What is Functional Neurological Disorder (FND)?

Functional Neurological Disorder (FND) is a diagnosis given when there is a problem with how the brain/nervous system is ‘functioning’. Whilst the basic wiring is intact, there is a problem with how the signals/messages are being sent and received to allow the body to function in the normal way. It is often likened to having a computer software issue. These software issues in turn impact on how the body is able to function, such as limited movement or levels of concentration, seizures and sensory issues. There are a number of factors that can lead to FND.

Physical / Biological impacts – these can vary from the brain having suffered physical trauma from an accident or possibly the bodies reaction to surgery or a viral infection.

Psychological / Social impacts – these could be from traumatic life events or stressful situations which in turn result in the body reacting with FND symptoms.


It is essential that an FND diagnosis comes from a Neurologist after receiving an appropriate examination / consultation, which will hopefully help inform how the FND has come about in the first place. Many patients with FND have other underlying conditions or ‘comorbidities’ which may also be a reason for the occurrence of FND eg. migraines. This is where it is essential that both symptoms are treated in their own right.

FND sits at the interface between Neurology and Psychology, with varying opinions on which has the greatest level of impact. Either way, it is important to note that however FND has come about, the condition requires appropriate treatment.

FND Symptoms

Functional Neurological Disorder (FND) presents with motor, sensory and/or cognitive neurological symptoms such as an inability to walk, tremors, paralysis, functional seizures, involuntary movements, blindness, bowel and/or bladder issues, speech and/or swallowing symptoms, along with pain and severe fatigue.

The box showing some of the symptoms below is by no means meant to scare or shock, but these are things that have been mentioned by others with FND. Not all will be relevant to every person, but those that are, need to be considered carefully, calmly and in some cases with the appropriate professional input.

Movement and motor symptoms

(Sometimes referred to as Functional Movement Disorder)

Tremor:  uncontrollable shaking, most often in an arm or leg, that can be sporadic and may disappear if the person is distracted.

Functional Dystonia: uncontrollable and often painful muscle spasms which may result in, for example, a hand clenched, or a foot fixed, or facial spasms.

Functional Myoclonus:  sudden uncontrollable movements such as jerks and jumps, without being startled.

Functional Tics: involuntary rapid and repetitive movement and sound.

Gait difficulties: problems with walking e.g. dragging a leg, sudden knee buckling (drop attacks), uneven steps (like walking on ice or lack of leg coordination).

Limb and muscle weakness: a feeling that your arm or leg doesn’t feel normal and is unable to bear weight. Can affect muscle control such as with the bladder and bowel. There may be some inconsistency with the weakness.

Paralysis: an inability to move any part of the body, which can last for a period of hours or even days, and most often returns in time. This may present in a stroke-like manner effecting one side of the body, a specific limb, effect both legs together or full body paralysis can occur.


Functional and Dissociative seizures

(Formerly known as Non-Epileptic Attack Disorder,  NEAD).

These seizures are similar in appearance to ‘Epilepsy’ but are not caused by the brain’s electrical activity. Functional seizures can exist alongside Epiliepsy and other Functional Neurological symptoms.

A functional seizure can differ from person to person and may present as dissociation, blackouts, collapsing, twitching and jerking. People can be aware (but not always) of what is occurring around them and can hear other people talking to them for example, however they may lack the ability to be able to communicate back.

What causes functional seizures?
It is currently believed that functional seizures are triggered by the brain’s response to overwhelming stress, which can be from emotional or physical (e.g. pain) triggers, but there may be other causes. For some people symptoms may proceed a specific traumatic incident (such as abuse, bereavement, an accident or following a medical procedure), for others an accumulation of stress over time, and for others no reason at all. Many people are confused by the diagnosis as they don’t feel particularly stressed, especially given it is common for people to have seizures during rest.

How is it diagnosed?
Due to the similarity with Epilepsy, functional seizures are diagnosed by neurologists or Epilepsy specialists. A detailed description of seizures, ideally seeing them in person or on home video, is the mainstay of diagnosis Further possible diagnostic tests can be performed, such as an EEG to measure electrical activity in the brain.


