Published on 16 August 2026

Functional neurology · Rehabilitation

Functional neurological disorder: a positive diagnosis, not a diagnosis of exclusion

A leg that will no longer lift, a tremor that disappears when the conversation moves on, a gait that collapses under the slightest gaze. The reflex is to look for what the MRI is missing. The right reasoning is the opposite: to go and look, at examination, for signs you do find, whose specificity exceeds 92 %.

16%

of new neurology patients: the second reason for referral, just behind headache

Stone 2010 · Clin Neurol Neurosurg · 3,781 patients

92- 100 %

of specificity for the 14 positive signs validated in controlled studies

Daum 2014 · JNNP · systematic review, 11 studies

of rediagnosis at five years, a figure stable since 1970

Stone 2005 · BMJ · 27 studies, 1,466 patients

Clinical summary

Functional neurological disorder (FND) denotes real, involuntary neurological symptoms, characterised by a failure of voluntary control and of perception, while the basic structure of the nervous system is normal¹⁴. ICD-11 classifies it under the label dissociative neurological symptom disorder, code 6B60, with a subtype for each dominant symptom.

It is not a diagnosis of exclusion, and that has changed officially. DSM-5 and then ICD-11 removed the requirement for a psychological precipitant and based the diagnosis on demonstrating an internal inconsistency at examination: the symptom behaves differently depending on whether it is observed directly or indirectly. That inconsistency is looked for; it is not inferred from a negative work-up³.

The signs have been measured. A systematic review retained 14 signs validated in controlled studies, 7 motor, 5 sensory and 2 of gait. Their sensitivity is low and highly variable (8 to 100 %), their specificity is high and consistent: 92 to 100 %⁶. A positive sign therefore points strongly, a negative sign rules nothing out.

The fear of missing a disease is no longer the argument it was. Across 27 studies and 1,466 patients followed for a median of five years, the proportion of patients who ultimately receive another diagnosis has fallen from 29 % in the 1950s to 4 % (95 % CI 2 to 6) since 1970, with no further fall since⁵. That is the order of magnitude of rediagnosis in many other neurological conditions.

The physiotherapist has a described role, and it is central. An international physiotherapy consensus, published in 2015, sets the frame: education about the mechanism, movement retraining that diverts attention away from the limb, self-management strategies, all within an explicitly non-blaming setting⁹. A twin consensus exists for occupational therapy¹³.

And the level of evidence has to be stated as it is. The phase 3 randomised trial Physio4FMD, 355 patients across 11 centres, did not show specialist physiotherapy to be superior to local neurological physiotherapy for physical function at 12 months (adjusted difference 3.5; 95 % CI −2.3 to 9.3; p = 0.23). More patients reported themselves improved and mental health scores were better, and both approaches proved safe¹⁰. Read correctly, that result does not say physiotherapy is useless: it says the specialist protocol did no better than ordinary neurological physiotherapy, in patients whose diagnosis had been made and explained.

ICD-11 6B60Signs to look for, not to inferSpecificity 92 to 100 %4 % rediagnosisPhysio4FMD: negative primary outcome

What is called functional neurological disorder, and how often?

This chapter sets out the vocabulary and the order of magnitude. Both count: a practitioner who thinks they are seeing a rare curiosity will treat as a rare curiosity something they meet several times a year, and a badly chosen word at the moment of diagnosis costs months of rehabilitation.

The definition, and what is precise about it

Functional neurological disorder produces genuine and involuntary neurological symptoms: weakness, tremor, dystonia, gait disturbance, seizures, sensory disturbance, speech disturbance. The wording used by the systematic review of the cost of the condition, published in Neurology in 2023, is useful because it is workable: it is a problem of voluntary control and perception, while the basic structure of the nervous system is normal¹⁴.

Two words in that sentence deserve emphasis. Involuntary : the patient is not feigning, and letting them think otherwise is the most costly error in their care. Basic structure normal : conventional imaging shows no lesion, which does not imply that the brain is working normally. The 2022 Lancet Neurology review describes precisely the mechanisms shared across subtypes, around attention directed to the limb, prior expectations and the sense of agency⁴.

The names, and why they changed

“Hysteria”, “conversion disorder”, “psychogenic”, “non-organic”, “functional”: all five denote overlapping territories at different times, and they do not carry the same charge. ICD-11 settles on dissociative neurological symptom disorder, code 6B60, broken down by dominant symptom: weakness or paresis (6B60.6), gait disturbance (6B60.7), non-epileptic seizures (6B60.4), tremor (6B60.82), and a dozen others. In clinical practice as in the rehabilitation literature, it is functional neurological disorder that has taken hold, because it describes the mechanism rather than assigning a cause.

