Key points you should know:
- Some people with Long COVID are receiving potentially unhelpful diagnoses of functional neurological disorder (FND), a condition in which people experience neurological symptoms that cannot be attributed to known or currently identifiable pathophysiological causes.
- FND proponents theorize that it is a “brain network” disorder characterized by factors such as hyperawareness of bodily sensations and faulty perceptions of self-agency, but the diagnosis does not explain Long COVID symptoms.
- Researchers, clinicians, and people with Long COVID say that FND treatments can be unhelpful or even harmful and that the diagnosis can lead to delays in appropriate care for symptom relief.
- Since having FND in medical records can lead doctors to attribute subsequent medical complaints to the condition, some seek to have the diagnosis changed or removed.
After a bout of COVID-19 early in the pandemic, Karen Hargrave, an English self-described “policy nerd” with a background in humanitarian relief, started to have cognitive difficulties, post-exertional malaise, and a rapid heart rate. When she began experiencing persistent weakness and tingling along her left side, from her head down through her leg, she was referred to a neurologist.
Basic medical tests showed nothing. After a physical exam, recalled Hargrave, the neurologist told her that he could not find any physiological problems that could explain the tingling and other symptoms. Rather, he later wrote in a letter, he thought her symptoms “most likely had the basis in something called a functional neurological disorder.”
Before the appointment, Hargrave said, she’d only vaguely heard of functional neurological disorder, or FND. In trying to explain the condition, the neurologist compared the brain’s structure and its communications systems to a computer and the programs required for it to operate. FND was a “software problem,” not a “hardware problem,” he told her.
Hargrave sensed that the doctor was uncomfortable being unable to identify a more specific cause for the weakness and tingling. “It just kind of felt like he wanted to get me out of the room as quickly as possible, to be honest,” she said.
The neurologist, she recalled, told her that “a lot of people with Long COVID are presenting with functional neurological disorder.” But she did not feel that the FND diagnosis was a good fit for her experience, and she did not see the neurologist again.
(Hargrave is a co-founder of #ThereForME, a U.K.-based awareness campaign for myalgic encephalomyelitis (ME), with which she and many others with Long COVID have been diagnosed. Her experience with the neurologist was a small part of the unsatisfactory experiences with healthcare services that prompted her advocacy.)
It just kind of felt like he wanted to get me out of the room as quickly as possible, to be honest.
Karen Hargrave, #ThereForME, about the neurologist who said she had FND
Although scientists have not yet solved the mysteries of Long COVID pathogenesis, they are focusing on immune dysregulation, possible viral persistence, autonomic dysfunction, and other factors to elucidate the mechanisms driving the symptoms. Ongoing or upcoming clinical trials are investigating a number of drugs presumed to target some of these biological processes.
A report on the definition of Long COVID, published last year by the National Academies of Sciences, Engineering, and Medicine, does not mention FND as either a component of the illness or as a comorbidity. A clinical guide for managing people with ME, Long COVID, and related disorders, from the Bateman Horne Center, a clinic near Salt Lake City, Utah, specifically advises medical providers to “monitor for inappropriate psychiatric relabeling (e.g., functional neurological disorder […]) by any member of the care team.”
Nonetheless, an unknown number of people with Long COVID are being told they have FND — and some of them, like Hargrave, are rejecting the diagnosis and recommended treatments, which they view as potentially harmful.
These people, as well as clinicians treating Long COVID and researchers studying it, say that the diagnosis doesn’t fit the symptoms. They also say treatment recommendations, which focus on psychotherapy and/or physical therapy, are inappropriate and unhelpful, and — especially in patients who experience post-exertional malaise (PEM) — can lead to relapses and potential decreases in baseline functioning.
Moreover, experts and patients say that having such a diagnosis on record could have a major impact on subsequent healthcare. “Future medical complaints will be attributed to FND,” said David Putrino, a neuroscientist and Long COVID expert at the Mount Sinai Health System in New York.
FND is the more recent name for conversion disorder, a traditional psychiatric diagnosis in which patients — mostly women — were said to have “converted” their psychological distress into physical symptoms. Many such patients might also have received diagnoses of hysteria. In classic conversion disorder, the cases fell into three distinct categories — motor disorders, sensory disturbances, and seizures not identified as epileptic.
It is well-known that, in some cases, such persistent and distressing neurological symptoms have no identified cause and do not correspond to recognized diseases. Neurologists, neuroscientists, and others who specialize in FND categorically assert that these conditions represent a “brain network” dysfunction, with symptoms linked to such factors as a hyperawareness of bodily sensations, disruptions to “the predictive machinery of the brain,” and faulty perceptions of self-agency.
