Shaking and Seizures As a Vaccine Reaction

What’s the first thing you think about if you hear that someone is have some kind of shaking episode?

Probably that they are having a seizure, right?

And if they had just gotten a vaccine, you are probably guessing that their shaking or seizure is from that vaccine, right?

But is it?

Shaking and Seizures As a Vaccine Reaction

First things first.

“Everything that shakes or faints need not be epilepsy.”

Jean Aicardi

It is important to understand that not every shake is actually a seizure.

Other movement disorders that can easily be confused with seizures include:

• tics
• tremors – involuntary, rhythmic muscle contractions that lead to shaking movements in one or more parts of the body, especially the hands
• nonepileptic myoclonus
• psychogenic movement disorders

So how do you know if it is a seizure or not?

Non-Epileptic Seizures
Movements are less stereotyped, asynchronous, flexor and extensor out of phase, waxing and waning, sudden onset/cessastion, bizarre character (side-to-side shaking, pelvic thrusting, flailing, rolling, whole-body shaking)

Seizure or not? Non-epileptic paroxysmal events in pediatrics

It can help if you witness an episode, especially if you are a neurologist who specializes in movement disorders!

Otherwise it can be very hard to tell if someone has a tic, tremor, myoclonus, or a seizure, and what exactly might be causing it.

“Psychogenic movement disorders (PMDs) are increasingly recognized as a cause of disability, but the diagnosis is still made largely at tertiary care movement disorders centers. The reported prevalence of PMDs varies between 2% and 20% based on the definition and clinical setting.”

Psychogenic Tremor: A Video Guide to Its Distinguishing Features

Or if whatever is causing their shaking might in fact be psychogenic (does not mean that the person is faking!!!), which is much more common than most folks likely realize.

Remember the cheerleader who developed “dystonia” after her flu vaccine during the 2009 H1N1 pandemic? The one who could run or walk backwards normally, but would otherwise shake? And who had somehow developed a British accent? She likely had psychogenic dystonia and not a flu shot reaction.

“A study of 3781 patients who were referred to neurologic centers in Scotland over a 1-year period identified 16% of patients as having psychogenic or psychological symptoms, which were the second most common symptoms after headaches.”

Psychogenic (Functional) Movement Disorders

Psychogenic movement disorders can be triggered by stress and be associated with anxiety and depression. They are treatable, but instead of a being caused by a neurological disease, these psychogenic movement disorders are caused by dysfunction of the nervous system.

Don’t know what’s causing your shaking? Be sure to see a neurologist that specializes in movement disorders. And don’t be quick to blame a recent vaccination, as shaking is likely not a vaccine reaction.

More on Vaccines and Shaking vs Seizures

• Do Vaccines Cause Tics or Tourette Syndrome?
• Does the MMR Vaccine Cause More Seizures Than Measles?
• Diagnosing Vaccine Injuries
• Vaccine Injuries vs Coincidences
• Mistaking Subsequence for Consequence
• Correlation and Causation
• COVID-19 VAERS Reports
• The Truth About COVID-19 Vaccines
• Fainting After Getting a COVID-19 Vaccine
• Deaths Following COVID-19 Vaccination – Understanding Background Rates
• Have Thousands Been Negatively Affected After Getting a COVID-19 Vaccine?
• Not Everything That Shakes Is a Seizure: A Case Report
• Seizure or not? Non-epileptic paroxysmal events in pediatrics
• NIH – Tremor Fact Sheet
• CDC – Diagnosing Tic Disorders
• What is a Seizure?
• Diagnosing Epilepsy
• Clinical Aspects of the Diagnosis of Epileptic Seizures and Epileptic Syndromes
• Functional Dystonia
• Psychogenic (Functional) Movement Disorders
• Psychogenic Tremor: A Video Guide to Its Distinguishing Features
• Functional (psychogenic) movement disorders
• Rating Scale for Psychogenic Movement Disorders (PMD)
• Psychogenic Movement Disorders
• Desiree Jennings on 20/20
• Dystonia from a flu vaccine? Almost certainly not.

Last Updated on January 13, 2021