Covid-19 might be over, but brain damage still rages on

Coronavirus and everything that came with it might seem now like a long-ago bad dream. However, for many people, it's still a present and unavoidable reality.

In January 2023, the World Health Organization declared that Covid-19 is no longer a global health emergency, putting a symbolic end to the pandemic humanity has been living in since 2020.

However, WHO Director-General Tedros Adhanom Ghebreyesu stressed that this doesn't mean the coronavirus is no longer causing harm: “That does not mean Covid-19 is over as a global health threat.”

Covid-19 has been a challenge for humanity since 2020 and a 2022 study published by Nature sheds light to what extent it can affect our brains permanently.

There were several clues that the coronavirus affected our brain. Losing the sense of smell while being infected was one of them, along with other symptoms related to long Covid, such as constant fatigue and brain fog.

A University of Oxford research team has proven that our worse fears about might be true.

The methodology of the study was very simple: A group of 800 people who previously were subjected to an MRI scan had another scan after they got infected with Covid-19. The team managed to discover some important changes in the brain.

The Oxford study was published in 'Nature' in March 2022 under the title 'SARS-CoV-2 is associated with changes in brain structure'.

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The scientists found a “greater reduction in grey matter thickness” in the brain of those who had overcome Covid-19.

The most affected areas in the brain, according to the article published in 'Nature', are those associated with the olfactory pathways (orbitofrontal cortex and parahippocampal gyrus).

However, the consequences of Covid-19 go beyond the sense of smell.

Researchers also found “greater changes in markers of tissue damage” in regions associated with the sense of smell and, overall, a reduction in brain sizes.

More worryingly, the Oxford team also detected a "larger cognitive decline" after subjecting the group to tests similar to those applied to people with neurodegenerative conditions.

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Another important finding from the study: Those who were infected by Covid-19 who were older, tended to show bigger damage in the brain matter.

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Research revealed that, on average, people in the sample group lost 0.3% of brain mass. However, in some extreme cases, it could be as much as 2%.

However, the Oxford team considered that it was too early to tell if these damages to the brain are permanent or if they can heal with time and rehabilitation.

The scientists also failed to mention if there's a correlation between the severity of Covid-19 and how much the brain is affected. Maybe lighter or asymptomatic cases have the same results as more serious infections.

The study published by 'Nature' also highlights the possibility that the damage could be the consequence of “a degenerative spread of the disease via olfactory pathways, of neuroinflammatory events, or of the loss of sensory input due to anosmia”.

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In simpler terms, when Covid-19 affects our sense of smell, a part of the brain stops working. Even if the person can smell again, cerebral atrophy remains.

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This would back the idea that Long Covid with neurological symptoms has its origins in the aftereffects of the virus in the human brain.

Before the Oxford study, previous research had found proof of the virus in brain tissue of people who had died of Covid-19, something unusual in respiratory infections.

Finding traces of the coronavirus in the heart and kidneys, which is also unusual, has also occurred.

The danger of the Coronavirus, as this and other studies have pointed out, resides in its ability to enter our bodies and spread out.

Also, being able to hide the gravity of the infection, such as with 'Walking pneumonia'. This condition only reveals its true range when it has caused a lot of harm.

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The Oxford research and many others serve as a reminder of the danger that coronavirus represents. The vaccine and other treatments have helped to mitigate the pandemic, but it's necessary to remain on the lookout.

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Probably the scariest part is that we still don't know the true scope of the damage caused by Covid-19.