Q&A: Functional neurological disorder is real, but not caused by ‘toxic vaccine effects’

Effective communication about the potential link between functional neurological disorder and COVID-19 vaccines “is critically important” to help inform the public and dimmish fears, according to a viewpoint published in JAMA Neurology.

These efforts will enable patients to make “informed decisions” about receiving the COVID-19 vaccine, the researchers wrote.

“As neurologists, and health care professionals more broadly, we must explain transparently and nonjudgmentally the nature of [functional neurological disorder], including that these symptoms are real but not the direct result of toxic vaccine effects. They can theoretically happen with a trigger such as injecting saline, and these events do not mean the current vaccines are unsafe,” David Perez, MD, MSc, faculty member in the departments of neurology and psychiatry and director of the functional neurological disorders clinic at Massachusetts General Hospital, and colleagues wrote. “Furthermore, not only is there a need to educate the public on [functional neurological disorder] (the most common neurological condition that most people have never heard of), but nocebo effects more broadly.”

Healio Neurology spoke with Perez to learn more about the viewpoint he and colleagues published in JAMA Neurology.

Healio Neurology: What prompted this publication?

Perez: Our goal with this JAMA Neurology viewpoint article was in part to raise awareness of the complexities of cause-and-effect relationships in medicine. We also sought to raise awareness of how brain-based conditions such as functional neurological disorder can be conceptualized using the biopsychosocial model. In the biopsychosocial model, one considers the interplay of predisposing vulnerabilities (risk factors), acute precipitants and perpetuating factors.

Healio Neurology: What, if any, adverse neurological events following COVID-19 vaccination have been documented and substantiated?

Perez: As we noted in the article, there are a range of physical symptoms that are experienced after being vaccinated, including fever/chills, headache, fatigue, myalgia/arthralgia, lymphadenopathy, nausea or local effects of swelling, erythema or pain. Post-marketing surveillance remains exceedingly important to ensure early detection of any potential adverse events. As we are seeing with the pause in the distribution of the Johnson & Johnson vaccine, there may also be differences across the vaccines that continue to be monitored closely by regulatory agencies.

That being said, functional neurological disorder, a condition at the intersection of neurology and psychiatry (and potentially the second most common outpatient neurological referral), can help us understand the complexities of relationships between vaccinations and post-vaccination symptoms. Both physical precipitating events and emotionally charged experiences have been recognized as triggering factors for the development of a functional neurological disorder. In functional neurological disorder, an important mechanism implicated in the pathophysiology is that attention toward the body can bring about or intensify symptoms.

Healio Neurology: Have there been any confirmed cases of functional neurological disorder in this setting?

Perez: Speaking in general terms, vaccines have been described as a trigger for the development of functional neurological disorder. I anticipate that, in the medical literature, case reports of documented functional neurological disorder following COVID-19 vaccinations will be reported in the coming months.

Healio Neurology: How should neurologists address these events with patients while underscoring the importance of the vaccine?

Perez: Neurologists and neuropsychiatrists are frontline in diagnosing functional neurological disorder. Functional neurological disorder is diagnosed based on physical examination signs and semiological features that have been shown to be specific for the condition. It is recommended by experts in the field to share with patients the rule in signs observed on examination as a way of helping the patient understand that the condition is being diagnosed based on positive diagnostic findings.

Healio Neurology: What specific educational points are important to cover?

Perez: For the interested reader, a helpful website to understand the range of functional neurological symptoms is www.neurosymptoms.org. There are also good educational materials provided by the multidisciplinary professional Functional Neurological Disorder Society (www.fndsociety.org) and patient advocacy groups such as www.fndhope.org. One of the reasons we wrote this viewpoint article is to help bring discussions regarding functional neurological disorder into mainstream medicine and public discourse. The documentary "Dis-sociated" that is freely available on YouTube is another educational resource that I would encourage interested individuals to watch.

Healio Neurology: How else can neurologists help reassure their patients about the COVID-19 vaccine and work to maximize uptake?

Perez: Transparency and open dialogue are critical themes to encourage. I would also like to see more educational campaigns (and clinical and research funding) directed toward functional neurological disorder. The application of the biopsychosocial model to formulate a range of medical, neurological and psychiatric conditions will also be important for underscoring the close interplay between physical health and mental health.

References:

Kim DD, et al. JAMA Neurol. 2021;doi:10.1001/jamaneurol.2021.1042.

Martin Vargas C. Dis-sociated. 2019. Available at: https://youtu.be/MA1EYAg95k. Accessed April 16, 2021.