Before the COVID-19 pandemic, Kevin Tock considered himself moderately healthy. He was overweight and experienced migraine attacks, but he otherwise felt pretty good for someone in his late fifties. Then he contracted COVID-19 in November 2020 and missed 31 days of work as he recovered at home. Now 60, the Fort Myers, FL, resident is back at work maintaining an irrigation system at a golf course, but he's far from fully recovered. Sometimes when he wakes up his arms and legs feel like they're still asleep. His head is often stuffy and heavy, and every now and then he gets an inexplicable ringing in his ears. And he's perpetually exhausted. If he didn't need the money, he wouldn't have returned to work. Most days, he comes home and goes straight to bed at 7 pm. A new problem is especially alarming: short-term memory loss.
“Everybody tells me, ‘Well, you're 60 now,’ but you don't go from remembering 90 percent of everything to not remembering the majority of things,” Tock says. “At work, when someone tells me to do something, I have to write it down or type it into my phone. If I don't, I'll do something else and totally forget.”
Tock says his ongoing symptoms are puzzling to him and to the doctors he's seen, who have not been particularly helpful or empathetic. “When you have all these weird symptoms,” he says, “and you go to a specialist and he looks at you like you're a nut case, it's the worst thing.”
At the outset of the pandemic, health experts said most people who got infected would experience mild illness and recover in about two weeks. But a year and a half later, it has become apparent that some people—including some who were not severely ill initially—experience the disease very differently. Survivors of COVID-19 have been sharing stories on social media, and with their doctors, of never-ending symptoms. The term “long COVID” came into use to describe what they were going through. Experts now refer to it by a new term: post-acute sequelae of SARS-CoV-2 infection, or PASC.
Liza Fisher, 37, of Houston calls her constant cycle of COVID-19 symptoms the “coronavirus hamster wheel.” In summer 2020 she contracted the virus and was hospitalized for a week with COVID-19-related pneumonia. Fisher subsequently developed postural orthostatic tachycardia syndrome (POTS)—a disorder of the autonomic nervous system characterized by an abnormal increase in heart rate triggered when moving from lying down to standing—and started having full-body tremors that make it difficult for her to walk.
She now uses a wheelchair for most of the day and has not returned to her jobs as a flight attendant and yoga instructor. “I've turned into a person with a chronic illness,” says Fisher, but notes that both her “better moments” and “hours of functionality” have increased in recent months.
For Lesley Tessler, a 74-year-old retired speech therapist from Oakland, NJ, the lingering impact of a COVID-19 infection has been the worsening of symptoms of cerebellar ataxia. Diagnosed five years ago with the progressive condition, which affects balance and movement, Tessler worried when the pandemic hit that she'd be at high risk for complications if she got the virus. She and her husband wore masks and went out only to go to the grocery store and to Tessler's physical therapy appointments.
Despite their vigilance, they both got sick in April 2020. Tessler was hospitalized for a week, during which she received oxygen. Since then, she has noticed an exacerbation of her neurologic symptoms. “My balance is worse, and I'm constantly light-headed,” she says. “I drive only locally now; before COVID, I could drive anywhere.”
The most difficult symptom for Tessler has been fatigue. “I am tremendously short of breath all the time,” she says. “I do the simplest thing and I have to lie down.” She finds it uncanny how the coronavirus has affected her: “It seems like it knows where to go. It knows the vulnerable areas of every person, and whatever area is compromised, it goes straight there.”
On the days when all Tessler wants to do is lie on the couch, her husband encourages her to be more active. She takes a low-dose antidepressant and attends physical therapy a few times a week. “I keep my mind busy and positive because it is really easy to shut down and let it all go,” she says.
