On December 30, The U.S. Department of Health and Human Services (HHS) announced about National Institutes of Health (NIH) research results. In an in-depth study of how COVID-19 affects a patient’s brain, National Institutes of Health researchers consistently spotted hallmarks of damage caused by thinning and leaky brain blood vessels in tissue samples from patients who died shortly after contracting the disease. In addition, they saw no signs of SARS-CoV-2 in the tissue samples, suggesting the damage was not caused by a direct viral attack on the brain. The results were published as a correspondence in the New England Journal of Medicine.
“We found that the brains of patients who contract infection from SARS-CoV-2 may be susceptible to microvascular blood vessel damage. Our results suggest that this may be caused by the body’s inflammatory response to the virus” said Avindra Nath, M.D., clinical director at the NIH’s National Institute of Neurological Disorders and Stroke (NINDS) and the senior author of the study. “We hope these results will help doctors understand the full spectrum of problems patients may suffer so that we can come up with better treatments.”
COVID-19 Symptoms And Danger
The coronavirus (COVID-19) disease continues to spread around the world, with almost 74 million cases and over 1.6 million deaths as of December 16, 2020. In the United States, the number of infections has risen dramatically since the first week of March, and the U.S. now has more confirmed cases and deaths than any other country worldwide. All 50 states have been affected, with New York reporting the highest number of deaths and Texas and California with the highest number of cases in the United States.
Although COVID-19 is primarily a respiratory disease, patients often experience neurological problems including headaches, delirium, cognitive dysfunction, dizziness, fatigue, and loss of the sense of smell. The disease may also cause patients to suffer strokes and other neuropathologies.
Several studies have shown that the disease can cause inflammation and blood vessel damage. In one of these studies, the researchers found evidence of small amounts of SARS-CoV-2 in some patients’ brains. Nevertheless, scientists are still trying to understand how the disease affects the brain.
The NIH Research
According to the information from HHS, in the NIH research, the researchers conducted an in-depth examination of brain tissue samples from 19 patients who had died after experiencing COVID-19 between March and July 2020. Samples from 16 of the patients were provided by the Office of the Chief Medical Examiner in New York City while the other 3 cases were provided by the department of pathology at the University of Iowa College of Medicine, Iowa City.
The patients died at a wide range of ages, from 5 to 73 years old. They died within a few hours to two months after 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. Another three patients collapsed and died suddenly.
Was used a special, high-powered magnetic resonance imaging (MRI). The scans revealed that both regions had an abundance of bright spots, called hyperintensities, that 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 the bright spots contained blood vessels that were thinner than normal and sometimes leaking blood proteins, like fibrinogen, into the brain. This appeared to trigger an immune reaction. 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 no immune response.
“We were completely surprised. Originally, we expected to see damage that is caused by a lack of oxygen. Instead, we saw multifocal areas of damage that is usually associated with strokes and neuroinflammatory diseases,” said Dr. Nath, – “So far, our results suggest that the damage we saw may not have been not caused by the SARS-CoV-2 virus directly infecting the brain. In the future, we plan to study how COVID-19 harms the brain’s blood vessels and whether that produces some of the short- and long-term symptoms we see in patients.”