SAN DIEGO, Calif. — Nearly one in five Americans who have had COVID-19 have long COVID. The CDC reports these long haulers experience fatigue, memory impairment, and coordination problems that can last months or even years. But what causes one person to feel symptom free within days of testing positive, while others suffer for months and months? Some researchers think the one thing that’s fighting the virus is also causing the problem.

Jeff Engman says, “The fatigue, I was really drained and, you know, could hardly get out of bed.”

Jeff Engman was one of the early ones to get COVID—but his symptoms stuck around.

“I’m talking pretty good now, but early on, I was trying to talk and I had trouble finding the words.”  Engman says.

“One of the most common symptoms of long haul COVID is having some type of what people are calling brain fog.” Explains Jennifer Graves, MD, PhD, Neurologist at UC San Diego Health.

Doctor Graves is leading a team tracking neurological symptoms in covid long haulers.

Doctor Graves says, “What we’ve realized is shortly after the infection and the first few weeks to months, folks complain of having headaches and fatigue. And then over time we see a shift of folks complaining more about memory problems and inattention and difficulty multitasking.”

They found 15 to 30 percent of long haulers’ cognitive skills were impacted. Of 56 long haulers, six months after getting COVID, two-thirds still reported persistent neurological symptoms. The most prevalent … memory loss.

 “One leading theory that I think is very probable is that it’s all triggered by the immune response to this virus. But even if the virus isn’t directly invading the brain, it’s triggering the immune system to behave in a way that triggers inflammatory response in the brain.” Explains Doctor Graves.

And so far, this response can last up to a year or even longer.

“The good news is the newer variants of this virus seem to be less likely to trigger this phenomenon.” States Doctor Graves.

UC-San Diego researchers are now working to find biomarkers in the brain or blood that could identify which patients are suffering COVID brain. That way treatment, such as cognitive rehabilitation, can begin sooner. Doctor Graves says other diseases like multiple sclerosis and dementia are also impacted by the immune system. They plan to follow the COVID long haulers long-term to see if they are now more susceptible to these diseases.