January 25, 2021
Everyday Health
Meryl Davids Landau

Some people who’ve recovered from COVID-19 continue to struggle for weeks or even months with short-term memory loss, concentration issues, and other cognitive symptoms. Neurologists believe “cog rehab” may help.

The term “COVID brain fog” has become a hashtag on social media, often used in a lighthearted way to denote the mental lapses that many of us are experiencing from the stress of the pandemic — finding those Brussels sprouts sitting in the oven days after you cooked them, or watching half a Netflix movie before realizing you saw it the week before.

But for COVID-19 long-haulers, who recover from the acute phase of the illness but continue to experience symptoms for weeks or even months, the term denotes something much more serious: It describes memory loss, concentration issues, and other cognitive problems that make it hard to get through a normal day.

Other common signs of ongoing impairment, nicknamed long-COVID, include exhaustion, body aches, and a hacking cough.

Cognitive slowing and mood problems after a person is infected with the novel coronavirus seem to be much more prevalent than with most other viral infections, says Serena Spudich, MD, a professor of neurology at the Yale University School of Medicine in New Haven, Connecticut, and a physician at Yale’s neuroCOVID-19 clinic, which opened in October. Dr. Spudich has spoken to dozens of people, some who were hospitalized with the disease and others who had only a mild case but couldn’t seem to shake their symptoms.

What Is Brain Fog?

Brain fog isn’t a technical term, but a shorthand way to describe an array of symptoms that affect thinking. Each person exhibits a different combination of issues, which can include confusion, memory loss, difficulty recalling words, slow thinking, trouble focusing, and easy distractibility.

One person who has experienced long-hauler brain fog is Fiona Lowenstein, a New York City–based TV producer and writer, who developed a case of COVID-19 last March that was severe enough to require hospitalization. The experience led Lowenstein to cofound the support group Body Politic, which now has more than 9,000 members who share over 60 channels on Slack.

Lowenstein describes a range of short-term memory issues that wreaked havoc on daily life:  walking to the cabinet to get detergent while doing laundry and then forgetting why, or staring at the computer trying to write, sometimes not recalling the topic and other times grasping for the proper word.

Others on Body Politic similarly complain that the brain fog affects their work, with some struggling to stay productive and others leaving their jobs because they find it impossible to function.

No One Knows How Many People Are Affected

As with much regarding COVID-19, a disease that emerged only a year ago, the prevalence of brain fog as a long-hauler symptom is not currently known.

French researchers queried 120 patients a month after they were released from the hospital for COVID-19 complications. Some 34 percent reported continued memory loss and 28 percent said they had problems concentrating. The study was published by the Journal of Infection in August 2020.

Brain fog is now listed as a “reported long-term symptom” by the Centers for Disease Control and Prevention (CDC), albeit a less common one than fatigue, shortness of breath, cough, joint aches, or chest pain.

Why the Brain May Fog

The reasons for brain fog are not yet clear.

Spudich believes the most likely cause relates to inflammation created by the body’s immune response rather than to the virus itself. She says an overactive immune response is similarly thought to be responsible for other symptoms of COVID-19, including the breathing problems that often land patients in the hospital.

Spudich points to HIV/AIDS as another condition in which an out-of-control immune system inflames the brain, leading to mental lapses.

If an immune response is to blame for brain fog, it may be that inflammation in the body becomes so widespread that it reaches the brain. Or it could be that immune cells “are going into the brain to chase a little virus there,” Spudich says, noting that all this is currently conjecture.

Of course, it’s possible the virus itself somehow gets into the brain, perhaps by traveling through the top part of the nose or by infecting cells known to cross the blood-brain barrier. But so far, examinations of spinal fluid (which comes from the brain) and autopsies have not demonstrated this for the vast majority of COVID-19 cases.

The good news is that physical damage to the brain is rare, as documented by MRI images in some people.

Cognitive Rehab Seems the Best Treatment Right Now

When patients complain of brain fog, Spudich says the first step is a thorough physical exam to rule out other medical causes, such as a stroke, which is known to occur from COVID-19.

Patients may then be referred for cognitive rehabilitation (aka cog rehab).

“Cognitive rehabilitation is like physical therapy, but it’s for the brain,” explains Jennifer Wethe, PhD, a neuropsychologist who codirects the concussion program at Mayo Clinic Arizona and is an assistant professor of psychology at the Mayo Clinic School of Medicine, in Scottsdale.

The first steps are written and oral tests, typically conducted by a neuropsychologist, to identify the specific problems. Then the rehab would focus on strategies to improve certain functions, like concentration, as well as techniques to compensate for brain fog, Dr. Wethe says. Rehab typically occurs several times a week for a month or more.

If concentration is an issue, for instance, the therapist might whip out a deck of cards and have you recall the card placed facedown, then the one before that one, then two before, and so forth. Later you might be asked to recall cards after an interruption.

Therapists also help patients develop “metacognitive” strategies aimed at making the thinking process more visible. “If you’re working as an assistant and the phone rings, you can learn to mentally mark your place in your current task before picking up the phone,” she says.

In addition to neuropsychologists, some occupational therapists and speech pathologists are trained in these methods.

Cognitive rehabilitation has been successful with traumatic brain injuries, strokes, and concussion, Wethe says. It is typically covered by insurance for some of these conditions; whether insurers will foot the bill for post-COVID complications is an open question.

Smartphone Apps Can Help

Wethe is a fan of using a smartphone to keep track of your tasks during the day, so everything is in one handy place. She suggests putting every appointment in the calendar and regularly using the reminder and notes apps.

There is some evidence that games like Lumosity and Brain HQ, played on your computer or phone, may also improve cognition, although the evidence for this is mixed.

Brain Fog Might Clear on Its Own

Doctors can’t predict how long post-COVID brain fog will persist, but Spudich thinks in many cases the fog may disperse on its own. “With HIV, once the virus is controlled, the cognitive issues resolve. There’s a real chance that with COVID people may just get over this themselves,” she says.

Plus, she notes, “As we continue to learn more, we may find therapies we can give to people to help them improve even faster.”