What is functional neurological disorder and is it connected to COVID-19 vaccines? Experts explain

TORONTO -

Beth Pardo is an insurance executive, former marathon runner, and one of the first patients to come out with her diagnosis of functional neurological disorder, an issue that surfaced after she got vaccinated against COVID-19.

But the disorder isn’t a side effect of the vaccine -- and as doctors work to understand and identify cases, they are also fighting against misinformation and conspiracy theories spreading online.

Functional neurological disorder (FND) is a complex, but common neurological condition. Often FND happens after trauma, stressful life events, injury or car accidents, with people developing neurological symptoms that have no physical cause.

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In Pardo's case, it started after her second COVID-19 shot in early July. Three days after getting the jab, she noticed her legs becoming more and more unsteady while out shopping.

“By the time I left the store that Sunday afternoon, I couldn't walk,” she told CTV News.

"I was terrified. I didn't know what was going on, I waited 24 hours and then I called my doctor, and she insisted I get to the ER right away.”

Video taken of her in hospital shows her wobbly, having difficulty walking.

She had many tests done, including blood work, CT scans and MRIS, all of which found nothing.

“Every scan came back perfectly clear,” she said.

Since vaccine rollouts began, videos have appeared on social media of people ascribing tremors, seizures and paralysis to their recent COVID-19 vaccination, while racking up thousands of views in the process.

But researchers in the U.S., Europe and now a study in Canada have confirmed that these are not adverse reactions to the vaccine, but rather manifestations of FND.

FND is a disorder where the issue is in the “functioning or 'software' of the nervous system rather than neurological damage, like a stroke, which would be like the ‘hardware’,” according to the Functional Neurological Disorder Society (FNDS).

So why is this happening after vaccination, if it’s not caused by the vaccine itself?

“FND is commonly triggered by minor physical injury or illnesses,” FNDS explained in an email to CTV News. “When people have a vaccine, of many types, they often have a sore arm, and can feel unwell. This is enough to trigger FND in someone who was previously well. It doesn’t mean that the vaccine has caused neurological damage. Other vaccines have also triggered FND in the past and we see it after people have blood tests or minor wrist sprains, for example.”

DIAGNOSING FND

After tests failed to explain what was happening to her, Pardo ended up in the office of neurologist Dr. Alfonso Fasano at the University Health Network who was finally able to diagnosis her as having FND.

One of the key details that aided in diagnosis was that while videos showed that Pardo was unsteady and having trouble walking, Fasano noticed that she could go down the stairs with relative ease -- a physical inconsistency that is a hallmark of FND.

“We look for specific features, particularly the inconsistency. The symptoms come and go, they don't have biological explanation according to what we know today of medicine,” Fasano explained.

With a functional brain disorder, there are no structural problems in the brain that could explain the symptoms a patient is experiencing. For clinicians who don’t know much about FND, it can be hard to diagnose. Fasano said this can exacerbate the problem.

Patients can present a variety of issues from the disorder including coma, seizures, tremors and problems with balance.

“There is a really variable manifestation of different problems,” Fasano said.

“And first thing is actually to tell the patient as soon as the diagnosis is formulated in the mind of the doctor, because sometimes the diagnosis is the treatment itself,” he added.

Since stress affects FND, going to so many physicians who can’t diagnosis you can only make the situation worse for patients.

“Receiving multiple diagnosis or even treatments sometimes doesn't help -- actually [it] makes things worse -- because the patient gets into a vicious circle,” Fasano said. “And it's difficult to get out if you wait too long.”

He explained that those who present with FND “have a predisposition where any medical interventions can trigger a number of problems.”

Because the news and social media has been full of discussions of vaccine side effects and concerns, “all these patients were already susceptible and at risk to develop these problems,” because they were extremely stressed about receiving the shot, he said.

“And sure enough, some of them developed new symptoms, which were in a way, triggered by the vaccination,” he said. "However, the vaccine itself has nothing to do with the problem itself.”

