The following text is copied from https://www.neurosymptoms.org/en_US/ a website run by Professor Jon Stone – Consultant Neurologist, Royal Infirmary of Edinburgh and University of Edinburgh, UK.
Disclaimer on his website:
DISCLAIMER: Please do not attempt to diagnose yourself or others using this website. The diagnosis of FND and of functional neurological symptoms can be difficult and depends on having experience and knowledge of different neurological problems. This is not a website about ALL neurological conditions. The views of this website are those of the author alone and not those of NHS Lothian, The University of Edinburgh, Scottish Government or CogniHealth.
Functional Neurological Disorder (FND):
FND describes neurological symptoms like limb weakness, tremor, numbness or blackouts, related to the movement and sensation parts of the nervous system…..
- Caused by a PROBLEM with the FUNCTIONING of the nervous system
- A “software” issue of the brain, not the hardware (as in stroke or MS)
- With positive diagnostic features typical of FND
- Cause day to day difficulties for the person who experiences them
Functional Neurological Symptoms are:

Troublesome symptoms that someone wishes to understand without necessarily having a ‘disorder’ are called functional neurological symptoms, and this site is for you too.
FND and functional neurological symptoms are surprisingly common but can be difficult for patients and health professionals to understand.
Symptoms
Most patients with functional or dissociative symptoms have more than one symptom. Experiencing lots of different symptoms at once can be a particularly baffling feature of these illness for patients.
In this section Professor Stone divided up the core symptoms of FND from other common associated symptoms like pain and fatigue that people with FND often get. Usually all of these symptoms are best seen as part of one illness rather than interpreted as multiple illnesses, but they are labelled differently. So for example chronic pain is not defined as part of FND.
FND Specific Symptoms
- Functional Limb Weakness – Weakness of an arm or leg
- Functional (Dissociative) Seizures – Episodes that look and feel like epileptic seizures or faints
- Functional Sensory Symptoms – Reduced sensation in a body part
- Functional Movement Disorders – Involuntary movements such as tremor, jerks, spasms or difficulty walking
- Functional Tremor – Uncontrollable shaking of the arm, leg, body or neck
- Functional Cognitive Symptoms – Problems with thinking, memory or concentration
- Functional Speech Swallowing Symptoms – Speech, swallowing and communication difficulties
- Functional Dizziness (PPPD) – PPPD is the name of persistent dizziness as a type of FND
- Functional Drop Attacks – A “Drop attack” is the medical term for a sudden fall to the ground without an obvious ‘blackout’
- Functional Dystonia – Spasm of a body part. In FND. Often a clenched hand or a turned in ankle
- Functional Gait Disorder – Problems walking
- Functional Facial Symptoms – Spasms of the eye and lower face
- Functional Jerks and Twitches – Sudden jerky or shock like movements
- Bladder symptoms and FND – Overactive Bladder, Chronic Urinary Retention and Scan negative Cauda Equina Syndrome
- Visual Symptoms – Visual blurring, field loss, double vision, light sensitivity and visual snow
- Functional Tics – Repetitive complex movements or vocalisations
Common associated Symptoms
- Dissociative Symptoms – Feeling spaced out, not there or not properly in your own body
- Fatigue – Fatigue, lack of energy and exhaustion
- Pain – Chronic pain is often due to an increased volume knob in the pain pathways of the nervous system
- Sleep Problems – Sleep disturbance includes insomnia (not enough sleep) and hypersomnia (too much sleep)
- Headache – Migraine, chronic daily headache and medication overuse headache
- Post-Concussion Syndrome – Post-concussion syndrome is a description given to a cluster of physical and cognitive symptoms that sometimes occurs after minor head injury
- Worry / Panic – Anxiety, Panic and Post traumatic Stress are common in in people with FND
- Health Anxiety – Health Anxiety describes relentless and distressing concern about health
- Low Mood – Depression, low interest, low mood can occur alongside FND
- Complex Regional Pain Syndrome – Complex Regional Pain Syndrome describes a chronic pain syndrome in a limb. Sometimes the clinical features can overlap with FND
- IBS, Chest and other symptoms – Irritable bowel syndrome, functional dyspepsia, atypical chest pain and dysfunctional breathing are all examples of other functional symptoms and disorders
All listed symptoms link to additional information on Professor Jon Stone’s website.