Long COVID can affect people in many ways, including neurologically and psychologically. In a survey of 3,762 people from 56 countries who'd had COVID-19, published in July in EClinicalMedicine, respondents reported a total of 203 symptoms, with each person experiencing on average more than 55 symptoms. The most frequently reported ones after six months were fatigue, post-exertional malaise, and cognitive dysfunction. But symptoms as wide-ranging as tremors, itchy skin, sexual dysfunction, heart palpitations, bladder control problems, shingles, hallucinations, memory loss, blurred vision, diarrhea, and tinnitus were reported. Most respondents still had symptoms seven months after first becoming ill.
The public health consequences of long COVID are profound enough that in December, Congress allotted the National Institutes of Health $1.15 billion over four years to fund research into PASC.
The exact number of people with PASC isn't known, but studies suggest it affects 10 to 30 percent of COVID-19 survivors, says Avindra Nath, MD, FAAN, clinical director of the National Institute of Neurological Disorders and Stroke in Bethesda, MD. PASC symptoms generally fall into three broad categories: dysautonomia (malfunctioning of the autonomic nervous system); cognitive impairment, which includes conditions such as brain fog, depression, and anxiety; and exercise intolerance and extreme fatigue.
A study published in Nature Medicine in March analyzing data from more than 4,100 people in the United States, the United Kingdom, and Sweden who tracked their COVID-19 symptoms on an app identified certain risk factors for long COVID: being female, being older, having five or more symptoms after the first week of being sick, having asthma, and experiencing symptoms severe enough to warrant possible hospitalization.
Unraveling a Mystery
Several hypotheses are circulating about how the coronavirus affects the body. One is that oxygen deprivation caused by the virus leads to lung and brain damage. Another is that the virus damages cells in the nervous system. And another, which Dr. Nath considers the most plausible, is that the virus causes indirect damage by triggering an intense immune response that confuses the body, making it attack healthy cells it thinks are foreign invaders.
“The theory of direct infection of the brain hasn't really panned out,” says Dr. Nath. “Some studies claim they've found virus in the brain, but they include only a few patients and the amount of virus in the brain is very small. Even if the theory is correct, it cannot explain the variety of symptoms we see.”
Another area of interest is how the virus affects the arteries throughout the body and brain that are too small to see on an MRI, says Jonathan Rosand, MD, MSc, co-founder of the McCance Center for Brain Health at Massachusetts General Hospital in Boston. “I'm wondering if the clots in tiny blood vessels that have been found in some patients with COVID-19 will yield important discoveries about what actually is causing COVID-related brain dysfunction,” he says.
Another possibility is that the virus attacks through the olfactory bulb, says Gabriel de Erausquin, MD, PhD, MSc, endowed professor of neurology at the Joe R. and Teresa Lozano Long School of Medicine at UT Health San Antonio. A structure near the front underside of the brain, the olfactory bulb contains nerves that transmit information about smells to the brain. “It might be enough for the virus to be just in the olfactory bulb to trigger an abnormal molecular process in the brain,” he says.
While researchers investigate causes, doctors are doing what they can to help patients. Once they've ascertained that there is no underlying, unrelated disease, doctors prescribe medications and therapies to treat symptoms. “Even without knowing the pathophysiologic mechanism, physicians can still make a difference in the quality of life of their patients,” Dr. de Erausquin says.
The growing number of patients with PASC has prompted many medical centers to open post-COVID-19 clinics, staffed by health care providers in various specialties such as physical rehabilitation, pulmonary medicine, infectious disease, neurology, psychology, and social work. Survivor Corps, an online support group for people with long COVID, has a map on its website showing the locations of these clinics.
Most patients of the Center for Post-COVID Care at Mount Sinai in New York City didn't have severe cases of COVID-19 and were never hospitalized, says Allison P. Navis, MD, lead neurologist at the clinic. That is consistent with what's been documented in published research: Most people with long COVID surveyed in the EClinicalMedicine study, for instance, were not hospitalized.
The most common symptoms Dr. Navis sees are brain fog, headaches, sensory disturbances, dysautonomia, and intense fatigue. She treats brain fog by addressing factors that may contribute to it, like poor sleep, depression, or anxiety.