The word “psychogenic” states an aetiology the diagnosis no longer assumes. Since DSM-5, no psychological factor needs to be identified for the diagnosis to be made.

ICD-11 places these subtypes in chapter 06 (mental, behavioural and neurodevelopmental disorders), under the dissociative disorders block. The physiotherapist mostly meets the first four in the table below.

Subtypes of dissociative neurological symptom disorder in ICD-11, with their code and the corresponding clinical picture.
ICD-11 code	Official label	What the rehabilitation clinician sees
6B60	Dissociative neurological symptom disorder	The parent category, all symptoms taken together
6B60.6	… with paresis or weakness	Motor deficit of one or more limbs, the target of Hoover's sign and the abductor sign
6B60.7	… with gait disturbance	Unsteady gait, giving way, a “skating” appearance, often without genuine falls
6B60.82	… with tremor	Tremor variable in frequency, sensitive to entrainment and distraction
6B60.83	… with dystonia	Fixed postures, often of sudden onset, frequently painful
6B60.4	… with non-epileptic seizures	Paroxysmal seizures with no electroencephalographic correlate
6B60.3	… with other sensory disturbance	Reduced or absent sensation in a non-anatomical distribution
6B60.5	… with speech disturbance	Dysarthria, aphonia, stammering of sudden onset

Frequency, measured twice in two ways

The most telling figure for a clinician does not come from a population study but from a census of referral reasons. A Scottish study included 3,781 new patients referred to neurology clinics, in every neurology centre in the country, over fifteen months. Functional and psychological symptoms accounted for 16 % of the initial diagnoses, the second category behind headache (19 %) and ahead of epilepsy (14 %)².

What actually fills a neurology clinic

Initial diagnoses made by neurologists across 3,781 new patients, every neurology centre in Scotland, 15 months of collection. After Stone 2010 (PMID 20646830).

A physiotherapist who receives patients referred from neurology statistically meets more functional disorders than multiple sclerosis.

Population measurements, harder to establish, converge. A systematic review published in 2025 in the Journal of Neurology, Neurosurgery and Psychiatry gathered 39 articles: incidence is estimated at between 10 and 22 cases per 100,000 person-years, and minimum prevalence at between 80 and 140 per 100,000, with a possible range of 50 to 1,600 depending on method. The authors stress that most studies underestimate, and that FND is probably more common than several neurological diseases better served by research¹.

10 - 22

new cases per 100,000 person-years (Finkelstein 2025)

80 - 140

prevalent cases per 100,000, minimum estimate (Finkelstein 2025)

1 - 18

per 100,000: estimated paediatric incidence (Finkelstein 2025)

4,964 - 86,722 $

of additional annual cost per patient, direct and above all indirect (O'Mahony 2023)

The cost deserves a word, because it documents what is at stake in diagnostic delay. The systematic review in Neurology retained 16 economic studies: the additional annual cost associated with FND ranges from 4,964 to 86,722 in 2021 US dollars, most of it indirect (sick leave, lost activity). Above all, several interventions reduce that cost by 9 to 90.7 %, and among them is simply making a firm diagnosis¹⁴.

FND is a disorder of voluntary control and perception, with a normal basic nervous structure. The symptoms are real and involuntary.
ICD-11: 6B60, dissociative neurological symptom disorder, broken down by dominant symptom.
16 % of new neurology patients, the second reason for referral. This is not a curiosity.
Incidence 10 to 22 / 100,000 / year, minimum prevalence 80 - 140 / 100,000, both probably underestimated.
The additional annual cost runs into tens of thousands of dollars, and making the diagnosis brings it down.

Why is this not a diagnosis of exclusion?

This is the pivot of the whole article. As long as we reason by exclusion, the patient waits, investigations pile up, cost rises and the prognosis worsens. Positive reasoning comes down to one sentence: we do not look for what the work-up is missing, we look for an inconsistency at examination.

What DSM-5 and ICD-11 changed

Up to DSM-IV, a diagnosis of conversion disorder required a psychological factor to be identifiable in connection with the onset of the symptom. That requirement has been removed. The central criterion has become the clinical demonstration of an incompatibility between the symptom and recognised neurological disease. The concepts review published in JAMA Neurology in 2018, signed by fifteen authors in the field, states the principle without hedging: the diagnosis rests on positive clinical features, not on the absence of findings³.

