When our planet was covered by the Covid pandemic, scientists began to worry: would a new infection damage the most important and irreplaceable organ: the brain?
Photo: Svetlana MAKOVEEVA
DOES THE BRAIN AGE AFTER COVID-19?
When our planet was covered by the Covid pandemic, scientists began to worry: would a new infection damage the most important and irreplaceable organ: the brain? Most of those who have been ill (according to research, up to 46%, that is, almost one in two) complain of characteristic symptoms of damage to the central nervous system (CNS), doctors note. This includes a violation of cognitive functions: memory, concentration, performance. Many people describe this condition as “brain fog.” But what exactly happens in the minds of those infected by the coronavirus? Does the brain suffer temporarily or do dangerous and irreversible changes occur? These questions are asked by researchers around the world.
Recently another scientific work appeared. And he was immediately invaded by rumors and speculation. “Covid is aging our brains by 20 years!” – Such terrifying headlines circulated in foreign and some Russian media. Having long been closely involved in the issues of aging and longevity, we at the KP science and medicine department immediately began to doubt: the assessment of brain decrepitude seems very suspicious. At least because today there are no precisely established and generally accepted criteria for measuring the biological age of this organ. Who and why decided that the brain after Covid ages at 20 years, and not at 5 or, say, 10 years? Are the changes in the central nervous system irreversible or do they disappear over time? After all, the resilience of the human body is known to be unique: the brain can function successfully even if an important part is lost.
To find out what the researchers really found, we turned to the primary source: a scientific publication by a team at the Infectious Neurobiology Laboratory at the University of Liverpool in the United Kingdom. And we discussed the results with the neurologist, specialist in cognitive dysfunction and neurorehabilitation, member of the European Academy of Neurologists, Oybek Turgunkhuzhaev.
WHAT AND HOW THE RESEARCHERS STUDYED
Researchers studied blood samples from patients who were hospitalized with moderate or severe Covid and subsequently complained of neurological symptoms, especially mental confusion. The tests were carried out in the acute phase of the disease, as well as immediately after recovery and after a period of 6 or more weeks, the scientific work reports. For comparison, we analyze the indicators of healthy people.
At the height of the infection, the patients had inflammatory markers in their blood, as expected. They are well known to anyone who has regular blood tests: elevated ESR (erythrocyte sedimentation rate) and elevated C-reactive protein. But in addition, scientists carried out in-depth studies that are not carried out in regular medical laboratories. That is, they measured biomarkers that are considered indicators of neuroinflammation. That is, an inflammatory process in the nervous tissue, including the brain. These are certain antibodies and proteins.
The result was alarming. “Markers of brain damage are present in the blood weeks after recovery, although blood tests for inflammation return to normal. “This suggests the possibility of ongoing inflammation and damage within the brain itself that cannot be detected by routine testing,” said lead researcher and director of the Infectious Neurobiology Laboratory at the University of Liverpool, Professor Benedict Michael. Let us keep in mind that in the scientific work not a single word is mentioned about the aging of the brain at 20 years old (or even any words at all).
“LIKE AN ABNORMAL RESPONSE OF THE IMMUNE SYSTEM”
“The signs of brain damage that we observed may be due to abnormal reactions of the body’s immune system,” write the authors of the scientific article. What does it mean? Why are there no indicators of inflammation in a routine blood test, but signs remain that indicate a latent inflammatory process in the brain?
“We are talking about fundamentally different types of inflammation,” explains Oybek Turgunkhuzhaev. – In the midst of Covid, like any infection or other acute condition, we see signs of acute inflammation. This is what a regular blood test shows: elevated ESR and C-reactive protein.
But there is also inflammation at another level. This is a systemic chronic inflammatory process. It is believed that it may be triggered by an abnormal immune reaction. In this case, our immune system fails. And it begins to fight not with real enemies – viruses, bacteria, as in acute inflammation, but with its own cells and tissues of the body. Neuroinflammation is associated with this inflammatory immune response in the brain.
With Covid, inflammation appears to cause damage to so-called glial cells. In fact, it is a framework that supports and helps ensure the vital activity of our nerve cells (neurons) and their processes (axons), says the expert. “Imagine the frame of a garland: if it collapses, the entire structure collapses. That is why the nerve cells of the brain cannot function normally,” describes the doctor.
The fact that markers of chronic neuroinflammation persist after recovery is a truly alarming fact, confirms Oybek Turgunkhuzhaev. Since such inflammation is associated with brain aging and the development of neurodegenerative diseases: Alzheimer’s, Parkinson’s and other ailments that lead to dementia. But! There are important nuances.
First of all, very little time has passed. We do not know in what scenario the situation will develop further for those affected by Covid. In principle, glial cells in the brain are capable of regenerating. At the same time, the chances of restoring normal functioning of the central nervous system will depend on how large a volume of neuroinflammation it has time to cover, the doctor notes. Today all this is unpredictable.
Secondly, there are still no convincing arguments that allow us to speak of irreversible aging of the brain after Covid for a certain number of years. Or claim that the coronavirus safely and significantly increases the risk of Alzheimer’s, Parkinson’s, etc. for all.
TO THE POINT
How to treat mental confusion?
“There are still many unanswered questions in this area,” says Dr. Turgunkhuzhaev. – But today clinical practice shows that the use of certain classes of antidepressants produces a notable effect.
The secret is that these drugs affect not only the emotional sphere. Antidepressants affect neurotransmitters, that is, substances that transmit various signals in the brain. “As a result of these reactions, we observed an improvement in memory and concentration in patients who complain of neurological complications after Covid,” explains the doctor.
