Patients who have had severe Covid risk brain aging for 20 years

People hospitalized for severe Covid could lose up to 10 points of IQ in the six months following the infection, that is an intellectual loss equal to the cognitive decline which is experienced on average from 50 to 70 years. While it is currently unclear how permanent this cognitive impairment is, given the large number of severely affected individuals around the world, the overall impact could be enormous. This was revealed by a study conducted by a team of scientists from the University of Cambridge and Imperial College published in a magazine linked to The Lancet.

The damage of Long Covid

There is growing evidence that Covid-19 can cause lasting cognitive and mental health problems, with recovered patients reporting various symptoms including fatigue, fog in the brain, trouble remembering words, sleep disturbances, anxiety, post-traumatic stress disorder. Long Covid pu affect up to 10% of those healed and cause symptoms such as depression and anxiety disordersUp to one year after the infection could arise cardiovascular diseases and there is a suspicion that Covid may also affect the intestinal microbiota.

Even mild cases can lead to persistent cognitive symptoms: a study by the University of Oxford e published in Nature concluded that Covid can reduce gray matter as much as 10 years of aging in people aged 51 to 81 infected but not hospitalized.

Cognitive tests

In this latest study, Cambridge researchers evaluated the outcome of several cognitive tests performed six months after infection on 46 patients admitted to intensive care for Covid, comparing them with the outcome of cognitive tests performed on a control population of 66,000 individuals. Sixteen of these patients underwent controlled mechanical ventilation and all had been hospitalized between March and July 2020, at Addenbrooke hospital.

To carry out the tests, the Cognitron platform was used, which measures different aspects of the mental faculties such as memory, attention and reasoning. Anxiety, depression and post-traumatic stress disorder were also assessed with specific scales. The data that emerged were compared with those of the control group.

The results

In those recovered from Covid, various cognitive deficits have emerged: from the reduction in the speed of information processing, to the reduction of the ability to understand language. The effects were stronger for those who required mechanical ventilation. Comparing the patients with 66,008 individuals in the control group, the researchers estimate that the extent of cognitive loss on average is similar to that sustained over the course of twenty years, between the ages of 50 and 70, and this is equivalent to losing 10 IQ points. . Previous studies have also shown that Covid affects the ability to use sugar as gasoline by neural areas that are neuralgic for attention, working memory, problem solving.

The Covid footprint

Professor David Menon of the Division of Anesthesia at the University of Cambridge, senior author of the study, said: Cognitive impairment common to a wide range of neurological disordersincluding the dementiaand even routine aging, but the patterns we’ve seen – the Covid-19 “fingerprint” was distinct from all of these.

Although it is now recognized that people who have recovered from severe Covid-19 disease can exhibit a broad spectrum of symptoms of poor mental health – depression, anxiety, post-traumatic stress, poor motivation, fatigue, low mood and disturbed sleep. – The team found that acute disease severity is the best way to predict cognitive deficits and there is a strong correlation between disease severity and cognitive decline.

The causes

Covid is likely to promote cognitive decline in various ways, for example by damaging the brain due to an excess of immune reaction or because the infection causes micro hemorrhages or micro ischemias in different neural areas. It remains to be seen how permanent this damage is and what the long-term resilience is.

The impact on the brain

The long-term impact of Covid on the brain is not negligible: in England alone 40,000 people have been hospitalized in intensive care due to Covid, this means that post-covid cognitive deficits can affect a large number of people in the world, Adam points out. Hampshire of Imperial College London, first author of the study. The research analyzed hospitalized cases but the team points out that even those who were not in such a serious condition as to need hospitalization could experience mild signs of impaired cognitive abilities.