Pain, fatigue, fuzzy thinking: how Long COVID disrupts the brain

A Patient’s New Reality.

Michelle Wilson got COVID three years ago. She’s still waiting for her brain and nervous system to recover. Wilson’s memory is spotty, she’s frequently in pain, and even a short walk leaves her exhausted. “I actually bought a cane that turns into a seat so I can go to the botanical garden,” she says. “This might be as good as it gets.”

A Public Health Crisis

Government surveys suggest that millions of people in the U.S. are living with neurological symptoms linked to long COVID. “It’s a public health crisis,” says Dr. Robyn Klein, who directs the Center for Neuroimmunology and Infectious Diseases at Washington University School of Medicine in St. Louis. “There are a lot of people suffering and those people need treatment yesterday,” says Dr. Ziyad Al-Aly, who holds positions at both Washington University and the Veterans Affairs St. Louis Health Care System. But treatment remains a distant promise.

How the Brain Gets Hit

The virus appears to do most of its damage to the brain indirectly, scientists say. An infection in the body triggers an immune response that leads to inflammation in the brain. And the inflammation can persist long after the virus has apparently been cleared. The brain may be especially vulnerable to COVID because the disease appears to weaken the blood-brain barrier, which usually protects the organ from both germs and the immune cells that follow them. Another possibility is that COVID-related inflammation affects the vagus nerve, which carries signals between the body and brain that are important to memory and attention.

Memory, Sleep, and Pain

Three years after getting COVID, Wilson continues to struggle with a range of symptoms, including an unreliable memory. “I have trouble with word retrieval, concept retrieval - and sometimes, like, remembering where I was going,” she says. Wilson also has problems sleeping at night, a condition Al-Aly says affects about 40 percent of people with long COVID. “As a result, they wake up fatigued,” he says, which contributes to their exhaustion from even moderate activity. Poor sleep can also contribute to the pain that many long COVID patients report.

Whole-Body Aches

“It’s not only ‘my wrist is hurting’ or ‘my knee is hurting,’” Al-Aly says. “It’s really almost like the whole body aches.” When Wilson first came home from the hospital, she was in agony. “The pain across my chest and in my arms was so bad that I slept with pillows under both arms because I couldn’t stand my arms to touch my chest,” she says.

Immune System on Overdrive

There’s growing evidence that even a mild case of COVID can cause long-term changes to the immune system that affect the brain and nervous system. Torgerson of the Allen Institute was part of a team that studied blood samples from 55 people who had symptoms at least 60 days after a COVID infection. “We saw persistent ongoing immune activation in about half,” he says, even though only a handful had been sick enough to be hospitalized. Once the immune system gets fired up, Torgerson says, it can affect the brain even if the virus itself doesn’t infect brain cells.

Recovery Is Rare

People with neurological symptoms do get better, Al-Aly says, but full recovery is rare. “Unfortunately, long COVID, as we know it now, can affect nearly every organ system, including the brain,” he says. Michelle Wilson, though, got infected before vaccination was an option. And she’d like a treatment that can undo what COVID has done to her brain. “We don’t know everything about COVID yet,” she says, “So I have hope.”