New research being investigated today brings us closer to understanding how covid-19 can cause brain damage. The study suggests that while the viral infection may not directly reach the brain in most cases, it can cause the kind of destructive inflammation seen with other neurological conditions, such as stroke.
The research was conducted by American 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 were between 5 and 73 years old, and some had pre-existing health problems such as diabetes and cardiovascular disease.
The researchers could not find any traces of the virus in these samples, suggesting that it did not infect the brain. But they found clogged, thinned and leaking blood vessels. Near some of these vessels, they also found signs of inflammation, such as higher levels of immune cells in the brain called microglia. The findings suggest that these patients and others like them develop an erroneous immune response that attacks the blood vessels of the brain – a response caused by coronavirus infection.
“We were completely surprised. Originally we expected to see damage caused by a lack of oxygen. Instead, we saw multifocal areas of damage commonly associated with strokes and neuro-inflammatory diseases, ”said senior study author Avindra Nath, clinical director at the NIH’s National Institute of Neurological Disorders and Stroke, in a statement. released by the NIH.
G / O Media can get a commission
Some studies have found testimony that the virus can directly penetrate the brain and parts of the body connected to the brain, especially the olfactory bulb that helps us process odor. Infection of these areas may at least in some cases still be responsible for certain symptoms that occur in covid-19, such as loss of odor. But the new results add to the material evidence that inflammation is an important factor in explaining how covid-19 can harm the body, including the brain. Other research has found that covid-19 may increase or exacerbate the risk of inflammation-related health conditions strokes and heart damage.
“While it is quite possible that we missed any infection in the brain with the virus, we think it is unlikely as we used various techniques to detect the virus,” Nath said in an email to Gizmodo said. “These other articles have found very low virus numbers in the brain, so it is unlikely to be the main driver of pathology.”
Although the patients in this study all died, the findings may also help explain why some survivors experience persistent complications even after the infection has resolved. Often, these complications appear to be neurological and include focus problems, memory problems, and other symptoms collectively known as brain fog.
“Although the patients died suddenly, they did not die of apparent neurological diseases,” Nath explained. The people included in this research are probably not outliers, he said, “the findings here may also be relevant to long-term survivors.”