MEDICAL NEWS TODAY
A loss of smell or olfaction is observable in most individuals with a SARS-CoV-2 infection, including after the acute phase.
Therefore, the researchers focused on brain regions either directly involved in processing olfactory information or those connected to the olfactory system.
They found a greater reduction in gray matter volume and a greater increase in tissue damage markers in specific brain regions associated with the olfactory system in participants with SARS-CoV-2 compared with controls.
The gray matter comprises mainly of cell bodies of nerve cells and is involved in information processing.
There was also a greater loss of gray matter across the entire brain and an increase in the volume of cerebrospinal fluid in participants with a SARS-CoV-2 infection.
In other words, besides changes in brain regions associated with olfaction, there were global changes in the brains of participants with SARS-CoV-2. Notably, these brain anomalies were observable in individuals with mild to moderate COVID-19.
Examining differences in cognitive function, the researchers found that the participants with SARS-CoV-2 showed deficits in executive function, which encompasses higher-level cognitive functions such as thinking, reasoning, and decision-making.
Additionally, there was a correlation between a lower performance in the executive function test and atypical brain changes in a part of the cerebellum known to be involved in cognition.
“These findings might help explain why some people experience brain symptoms long after the acute infection. The causes of these brain changes, whether they can be prevented or even reverted, as well as whether similar changes are observed in hospitalized patients, in children and younger adults, and in minority ethnic groups, remain to be determined,” said Dr. Taquet.
However, the researchers noted that they did not have data on whether the participants with a SARS-CoV-2 infection had symptoms of long COVID.
They were also unable to assess the association between the brain anomalies and potential long COVID symptoms. Read more.