For patients who develop a tremor, Dr. Navis may prescribe drugs commonly used for essential tremor and seizures. Some long-haulers have also reported an internal vibration sensation—for which Dr. Navis has prescribed gabapentin, an anticonvulsant and painkiller. She says the cause of these symptoms is unclear, but it could be COVID-19's damage to nerves.
“We've yet to see one thing that provides relief for everything,” Dr. Navis says. “We target individual symptoms and see if we can eliminate or diminish them. One symptom can trigger others. Physical or mental exertion can lead to fatigue or headaches, for example.”
Dr. Navis used to order diagnostic imaging and autonomic function tests to try to trace the cause of patients' symptoms. But results often came back normal, so now she's more likely to skip the testing and go straight to treatment. And the management course is generally the same no matter what the tests show.
“It's frustrating not getting answers, but that doesn't mean nothing's going on,” Dr. Navis says. “Either the tests aren't sensitive enough or we're not looking for the right things. As the research scales up, we're going to learn more, but it will take time.”
Long COVID is similar to other diseases known or thought to be caused by viruses, such as chronic fatigue syndrome, Middle Eastern respiratory syndrome, and severe acute respiratory syndrome, says Nicholas R. Mathenia, DO, director of general neurology at the Edward Neurosciences Institute in Naperville, IL. Another condition that can develop after viral infections, including COVID-19, is POTS, which Liza Fisher has experienced. Its symptoms are similar to those of long COVID: fatigue, light-headedness, brain fog, headaches, and an abnormally fast heartbeat when standing up.
“A significant number of people with lingering long COVID symptoms have a higher resting and standing heart rate due to some type of autonomic dysfunction,” says Svetlana Blitshteyn, MD, director and founder of the Dysautonomia Clinic and assistant professor of neurology at the Jacobs School of Medicine in Buffalo, NY.
The Healing Journey
Recovery from long COVID is gradual, and getting back to normal activities slowly is key, says Dr. Navis, who cautions against pushing too hard, which can aggravate symptoms. “Scheduling lots of breaks is important,” she says.
Lifestyle changes are also recommended, says Janna L. Friedly, MD, director of the UW Post-COVID Rehabilitation and Recovery Clinic at Harborview Medical Center in Seattle. Patients with insomnia are advised to stop looking at their smartphones and television screens close to bedtime and to maintain a regular sleep schedule; they may be prescribed melatonin or other sleep aids as well.
"It takes longer than initially thought to recover from long COVID, but we're seeing a lot of improvement,” says Dr. Friedly, who contracted COVID-19 herself in April 2020 and had symptoms that lasted months.
Patients with cognitive problems should get adequate sleep, exercise, eat healthy foods, and reduce stress, says Lindsay McAlpine, MD, BSc, a neurologist in the NeuroCOVID Clinic at Yale New Haven Hospital in Connecticut. Doctors recommend seeing a psychiatrist for treatment of anxiety or depression. For patients who continue to have problems with concentration, Dr. McAlpine prescribes ADHD medications.
An ADHD drug has helped Liza Fisher, who is receiving care through the Post-COVID-19 Recovery Clinic at UT Health San Antonio. “For the first time, I was able to have a conversation with somebody and not sound off-the-wall,” she says. She hopes to be able to resume reading every night, as she used to do before getting sick. Fisher also takes beta-blockers and corticosteroids, and says they have reduced her tremors.
Research continues for a treatment that will change the course of PASC. Dr. Nath, for one, is undertaking a study to test treatment with a corticosteroid and intravenous immune globulin against a placebo to see how the combination affects recovery.
As patients wait for research to yield answers, they remain optimistic. Kevin Tock looks forward to an appointment at a post-COVID-19 clinic in Hollywood, FL. Liza Fisher is encouraged that she's now able to lift both feet while holding on to bars during rehabilitation training.
“Ride the roller coaster and take it for what it is,” she advises people with long COVID. “Let the bad moments be, knowing that the good moments always come after the bad.”