Functional Neurological Disorders

FND stands for Functional Neurological Disorder. Other names that may be used are Functional Neurological Symptom Disorder, Functional Movement Disorder, and Dissociative (non-epileptic) seizures/attacks. FND symptoms can be single, multiple, episodic or persistent. 

Symptoms may include:

  • 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 twitches.
  • 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 weakness: a feeling that your arm or leg doesn’t feel normal and is unable to bear weight. 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.


  • Dizziness: feeling lightheaded and off balance, described as feeling like surroundings are spinning.
  • Hypersensitivity: being very sensitive to light, sound, smell, touch or taste.
  • Fleeting sensations: feeling like skin is crawling, ‘electric shock’ sensation, twitching.


  • Short term memory difficulties.
  • Poor concentration.
  • Word finding difficulty.
  • Difficulties with speech.

Broadly speaking FND relates to a problem with the nervous system functioning rather than structural disease. Symptoms may appear similar to neurological disorders such as Multiple Sclerosis, Parkinson’s and Epilepsy, and are associated with similar levels of disability and distress. 

Other conditions/symptoms to commonly co-occur with FND include chronic pain (including Fibromyalgia), fatigue, cognitive symptoms, dizziness, migraine, Irritable Bowel Syndrome, anxiety and depression. FND should usually be diagnosed by a physician familiar with the diagnosis of neurological disease. 

Historically FND has been thought to be tightly linked to recent stress or past emotional trauma. In fact, this is not to be the case for some patients with FND and psychological factors should not be used to make the diagnosis. 

The exact prevalence of FND is unknown. However, research suggests FND is the second most common reason for a neurological outpatient visit after headache/migraine; accounting for one sixth of diagnoses. This means FND is as common as multiple sclerosis or Parkinson’s disease.


The exact cause of FND is unknown, although ongoing research is starting to provide suggestions as to how and why it develops. Many different predisposing factors can make patients more susceptible to FND such as having another neurological condition, experiencing chronic pain, fatigue or stress. However, some people with FND have none of these risk factors.

At the time FND begins, studies have shown that there may be triggering factors like a physical injury, infectious illness, panic attack or migraine which can give someone the first experience of the symptoms. These symptoms normally settle down on their own. However, in FND the symptoms become ‘stuck’ in a ‘pattern’ in the nervous system. That ‘pattern’ is reflected in altered brain functioning. The result is a genuine and disabling problem, which the patient cannot control. The aim of treatment is to ‘retrain the brain’, for example by unlearning abnormal and dysfunctional movement patterns that have developed and relearning normal movement.

One way of thinking about FND is looking at it as a bit like a ‘software’ problem on a computer. The ‘hardware’ is not damaged but there is a problem with the ‘software’ and so the computer doesn’t work doesn’t work properly. 


Treatment plans must be tailored to suit the person’s individual need. Collaborative care may include: physiotherapy, psychotherapy, medication management, occupational therapy, and carer/family support.

Psychological Treatment

FND is a very complex disorder and exists at the interface between neurology and psychiatry therefore the brain and the mind. We don’t understand much about why and how FND occurs, but we do know that it is a disorder that responds quite well to psychological treatments, such as CBT. CBT can be beneficial for these symptoms even if you don’t have depression, anxiety or any other psychological problems that may be a result of living with FND. However, if these do co-exist CBT can be particularly helpful.

Similarly to other forms of treatment for FND, such as physiotherapy or medication, psychological therapies are not guaranteed to work for all patients. It is also currently not possible to know in advance which patients are likely respond to psychological therapies. 

Cognitive Behavioural Therapy (CBT) is the most commonly used psychological treatment for FND. CBT has been developed from a strong theoretical basis centred on research in both psychology and the broader neurosciences. It has been used in different forms to treat many psychological problems, particularly depression and anxiety disorders (e.g. phobias and panic attacks), which can co-exist with FND for a variety of reasons.

In the context of FND, CBT focuses on identifying precipitants (‘triggers’) of physical symptoms (e.g. seizures) and finding ways to stop these symptoms occurring, such as using distraction or relaxation techniques. It also can be used to discuss how thoughts, feelings, bodily sensations and actions can be interconnected and how this might occur in the individual patient.

Key areas that may be addressed in treatment may include avoidance behaviours (i.e. what the person avoids doing because of their symptoms or concerns of experiencing symptoms), thoughts that relate to their condition and how emotions are dealt with. It therefore tends to focus on ‘the here and now’ rather than on issues from the past, although these can be incorporated into the treatment if relevant. It also tends to be quite brief in that the number weekly sessions (normally an hour each) normally run for around 10-14 weeks. 

Sometimes ‘booster’ sessions can be given after this initial course of therapy. Carers and/or family members may be included in therapy sessions although not in the context of formal family therapy.  Illness models/beliefs can also be discussed along with the evidence supporting them in the individual.

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