitive impairment is common to a wide range of neurological disorders, including dementia, and even normal aging,” says neurologist David Menon. The senior author of the study was Cambridge University in the United Kingdom.
The new document does not worry many of us with COVID, but rather examines the severity of cognitive changes after severe cases of infection, so we begin to understand how to mitigate them.
“In the UK alone, tens of thousands of people have received intensive care with COVID-19 and many more have become seriously ill but not hospitalized,” said Adam Hampshire, a lead researcher and cognitive scientist at Imperial College London.
“It means that a lot of people are still having cognitive problems after many months. We urgently need to look at what can be done to help these people.”
The experiment involved 46 people who visited Addenbrook Hospital in Cambridge between March and July 2020 due to COVID-19. Sixteen of them were placed in mechanical ventilation during their stay.
Researchers used a test tool called Cognitron, an average of six months after infection, to see how they worked in areas such as memory, attention, and thinking, as well as anxiety, depression, and post-traumatic stress disorder.
The researchers did not have test results to compare these people before they became ill with COVID. Instead, they did the next best thing and compared the results with a control group of 460 people.
These results were mapped based on 66,008 members of the general public to see how far they had deviated from expected scores in terms of age and demographics.
The results showed that survivors of severe COVID responded more vaguely and more slowly than the general public.
The magnitude of the cognitive losses was similar to the effects of aging between the ages of 50 and 70, and was equivalent to a loss of 10 IQ.
The accuracy of verbal analogy tasks — people being asked to find similarities between words — had the greatest impact. This is an anecdotal report that people have difficulty finding the right word after an infection and that their brains seem to be moving slowly.
Interestingly, although patients reported varying degrees of fatigue and depression, they found that the severity of the initial infection was better able to predict cognitive outcome than the survivor’s current mental health.
“These results show that both fatigue and mental health are known to be chronic [consequences] COVID-19 may be somewhat independent of the cognitive deficits observed in their severity, ”the researchers wrote.
A little good news, later, was that there were some signs of recovery, but it was gradual.
“We observed some patients up to ten months after an acute infection, so we noticed a very slow improvement,” Menon said.
“While it’s not statistically significant, it’s at least going in the right direction, but some of these people may never fully recover.”
This study looked at only the most extreme of hospitalized patients, but there are many other studies that have shown that “mild” cases can also cause similar cognitive effects.
It is still unclear why and how the SARS-CoV-2 virus causes this cognitive decline.
Previous studies have shown that during severe COVID, the brain reduces glucose consumption in the frontoparietal area, which is involved in attention, problem solving, and memory. It is also known that the virus can directly affect the brain.
However, the researchers believe that the alleged culprit is not a direct infection, but a set of factors: a lack of oxygen or a lack of blood supply to the brain; vascular coagulation; and microscopic blood.
There is also evidence that the body’s own immune and inflammatory reactions can have a significant effect on the brain.
“Future work will focus on mapping the cognitive deficits of biomarkers of major neurological pathologies and inflammation and long-term monitoring of recovery in the chronic phase,” the researchers wrote.
Until then, if you still feel slow and foggy after recovering from COVID-19, you are certainly not alone.
The study was published eClinical Medicine.