What is functional neurological disorder (FND)?
FND is where the patient has symptoms but no identifiable structural pathology. This does not mean the patient is imagining the symptoms or making things up.
The range of symptoms that can arise from FND is very wide and can range from cognitive issues to weakness to movement disorders or seizures.
The underlying cause is not known but may be stress, trauma or the bodies response to a virus or other inflammatory condition.
How is FND treated?
There is no medical treatment which can cure FND, but it is possible to manage the symptoms to some degree with:
- medication
- physiotherapy, or
- talking therapy
You can find out more on the FND resources page.
The GP or patient doesn't accept the FND diagnosis, has something has been missed?
Misdiagnosis of FND is rare and between 0.4-4% of people who are diagnosed with FND turn out to have another condition. With modern imaging and diagnostic techniques it is likely to be towards the lower end of this range.
For GPs or patients that are worried about a brain tumour or other structural pathology, it is often possible to get appropriate imaging via the advice and refer (A&R) service or the direct access imaging pathway.
Some conditions are notoriously difficult to spot, especially in the early stages, or they are episodic and may seem bizarre. The following is not a comprehensive list, but might be worth considering if you have a patient who is worrying you:
- Parkinson’s disease (PD) or another neurodegenerative condition – patients with falls, general decline or weakness. 40% of people with PD do not have a tremor
- Muscle or neuromuscular junction disease – patients with fatigue especially on exercise. Remember to check for statins, raised CK or low vitamin D
- Hereditary spastic paraparesis – younger patients complaining of deteriorating mobility. Check for upgoing plantars
- Channelopathies – myotonic dystrophy, episodic ataxia, periodic paralysis, dopa responsive dystonia. Ask the patient to get a video or photo of the event
- Cataplexy – patients with recurrent collapses. Ask about other features of narcolepsy:
- Hypersomnolence
- Hypnogogic
- Hallucinations
- Sleep paralysis
Please contact the advice and guidance (A&R) service if you feel something is not right. No one is right every time and we will see the patient again in the right circumstances.
If a GP or patient wants a second opinion from another neurologist or neuropsychologist, refer the patient to one of the listed specialist care services.
Why are my patient’s symptoms not multiple sclerosis (MS)?
MS can cause many different symptoms, but if the patient has had an MRI brain scan which doesn’t show MS, then MS is extremely unlikely to be causing the patient’s symptoms. It does not rule out the possibility of the patient developing MS in future.
MS usually has quite a typical history. To find out more about what MS is like clinically, please see the MS clinical presentation page.
Why are my patient’s seizures not epilepsy?
Functional seizures are sometimes referred to as psychogenic seizures, pseudoseizures or non-epileptic attack disorder (NEAD). We currently prefer the term dissociative seizures as patients often experience dissociation either before or during the seizures.
You can often differentiate epileptic seizures from dissociative seizures clinically. Descriptions of both are available on the epilepsy and seizure referral section.
The best diagnostic test is actually a video of one or more seizures. If and when the patient is seen by a neurologist, they may be asked to upload some videos to the vCreate video sharing system.
My patient is not under stress, how can this be FND?
FND may or may not be related to stress or psychological trauma. We don’t know enough about it to really say what the cause is.
It is definitely true that not everyone with FND can identify a triggering incident and trying to identify one can sometimes be alienating.
That being said, coming to terms with the complexity, uncertainty and chronic nature of FND is definitely aided by talking therapies and we would advise that patients with FND seek psychological input.
Last reviewed: 06 September 2024