Overall, prognosis is poor, with or without treatment.
“They told me my brain was wired wrong and it was causing symptoms,” said a 21-year-old man from Switzerland, who suffered from severe PEM and other symptoms following COVID-19 and received an FND diagnosis in 2022. A neurologist told him that he needed to try to increase his activity levels and stop using a wheelchair.
“They told me the wheelchair wouldn’t let me get any better, it would keep me ‘comfortable’ and in ‘entrenched thoughts’ and I’d never improve,” recalled the patient, who asked to remain anonymous to protect his medical privacy. He didn’t take the advice, noting that he was “already essentially bedbound” at that point.
They told me the wheelchair wouldn’t let me get any better, it would keep me ‘comfortable’ and in ‘entrenched thoughts’ and I’d never improve.
patient diagnosed with FND
Expert: Appropriating Long COVID into FND is “a land grab”
Since 2020, controversial articles in some prominent news outlets, such as The New Republic and Slate, have endorsed the FND perspective, positing that the wave of Long COVID cases has largely been forged from the anxiety, depression, and psychological distress associated with the pandemic. In the former article, a leading FND expert noted that one man’s leg paralysis was “likely triggered by his traumatic hospitalization early in the pandemic” — a claim that is difficult to prove or disprove.
(Editors’ note: The Sick Times’s executive editor, Miles Griffis, coauthored letters requesting retraction for those articles.)
In a 2024 review paper called “Long COVID Is Not a Functional Neurological Disorder,” leading clinicians and researchers noted that “a significant number of patients with Long COVID are being misdiagnosed with FND” while “the primary Long COVID pathophysiology” remains unrecognized and unaddressed. For these people, the review argued, an FND diagnosis and related treatment can lead to delays in medical care targeting specific Long COVID symptoms.
“There’s enough information about the pathobiology of Long COVID to be able to say that it is not, by its nature, FND,” said Todd Davenport, the paper’s lead author and a professor of physical therapy at the University of the Pacific in Stockton, California.
Michael Stingl, an Austrian neurologist who works with people with Long COVID and ME, agreed. He noted that motor and sensory dysfunctions and seizures — the symptoms traditionally diagnosed as conversion disorder under FND’s previous iteration — are not generally among the core complaints of people with Long COVID.
“What’s happened here in the last couple of years is kind of a land grab where they are trying to appropriate Long COVID and ME/CFS into this FND domain,” he said.
As Hargrave learned, FND is often described as a problem with the brain’s “software,” or functioning processes and communications networks, rather than with its “hardware,” or structural elements.
Despite the popularity of this metaphor, brain scan research shows that FND is associated with a range of differences in cerebral structure as well as in processing networks. The software/hardware framing also excludes the impacts of a range of possible cellular, intracellular, or extracellular mechanisms and changes, such as mitochondrial or epigenetic alterations.
What’s happened here in the last couple of years is kind of a land grab where they are trying to appropriate Long COVID and ME/CFS into this FND domain.
Michael Stingl, neurologist
In an example of the phenomenon referred to as “diagnostic creep,” the name change from conversion disorder to FND has been accompanied by an increase in the kinds of symptoms that experts categorize as part of their domain. In particular, in the last decade or so, the FND field has increasingly sought to extend its purview beyond the three categories of conversion disorder — motor and sensory dysfunctions and non-epileptic seizures.
These days, FND experts view many cases of cognitive dysfunction and dizziness as falling within their domain, rechristening them, respectively, as functional cognitive disorder (FCD) and persistent postural-perceptual dizziness (PPPD). In the SARS-CoV-2 era, these two emerging FND subtypes seem ripe for expansion, given that “brain fog” and dizziness are two commonly reported symptoms of Long COVID.
In August 2021, an American scientist living in the U.K. saw a neuropsychiatrist for prolonged cognitive symptoms after an illness that was later diagnosed as COVID-19.
“My executive functioning was just complete trash,” said the scientist, who requested anonymity to protect her medical privacy. “I wasn’t able to read and understand text. I would look at my emails and not be able to figure out what they meant or what I needed to do next.”
The neuropsychiatrist, a leading FND expert, quickly diagnosed her with FCD. The scientist, who has not been able to return to work, recalled the clinician saying that her FCD would improve if she did not focus on it.
