COVID-19 vaccination can be one of a number of events that may trigger functional neurological disorder (FND), experts said.
Two cases of young women manifesting FND after COVID-19 vaccination
were reported by Alfonso Fasano, MD, PhD, of the University of Toronto,
and Antonio Daniele, MD, PhD, of Università Cattolica del Sacro Cuore in
Rome, in a letter to the Journal of Neurology, Neurosurgery, and Psychiatry.
Two
other published reports showed probable FND precipitated by COVID-19
vaccine administration, highlighting that FND should be considered when
assessing post-vaccine neurologic symptoms, wrote Matthew Butler, MD, of
Kings College London in England, and co-authors in the Journal of Neuropsychiatry and Clinical Neuroscience.
FND involves a disruption in normal brain mechanisms for controlling
the body. It can be triggered by physical or emotional events including
head injury, medical or surgical procedures, or vaccinations. People
with FND may present with a range of neurological symptoms such as
seizures, sensory abnormalities, gait or balance disturbance, or
weakness. FND is distinct from feigning because patients perceive their
symptoms as involuntary. Once it is recognized and diagnosed, FND can be treated.
"We strongly encourage clinicians to be aware of the possibility for FND in response to SARS-CoV-2 vaccinations," Butler told MedPage Today.
"FND can be a serious and debilitating condition; however, it does not
implicate any vaccine constituents and should not hamper ongoing
vaccination efforts."
"Making
clinicians aware of this can benefit people with FND reactions to
vaccines, as well as maintaining public confidence in the vaccine,"
Butler added. "Rigorous causality assessments should occur when FND
reactions are suspected."
"Among the various adverse events which might be observed after
COVID-19 vaccination, the occurrence of functional -- once called
psychogenic -- neurological disorders might be a challenging issue for
healthcare providers, media, and public opinion with a negative impact
on vaccination campaigns," noted Fasano and Daniele.
"In our view, FND following COVID-19 vaccination will not be a rare
phenomenon and will be widely covered by the media, being interpreted as
a direct consequence of the vaccine, as already seen in the past," they
wrote.
The first case from Fasano and Daniele involved a woman who presented
with a short episode of generalized psychogenic non-epileptic seizures
20 minutes after receiving her second dose of the Pfizer-BioNTech
vaccine. The event was followed by different episodes that included an
inability to move her whole body. No postictal period followed these
episodes, some of which were captured by video-electroencephalography
and did not show any epileptic activity.
The
second patient had persistent dizziness and reported loss of tactile
sensitivity in her right arm and leg about 2 weeks after receiving the
AstraZeneca vaccine. Her brain CT scan was unremarkable, and
neurological examination did not show objective loss of tactile or pain
sensitivity.
"In both patients, neurological symptoms were characterized by a
sudden onset and overt inconsistency, as typically observed in patients
with FND," Fasano and Daniele wrote.
The cases reported by Butler and colleagues involved previously
healthy women, both in their 30s. One had probable FND after her first
dose of the Pfizer-BioNTech vaccine; the other, after her first Moderna
shot.
"The close development of functional motor symptoms after the vaccine
does not implicate the vaccine as the cause of those symptoms,"
observed Alberto Espay, MD, MSc, of the University of Cincinnati, who
was not involved with the case reports.
"Correlation does not imply causation," Espay told MedPage Today.
"If neurological symptoms following vaccination are determined to be
functional during a neurological exam, then the vaccination can only be
considered a stressor or precipitant, much like any other stressor
might, such as a motor vehicle accident or sleep deprivation."
Earlier this year, a group led by David Perez, MD, MMSc, of Massachusetts General Hospital in Boston, published a paper in JAMA Neurology
that discussed videos that had emerged on Facebook, YouTube, and other
channels showing people with severe neurological symptoms, such as
convulsions and difficulty walking, after receiving a COVID-19 vaccine.
"The spread of these videos could fuel vaccine hesitancy by giving an
overly simplistic impression of potential links between the vaccine and
major neurological symptoms," Perez said in a statement. "Instead,
these are symptoms of a real, brain-based disorder that sits at the
intersection of neurology and psychiatry."
"It is recognized that physical events such as head injury,
surgeries, or vaccinations in some individuals can precipitate the
development of FND," Perez told MedPage Today. "In such instances, one of the important mechanisms is the attention drawn to the body."
Neurologists and other healthcare professionals have an obligation to explain FND to the public, he added.
While
health experts have tried to stress that in most cases, there is no
direct link between COVID-19 vaccines and various media-covered adverse
events, more needs to be done, Fasano and Daniele noted.
This is especially true in light of misinformation and conspiracy
beliefs about the COVID-19 pandemic, which are "now enriched by the
theories of anti-vaccine movements," they wrote. "We suggest that the
medical community should be more vocal in informing the media and public
opinion about FND, thus making a further step towards the establishment
of 'eHealth literacy.'"
Last Updated August 23, 2021
-
Judy George
covers neurology and neuroscience news for MedPage Today, writing about
brain aging, Alzheimer’s, dementia, MS, rare diseases, epilepsy,
autism, headache, stroke, Parkinson’s, ALS, concussion, CTE, sleep,
pain, and more. Follow
Disclosures
The study by Fasano
and Daniele was funded by the University of Toronto and the University
Health Network Chair in Neuromodulation and Multidisciplinary Care.
Fasano and Daniele reported no competing interests.
Butler
and co-authors reported relationships with the National Institutes of
Health Research, the NIH National Institute of Neurological Disorders
and Stroke, the United Kingdom Research and Innovation/Medical Research
Council, and the European Union's Horizon 2020 research and innovation
program ZikaPLAN.
Defeng Hua1
Zhen Guo
Shunchao Ci
Di Li
Feng Wang