THE ESSENTIAL
- Patients who have been infected with Covid-19 can have cognitive after-effects up to a year later, according to two new studies.
- These are characterized by reduced cognitive performance, particularly with regard to executive functions such as solving a puzzle.
- In older people, symptoms are more severe than in younger people.
Over the years, we have become better and better aware of the long-term consequences of Covid-19. Two studies, recently published in the journals The Lancet et Nature Medicineprovide new knowledge on the impact of the virus on cognitive functions.
Covid-19: a greater reduction in cognitive abilities among seniors
The common point of this work is to focus on prolonged cognitive aftereffects. But the population analyzed is not the same. In the study of The Lancetthe thirty-four participants were young and healthy. On the other hand, in that of Nature Medicinethe patients were 54 years old on average.
Results: the researchers observed, in both studies, an impact of Covid-19 on the cognitive faculties of the participants. It is mainly a reduction, particularly in executive functions such as adapting to new situations, finding the solution to a problem, etc. Unsurprisingly, older people have more serious after-effects than young people.
Gray matter atrophy in patients who contracted the coronavirus
“Covid-19 is not always a ‘one shot’ that we get rid of completely“, explains Mahmoud Zureik, professor of epidemiology, at Monde. Indeed, in these two studies, cognitive faculties can be affected for a long time, up to a year after infection.
Scientists have also discovered that Covid-19 can impact the gray matter of the brain. According to theAcademy of Medicinethe latter can be defined as a part of the central nervous system which corresponds to the nerve centers. “The gray matter acts as a nerve center: reception of messages, complex analysis of information, development of responses, can we read in the Larousse Medical. It is characterized by the importance and complexity of its intercellular connections. (…) Degeneration of the gray matter of the cortex is the cause of dementias such as Alzheimer’s disease”.
Thus, during their research, scientists discovered that certain patients who had Covid-19 presented gray matter atrophy. This could also explain certain cognitive difficulties several months after infection with SARS-CoV-2.
