Covid may diminish cognitive abilities: Study
NEW DELHI: People who have recovered from Covid-19 possibly suffer from significant cognitive deficit, a study of more than 81,000 people in the UK who took an intelligence test online has suggested, offering more scientific basis to the anecdotal evidence from a growing number of people who report “Long Covid“brain fog.
The research, published in The Lancet’s E clinical Medicine journal late last month, builds on what is slowly emerging in multiple scientific and clinical studies: the Sars-cov-2 virus impacts the brain and its effects can be felt long after people recover.
“Our analyses provide converging evidence to support the hypothesis that Covid-19 infection is associated with cognitive deficits that persist into the recovery phase,” said the team of researchers led by Adam Hampshire of London’s Imperial College, in their report.
The study found that the deficit in cognition was worse among people who had more severe respiratory symptoms and among those who received a confirmed positive test. The researchers adjusted their analysis to account for differences based on age, gender, education or other demographic and socioeconomic variables.
The report is the third in two months to flag the impact Covid-19 has on the brain.
On June 15, a team led by neuroscientists and researchers in Oxford university published the result of their analysis of brain scans of people before and after they had Covid-19. In close to 400 people whose brain scans from before and after the illness were available, they found significant loss of grey matter – which indicates some brain damage – and the areas that were affected involved functions relating to smell and taste, cognition and memory formation.
On July 29, scientists and clinicians attending the 2021 Alzheimer’s Association International Conference reported findings from Greece and Argentina that suggested Covid-19 left older adults with cognitive impairment, including lasting lack of smell and early Alzheimer-like symptoms. “We’re starting to see clear connections between Covid-19 and problems with cognition months after infection,” said one of the scientists, Gabriel de Erausquin of the University of Texas Health
Science Center at San Antonio Long School of Medicine, at the time. “It’s imperative we continue to study this population, and others around the world, for a longer period of time to further understand the longterm neurological impacts of Covid-19,” Erausquin added.
The report from the study led by Hampshire found that the loss in cognitive function may be substantial – more than the average 10-year overall decline people between the age of 20-70 report. “It was larger than the mean deficit of 480 people who indicated they had previously suffered a stroke (0.24SDS) and the 998 who reported learning disabilities (0.38SDS),” the authors wrote.
The test was offered to people who visited popular websites such as those of the BBC as a general intelligence test, and participants were later subsequently asked to answer if they had Covid-19, before more details about their backgrounds were logged by the test.
The assessment was designed to measure distinct aspects of human cognition, spanning planning/reasoning, working memory, attention and emotion processing abilities, the researchers said.