The filming is worrying, even alarming. In a series of videos posted online and already watched millions of times on social networks, two separated American women seem to experience seizures and involuntary body movements.
There is no direct link between women, except that both received COVID-19 vaccines shortly before their onset of symptoms, which some linked to the onset of these tremors. But scientists say there is another valid explanation for what we see in the footage.
While there is absolutely Not suggesting that anyone who feels these symptoms, the researchers believe that the content of COVID-19 vaccines does not cause tremors and seizures.
Instead, these viral videos may describe a rare and poorly understood condition called a neurological functional disorder (NDF) – a neuropsychiatric disorder that is thought to be triggered by a range of stimuli, including physical or emotional events, injuries, procedures. medical and sometimes even the act of injecting a needle.
“Some people with FND have an increased awareness of their body and an increased state of arousal and threat, which can disrupt the normal neural networks that control voluntary movements,” says neurologist David Perez of Massachusetts General Hospital (MGH).
“FND teaches us quite a bit about the complexities of the human brain.”
Functional neurological disorder, sometimes known as conversion disorder, cannot be definitively diagnosed when watching videos, but the types of body control problems observed – limb weakness, gait problems, jerky movements, tremor, and facial spasms – are all symptoms of FND.
For this reason, the US FND Society issued a press release in January shortly after the videos began to draw attention on social media, noting that the clinical features of the FND were appropriate for what appeared in the footage.
“We would expect FND to develop in some individuals after vaccination due to a combination of increased stress due to the pandemic, feelings of uncertainty about the vaccine and normal transient physical symptoms and discomfort after vaccination,” the FND Society wrote.
Now, to support a similar type of point and to help increase public understanding of the FND, Perez and his co-authors have written a new comment in JAMA Neurology, noting that the videos look like potential episodes of FND, which – if true – could have been triggered by vaccine injections, but probably not by the vaccines themselves.
‘Precipitating factors, although close to the development of symptoms, are not caused directly by the substances in the vaccine in the same way as, for example, Neisseria meningitidis it is the cause of meningitis, “the researchers explain.
“In contrast, factors such as expectations, beliefs, increased body attention, arousal, and emotional threat / processing play important mechanistic roles in FND pathophysiology.”
It is a particularly important topic today, urges researchers, because videos of this kind sometimes attract thousands of views and can also be shared by those who advocate conspiracy theories and anti-vaccination beliefs.
In the face of a modern health crisis, such as COVID-19, it is important to speak out about the strong possibility that these videos actually show rare cases of NDF.
“The spread of these videos could fuel the vaccine’s hesitation, giving too simplistic an impression of the potential links between the vaccine and major neurological symptoms,” says Perez.
Instead, they are symptoms of a real, brain-based disorder at the intersection of neurology and psychiatry.
To date, US federal health authorities, such as the CDC, have not had much to say about the potential role of the FND in such videos, mainly emphasizing that the side effects of COVID-19 vaccinations tend to be ” mild and moderate and disappear quickly ”.
This is an important clarification that the public needs to hear, but it doesn’t go far enough in educating people about what FND really is, the researchers say, especially when viral videos with shaking symptoms look like scary records millions of views – uploaded by people requesting vaccines are directly responsible.
“A lack of direct messages can be falsely perceived by the public that the Centers for Disease Control and Prevention does not adequately monitor adverse symptoms or, worse, hide them,” the researchers explain.
“We need to explain transparently and without judgment the nature of the FND, including that these symptoms are real, but not the direct result of the toxic effects of the vaccine.”
The findings are reported in JAMA Neurology.