The distinction, Fasano said, is that there’s nothing inside the COVID-19 vaccine itself that causes neurological effects like this. FND symptoms result from a combination of factors such as existing stress, stress around the vaccine process, and the minor pain that comes with being vaccinated.

When Pardo first went to the hospital with her symptoms, she says there was the fear that it could be something far more serious, such as a stroke or multiple sclerosis.

“So the fact that this is something that treatable, that it is something that I am recovering from, I think more people need to hear that, that it is something that is just fixed,” Pardo said.

Pardo said that before she received her proper diagnosis, some doctors told her it was “biologically impossible for the vaccine to have triggered it,” while others told her it was definitely connected to the vaccine. Now that she knows more, she believes that spreading awareness that it is not an adverse reaction to the shot is crucial.

“It's important to hear that, while the [shot] of the vaccine may have triggered it, it’s not the vaccine itself that did this to me,” she said.

STUDYING THE MIND-BODY DANCE

Fasano is one of the authors of a recent Toronto study that looked at the case studies of two patients who presented FND after vaccination. One patient received the Pfizer vaccine, while the other received AstraZeneca.

One woman in the study who was in a coma-like dissociative state improved quickly after being given a diagnosis and went home.

“The study was basically to make everybody aware in this field that this is happening, that it’s going to happen more and more,” Fasano said.

There haven’t been many reported cases in Canada yet, but Fasano believes we could see more soon as the pandemic and vaccination campaigns continue. He says he’s seen five patients so far who were referred to him by the COVID-19 unit, but said he’s heard of more.

For some patients, it’s a transient issue that clears up before they can be referred. The patients that he sees are the ones who have gone through multiple diagnosis attempts and tests, but the problem persists.

Right now, researchers say it’s unclear why FND is happening to certain patients and not others.

Fasano noted that it’s not as simple as categorizing it as mental illness.

“The body and the mind are in constant crosstalk,” he said. “There is no distinction, according to neurobiology, between mind and body. Sometimes the body expresses what's in the mind. Sometimes the mind is not even aware of the problem, yet the body manifests the issue.”

A case study from Italy published in July looked at a 41-year-old man who had bilateral facial paralysis following his first dose of a COVID-19 vaccine. His symptoms came and went for about a two month period.

A recent U.K. case study also described two patients who presented with FND after vaccination. Dr. Matt Butler, an academic neuro psychiatrist, based at King's College in London, is one of the authors of this paper.

“Functional neurological disorder, or FND, is under-recognized both by the public, but also by doctors,” Butler told CTV News. “It's actually probably the second most common neurological disorder that comes to see neurologists in outpatient clinics, but yet many doctors, including me several years ago, hadn't heard of this disorder.”

In Butler’s study, they looked at two case studies of young women in the U.K. who presented FND after receiving their second shot of the vaccine.

“In both cases, there were similarities in that the patients had a weakness,” he explained.

"There was a patient who had what … looked like a stroke. And indeed when she went to the emergency department, it was felt to be a possible mini stroke that had resolved.”

But when neurologists reviewed the case afterwards, they found it matched up with FND.

"In both cases, these patients receive physiotherapy and the aim of physiotherapy in these cases is to always retrain the brain … for it to really learn how to use the affected parts of the body that have been affected by the FND,” he said, adding that both patients have seen improvement.

He said that the amount of people presenting with FND following vaccination is “probably a tiny percentage, but not insignificant.

“I think it's certainly going on more than we recognize from the literature, but it's still a very sort of small percentage,” he said. “The vast majority of people who get vaccines might feel a bit ill for a bit, but that's again the healthy response and then they're back to normal.”

THE ONLINE PROBLEM

FND has been reported after other vaccines in the past, Butler said, including with the swine flu vaccines and HPV vaccines.

