SEATTLE — A University of Washington research team has found the neurological symptoms of long COVID, such as brain fog, are due to neuroinflammation.
The research from Dr. Elizabeth Rhea, a research assistant professor at the University of Washington, and others was published in the March issue of Brain, Behavior and Immunity. It concludes that similar to the respiratory inflammation caused by COVID in the lungs, the same infection can cause inflammation in the brain.
Despite being known as a respiratory virus, COVID can also have neurological effects. She used the metaphor of a train system, in which the train station that regulates who gets to travel between cities is similar to the blood-brain barrier. This barrier protects the brain by determining what can get in and out. However, after infection, there is a spike protein (also called the S1 protein) on the surface of the virus that is the key to crossing through the blood-brain barrier and into the brain.
Her study used mice and found that the neuroinflammation was present after one day of infection, lasting up to four days. However, she says there is still more work to be done in order to learn more.
"We would need to do follow-up studies to determine how quickly [inflammation] can resolve," Rhea said. "And just like humans, mice are different and so depending on which mouse model you study, you may get a different effect on how long it lasts in the brain."
Rhea concludes the results of her studies show that symptoms such as brain fog are likely due to neuroinflammation.
"So if we can begin to target that neuroinflammation, then we can begin to resolve this long-term COVID effects," she said.
What is long COVID?
Rhea said it's a newer condition where individuals have persistent effects that last long after common symptoms, such as cough and congestion, have resolved. This usually occurs up to four weeks after a COVID diagnosis.
What are the symptoms of long COVID?
Some symptoms include memory impairment and brain fog, which Rhea's study focuses on. According to the Centers for Disease Control and Prevention (CDC), other common symptoms can include headaches, changes in smell or taste and fatigue.
How long does long COVID last?
There is not yet definitive research on the exact duration of long COVID, as it depends on the individual. Symptoms of long COVID could last anywhere between a few weeks to months.
How can I prevent long COVID?
According to the CDC, there is research that shows vaccinated people who experience an infection are less likely to have post-COVID conditions, compared to unvaccinated people.
"It's also been shown to reduce the symptoms associated with COVID so you have a less severe reaction to it if you've had a vaccine," she said, "so if this response isn't as strong, you're not going to have as much neuroinflammation."
How is long COVID treated?
Current treatment depends on the symptoms of the individual. Nonmedicated treatment can include physical, occupational or speech therapy, while medicated treatments are available for symptoms such as headaches.