COVID-19’s Hidden Toll: How Severe Infection Can Steal 20 Years of Brain Function in an Instant

Photo = Getty Images Korea. Those who were hospitalized for severe symptoms of a novel coronavirus (COVID-19) infection were found to have shrunken brains and deteriorated cognitive function. Brain aging, which would normally take 20 years, has accelerated in an instant due to COVID-19.

It is the result of joint research conducted by the University of Liverpool, UK, with the participation of King’s College London and the University of Cambridge. The study was conducted as part of the “COVID-19 Clinical Neuroscience Research” (COVID-CNS) supported by the British government and was published in the medical science journal “Nature Medicine” on the 23rd (local time).

According to a research press release from the University of Liverpool, research subjects admitted to hospital due to severe COVID-19 symptoms were found to have reduced cognitive function even after 12-18 months.

When the brain was imaged using a magnetic resonance imaging (MRI) device, brain volume in key areas was reduced and abnormally high levels of brain-damaging proteins were detected in the blood.

The most surprising thing is that the cognitive decline after corona infection confirmed in this study is equivalent to 20 years of normal aging. However, this has been observed in seriously ill patients requiring hospitalization and should not be generalized to everyone who has experienced COVID-19.

However, the researchers stressed that the decline in function seen in all cognitive tests tested and concerns about brain damage shown in blood test results are the clearest evidence yet that the coronavirus may have a significant impact on the brain and mental health. even after recovery from respiratory problems. .

First author Dr Greta Wood from the University of Liverpool said: “After being admitted to hospital with COVID-19, many people complain of persistent cognitive symptoms called ‘brain fog’ (a persistent feeling of being dizzy, as if there was fog in the head). “However, it was unclear whether there was objective evidence of cognitive decline, if so, whether there was biological evidence of brain damage and, importantly, whether patients recovered over time,” he said, explaining the context. of the study.

The researchers compared 351 people with a history of hospitalization for COVID-19 with 2,927 normal controls. A comparative study of cognition, serum biomarkers, and neuroimaging was conducted over one year.

Among the 351 people, there was a mix of people (54%) who suffered neurological complications due to COVID-19 infection and people who did not (46%).

Overall, cognitive decline appeared. A significant correlation was found between the severity of the initial infection, psychiatric symptoms after the acute phase, and the development of encephalopathy due to complications. Cognitive decline has been associated with increased biomarkers of brain damage in the blood and decreased gray matter volume in the brain. Even in patients without neurological complications, overall cognitive problems were found. Cognitive function showed some improvement immediately after discharge, but subsequent recovery stalled, and most patients remained in a persistently impaired state even a year after infection.

Photo = Getty Images Korea.

“In this latest study, we studied 351 hospitalized COVID-19 patients with and without neurological complications. We found that both patients with and without acute neurological complications of COVID-19 had impaired cognitive function relative to their age, gender, and education level. “This study compared the results with a control group of 3,000 people,” added Dr. Wood.

Benedict Michael, professor of neuroscience at the University of Liverpool, said: “COVID-19 is not simply a lung disease. “The most severely affected patients often experience brain complications,” he said. The study findings show that cognitive decline may be common in people with a history of severe hospitalization after COVID-19 infection worldwide.

He said that cognitive decline was confirmed even after 12-18 months: “This continued cognitive decline was observed not only in patients with neurological complications but also in patients without, suggesting that COVID-19 itself may cause cognitive impairment even without a neurological diagnosis. “. “Furthermore, the association of biomarkers of brain cell damage in the blood with volume loss in brain regions identified by MRI suggests the possibility that there is a measurable biological mechanism that could explain this phenomenon.”

Park Hae-sik, Donga.com reporter pistols@donga.com