In practice, an internal inconsistency is observed in three ways: the symptom varies with the attention paid to the limb, it disappears during an automatic movement while persisting on command, or it matches no recognised anatomical distribution. All three are looked for at examination, with the hands.

Two lines of reasoning, two patient trajectories

On the left, the reasoning by exclusion, as diagnostic delay produces it. On the right, positive reasoning, the kind DSM-5 and ICD-11 describe. The consequences at the foot of each column are documented by Gelauff 2014 (PMID 24029543) for prognosis and O'Mahony 2023 (PMID 37339887) for cost.

Both columns start from the same patient. What separates them is an intention at examination, not a piece of equipment.

The rediagnosis argument no longer holds

The classic objection is the fear of being wrong: what if a disease revealed itself later? It has been quantified. A systematic review published in the BMJ gathered 27 studies and 1,466 patients with unexplained motor or sensory symptoms, with a median follow-up of five years. The proportion of patients who ultimately receive another diagnosis fell from 29 % in the 1950s to 4 % since the 1970s, and that figure has not moved across three decades. The authors attribute the fall to improved study quality, and not to the arrival of the CT scanner⁵.

The rediagnosis rate, decade by decade

Proportion of patients initially labelled with “conversion symptoms” who subsequently receive another diagnosis explaining their presentation. Random-effects meta-analysis, 27 studies, 1,466 patients, median follow-up 5 years. After Stone 2005 (PMID 16223792).

The plateau reached in the 1970s has not moved since: the fear of the missed diagnosis belongs to a poor-quality literature, not to current practice.

A positive sign does not mean “nothing else”

This is the nuance that guards against the opposite misreading. Finding a positive Hoover's sign establishes that a functional component exists, not that no other disease is present. The two regularly coexist, and FND readily arises in patients with a neurological disease. Clinical reasoning therefore remains: which part of this picture is functional, and which part is not.

What should reopen the file despite positive signs

Sudden onset of a new anatomically distributed deficit, particularly with facial asymmetry, speech disturbance or altered consciousness: the question of a vascular emergency arises independently of any functional sign known otherwise.
Steady, monotonous progression of the deficit over weeks, without the fluctuation that characterises FND.
Clear objective signs : wasting, fasciculations, brisk spreading reflexes with an extensor plantar response, a clear sensory level.
Bladder or bowel symptoms appearing with a lower limb deficit, which require cord compression or cauda equina syndrome to be ruled out.
A particular context : known cancer, immunosuppression, fever, weight loss, advanced age with a first episode.
What should NOT reopen the file : the mere fact that the patient is anxious, that they have experienced trauma, or that their presentation is “theatrical”. None of these is a criterion, and DSM-5 explicitly removed the requirement for a psychological factor.

The diagnosis rests on an internal inconsistency demonstrated at examination, not on a negative work-up. DSM-5 and ICD-11 both put it that way.
The psychological precipitant is no longer a criterion. Looking for it in order to validate the diagnosis is a misreading.
4 % rediagnosis since 1970, stable. The argument for indefinite caution rests on nothing.
A positive sign establishes the functional component, not the absence of any other disease. The two often coexist.

What are the positive signs worth, one by one?

The practical chapter. The signs are numerous in the literature, only fourteen have been validated in controlled studies, and their performance is very asymmetrical: they serve to confirm, never to exclude. This chapter describes those a physiotherapist can perform in a session, and what each allows you to conclude.

What the systematic review measured

Daum, Hubschmid and Aybek searched Embase, Medline and PsycINFO from 1965 to June 2012, retained 11 controlled studies from 147 eligible articles, and documented 14 signs : 7 motor, 5 sensory, 2 of gait. The result comes down to two numbers: sensitivity of 8 - 100 %, specificity of 92 - 100 %. The authors set out the limitations without softening them: class III level of evidence, only two blinded studies, and no data at all on inter-rater reproducibility⁶.

Low sensitivity, high specificity: a positive sign moves things a long way forward, a negative sign moves nothing back. All the value of the examination lies in the first case.

Hoover's sign

It is the best known and the most useful in practice. The principle is this: hip extension is weak when asked for directly, and becomes normal when it happens automatically, in synergy with flexion of the opposite hip against resistance.

Hoover's sign: two steps, one single difference

Diagram of the principle. The performance figures come from the prospective cohort of McWhirter 2011 (PMID 22118379), 337 patients referred with suspected stroke, of whom 124 had a lower limb deficit.

