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August 13, 2020

'Covid fog': The latest emerging, long-term symptom of Covid-19

Daily Briefing

    Up to one-third of people who had Covid-19 report lingering neurological and psychological symptoms due to the disease, ranging from numb limbs to a mental slowness some people are calling "Covid fog"—a finding that "reflect[s] a growing consensus that the disease can have lasting impact on the brain," Elizabeth Cooney reports for STAT News.

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    According to Cooney, early reports from China and Europe revealed that some patients recovering from Covid-19, the disease caused by the new coronavirus, experienced anxiety and depression. Further, experts told STAT News that, in addition to mood disorders, they've seen patients who recovered from their coronavirus infections experience neuropsychological symptoms including dizziness, numbed limbs, brain fog, long-term loss of smell and taste, muscle weakness, and nerve damage so severe that patients struggled to walk. And that's on top of the long-term physical symptoms Covid-19 can cause, including damage to the heart, kidneys, and liver, Cooney reports.

    Teodor Postolache, a professor of psychiatry at the University of Maryland School of Medicine, estimates that "between 30% and 50% of people with [a coronavirus] infection that has clinical manifestations are going to have some form of mental health issues," ranging from "anxiety or depression but also nonspecific symptoms that include fatigue, sleep, and waking abnormalities, a general sense of not being at your best, not being fully recovered in terms of the abilities of performing academically, occupationally, potentially physically."

    John Bonfiglio, 64, reported many such symptoms after he recovered from a serious bout with Covid-19 at Newton-Wellesley Hospital, Cooney reports. Once Bonfiglio was finally transferred out of the ICU—after spending 17 days on a ventilator—he said he was so confused that he forgot his name, forget where he was, and sometimes tried to slide from his bed to the floor.

    Bonfiglio said he also felt more emotional than usual during his recovery and experienced persistent dizziness, hand tremors, and muscle weakness—so much so that he had to relearn how to walk. Bonfiglio said he's since regained some strength and the dizziness and tremors are now gone.

    Similarly, Fred Pelzman, an internal medicine physician from New York who fell ill with Covid-19 in March, said he is still experiencing symptoms of the disease, including depressed abilities to taste and smell. And, according to Pelzman, his patients also have reported lingering effects from Covid-19, with one unable to complete simple math calculations in her head and others struggling to find correct words when communicating.

    What's causing the neurological symptoms?

    According to Cooney, researchers at the moment can say little "definitively about how best to prevent and treat neuropsychological manifestations of Covid-19. Nor do they know for certain why the brain is affected."

    Victoria Pelak, a professor of neurology and ophthalmology at the University of Colorado School of Medicine, said treating Covid-19 patients with neurological symptoms has been like "trying to put out the fire." She explained, "Because you are so concerned with the raging fire," of Covid-19, "you haven't really been able to pay attention to the nervous system as much as you normally would."

    But doctors have started putting some pieces together, Cooney writes. They think, for instance, that the new coronavirus damages the brain and nervous symptom through inflammation, not through a direct attack on those systems.

    Lena Al-Harthi, chair of the department of microbial pathogens and immunity at Rush Medical College, explained that bits of the virus—rather than the virus multiplying—can spur the brain's inflammatory response.

    "If you have an uncontrolled level of inflammation, that leads to toxicity and dysregulation," Al-Harthi said. "What I am concerned about is long-term effects, obviously in the [Covid-19 patients] who have been hospitalized, but I think it's definitely time to understand long-term sequelae for those individuals who have never been hospitalized"—and it's not just limited to "older individuals," but includes "young [ones], too."

    Physicians also are assessing whether the novel coronavirus is more likely than other viruses to cause a syndrome called demyelination, in which inflammation in the brain causes the immune system to attack the protective coating of nerve cells, Pelak said. According to Cooney, the syndrome can "cause weakness, numbness, and tingling. It can also disrupt how people think, in some cases spurring psychosis and hallucinations."

    A long-term outlook

    As for treating and preventing these longer-term issues, Ross Zafonte—CMO at Spaulding Rehabilitation Hospital, which provides care to recovering Covid-19 patients—said he's "trying to … do a longitudinal study to see what are the comorbid factors." According to Zafonte, questions that need to be answered include: "What are the characteristics of people who don't get back to normal? How can early intervention try to deal with that? Are there some biomarkers of risk? [and] Can we try to define better targets for early intervention?"

    Some physicians have voiced concerns about the long-term outlook for individuals who were infected with the coronavirus and are experiencing these symptoms. Postolache, for instance, said a coronavirus infection might serve as a "priming event," meaning that future stressors may reactivate the emotional and behavioral symptoms originally spurred by the infection. "We don't really say this is permanent," he said, "but considering all complexities of human life, it's unavoidable."

    Wes Ely, a pulmonologist and critical care physician at Vanderbilt University Medical Center, echoed similar concerns, noting that while researchers will continue psychiatric evaluations and diagnostic imaging to get to the bottom of the symptoms, everything physicians know about the neurological symptoms of Covid-19 so far indicate that the disease could be "not only an acute problem," but "a chronic illness." Ely added, "The problem for these people is not over when they leave the hospital."

    Keeping those factors in mind, Ely recommended three steps providers can take now to address the issue: "We can open the hospitals back up to the families" so patients are less isolated, "tell the families about [this issues] so that the families will know that this is coming," and offer "counseling and psychological help on the back end" (Cooney, STAT News, 8/12).

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