Sensory symptoms

(Important to be aware that sensory symptoms can also be associated with emotional/mental health problems, other diagnoses and general aging. With FND, the underlining cause is different).

Fleeting sensations: feeling like skin is crawling, or electric shock sensation, or twitching.

Hypersensitivity: being over sensitive to light, sound, smell, touch or taste.

Cognitive problems: such as memory loss, poor concentration, word finding difficulties, and speech disturbances.


How FND Affects the Individual

The wide range of symptoms related to FND cannot be understated when considering the affects it may have on the individual’s daily life and routine. One must also take into consideration the variable nature of FND. One day a person’s symptoms might be less pronounced and therefore they attempt to do more, however, this can lead to a ‘boom and bust’ scenario as the impact of doing more can result in a ‘flare up’ of their symptoms. All of the above symptoms can leave an individual nervous about going out in fear of the onset of symptoms or being judged by others who do not understand. This can result in increased isolation, something that many people describe as one of the key impacts of FND.

FND needs greater acknowledgement of its wider impacts which include:

  • Physical Wellbeing
  • Economic Wellbeing
  • Social Wellbeing & Inclusion
  • Mental Wellbeing.

All aspects of living with a chronic (long-term) condition need to be addressed.   As with any chronic condition, an individual’s mental health is bound to be a factor on how they cope with everything else going on in their lives and vice versa. FND Dimensions aims to be part of that support where needed and where we are unable to support, we will try our best to signpost you to the most appropriate guidance and support options.

FND Treatments

“Because FND is different in mechanism from other causes of neurological symptoms, the treatment needs to be different too. Treatment is therefore focussed on rehabilitation or “relearning” of normal function. This can happen with help from a variety of people including neurologists, neuropsychiatrists, physiotherapists, psychologists, occupational therapists, speech therapists, pain management specialists, fatigue management specialists and others.  Most importantly, treatment needs to be individualised to the problems a particular person with FND has: there is not a ‘one size fits all’ treatment”.  Mark Edwards, Professor of Neurology, Kings College London, November 2022 

As FND can result in a wide range of symptoms, which vary from person to person, treatment needs to be tailored to the individuals’ symptoms which might include any or all of the above mentioned areas of medical disciplines.  There are a range of medications that can be prescribed for FND, but it must be emphasised that there is no ‘Silver Bullet’ or cure.

Treatment may include:

  • Physiotherapy (and neurophysiotherapy)
  • Medications
  • Speech therapy
  • Hydrotherapy
  • Speech therapy
  • EMDR – Eye Movement
  • Desensitization and
  • Reprocessing
  • Other psychological therapies (CBT, compassion focused or psychodynamic).

Treatments for FND are said to be most effective when Multidisciplinary Teams are applied (i.e. when there are different specialists coming together to form a treatment plan for an individual).  However, in many areas due to reduced funding and lack of awareness of FND this is not always a possibility.  Instead you may find that treatment might focus around a core specialist (from neurology or psychology) and that this specialist helps you to navigate you through the stages of your treatment.  In some cases, specialists may aim to target the most troubling symptom first before moving onto other symptoms.

Because of the unique nature of FND, the condition falls between the worlds of Neurological and Psychological services.  Psychological intervention may be beneficial for those who have trauma as a triggering factor but can also be beneficial in managing the condition and in dealing with (and better understanding) this difficult diagnosis.  Similarly, neurology services can be extremely beneficial for those who have symptoms associated with their movement.  The type of specialist leading your treatment is not always reflective of the cause of illness, but is likely the best option in your area.

Treatment of FND is not sporadic and it might often take several trials or a combination of different interventions to effectively reduce a person’s symptoms.  This can therefore also take a long time before people find themselves in a position where they can manage on a day to day basis.  A large part of treatment is also focused around self-management which may include the learning of techniques such as:

  • Grounding
  • Pacing
  • Mental health/ mindset management
  • Healthy diet and lifestyle.

Such techniques can be beneficial in maintaining symptoms through periods of remission, dealing with the onset of new symptoms which may occur and in prolonging the effectiveness of some treatments.