Functional neurologic (nerve) disorder (FND) is a communication failure between the body and the brain. It can be difficult to diagnose and is often overlooked as a diagnosis. It refers to a group of common neurological movement disorders caused by an abnormality in how the brain functions.

January 31, 2024

Functional neurologic (or nerve) disorder (FND) is a communication failure between the body and the brain. It can be difficult to diagnose and is often overlooked as a diagnosis. It refers to a group of common neurological movement disorders caused by an abnormality in how the brain functions.

The exact cause of FND is unknown. FND is not thought to cause significant structural damage in the brain. It appears to be triggered by physical and mental stressors, so flare ups can be more frequent in Long COVID.

FND is often mistaken for attention seeking behavior, faking, dementia or Alzheimer’s. Although someone may not have epileptic episode or stroke, they may be still be having a different type of seizure or episode.

How does COVID-19 cause this?

COVID triggers an immune response that releases of cytokines, the chemicals that normally fight infection and keep you healthy. But COVID interferes with the cytokine control mechanism, so it doesn’t know when to turn off, leading to cytokine storm.

In turn, the cytokine storm leads to mast cell activation syndrome (MCAS) and the body starts to over produce histamines that cause inflammation of the brain, nervous system, organs, and tissues. This is called multiorgan inflammation syndrome (MIS). MIS-C refers to children, MIS-A refers to adults.

Histamines are chemicals that occurs naturally in the body and some foods. They normally regulate the body’s response to foreign substances and injury, and are involved in things like allergies, stress reactions, and inflammation in the human body.

When the brain is affected by post COVID inflammation, it is unable to send and receive signals properly and there is a disconnection in the function of the lobes and emotional processing.

Memory, concentration, cognition, and the processing of sensations also can be affected. Someone with FND can generally function normally, except during an episode. In times of physical or mental stress, episodes may be more frequent and disruptive to the activities of daily living such as driving, work or exercise.

Long COVID is an example of a physical stressor that can trigger FND symptoms or episodes. There appears to be a strong connection to the hormones associated with fight or flight (corticosteroids, adrenaline, noradrenaline, serotonin, etc.).

FND causes real symptoms that significantly interfere with how you function and cope with daily life. If you have FND, your unplanned movements and symptoms occur without you consciously starting them and are inconsistent and distinct from symptoms that are intentionally produced. FND can involve any part of your body. Symptoms may appear suddenly, increase with attention to them, and decrease when you are distracted.

FND can be difficult for you, your family, and doctors to understand. Early diagnosis and treatment can help lessen symptoms and aid in healing.

Stress triggers Long COVID symptom flare ups

Minimizing stress is critical. The body cannot heal when it is using its energy to cope with stress because it senses a physical or psychological threat.

No matter what the stressor is, your body reacts the same way, by releasing adrenaline and other stress hormones that change the way your body is functioning. This is called the fight or flight reaction, which is a protective response to danger, regardless of what the danger is such as:

Reading an upsetting article
Arguing with someone
An accident or a threat of an accident
A threat to your life
Fear about being sick, losing your job, an animal… anything that causes fear
Frustration, concern or worry about family, kids or friends
Extreme or rigorous exercise
Small things you react to quickly like spilled milk or burning your finger.

No matter what the stressor is, the fight or flight activation is physically triggering histamine release and diverting your energy and oxygen from its normal pathways that supply your brain and organs with oxygen to you large muscles in preparing to run or defend yourself.

FND case study published on January 28, 2022

From the National Institute of Health (NIH): A possible overlap exists between this condition and the functional neurological disorders (FNDs). We report a 23-year-old man who developed, after asymptomatic COVID-19, a complex symptomatology characterized by fatigue, episodic shortness of breath, nocturnal tachycardia, and chest pain. He also complained of attention and memory difficulties, fluctuating limb dysesthesia, and weakness of his left arm.

After neurological examination, a diagnosis of FND was made. Notably, the patient was also evaluated at a post-COVID center and received a diagnosis of long COVID-19 syndrome. After 4 months of psychoanalytic psychotherapy and targeted physical therapy in our center for FNDs, dysesthesia and motor symptoms had resolved, and the subjective cognitive complaints had improved significantly. However, the patient had not fully recovered as mild symptoms persisted limiting physical activities.

Long-term post COVID symptoms and FNDs may share underlying biological mechanisms, such as stress and inflammation. This case suggests that functional symptoms may coexist with the long COVID symptoms and may improve with targeted interventions. In patients presenting with new fluctuating symptoms after SARS-CoV-2 (COVID-19) infection, the diagnosis of FNDs should be considered, and the positive clinical signs should be carefully investigated.

Functional neurological disorder names

FND
Non-epilectic seizures
Non-epicleptic attack disorder (NEAD)
Non-epileptic events
Disassociative seizures
Pseudo seizures
Pseudo epileptic seizures
Psychogenic seizures
Pseudo epileptic seizures
Psychogenic seizures
Conversion seizures
Conversion disorder

FND events are like electrical storms in the brain. They can be observed with an electroencephalograph (EEG), a diagnostic test involving electrodes taped to the scalp that record neuronal activity.

FND is debilitating, misunderstood, and can be intensely frustrating to suffers of this condition.

Barriers to diagnosis

FND was previously thought to be stress related caused by diagnoses such as PTSD or depression. Mental and physical stressors can trigger an episode, but some people show symptoms in the absence of stress.

Physical and or psychological risk factors can cause functional symptoms which include a variety of physical, sensory, and cognitive symptoms that have yet to be explained by a recognized disease.

