As the world continues to grapple with SARS-CoV-2, the virus that causes Covid-19. There are increasing number of studies being conducted to understand the virus and its implications on the body better. By far it is understood by now even after a person is cured, the body experiences fatigue and the virus takes a long time to recuperate. This research has helped better understand the virus and the possible cure for it. Similarly, researchers have been studying the effect of Covid-19 on the brain.
According to a new study, SARS-CoV-2 does not infect the brain directly, but can still inflict damage to the neurological system. This new finding paves way for providing better treatment to the patients of Covid-19 and also expecting after-effects of the virus on the neurological system.
The study was conducted basis previous experiences sighted by Dr Gabriel A. de Erausquin, a professor of neurology at The University of Texas Health Science Center at San Antonio. He notes that “Since the flu pandemic of 1917 and 1918, many of the flu-like diseases have been associated with brain disorders.” “Those respiratory viruses included H1N1 and SARS-CoV. The SARS-CoV-2 virus, which causes COVID-19, is also known to impact the brain and nervous system,” adds the researcher.
The findings of the study on specifically Covid-19 was published in the journal Brain. The study suggests that the damage to the neurological system, seen in the study, could be a result of the trigger caused by inflammation in other parts of the body. It could also be because of the brain's blood vessels.
"We've looked at more brains than other studies and we have used more techniques to search for the virus. The bottom line is that we find no evidence of viral RNA or protein in brain cells," said researcher James E. Goldman from Columbia University.
For the purpose of the study, the team of researchers examined the brains of around 41 patients, who had died due to the infection. The patients considered for the study were aged between 38 to 97. Most of these patients had been intubated (been on a ventilator) and all had lung damage caused by the virus. The patients had also undergone MRI and CT scans.
The researchers also studied the neurons and the glial cells in the brain through various intensive methods such as RNA. This method can detect viral RNA in the cells.
But despite their intensive search, there was no evidence found of the virus affecting the brain directly. The researchers did find very low levels of viral RNA by RT_PCR, but it was likely due to the virus in the blood vessels.
We already know of people who have lost the sense of smell and taste after getting infected by the virus. According to an article published on Health.Harvard.edu, strokes due to Covid-19 are common, especially in those over 70 years of age. The article was published by Dr Andrew E. Budson, the chief of cognitive & behavioural neurology at the Veterans Affairs Boston Healthcare System. He is also the lecturer of neurology at Harvard Medical School. Budson also chairs the Science of Learning Innovation Group at the Harvard Medical School Academy. The article titled 'The hidden long-term cognitive effects of Covid-19' mentions that silent strokes during the infection occur frequently. The patients are also at the risk factor for both large strokes and dementia. "Silent strokes typically affect the brain’s white matter — the wiring between brain cells that enables different parts of the brain to communicate with each other. This wiring is essential for attention, and when it is damaged, sustained attention is impaired," writes the author.
For the study mentioned early, tests were conducted on more than two dozen brain regions, including the olfactory bulb (responsible for the sense of smell). This was studied because people around the world have been reporting that the virus travels through the nose and affects the sense of smell.
"Even there, we didn't find any viral protein or RNA. Though we found viral RNA and protein in the patients' nasal mucosa and in the olfactory mucosa high in the nasal cavity," Goldman said.