As COVID-19 infects more and more of us relentlessly, scientists are investigating the strange and frightening damage it can do to our body.
We have known since early in the pandemic that this disease causes more than just the respiratory system, which also causes gastrointestinal conditions, heart damage and blood clotting disorders.
Now, a year into the pandemic, in-depth autopsies of COVID-19 patients have revealed greater details about widespread inflammation and damage to brain tissues. It can help explain the avalanche of neurological symptoms that manifest in some patients, from headaches, memory loss, dizziness, weakness and hallucinations to worse seizures and strokes.
Some people estimate that up to 50 percent of those hospitalized with COVID-19 may have neurological symptoms that can make people struggle to perform even ordinary daily tasks such as preparing a meal.
“We were completely amazed. Originally we expected to see damage caused by a lack of oxygen,” said Avindra Nath, physician and clinical director of the National Institutes of Health (NIH).
“Instead, we have seen multifocal areas of damage commonly associated with strokes and neuro-inflammatory diseases.”
The NIH researchers, including Dr. Myoung-Hwa Lee and Nath, carefully examined the brain tissues of 19 deceased patients. They ranged from 5 to 73 years old and many have risk factors for severe coronavirus, including diabetes and cardiovascular disease.
Using powerful MRI microscopy, Lee and the team identified ten patients with brain disorders. Closer examination under a microscope gave rise to hyperintensities – bright spots in the micrographic image of the brain samples – which showed that the fluorescent microscopy was leaking fibrinogen (a blood protein).
T cells and the brain’s specialized immune cells, microglia, surrounded these spots in a number of patients. there were also dark areas with blood clotting. As a result, the researchers concluded that patients experienced multiple, mini-cerebral hemorrhages – a type of damage usually associated with inflammation in the brain.
“The very small blood vessels in the brain were leaking,” Nath told NPR. “And it was not proportionate – you would find a small blood vessel here and a small blood vessel there.”
It is not only those who are seriously ill enough to require intensive care or to have conditions that have displayed neurological symptoms of COVID-19.
“We have seen this group of younger people without conventional risk factors who have strokes, and patients with acute changes in mental status that are not explained otherwise,” said neurologist Benedict Michael of the University of Liverpool. Earth back in September.
Patients developed errors and developed psychosis. In one case, a 55-year-old woman began seeing lions and monkeys in her home, before believing a friend or family member had been replaced by an identical fraudster (a Capgras delusion).
Despite tests to detect the virus in the brain tissue, Lee and the team found no trace of SARS-CoV-2, but in their report they were cautious: ‘It is possible that the virus has been removed by the time of death or that the number of viral copies was below the detection level by our tests. “
While other studies have found traces of the virus in the brain, the levels were low and seem scarce.
“So far, our results suggest that the damage we saw may not have been caused by the SARS-CoV-2 virus that directly infected the brain,” Nath said. Instead, the damage may be due to the body’s inflammatory response to the virus, he explained.
Due to the low sample size and limited clinical information, the team says they can not draw any direct conclusions yet. However, their findings are consistent with EEC tests that have revealed encephalopathy in COVID-19 patients – disorders in the typical electrical activity of the brain that can mean swelling and inflammation.
It also joins studies showing that the virus can cause other dangerous immune responses that in some cases can cause even more damage than the virus itself has directly.
Researchers are concerned about the implications of encephalitis on people’s long-term health, as it is linked to memory loss and Alzheimer’s disease, and some patients are already suffering from persistent neurological consequences such as chronic fatigue and Guillain-Barré syndromes.
“In the future, we plan to study how COVID-19 damages the blood vessels of the brain and whether it produces some of the short- and long-term symptoms we see in patients,” Nath said.
Their report is in the New England Journal of Medicine.