FND functional neurological disorders are considered multi factorial, which means many different risk factors can contribute to the development of the disorder. The symptoms are real and can cause impairment in quality of life that is similar to and in some aspects worse than other neurological conditions.

FND is a condition where the body can exhibit a variety of symptoms without a recognized disease or condition causing them.

This does not mean that the symptoms are made up or imagined, they are very real and very much outside of the patient’s control.

Symptoms of FND most often appear suddenly and progress rapidly. People can go years without ever suffering symptoms, and then suddenly be hit with issues and find the episodes increasing in intensity and frequency. Symptoms can also fade, seemingly disappearing altogether without reason, only to return out of nowhere.

FND episodes can also be triggered by other illness, injury, or severe stress, indicating that the fight or flight response associated with stress is activating nervous system symptoms.

Common presentations (symptoms) of FND

Internal vibrations
Internal shaking
Anger outbursts
Bladder/bowel issues
Cognitive difficulties involving memory or concentration
Communication issues
Fatigue
Forgetfulness
Feeling drunk
Deafness or hearing difficulties
Difficulties walking
Dissociative episodes
Dizziness
Facial sensory disturbance
Facial spasms
Fatigue
Feeling a limb doesn’t belong to you
Functional limb weakness
Headache
Health anxiety
How my sensory syndrome
Irritability
Issues following conversations / blanking out
Light sensitivity
Low or depressed mood
Memory loss
Physical seizures
Random pain without injury
Seizures
Sleep issues such as insomnia/oversleeping
Slurred speech
Stroke like episodes
Sudden falling without blackout
Tinnitus
Tremors
Twitches and sudden jerks
Vision, hearing, or speech issues
Worry and panic
And more.

Things you can do to help yourself

Minimizing physical & psychological stressors is essential in recovery from Long COVID.

Nutrition: Try to eat protein and fresh vitamin rich foods daily and avoid chemicals, preservatives, sugars, fast foods, prepared foods and high histamine foods.
Don’t skip meals. Your body needs protein , vitamin C, and vitamin D to heal from any injury or illness. A low histamine or low carbohydrate (sugar) diet is recommended by doctors treating Long COVID (PASC), and many people report a reduction in symptoms within 1-3 days of the diet change, including decreases in sneezing, itching or hives, irritable bowel syndrome, body pain, along with a reduction in swelling and inflammation.
Hydration: A minimum of eight 8 oz glasses of plain water daily is recommended.
Avoid drinks with chemical additives. You can easily make a fresh electrolyte drink yourself by adding a dash of mineral rich Epsom salt and a piece a fruit like a raspberry for flavor instead of spending money on commercial drinks like Gatorade that contain chemicals and sit in plastic bottles for long periods of time. Remember that caffeine and alcohol have dehydrating effects.
Sleep hygiene: Getting 7-9 hours of sleep so your body can repair itself. You need at least 4 hours of uninterrupted sleep to get into the restorative phase of sleep.
Avoid stimulating activities after dinner like thrilling movies or books, arguments, negative news or frustrating stimuli.
If you wake up frequently or with a startle, you may be experiencing drops in your oxygen level, which signal your brain to release adrenaline to force you to take a breath. This could be a temporary inflammation issue or more enduring sleep apnea. Ask your doctor for a sleep study to evaluate your need for a CPAP or BiPAP, a machine that pushes air into your lungs when it senses an apneic episode (periods of not breathing).
Stress management: Stress affects every component of your life.
The only thing you can control about stress is your reaction to it. Try to avoid or minimize your exposure to stressful situations: Turn off the news, make family visits that end unpleasantly short, wait for the morning to have intense discussions, let go of things that annoy you but don’t really matter in the big scheme of things, avoid intense conversations or entertainment in the evening.
Exercise within tolerance: Pace yourself and do not push your body to extremes in any way.
For some this may mean seated breathing exercises, walking to the mailbox. Rest when your body says to slow down. Gradually build on your activity endurance as your body cues you to progress. This can be hard to gauge, because when you feel good you naturally do more, but if you do too much you may experience symptom flare ups 1-3 days later as the post exertion inflammation builds. Some people describe this as post exertional malaise, others experience severe recovery set backs.
Breathwork: You can literally stop the fight or flight reaction by taking slow deep breaths.
Deep slow breathing shuts down the adrenaline flow, slows your heart rate, lowers your blood pressure and decreases stress related histamine release. When you do this, your blood reroutes back to your brain and nervous system to allow you to think clearly. It also allows your body to use its energy and oxygen to heal your inflamed nerves and organs.

Long COVID Support

**ProMedView** **Nurse Coaches - We get it.**

Our clinical experts advocate for those with Long COVID.
Individual coaching
Group Q&A sessions
Peer support groups

Learn More

Long COVID Innovations

Formula C - Clinically shown to alleviate Long COVID symptoms

Stellate Ganglion Blocks can restore taste and smell

Nattokinase - Strengthens the body against the spike protein

RAIsonance products thumbnail 07.2023.png

Keep moving, keep breathing.

Brought to you by covidCAREgroup, connecting the dots of long COVID through education, research and resources.

Did this article help you? Please consider making a gift, donating, or purchasing a $25 annual membership. The covidCAREgroup is run by volunteers. 100% of our funding comes from community donations are used to support our continued outreach initiatives.

Make a gift

COVID Care Group, LLC, is not a “not for profit” organization. Donations, gifts & memberships are not tax-deductible.

COVID Care Group, LLC is not a healthcare provider and does not provide medical advice, diagnosis, or treatment.