Patients who recover from coronavirus may suffer from cognitive issues post-infection, particularly those who develop a severe case of the illness, a new study suggests. The study, which is not yet peer-reviewed, analyzed data from 84,285 Great British Intelligence Test participants who completed a questionnaire regarding suspected and biologically confirmed COVID-19 infection.
The test is part of an ongoing collaborative project with BBC2 Horizon and was not advertised as a coronavirus-related questionnaire, the study authors noted.
Of the test participants, 60 reported being put on a ventilator, 147 others were hospitalized but did not need a ventilator, 176 received medical assistance at home for respiratory difficulties, 3,466 had respiratory issues but did not receive medical assistance, and 9,201 were ill without respiratory symptoms. The team said 361 self-reported having a positive biological test.
The research team, led by Imperial College London’s Dr. Adam Hampshire, found that people who had recovered exhibited significant cognitive deficits when accounting for age, gender, education level, income, racial-ethnic group and pre-existing medical disorders.
For participants who reported being hospitalized and placed on a ventilator, researchers found a 10-year decline in cognitive performance. The researchers said the findings echo previous studies involving patients hospitalized for respiratory diseases, but were surprising for patients who remained at home.
“[Cognitive deficits] were of substantial effect size for people who had been hospitalized, but also for mild but biologically confirmed cases who reported no breathing difficulty,” the researchers wrote in a post published on MedRxiv. “Finer grained analyses of performance support the hypothesis that COVID-19 has a multi-system impact on human cognition.”
However, experts not involved in the study told Reuters that findings should not be viewed as definitive, as the test did not measure for cognitive function pre-infection, and did not complete lengthy follow-up.
“Overall (this is) an intriguing but inconclusive piece of research into the effect of COVID on the brain,” Derek Hill, a professor of medical imaging science at University College London, told Reuters. “As researchers seek to better understand the long term impact of COVID, it will be important to further investigate the extent to which cognition is impacted in the weeks and months after the infection, and whether permanent damage to brain function results in some people.”
The team said their findings should prompt more research into cognitive deficits in people who have survived coronavirus.