Results from a study of 19 deceased COVID-19 patients in the U.S. suggests that those who contract a SARS-CoV-2 infection may be susceptible to brain damage.
Scientists at the National Institute of Neurological Disorders and Stroke (NINDS) have conducted an in-depth examination of brain tissue samples from 19 coronavirus patients who had died between March and July 2020.
After examining the brain tissue samples, scientists say they spotted brain damage caused by thinning and leaky brain blood vessels. The results were published in a letter to 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” Dr. Avindra Nath, clinical director at NINDS, said in a statement. “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.”
Despite the damage that was found in the brain tissue samples, researchers found no signs of SARS-CoV-2 in those tissues, which suggests that the damage was not caused by a direct viral attack on the brain.
“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,” Nath said.
Researchers initially used a special high-powered MRI scanner that is four to 10 times more sensitive than the ones used in most hospitals, to examine brain tissue samples from each patient. The olfactory bulbs and brainstem are regions that are thought to be highly susceptible to COVID-19. Olfactory bulbs control our sense of smell while the brainstem controls our breathing and heart rate.
According to a press release from the NINDS, 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.”
After examining the spots more closely under a microscope, researchers were able to verify the thin leaky blood vessels and inflammation.
“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," Nath said.