The images are alarming, even alarming. In a number of videos posted online and viewed millions of times on social media, two separate American women appear to be experiencing bouts of tremors and involuntary body movements.
There is no direct link between the women, other than that both had received COVID-19 vaccines shortly before their symptoms appeared, a fact that some have linked to the occurrence of these tremors. But scientists say there is another valid explanation for what we see in the images.
While there absolutely No suggest that someone is faking these symptoms, researchers think that it is not the contents of the COVID-19 vaccines that cause the shaking and convulsions.
Instead, it is possible that these viral videos depict a rare and little understood medical condition called functional neurological disorder (FND) – a neuropsychiatric condition believed to be caused by a range of stimuli, including physical or emotional events, injuries , medical procedures and sometimes even the act of injecting a needle.
“Some people with FND have heightened awareness of their bodies and an increased state of arousal and threat, which can hijack normal neural networks that control voluntary movements,” says neurologist David Perez of Massachusetts General Hospital (MGH).
“FND teaches us quite a bit about the complexity of the human brain.”
Functional Neurological Disorder, sometimes also known as Conversion Disorder, cannot be definitively diagnosed by watching videos, but nonetheless, the types of body control problems we see – limb weakness, walking difficulties, jerky movements, tremor and facial cramps – are all symptoms from FND.
For that reason, the US-based FND Society released a press release in January, shortly after the videos began to attract attention on social media, noting that the clinical features of FND matched what appeared in the images.
“We expect that FND will develop in some individuals after vaccination as a result of a combination of increased stress from the pandemic, feelings of uncertainty about the vaccine and normal transient physical symptoms, and post-vaccination discomfort,” wrote the FND Society. .
To make a similar point and to increase public understanding of FND, Perez and his co-authors have written a new commentary in JAMA Neurology, noting that the videos look like possible episodes of FND, which – if true – could have been caused by the vaccine injections, but probably not the vaccines themselves.
Precipitating factors, although proximal to the development of symptoms, are not directly caused by the substances in the vaccine in the same way that, for example, Neisseria meningitidis is the cause of meningitis, ”the researchers explain.
“Instead, factors such as expectations, beliefs, increased physical attention, arousal, and threat / emotional processing play an important mechanistic role in the pathophysiology of FND.”
It’s a particularly important theme right now, the researchers insist, as videos like this sometimes draw thousands of viewers and may also be shared by those advocating conspiracy theories and anti-vaccination beliefs.
In the face of a modern health crisis like COVID-19, it’s important to make it known that these videos show really rare cases of FND.
“The dissemination of these videos could fuel hesitancy about vaccines by providing an overly simplistic impression of possible links between the vaccine and key neurological symptoms,” Perez said.
“Instead, these are symptoms of a real brain-based condition at the intersection of neurology and psychiatry.”
Until now, US federal health authorities such as the CDC have not had much to say about the possible role of FND in videos like this one, especially emphasizing that side effects from COVID-19 vaccinations are usually “mild and moderate and disappear quickly.”
That’s an important clarification the public should hear, but it doesn’t go far enough to educate people about what FND really is, the researchers say, especially when viral videos of terrifying shaking symptoms are viewed millions of times – uploaded by people who claim the vaccines are directly responsible.
“A lack of direct reporting may be misconceived by the public that the Centers for Disease Control and Prevention are not keeping a close eye on adverse symptoms or, worse, hiding them,” the researchers explain.
“We must explain transparently and without judgment the nature of FND, including that these symptoms are real, but not the direct result of toxic vaccine effects.”
The findings are reported in JAMA Neurology