Covid, brain damage: “aged 20 years” after more than a year in hospital

A Hospitalization for severe Covid can be so severe that, after 12-18 months, there are still signs of loss of cognitive function. The extent of the damage observed by the researchers? As if the brain had aged 20 years. The largest study to date in the UK to capture the immediate and long-term impact of Covid-19 on patients’ minds has revealed that more than a year after being admitted to hospital, these people have worse cognitive function than control participants who were matched in the study for comparison. The findings correlate with reduced brain volume in key areas, seen in MRI scans. Experts also found evidence of abnormally high levels of proteins in the blood that indicate brain damage.

The research team that investigated these post-Covid cognitive deficits was led byUniversity of Liverpool and King’s College London and involved a large number of scientists from other universities such as the University of Birmingham. The results – obtained as part of the Covid-CNS consortium – are published in ‘Nature Medicine’. “After hospitalization for Covid-19, many people report persistent cognitive symptoms, often referred to as ‘brain fog'”, explains the author of the study Greta Wood, of the University of Liverpool. But “it is unclear whether there is objective evidence of cognitive deterioration and, if so, whether there is biological evidence of brain damage. And, more importantly, whether patients recover over time. In this research we studied 351 Covid patients who were hospitalized. We found that both those with acute neurological complications and those without had worse cognition than would be expected for their age, sex and education level, based on 3,000 control subjects”.

It is true, observe the authors Matthew Broome and Thomas Jackson (University of Birmingham), “the post-Covid cognitive deficits observed in this study are equivalent to 20 years of normal ageing, but we should remember that” the people studied “are patients who have been admitted to hospital with Covid. The results therefore should not be overgeneralised to all people who have had an experience of Covid”, they reassure. “However, the extent of the deficit in all the cognitive abilities tested and the links with brain lesions in brain scans and blood tests, provide the clearest evidence to date that Covid can have significant impacts on brain and mental health long after recovery from respiratory problems”.

In other words, for people affected by these brain injuries, it can be like suddenly going from having the mental alertness of a 50-year-old to that of a 70-year-old, to give an idea of ​​the magnitude of the impact. The work is part of the University of Liverpool’s Covid-CNS clinical neuroscience study, which addresses the critical need to understand the biological causes and long-term outcomes of neurological and neuropsychiatric complications in Covid patients hospitalized. One thing is now certain: “Covid-19 is not simply a lung disease. Often the most severely affected patients are those with complications at the brain level – observes the corresponding author, Benedict Michael, professor of neuroscience at the University of Liverpool – These results indicate that hospitalization with Covid can lead to global and objectively measurable cognitive deficits that can be identified even 12-18 months after hospitalization”.

“The association with biomarkers of brain cell damage in the blood and the reduced volume of brain regions on MRI suggest that there may be measurable biological mechanisms underlying all of this,” the expert continues. “Our group is now working to understand whether the mechanisms we have identified in Covid may also be responsible for similar results in other serious infections, such as influenza.” Long-term research, concludes Gerome Breen of King’s College London, “is now essential to determine how these patients recover or who may worsen and to establish whether this problem is unique to Covid-19 or a brain injury common with other infections. Our work can help guide the development of similar studies on those who have developed Long Covid.” Often these patients “have much milder respiratory symptoms and report cognitive symptoms such as brain fog.” Insight into the dynamics may pave the way “to develop therapeutic strategies.”