Inflammation is likely the cause of brain fog and memory loss during a long period of COVID, according to a new study from the University of Washington Medicine.
Dr. William Banks, a professor in the UW Division of Gerontology and Geriatric Medicine and associate chief of staff for research and development at the VA Puget Sound Health Care System, had a case of long COVID, which is a version of the virus that persists for months and increases the risk of long-term impairment.
“I couldn’t remember things and I lost my ambition to remember,” Banks said. “The two together were terrible.”
Banks, Shelly Erickson and a team of researchers from the University of Washington School of Medicine, the Puget Sound Veterans’ Health Care System and Oregon University of Health Sciences conducted a study on COVID.
The findings add a major piece to the puzzle of how COVID-19, a lung disease, becomes long COVID, a brain disease, UW Medicine said.
Using mice, they observed that the S1 protein, after attaching to all SARS-CoV-2 variants, crosses the blood-brain barrier. Once there, the protein caused inflammation. This inflammation can spur learning and memory problems and hasten the effects of Alzheimer’s disease and other cognitive disorders, Banks said.
“SARS-CoV-2 causes inflammation in the brain. This is the critical point,” Banks said. “Basically, the S1 protein, either on its own or as part of the virus, enters the brain and you’re off to the races.”
In the study, the researchers used two viruses that were non-infectious and both easily entered the brains of mice. The S1 protein is the little red flower in most images of the coronavirus and determines where the virus goes. The researchers showed that the virus could not cross the blood-brain barrier without the S1 protein. Of the five COVID variants, Omicron broke through the barrier the easiest.
They also discovered that the S1 protein can be blocked from the brain with antibodies.
That’s another reason to get vaccinated since the vaccine produces antibodies that block the S1 protein from entering the brain, Banks said.
People with Alzheimer’s disease and similar illnesses appear to be particularly at risk when the S1 protein crosses the brain.
“It can make it worse, bring it on earlier, or cause its own version of cognitive impairment,” Banks said. “By analogy, that’s what diabetes does. It increases the risk of Alzheimer’s disease and also creates its own version of cognitive impairment. This stuff increases the chances that something like this could happen with SARS-CoV-2. »
The next step in the study is to examine animals to see the long-term effects of inflammation on a COVID-infected brain. Months are years for mouse brains, allowing for a more advanced understanding of disease. Researchers also want to test drugs that may block or prevent certain types of brain inflammation.
“I think the other big concern is that we’re showing that the Alzheimer’s model has a lot more inflammation, so the study really advances everything that we had feared,” Banks said. “But on the other hand, if it’s true that brain inflammation is the culprit, which we also think is the culprit in cognitive impairment and brain damage in football injuries and everything else, then we’re a bit closer to determining what needs to be studied.”