Researchers have been steadily gathering important insights into the effects of COVID-19 on the body and brain. Two years into the pandemic, these findings are raising concerns about the long-term impacts the coronavirus might have on biological processes such as aging.
Peering in at the Brain’s Response to COVID-19In a large study published in the journal Nature on March 7, 2022, a team of researchers in the UK investigated brain changes in people ages 51 to 81 who had experienced COVID-19. This work provides important new insights about the impact of COVID-19 on the human brain.
The research team compared people who had experienced COVID-19 with participants who had not, carefully matching the groups based on age, sex, baseline test date and study location, as well as common risk factors for disease, such as health variables and socioeconomic status.
The team found marked differences in gray matter – or the neurons that process information in the brain – between those who had been infected with COVID-19 and those who had not. Specifically, the thickness of the gray matter tissue in brain regions known as the frontal and temporal lobes was reduced in the COVID-19 group, differing from the typical patterns seen in the people who hadn’t had a COVID-19 infection.
In the general population, it is normal to see some change in gray matter volume or thickness over time as people age. But the changes were more extensive than normal in those who had been infected with COVID-19.
Interestingly, when the researchers separated the individuals who had severe enough illness to require hospitalization, the results were the same as for those who had experienced milder COVID-19. That is, people who had been infected with COVID-19 showed a loss of brain volume even when the disease was not severe enough to require hospitalization.
Finally, researchers also investigated changes in performance on cognitive tasks and found that those who had contracted COVID-19 were slower in processing information than those who had not. This processing ability was correlated with volume in a region of the brain known as the cerebellum, indicating a link between brain tissue volume and cognitive performance in those with COVID-19.
What Do These Changes in Brain Volume Mean?Early on in the pandemic, one of the most common reports from those infected with COVID-19 was the loss of sense of taste and smell.
Looking AheadThese new findings bring about important yet unanswered questions: What do these brain changes following COVID-19 mean for the process and pace of aging? Also, does the brain recover from viral infection over time, and to what extent?
Learning how all of these puzzle pieces fit together will help us unravel the mysteries of aging so that we can help improve quality of life and function for aging individuals. And now, in the context of COVID-19, it will help us understand the degree to which the brain may recover after illness as well.