A team of researchers from the National Institutes of Health, in an in-depth study of how Covid-19 affects patients’ brains, has consistently seen signs of damage caused by thinning and leaky brain blood vessels in print samples. These signs of damage were seen in patients who died shortly after infection.
Furthermore, they showed no signs of SARS-CoV-2 in the print samples, suggesting that the damage was not caused by a direct viral attack on the brain. The findings were published as letters in the New England Journal of Medicine.
“We found that the brains of patients who become infected with SARS-CoV-2 can be prone to micro-blood damage. Our findings suggest that this may be caused by the body’s inflammatory response to the virus ”said Avindra Nath, MD, clinical director at the NIH National Institute on Neurological Disorders and Stroke (NINDS) and lead author of the study. “We hope these findings will help doctors understand the full range of problems that patients may face so that we can find better treatments.”
Although Covid-19 is primarily a respiratory disease, patients often experience brain problems including headache, delirium, cognitive dysfunction, dizziness, obesity, and loss of sense of smell. The disease could also cause strokes and other neuropathologies. Several studies have shown that the disease can cause inflammation and damage to blood vessels. In one of these studies, the researchers found evidence of small amounts of SARS-CoV-2 in the brains of some patients. Nevertheless, scientists are still trying to understand how the disease affects the brain.
In this study, the researchers conducted an in-depth study of brain tension samples from 19 patients who died after experiencing Covid-19 between March and July 2020. Samples from 16 of the patients were provided by Office the Chief Medical Examiner in New York City while the other 3 cases were referred by the pathology department at the University of Iowa College of Medicine, Iowa City. Patients died at a wide range of ages, from 5 to 73 years old. They died within a few hours to two months of reporting symptoms. Many patients had one or more risk factors, including diabetes, obesity and cardiovascular disease. Eight of the patients were found dead at home or in public settings. Three other patients fell and died suddenly.
The researchers first used a magnetic resonance imaging (MRI) scanner that is 4 to 10 times more sensitive than most MRI scanners, to examine samples of the olfactory bulbs and brainstems. from all patients. These regions are thought to be highly susceptible to Covid-19. Decorative bulbs control our sense of smell while the brain system controls our breathing and heart rate. The scans showed that there were plenty of bright spots in both regions, called hyperintensities, which often indicate inflammation, and dark spots, called hypointensities, that represent bleeding.
The researchers then used the scans as a guide to examine the spots more closely under a microscope. They found that blood vessels in the bright spots were thinner than normal and sometimes released blood proteins, such as fibrinogen, into the brain. This was likely to have a protective effect. The spots were surrounded by T cells from the blood and the brain’s own immune cells called microglia. In contrast, the dark spots contained both clotted and leaky blood vessels but there was no immune response.
“It simply came to our notice then. First, we expected to see the damage caused by lack of oxygen. Instead, we saw multifaceted areas of damage typically associated with strokes and neuroinflammatory diseases, ”said Dr Nath.
Finally, the researchers found no signs of disease in the brain tight samples although they used several methods to detect genetic material or proteins from SARS-CoV-2.
“So far, our results show that the damage we saw directly to the brain may not have been caused by the SARS-CoV-2 virus,” said Dr. Nath. “In the future, we plan to study how Covid-19 damages the blood vessels of the brain and whether it causes some of the short-term and long-term symptoms. time we see in patients. ”
(This story was published from a wire group group without text modification.)
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