Much of what we know about how COVID affects the brain comes from the study of severe infections. In people with severe COVID, inflammatory cells from outside the brain invade brain tissue and Spread inflammation..May change Blood vessels.. Brain cells Alzheimer’s disease..
first time, New research We investigated the effects of mild COVID (that is, infections that do not lead to hospitalization) on the brain. Findings may further explain some of the brain changes that contribute to long COVID.
Brain scans and tests show change
Many people who have been infected with COVID report problems with “brain fog,” malaise, concentration and memory long after the initial symptoms have subsided. These problems are collectively referred to as “long COVIDs” and can last for months after a mild infection.
Long COVIDs are very common and can have an impact More than half of the people People infected with COVID, even in mild cases.
Scientists have collected data as part of a larger one UK Biobank Database. They examined 785 volunteers evaluated before the pandemic for magnetic resonance imaging (MRI) scans and tests of brain function. We then compared this to the same data collected three years later. At this time, about half of the participants had mild COVID infection and the other half were not COVID infected. This allowed scientists to determine the specific effects of mild COVID infection on brain structure and function.
In the group who developed mild COVID 5 months ago on average, brain tissue was thinned in some brain regions, ranging from 0.2% to about 2% compared to pre-COVID infection scans.This is 1 to 6 years Normal brain aging. The affected brain regions include the parahippocampal gyrus ( memory) And the orbitofrontal cortex are located in the anterior part of the brain Smell and taste..
The post-COVID group also showed a decrease in overall brain size between MRI scans, which was not seen in the non-COVID group, and changed connections between different brain regions of the sensory cortex, which are the areas related to the sense of smell. ..
They had poor performance on tests of attention and mental flexibility. These are findings associated with the sense of smell and volume loss in parts of the cerebellum. Social relations..
Further research is needed to see if COVID affects the brains of young people as well.
Comparison with other illnesses
To show that these changes are unique to COVID and not just associated with respiratory illness, scientists also examined a group of people suffering from pneumonia. They did not see the same change and confirmed that it was related to COVID.
Decreased brain volume is common to many brain disorders and disorders associated with degeneration. Mild cognitive impairment, Alzheimer’s disease, depressionWhen Traumatic brain injuryAbove all.
Memory and attention problems are also common in people with these illnesses and disabilities, indicating that mild COVID infections can accelerate degeneration of the brain. These changes may explain the reported symptoms of long COVID, such as brain fog.
This study does not investigate the mechanism of mild COVID in the brain. However, the authors suggest that this may be due to inflammation, degeneration that spreads through odor-related brain pathways, or sensory deprivation due to odor loss.
Are you all the same?
So does this study prove that all people with mild COVID infections experience these same brain changes and long-term brain degeneration? necessarily.
There are some important things we don’t know yet. This includes whether these brain changes worsen over time or return to normal or previous levels of functioning. Further research over time will help us understand the trajectory of changes in the brain.
It is unclear whether these findings are relevant to young people or children, as this study included only people between the ages of 51 and 81.
The brain changes found in this study were more pronounced in older participants, so older people may be more sensitive. Another study is needed to determine if the same brain changes occur in younger people, or if these findings are common only to older people.
Prior to COVID, there were some differences between the groups, with a small amount of areas deep in the brain. However, these were in different brain regions than those affected after COVID.
Scientists also found that in the COVID-infected group, their thinking and memory brain function scores were slightly reduced.This study did not specifically exclude people with degenerative brain disorders such as:[{” attribute=””>Alzheimer’s or Parkinson’s diseases, but the scientists do not think these would explain the changes they found.
The teenage years are an important period for brain development. So what happens to the brain if milestone events are cancelled?
How can we help students positively refrain their COVID experiences? @Griffith_Uni @WellingtonUni https://t.co/530QPT4pfF
— The Conversation (@ConversationEDU) February 18, 2021
Effects of different variants and vaccination unknown
Because of the nature of the study, information about the strain of COVID people were infected with was not available. So we can’t assume the findings would be the same for people with the now more prevalent Omicron strain.
We also can’t determine the effect vaccination may have in lessening brain changes. Given the timing of the study, it is likely most of the people in the post-COVID group were infected in 2020, so may not have been vaccinated.
This study provides the first important information about brain changes in people with mild COVID infection. Until we have all the information, we should be alert but not alarmed at emerging findings.
Written by Sarah Hellewell, Research Fellow, Faculty of Health Sciences, Curtin University, and The Perron Institute for Neurological and Translational Science, Curtin University.
This article was first published in The Conversation.
