Covid infections can damage essential brain functions that regulate memory and thought processes, according to new research.
Researchers at King’s College London have shown that when brain cells are directly exposed to blood drawn from delirious Covid-19 patients, there is an increase in cell death and a decrease in the formation of new brain cells.
Previous research shows that 20 to 30 percent of Covid-19 patients develop neurological symptoms such as delirium.
Delirium is a state of mental confusion that can occur when you become medically ill and is associated with undesirable consequences, including prolonged hospitalization and death.
This study provides insight into the general effects of Covid-19 infection on the brain.
The researchers took the cells from the hippocampus – an area of the brain associated with cognitive, memory and learning skills – and assessed how they were affected by exposure to the serum of infected patients.
The findings, published in Molecular Psychiatry, could help inform potential treatments to reduce symptoms of confusion, disorientation and memory deficits in Covid-19 patients.
“Research is mounting to suggest that severe Covid-19 infection has a neurological element, but we have little understanding of what’s happening in the brain to produce these symptoms,” said Dr. Alessandra Borsini, first author of the study.
This is the first research using blood samples from Covid-19 patients suffering from delirium to study how the infection affects brain functions, including memory and thought processes.
“We found that new brain cell formation falls sharply and cell death increases, and these are likely mechanisms behind delirium and possibly other neurological symptoms in Covid-19 patients.”
Although the respiratory symptoms of Covid-19 are well known, the cellular and molecular mechanisms explaining delirium and other neurological symptoms are not well understood.
The development of neurological symptoms in Covid-19 patients likely involves an overactive immune response, known as a cytokine storm, with overproduction of several inflammatory proteins.
Once these cytokines have been produced by the immune cells in the body in response to infection, they can then travel from the blood to the brain and affect brain mechanisms directly. However, which cytokines are directly relevant for the development of neurological symptoms is currently unknown.
The study collected serum samples from 36 patients admitted to the NHS Foundation Trust at Guy’s and St Thomas in London during the first wave of the Covid-19 pandemic in the UK.
Half of these patients had symptoms of delirium, while the other half did not have these symptoms at the time of hospital admission.
Researchers treated cells from the hippocampus directly with the serum samples and observed the effects on cell generation and cell death, as well as levels of various cytokines.
The results showed that treatment with serum from delirious Covid-19 patients increased cell death and reduced the formation of new brain cells.
‘These neurological symptoms are of great concern to patients and their families and we hope our research can help identify which treatments are best suited to alleviate or prevent these symptoms,’ said Professor Carmine Pariante, another author the study.
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https://metro.co.uk/2022/10/07/severe-covid-infections-can-harm-key-brain-functions-finds-study-17523034/ Severe Covid infections can impair important brain functions, a study finds