WEDNESDAY, Feb. 17, 2021 (HealthDay News) -- One of the least understood effects of COVID-19 infection is "brain fog," a kind of mental confusion that can take hold among seriously ill patients, sometimes lingering long after recovery.
Now, a new study has spotted a possible neurological clue in the form of highly unusual cell clusters in the brains of people who had COVID-19.
"What we're talking about is a situation where patients feel fuzzy and foggy in their thoughts," said study lead author Dr. David Nauen.
"It's when you're extremely tired and sluggish, and your mental activity just doesn't seem to be working as crisply and sharply as usual. And it's been reported among COVID-19 patients still under care and afterwards, during the long recovery phase," he explained.
"We thought it must be due to something affecting the brain, because we know other viruses can certainly affect the brain, sometimes with severe neurologic consequences," said Nauen, who's an assistant professor in the department of pathology at Johns Hopkins University, in Baltimore.
So Nauen and his colleagues set out to analyze the brains of COVID-19 patients who had succumbed to their illness.
Between April and May of 2020, autopsies were performed on the brains of 15 randomly selected COVID-19 patients, as well as on two patients who had not been infected.
The first surprise? "There was none of the classic signs of viral disease of the brain, like inflammation and lymphocytes [white blood cells]," Nauen said.
The second surprise? "Instead, we saw unusual cells in the capillaries, called megakaryocytes, that I had never seen in the brain," he noted.
A megakaryocyte "is a cell that normally lives in the bone marrow, where we make red and other blood cells. It makes the platelets that help us clot, in order to heal," Nauen said. "But it's really, really unusual to see them in the capillaries of the brain, because capillaries are like fine little tubes bringing oxygen throughout the brain. So finding megakaryocytes in these tubes is like finding a football stuffed into a really small pipe in your house. Nothing is going to go through."
Story Credit to Alan Mozes and WebMD