Something specific to the COVID-19 pandemic, however, has been the social media factor; people posting about their experiences online and linking the cause unequivocally to the COVID-19 vaccine, warning others not to get the shot. These videos have, in some cases, been seized upon by anti-vaccine groups as evidence that the vaccine is dangerous.

Some of these videos on social media have been viewed millions of times, but experts point out that these videos are unsubstantiated, and it’s not definitively known if the COVID-19 vaccine was administered in all cases.

In a research letter published in JAMA Neurology in April, experts warned that these unverified videos may fuel vaccine hesitancy.

“As neurologists, and health-care professionals more broadly, we must explain transparently and non-judgmentally the nature of FND, including that these symptoms are real, but not the direct result of toxic vaccine effects,” the letter stated.

A press release from the Functional Neurological Disorders Society also stated that while they could not comment on specific cases, many of these videos available online show symptoms that are consistent with FND.

“It is important that these conditions are recognized for what they are – in part so that the patient can be appropriately reassured and can, if necessary, access appropriate treatment, and to prevent a misleading impression of neurological complications of the vaccines,” the release stated Fasano said that when patients don’t receive a prompt diagnosis and then make videos about their symptoms that spread widely, they can “fuel vaccine hesitancy.”

“This is really important for the population to understand that not everything that shows up on social media, not all the claims of side effects from patients, are actually real side effects,” he said.

“There are real side effects, I’m not denying [those]. But we need to be aware that functional problems are actually very common in general, and even more common during the stress of this pandemic.”

Misinformation about vaccines can contribute to one’s stress about getting the shot. Fasano explained that anxiety around the vaccination process directly affected one of his patients, who suffered from symptoms of dissociation.

“The stress in this particular case was triggered by the fact that she was injected initially with one vaccine, and then the second dose was another type of vaccine,” he said. “And after her having heard all these problems on the internet, on the media, she was extremely worried about possible side effects of the vaccination.”

During the pandemic, the public has been confronted with an overwhelming amount of information -- some true and some not -- which Fasano calls an “infodemic.”

The circumstances of the pandemic, such as lockdowns, layoffs, isolation and disease, have “exposed the most vulnerable part of the society to an enormous amount of stress that was never experienced before, at least for a century,” Fasano said.

In Pardo's case, she had been injured in a car accident a decade ago, and then had the stress of contracting COVID-19, followed by two vaccine shots, all of which may have played a role in her reaction.

While stress plays a role in FND, Butler noted that it can’t be minimized into purely a stress-caused issue.

“I think it's a very complex and heterogeneous disorder,” he said.

Moving forward, experts are hoping that added awareness about FND and vaccines will aid both patients and clinicians by lessening fear and making early diagnosis easier.

If FND is caught early, before patients have received medical interventions designed for other issues that they don’t have, patients can be empowered to realize that they do have some degree of control over the condition, and can begin to recover, Fasano said.

Since her diagnosis, Pardo has been undergoing physiotherapy, and has improved to where she is living a normal life again.

“As much as I was relieved, I was a little embarrassed,” she said. “I felt like this was in my brain a little bit, or under my control, or there was something I could have done to maybe not have this happen to me.”

Fasano said many patients are ashamed if they have functional disorders, and too many doctors still believe that a functional disorder “means that the patient is faking it, [that] it’s all in the patient’s head.

“It's not, it's a biological response to the body, triggered by stress,” he said.

Pardo said that Fasano was good at reassuring her that FND is “a very real condition, but very, very treatable.”

“I really want to reiterate the take home message, which is that vaccines are really safe,” Butler said.

Conspiracy theorists may try to use FND cases to spread the idea that something in the vaccines themselves can rewrite the brain, but experts say that is not true. Fasano said a greater awareness of FND among doctors will help patients get the proper treatment.

“My message to the population out there and to the doctors is, keep in mind that functional disorders are relatively common, and are certainly more common during the stress caused by the pandemic,” Fasano said.