Cognitive damage from severe Covid-19 is equivalent to 20 years of aging

Cognitive impairment as a result of covid-19 severe is similar to that suffered between the ages of 50 and 70, and is equivalent to losing 10 IQ points. So says a team of scientists from the University of Cambridge and Imperial College London (United Kingdom), in a study published in the journal ‘eClinicalMedicine’.

The work suggests that the effects of covid-19 are still detectable more than six months after the acute illness and that any recovery is gradual, at best. There is growing evidence that covid-19 can cause long-lasting cognitive and mental health problems, and recovered patients have symptoms including fatigue, ‘brain fog’, trouble remembering words, sleep disturbancesanxiety and even post-traumatic stress disorder months after infection.

In the UK, a study found that one in seven people surveyed reported having symptoms including cognitive difficulties 12 weeks after a positive COVID-19 test. While even mild cases can cause persistent cognitive symptoms, one-third to three-quarters of hospitalized patients reported experiencing cognitive symptoms three to six months later.

To explore this link with greater detail, a team of researchers analyzed data from 46 people who received hospital care -in the ward or in the intensive care unit- for covid-19 at Addenbrooke’s Hospital, which is part of the hospital network of the University of Cambridge. Sixteen patients received mechanical ventilation during their stay at the center. All patients were admitted between March and July 2020.

Patients underwent detailed cognitive tests an average of six months after their acute illness using the Cognitron platform, which measures different aspects of mental faculties, such as memory, attention and reasoning. Scales measuring anxiety, depression and post-traumatic stress disorder.

The effects were strongest for those who required mechanical ventilation. Comparing the patients with 66,008 members of the general public, the researchers estimate that the magnitude of cognitive loss is similar on average to that which occurs with aging 20 years, between ages 50 and 70, and that this equivalent to losing 10 IQ points.

Survivors of severe covid-19 scored particularly low on tasks such as verbal analogical reasoning, a finding that supports the commonly reported problem of word-finding difficulty. They also showed slower processing speeds, which aligns with previous post-Covid-19 observations of decreased brain glucose consumption within the brain’s frontoparietal network, which is responsible for attention, complex problem solving, and memory of events. work, among other functions.

“Cognitive impairment is common to a wide range of neurological disorders, including dementia and even routine aging, but the patterns we saw, the ‘fingerprint’ cognitive impairment of covid-19, was distinct from all of these,” David says. Menon, from the Division of Anesthesia at the University of Cambridge. While it is now well established that people who have recovered from severe illness from covid-19 can have a wide spectrum of symptoms of poor mental health (depression, anxiety, post-traumatic stress, low motivation, fatigue, low mood, and sleep disorders)the team found that severity of acute illness best predicted cognitive deficits.

Patients’ scores and reaction times began to improve over time, but the researchers say any recovery in cognitive abilities was gradual at best and was likely influenced by a number of factors, including age. disease severity and its neurological or psychological impacts.

“We follow some patients until 10 months after your acute infection, so we could see a very slow improvement. While this was not statistically significant, it is at least going in the right direction, but it is very possible that some of these people may never fully recover,” Menon said. There are several factors that could cause cognitive deficits, according to the researchers. It is most likely due to a combination of factors, including inadequate oxygen or blood supply to the brain, blockage of large or small blood vessels due to coagulation, and microscopic hemorrhage.However, emerging evidence suggests that the underlying mechanism important may be the damage caused by the body’s own inflammatory response and immune system.