For the first time in the world, a team of Hungarian experts dealt with the brain effects of the coronavirus. From their leader, we learned what functions in the brain can be changed by COVID forever.
Mandiner interview with Ádám Dénes, researcher at the Experimental Medicine Research Institute. Details.
Already at the beginning of the epidemic, it was possible to guess that COVID is a type of disease that, in addition to the lungs, will affect most of the organs, including the brain, by influencing the vascular system and the immune system. At the same time, it was possible to see that patients suffering from COVID-19 show a wide variety of neurological symptoms, and there was more and more information that those who have experienced the disease persist for a long time.
Previously, we dealt with the mechanisms of brain viral infections and how the brain's immune system fights against them. We managed to identify the role of the brain's number one immune cells - the so-called microglia cells - which are extremely important in controlling all kinds of brain viral infections.
We found that if these cells are taken out, or if they don't work well, the viral infection in the brain takes hold, resulting in severe neurological symptoms in experimental models. We hypothesized that something similar could happen in patients suffering from COVID: the inflammation in the brain, and the brain's immune system not reacting properly to it, could explain some of the neurological symptoms caused by the coronavirus.
What exactly are the symptoms of this?
General symptoms of brain virus infections can be: confusion, movement or sleep disorders, and even coma and death in severe cases. These are well known for viral infections that can attack the brain.
At first, we did not know if SARS-CoV-2 could do this, and if so, to what extent, but some symptoms, such as the loss of taste and smell, or the circulation and often sudden deterioration of respiratory functions in patients whose lung conditions make this possible would not justify it, typically suggesting that although the primary infection is in the lungs, the brain may also be involved. Direct or indirect involvement of the central nervous system may also explain why the outcome of COVID-19 may be more severe in some patients. This assumption is supported by the fact that post-covid patients have psychiatric problems such as anxiety, depression, and many other personality disorders.
In fact, there are also patients who, after experiencing COVID, have had diseases that were previously well under control for years, such as personality disorders, anxiety, or attention and memory disorders. Highly qualified senior managers are also known to have lost their ability to work as a result of COVID-19 because they suffer from severe memory impairment. These so-called loss of functions all indicated that normal brain function was impaired.
He mentioned that respiratory function has also collapsed in COVID patients whose lung conditions would not have warranted it.
Strokes were diagnosed in several young people with the coronavirus who did not have this tendency before. Is there an explanation for this? It is a well-known phenomenon that in late winter and early spring, when the flu is raging, the incidence of stroke also increases. This is partly because the infection can disrupt blood clotting processes, which is true for all inflammatory infections, including COVID. During the coronavirus infection, inflammatory substances are produced in the body, as a result of which platelets clump together more easily, and then thrombi (blood clots) can form. In many young people, it was clearly shown that these thrombi caused the blood vessel blockage, and in the case of COVID-19, it is often in the venous system, which is not so typical for acute brain events. This also indicated that the inflammatory state caused by COVID can also affect nervous system processes.
Until now, we knew that the coronavirus is an infection that attacks the lungs.
From what you say, I can hear that the virus can trigger even harder processes in the brain. It is important to emphasize that the lungs are the primary site of infection, but the resulting systemic inflammation already affects many organs. I wouldn't rank them, rather I would say that in addition to the lungs, in addition to organs that are also sensitive to inflammation, such as the spleen, liver or kidney, the brain that regulates their functioning is also very seriously affected.
Since last spring, we have been examining the brain tissue of patients who died of COVID, and we are trying to assess the changes that occur through inflammation, which we also know in other diseases.
You can read the article in its entirety
In our opening picture, Ádám Dénes, a researcher at the Experimental Medicine Research Institute. Photo by Árpád Földházi
