Home › What is FND?
The conditionFND is one of the most common conditions in neurology – and yet barely known. Here you will find an understandable, scientifically grounded explanation: what FND is, how it is recognised, how common it is, and why it is treatable.
A Functional Neurological Disorder (FND) is a condition of the nervous system in which it is not the structure that is damaged – as in a stroke or multiple sclerosis – but the function: the processing of signals between brain and body runs differently. The symptoms – such as paralysis, tremor, seizures or speech disturbances – are real, not imagined and not produced voluntarily. And because the underlying patterns are partly learned, the brain can also re-learn them: FND is treatable.
A helpful image: with a computer, the hardware can be broken – or the software can run faultily even though the hardware is intact. FND is a “software problem” of the nervous system. All pathways and structures are present; MRI and lab values are therefore typically normal. According to the currently leading scientific model, faulty predictions of the brain and an attention directed too strongly at the body play the central role: the brain constantly predicts movement and body signals – and when these predictions take on a life of their own, real symptoms arise without any structural damage being present.1,2 Typical of FND is that symptoms become stronger when attention is directed at them, and ease when they happen “in passing” – and this is exactly where treatment begins.
No – FND is neither imagined nor faked. The condition is a recognised, independent diagnosis (ICD-11: 6B60).3 Older terms such as “psychogenic”, “hysteria” or “conversion disorder” implied a purely psychological cause – today’s understanding goes beyond that: psychological strain can play a role, but it does not have to. Body and mind work together in FND, without one “disproving” the other – partly psychologically influenced never means unreal. More on this in the article “Body and mind – taking the psyche out of the corner”.
More common than many believe. Reliable figures specifically for Germany are still lacking; according to international studies, functional disorders make up about 5 to 15 per cent of patients in neurological clinics.4 In a much-cited Scottish study, they were among the most frequent reasons for presentation in neurology outpatient clinics at all.5 FND can affect people of any age and can considerably restrict everyday life – and yet the condition is little known. That is exactly why our network exists.
FND presents very differently; often several symptoms occur together, they can fluctuate or appear suddenly. Among the most common forms are:
A widespread misunderstanding is that FND is a pure “diagnosis of exclusion” (“we found nothing, so it is functional”). The opposite is true: today FND is actively established – on the basis of typical positive clinical signs, such as Hoover’s sign in functional leg weakness or characteristic tremor patterns. This is also emphasised by the current guideline of the German Society of Neurology.6 An early, well-explained diagnosis is important: it ends the wearing search for the “missing finding” and opens the way to the right treatment. In detail: Causes & diagnosis of FND.
Yes. There is no guarantee, but the symptoms can improve considerably and sometimes recede entirely – even after a long duration of illness. Usually effective is a coordinated, multimodal approach: active physiotherapy, psychotherapy where needed, as well as occupational therapy and speech and language therapy, tailored to the individual symptoms.7 There is no medication against the underlying disorder itself. More on this: Treatment of FND and Physio, OT & speech therapy. FND-experienced points of contact can be found in our clinic and practice overview.
No. The symptoms in FND are real. The nervous system is not structurally damaged, but the processing of signals between brain and body runs differently. FND is a recognised, independent diagnosis (ICD-11: 6B60). Psychological strain can play a role, but it does not have to – “functional” does not mean “imagined”.
There is no guarantee, but the symptoms can improve considerably and sometimes recede entirely. What matters is a positively made, well-explained diagnosis and suitable treatment specialised in FND. Even long-standing symptoms can still improve – a long duration of illness does not mean it is “too late”. More in the article Prognosis in FND.
Not by merely excluding other conditions, but through positive clinical signs (such as Hoover’s sign or entrainment). This is also emphasised by the current DGN guideline. FND is therefore something that can be actively established.
Usually a transdisciplinary combination – active physiotherapy, psychotherapy where needed, as well as occupational or speech and language therapy, tailored to the individual symptoms. There is no medication against the underlying disorder itself. Important is support experienced with FND.
No, rather the opposite: FND is more common than many believe. Reliable figures specifically for Germany are lacking; according to international estimates, functional disorders make up about 5 to 15 % of patients in neurological clinics. And yet the condition is little known.
Because FND treatment differs from classic approaches, it is worth going to a specialised or experienced point of contact. A growing overview of clinics, centres and practices can be found on our page Clinics & practices.
The information on this page serves general education and does not replace medical advice, diagnosis or treatment.