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Functional Neurological Disorder (FND) : a patient's guide

including Functional/Dissociative (non-epileptic) Seizures,  Functional Movement Disorder and other functional symptoms


Other Functional Disorders and Symptoms



Studies have shown that patients with functional neurological symptoms have a higher frequency of experiencing functional symptoms elsewhere in the body.


These may include:


Irritable Bowel Syndrome

Unexplained heartburn and indigestion (functional dyspepsia)

Fibromyalgia (see pain)

Temporomandibular Joint Dysfunction

Atypical Facial Pain

Loin Pain Haematuria Syndrome

Chronic Unexplained Fatigue (see fatigue)

Chronic Pelvic Pain / Painful heavy periods

Atypical chest pain

Chronic Hyperventilation


Sometimes, this reflects a very longstanding vulnerability to these symptoms with different symptoms coming and going since late teenage / early twenties.


This is not always the case. You can have any of the functional symptoms described in this website in isolation or you can be very healthy for 40 or 50 years and then get lots of functional symptoms even when you have never had them before.


But it can be useful to see that, if you do find yourself seeing your GP or different specialists with lots of different genuine symptoms and ‘nothing seems to turn up’, that you are not alone and this pattern of illness is well recognised. See ‘ Labels’ for more discussion of this.



Irritable Bowel Syndrome (IBS)

This common condition usually presents with abdominal bloating or pain associated with constipation and/or diarrhoea. Together with other functional abdominal problems it accounts for one third to one half of all patients seen in gastroenterological clinics in hospital As with functional neurological symptoms, there is no structuaral disease process causing the symptoms. Gastroenterologists view IBS as a genuine problem which is caused by a disorder in the function of the gastrointestinal tract. The focus of attention in this condition has been looking at disturbances in the nervous control of the bowel (including the brain)


Irritable Bowel Syndrome has been defined by gastrointestinal specialists as:


At least 3 months, with onset at least 6 months previously of recurrent abdominal pain or discomfort* associated with 2 or more of the following:

•Improvement with defecation; and/or

•Onset associated with a change in frequency of stool; and/or

•Onset associated with a change in form (appearance) of stool

*Discomfort means an uncomfortable sensation not described as pain.



Functional Dyspepsia (IBS)

This is when people have heartburn or indigestion symptoms but nothing can be found to explain the symptoms with camera or other tests. Functional dyspepsia has been defined by gastrointestinal specialists as:


At least 3 months, with onset at least 6 months previously, of 1 or more of the following:

•Bothersome postprandial fullness

•Early satiation

•Epigastric pain

•Epigastric burning and

•No evidence of structural disease (including at upper endoscopy) that is likely to explain the symptoms



Chronic Pelvic Pain / Painful heavy periods

In women with functional neurological symptoms there is a striking increased frequency of previous  gynaecological problems. This may include


•Excessive Period pain

•Heavy periods

•Chronic pelvic pain


As a result of these symptoms, there is a much higher rate of hysterectomy (removal of the womb) in patients with functional neurological symptoms than the general population


Whilst there is a clear association with these gynaecological problems, it is not known clearly what lies behind it. A vulnerability to pain symptoms and syndromes may be important.


The most useful thing to know here is that if you do have a history of gynaecological trouble and now have functional neurological symptoms, then this may not be a complete coincidence.


Men with functional neurological symptoms are also probably more prone to developing testicular pain in the same way, although the literature on this is smaller.



Atypical Chest Pain

When people present to a chest pain clinic, around one third of patients have no evidence of coronary artery disease, stomach/gullet or other recognised cause for pain. Their pain is all too real though, may be recurrent and be frightening as it feels as if they are having symptoms of angina or a heart attack.


Often this presentation is called ‘atypical chest pain’. It is another functional symptom best thought of as a pain syndrome affecting the chest (see pain). Pain in the chest is alarming. Also, alarm, in the form of acute severe anxiety (called panic), typically causes a feeling of chest tightness. So it is easy to see how these two conditions can make each other worse in a vicious circle.


It is important to recognise that nany people with atypical chest pain are not that anxious and do not panic.



Chronic hyperventilation

People who chronically hyperventilate (breathing too fast and/or too deeply) can have a range of neurological symptoms including dizziness, tingling, tiredness and breathlessness. Patients may have a low carbon dioxide in their bloodstream from breathing too much and this exacerbates the symptoms in a physiological way.


Typically hyperventilation is part of a symptom complex rather than being the root cause. Nonetheless treatment designed at improving breathing, sometimes called breathing retraining, can be very helpful at improving other symptoms.


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