“I was told not to worry about it,” she said. “It just seemed like it came down to, ‘Think good thoughts, and it’ll get better.’” She was referred for psychotherapy but found it unhelpful in relieving her cognitive symptoms.
Many scientists and clinicians dismiss the categorization of cognitive dysfunction and dizziness, among other complex manifestations of Long COVID, as subtypes of FND. Rather, they are investigating biological processes for answers. For example, studies have suggested that cognitive problems, such as issues with concentration and memory, are likely related to factors like neuroinflammation and insufficient blood flow to the brain.
Similarly, the dizziness reported by some with Long COVID could trigger a diagnosis of the FND subtype PPPD — when it may actually be the result of dysautonomia, or disruptions of the autonomic nervous system, which controls involuntary functions like the heart rate. These disruptions can lead to postural orthostatic tachycardia syndrome (POTS) and other forms of orthostatic intolerance — a category of conditions in which people experience dizziness, nausea, and other symptoms when upright.
Pushing back against an FND diagnosis
Despite abundant Long COVID research documenting significant and persistent biological abnormalities, patients report that medical providers can present an FND diagnosis in a categorical manner that brooks no challenge.
“I was asking questions about it, but it just felt like there was no way to argue against it,” said the American scientist diagnosed by a U.K. neuropsychiatrist. “There was no way to say, ‘Well, that doesn’t quite fit my situation, what else could be going on here?’ It was like, ‘No, this is what’s happening.’”
She recognized that the FND diagnosis in her record could lead healthcare providers to attribute any subsequent medical issues to that. She objected to the term in her next conversation with the neuropsychiatrist, who agreed to change it to “prolonged cognitive symptoms.”
So what should people with Long COVID do if they receive an FND diagnosis that does not explain their medical concerns? Here are a few tips:
First, ask about the basis for the diagnosis. A clinician may render an FND diagnosis when medical tests are negative. That means people with Long COVID and other conditions that lack validated biomarkers might be particularly vulnerable to misdiagnosis. However, FND is not supposed to be a diagnosis of exclusion — that is, a diagnosis given solely because nothing else has been found.
According to current practice, a diagnosis of FND requires an affirmative clinical indication, often called a “positive” or “rule-in” sign, that appears to contradict normal neurological responses and process — a strong reflex in a limb reported as weak or paralyzed, for example, or the abating of a tremor or other symptom when a patient’s attention is diverted.
Find out what specific clinical signs were positive in this instance. Then ask for the research documenting the accuracy of any signs mentioned. In general, the evidence supporting many of these signs is limited. While positive signs might indicate something isn’t working properly, they cannot establish that the cause is a “brain network” dysfunction.
Second, don’t automatically accept the diagnosis as final. “Don’t be afraid to question it if it doesn’t feel like the diagnosis fits your symptoms,” said Hargrave. Davenport echoed that advice. “Don’t take it for a definitive answer,” he said. “It’s okay to seek another opinion.”
That opinion, he added, should be from a clinician who has expertise in Long COVID and ME. Provide healthcare personnel with helpful resources, such as the Bateman Horne Center’s clinical care manual and the report on a Long COVID definition from the National Academies of Sciences, Engineering and Medicine. These resources do not endorse the view that FND explains the disabling symptoms.
Third, keep a full account of your medical care, said Joffe, the Australian expert. “Carefully document all neurological interactions,” he said. “Keep copies of the letters written and all the results. That’s crucial. Not infrequently, I find that something has been missed or overlooked in my patients. Having the original letters and studies is very illuminating.”
Given that reality, said Joffe, clinicians should consider FND to be only a “working diagnosis,” subject to regular reevaluation based on new tests, symptoms, and physical exams. Long COVID, he said, “is too complex and vast to simply dismiss people with a FND label.”
Fourth, be aware that having an existing FND diagnosis in medical charts might influence the judgment of subsequent clinicians, and take steps to address this issue. David Putrino recommends working with your primary care provider “to have that diagnosis removed from your medical records.”
First, ask about the basis for the diagnosis.
Second, don’t automatically accept the diagnosis as final.
Third, keep a full account of your medical care.
Fourth, be aware that having an existing FND diagnosis in medical charts might influence the judgment of subsequent clinicians, and take steps to address this issue.
David Tuller is a senior fellow in public health and journalism at the Center for Global Public Health at the University of California, Berkeley. His academic position is supported by crowdfunded donations to UC Berkeley, largely from people with ME/CFS and, more recently, Long COVID.
All articles by The Sick Times are available for other outlets to republish free of charge. We request that you credit us and link back to our website.
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