New research today aims to bring us closer to understanding how covid-19 can cause brain damage. The study suggests that while viral infection may not reach the brain directly in most cases, it can cause the kind of destructive inflammation seen with other neurological conditions, such as stroke.
The research was conducted by U.S. government scientists from the National Institutes of Health and is published in the New England Journal of Medicine. The team studied the brains of 19 people who died after contracting covid-19, using highly sensitive MRI scans, as well as looking at brain tissue under a microscope. These patients ranged in age from 5 to 73 years, and some had health problems such as diabetes and cardiovascular disease.
The researchers were unable to find a trace of the virus in these samples, indicating that it had not infected the brain. But they found blood vessels clogged, thinned and leaking. Near some of these vessels, they also found signs of inflammation, such as higher levels of immune cells in the brain called microglia. All in all, the findings suggest that these patients and others like them develop a defective immune response that attacks the blood vessels in the brain, a response caused by coronavirus infection.
“It simply came to our notice then. Originally, we expected to see damage caused by lack of oxygen. Instead, we saw multifocal areas of damage that are often associated with stroke and neuroinflammatory disease, “said lead author Avindra Nath, clinical director of the National Institute of Neurological Disorders and Stroke. NIH. released by the NIH.
G / O Media may receive a commission
Some studies have found tests that the virus can directly invade the brain and parts of the body connected to the brain, particularly the olfactory bulb that helps us process the smell. Infection of these areas could still explain certain symptoms observed with covid-19, such as loss of smell, at least in some cases. But the new results add to the substantial evidence that inflammation is a key factor in explaining how covid-19 can damage the body, including the brain. Other research has found that covid-19 may increase the risk or worsen inflammation-related health conditions, such as cops i heart damage.
“While it is very possible that we have lost any brain infection with the virus, we believe it is unlikely as we have used various techniques to detect the virus,” Nath told Gizmodo in an email. “These other documents found a very low number of virus copies in the brain, so it is unlikely to be the main driving force behind the pathology.”
Although all patients in this study died, the findings may also help explain why some survivors continue to experience persistent complications even after they have cleared the infection. Often, these complications appear to be neurological and include difficulty focusing, memory problems, and other symptoms collectively known as brain fog.
“Although the patients died suddenly, they did not die from an apparent neurological disease,” Nath explained. The people included in this research are probably not atypical, he said, so “the findings here may also be relevant to long-term survivors.”