The possibility that SARS-Cov-2 could directly infect the brain has been a topic of debate among researchers, but a new study confirms that this does not happen, even though the virus can cause significant neurological damage.
In an investigation published in the scientific journal Brain led by the Irving Medical Center at Columbia University in the United States, the autopsies of Covid-19 victims were analyzed, with no signs of the virus present inside the brain cells.
However, the researchers observed “several pathological changes” in the brain, which could explain why critically ill patients experience confusion, delirium, and other neurological influences, and why light patients experience “brain fog” for weeks and months, according to James Goldman, who led the study. Cited by EFE.
Research indicates that the neurological changes that occur frequently in these patients may be due to the inflammation that the virus causes in other parts of the body or in blood vessels in the brain.
Researchers scanned the brains of 41 patients who died during hospital treatment, between the ages of 38 and 97, nearly half of whom had been intubated and all had suffered lung damage from the virus.
The team used several methods to find traces of the coronavirus, such as “in situ” hybridization of RNA, detection of intracellular viral proteins, and the PT-PCR technique.
However, they did not find evidence of a brain cell virus, although they did find very low levels of viral RNA by RT-PCR, which may be – as they consider – the presence of the virus in the blood vessels or leptomeninges covering the brain.
James Goldman said: “We studied the brains more than other studies and used more techniques to find the virus. The bottom line is that we did not find any evidence of the presence of RNA or viral proteins in the brain cells.”
Although some studies confirm that they have discovered its presence in neurons or glial cells (cells responsible for ensuring the survival of neurons), the team believes that this is “the result of contamination and that any virus in the brain is inside the blood vessels”. member.
Although SARS-Cov-2 is not found in the brain, the team discovered an important brain pathology that mostly falls into two categories.
On the one hand, the team found many areas that had been damaged by lack of oxygen, which was not surprising to James Goldman, because the deceased patients were suffering from acute lung disease due to Covid-19.
Some were large areas due to strokes, but most of them could only be detected under a microscope.
The research team believes that these small areas of hypoxia-related damage were caused by blood clots common in severe COVID-19 patients.
The second result was “even more surprising,” given that in most brains, the researchers saw a large number of microglia, an immune cell that lives in the brain and can be activated by pathogens.
There were clusters of microglia that attacked the neurons, and since no virus was found in the brain, it was possible that they were activated by inflammatory cytokines, such as interleukin-6, associated with SARS-Cove-2 infection, Peter Cannul said. Citing EFE, et al.
James Goldman indicated that it is necessary to continue the investigation to understand why some patients continue to develop symptoms after recovering from Covid-19, and are now examining the autopsies of people who died several months after their recovery.
The Covid-19 pandemic has killed at least 298,7891 people around the world, resulting in more than 139 million cases, according to a report issued by Agence France-Presse.
In Portugal, 16,937 people died out of 829,911 confirmed cases, according to the latest bulletin issued by the General Directorate of Health.
The disease is transmitted by a new corona virus, which was discovered in late 2019 in Wuhan, central China.