The new coronavirus does not need to directly invade brain tissue to damage it, a new study suggests.
Researchers examined the brains of 19 patients who died from COVID-19, focusing on tissues from regions thought to be highly susceptible to the virus: the olfactory bulb, which controls the sense of smell, and the brainstem, which controls breathing and heart rate.
In 14 patients, one or both of these regions contained damaged blood vessels – some clotted, and some leaking. The areas with leakage were surrounded by inflammation from the body’s immune response, they found.
But the researchers saw no signs of the virus itself, they report in The New England Journal of Medicine. “We were completely surprised,” said coauthor Dr. Avindra Nath of the National Institute of Neurological Disorders and Stroke in a statement.
The damage his team saw is usually associated with strokes and neuroinflammatory diseases, he said. “So far, our results suggest that the damage … may not have been caused by the SARS-CoV-2 virus directly infecting the brain,” Dr. Nath said. “In the future, we plan to study how novel coronavirus harms the brain’s blood vessels and whether that produces some of the short- and long-term symptoms we see in patients.”