What does Functional Neurological Disorder mean?

Functional Neurological Disorder refers to a problem with the functioning of the nervous system in a structurally normal brain. Functional symptoms are understood to be caused by a deficit in the brain’s ability to correctly send and receive messages from the nervous system, though not caused by an organic disease. In layman’s terms we could say ‘the hardware works but the software doesn’t.’.

So, what exactly is a Functional Neurological Disorder?

It is especially important to appreciate that these are not simply unexplained symptoms, but a discrete group of disorders with positive physical diagnostic criteria that have been the subject of numerous epidemiologic and treatment studies
— American Academy of Neurology/Dr Jon Stone

Much like IBS, the designation of ‘Functional Neurological Disorder’ is an umbrella term encompassing a variety of conditions, and no two patients experience the exact same indicators. There are myriad symptoms including (but not limited to) functional tremors, a deficit in memory and concentration, sleep disorders, nerve pain and complex regional pain, dystonia, headaches (though this could be an unrelated migraine condition), dizziness, issues with speech and language, fatigue and chronic fatigue, sensory symptoms, and functional limb weakness or hemiplegia. There are conditions which are defined by seizures and dissociative symptoms- these symptoms are given the diagnosis of Non-Epileptic Attack Disorder. There patients who experience issues with mobility, relying on wheelchairs, sticks, and walkers to get around, and others who have lost dexterity or complete use of one or both of their upper limbs - these conditions may also be referred to as Functional Movement Disorders. There will be those who develop difficulties with speech and language whilst others might lose vision or develop nystagmus in one or both eyes. In short- there could be a plethora of symptoms which all add up to creating the bigger FND picture.

 So, if it’s not a disease, is it actually all in my head?

This is a question which has hit the majority of patients when faced with the diagnosis of a Functional Neurological Disorder. One of the big concerns facing patients with Functional Neurological Symptoms is a feeling that they are not being believed. The scans and test have all come back clear- so that means it’s not real, right? In one word- NO! You are not making up your symptoms or even imagining them and convincing yourself that they are real. You are certainly not going crazy! It is useful to compare your experiences with those of a migraine sufferer. With a migraine condition there can be similar neurological symptoms be loss of vision, hearing, visual disturbances, stroke like symptoms, and even paralysis. The scans and tests are all normal but yet we never query that these patients are fabricating their symptoms. Yes, in migraines we know a little more about which systems are not working correctly but it is still a diagnosis, like FND, made based principally on your history and the lack of evidence of other organic diseases. The research for FND is coming and more funding is being given to understand this condition, we must just be patient. There are opportunities appearing for those who may be willing to participate in trials and studies involving FND.

How do you know if you have a Functional Neurological Disorder?

To be diagnosed, all organic conditions will be initially ruled out and to do this, it is likely that the patient will have undergone MRI and CAT scans to review the state of the brain. However, whilst traditional MRIs cannot detect functional symptoms, there is currently being research undertaken to look at the use of functional MRIs in documenting the differences in the working of a healthy brain vs one of a patient experiencing functional symptoms. Think of the different MRIs in these terms- a traditional MRI is much like a camera and will take a snapshot of the structure of the brain, whereas the fMRIs are like a video camera, taking a film of the signals being sent whilst the patient undertakes different tasks in the scanner.

What causes Functional Neurological Disorders?


Ah- now this is a tricky question and the short answer is that nobody is really 100% certain. A Functional Neurological Disorder can arise as the result of both physiological and psychological factors. We have already seen that there are a plethora of different symptoms and the causes can be similarly diverse. There are patients whose Functional Disorder was triggered by a traumatic event in the past (this is known as Conversion Disorder), patients whose symptoms developed after a serious illness or infection, patients who will have no idea where their FND started, and those who fall into many categories in between. A potential genetic link has been hypothesised but again, this cannot be stated to be the hard and fast rule. Ultimately, it is enormously difficult to pinpoint one single factor causing FNDs as there are simply countless interactions which could fail within the brain itself, and still further biological, psychological, and social factors which can be impacted by the external stimuli we experience in daily life.

OK, I have the diagnosis, what should I expect next?

Well, again this can be different depending on the patient. The most common treatment for a Functional Disorder is a combination of medication, Neurological Physiotherapy Rehabilitation and Occupational Therapy, and Psychology. I’ll briefly explain these individually.

DISCLAIMER: This is not professional medical advice, just an outline of the treatments that  may  be offered. Always consult your doctor.

DISCLAIMER: This is not professional medical advice, just an outline of the treatments that may be offered. Always consult your doctor.


There are a variety of medications which may be prescribed- antidepressants, neuropathic painkillers, anti-seizure, to cover a few. None of these are treating FND as a whole but are addressing elements of your condition.The main ones I want to talk about are antidepressants used as neuropathic painkillers (such as amitriptyline) which can be used to limit your daily general pain. Your initial reaction may be similar to mine- ‘I don’t want to take antidepressants, I’m not depressed!’. OK- so these are not being prescribed for their antidepressant qualities, but for their abilities to treat a variety of symptoms, predominantly severe pain and sleeping disorders. If these were prescribed under any other name, we wouldn’t be having this conversation, so (as hard as it may be) try not to worry about it. I would encourage you to always be open and communicative with your doctor, the more you understand about the drugs you have been prescribed, the more confident you will be in taking them.




This helps retrain your brain and your nervous system in how to correctly fulfil their roles. Your nurse and therapist will help you to work on exercises to strengthen parts of your body where you have lost sensation/mobility. This is by no means a passive treatment, you must be prepared to work hard and do your homework, but the success rates of neurological rehab are incredibly encouraging.

Neuro Rehab is often undertaken in conjunction with...




OK, so we have firmly established that this is not all in your head- so why are you being sent to a psychologist?! Well, it’s not because of the causes of your Functional Disorder, but rather to address how you cope with this condition. In the same way that a patient with Parkinson’s or Multiple Sclerosis will find their mood fluctuating with the stress of learning to live with a ‘new normal’, this is going to take its toll on even the most chipper of patients. Rather than resisting this help, use it to your advantage and give yourself a chance to find the strength you may need to undertake your other treatment plans.

Why is there sometimes a stigma attached to the diagnosis of a Functional Disorder?

In the dim and distant past, FND was considered to be a purely psychological condition, indeed a mental illness, with past trauma being the only influencing factor; whereas today it is widely recognised that there can be a variety of underlying causes encompassing biological, physiological, psychological, and social elements. Thankfully, we are no longer stuck in the bleak medical landscape of the 1970s where anything unexplainable, including homosexuality, was considered to be a mental illness.

Unfortunately, there are still some medical professionals who may approach the disorder as a mental or psychosomatic illness. This can sometimes be in part to a lack of training in interactions with physical symptoms that are not due to disease, along with the relative dearth of research in these areas. As Dr. Tim Nicholson (Maudsley Hospital and Institute of Psychiatry Psychology & Neuroscience, King’s College London, ) states: ‘many patients can feel stigmatised by healthcare professionals because of their FND diagnosis as the condition is so poorly understood by many healthcare professionals – this lack of understanding can become a significant roadblock in their care. This experience can then become a form of ‘medical trauma’, taking on a life of its own, and potentially feed a cycle of symptoms and stress.'

There should be no expectation of coming up against negativity and prejudice in your interactions with medical staff and if you have been seriously affected by these, there are services to help mediate and raise concerns about your treatment. I you are concerned about your care or nervous when asking for help, it may be helpful to take information with you in order to help you fully explain your symptoms and condition.

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