The specificity, measured across 116 patients without a functional disorder, is the solid figure. The sensitivity, calculated on 8 patients, is not.

The prospective cohort of McWhirter and colleagues remains the best available measurement in real conditions. The sign was tested in 337 consecutive patients referred with suspected stroke; among them, 124 had a lower limb deficit, of whom 8 ultimately had a functional disorder. Sensitivity 63 % (95 % CI 24 to 91), specificity 100 % (95 % CI 97 to 100). The authors themselves conclude that the sign is moderately sensitive and highly specific, and call for larger series as well as a study of inter-observer variability⁷.

The abductor sign

Less well known, it answers a real weakness of Hoover's: in a patient with powerful hip extensors, Hoover's becomes uninterpretable. Sonoo described it in 33 patients with unilateral paresis of one lower limb, 17 of structural origin and 16 functional. The examiner asks for abduction of each hip while resisting it; it is the behaviour of the opposite leg that settles it. The sign correctly classified all 33 cases, whereas Hoover's was uninformative in 16 patients because the extensors were too strong, and in 2 others because the flexors were too strong⁸.

Two reservations are needed. The series is small and single-centre, and it dates from 2004: that perfect result has not been replicated at this scale. It remains that the sign is simple, quick, and that it covers exactly the case in which Hoover's fails.

The sternocleidomastoid sign

For the upper limb and the trunk, validated signs are rarer. Horn and colleagues prospectively compared 30 patients with a functional motor disorder and 40 controls with a unilateral structural deficit. The sternocleidomastoid sign (weakness of head rotation towards the affected side, when that muscle turns the head to the opposite side and should not be involved) had a specificity of 90 % (95 % CI 77 to 96) for FND. Conversely, the platysma sign reached 100 % specificity for a structural origin. The combination of a positive SCM sign and a negative platysma sign carried a specificity of 95 % and a sensitivity of 63 %¹¹.

Entrainment and distractibility, for movement disorders

Faced with a tremor, two manoeuvres are classic: asking the patient to tap a voluntary rhythm with the unaffected limb (entrainment shows itself as a tremor that adopts that frequency or stops), and diverting attention with a cognitive task ( distractibility shows itself as a clear reduction). It is worth knowing what these manoeuvres are worth when instrumented: a systematic review of 38 diagnostic accuracy studies in clinical neurophysiology concludes that baseline features and task-related features overlap widely between tremor syndromes, and that no single feature distinguishes them all. It is the combined analyses that add something¹².

In other words: at the bedside, entrainment and distractibility are arguments, not proof. In case of doubt, multimodal electrophysiology exists, and it is the neurologist who requests it.

Positive signs of functional neurological disorder, with their measured performance and their source.
Sign	What you observe	Measured performance	Source
Hoover	Weak hip extension on command, normal in synergy with resisted contralateral flexion	Se 63 % (24 to 91), Sp 100 % (97 - 100)	McWhirter 2011, 337 patients⁷
Abductor	The opposite leg goes into hyperadduction instead of staying fixed	33 / 33 cases correctly classified, single series	Sonoo 2004, 33 patients⁸
Sternocleidomastoid	Weakness of head rotation towards the affected side, incompatible with the muscle's action	Sp 90 % (77 - 96)	Horn 2017, 70 patients¹¹
SCM positive + platysma negative	Combining the two manoeuvres of the same examination	Sp 95 % (83 to 99), Se 63 % (44 - 80)	Horn 2017¹¹
Entrainment, distractibility	The tremor adopts the imposed frequency, or gives way to a cognitive task	Considerable overlap between syndromes; no single feature settles it	van der Veen 2021, 38 studies¹²
The 14 validated signs, together	7 motor, 5 sensory, 2 of gait	Se 8 - 100 %, Sp 92 - 100 %, class III	Daum 2014, systematic review⁶

14 validated signs in controlled studies, specificity 92 to 100 %, sensitivity 8 to 100 %. They confirm, they do not exclude.
Hoover : Se 63 %, Sp 100 % in real conditions. It is the sign to know by heart.
Abductor : the answer when the hip extensors are too powerful for a Hoover to be interpreted.
No data on inter-examiner reproducibility exist for any of these signs. A doubtful sign is repeated, and checked against another examiner.
Faced with a tremor, entrainment and distractibility are clinical arguments, not instrumental proof.

Why is delivering the diagnosis the first treatment?

This chapter deals with the one intervention whose effect is documented both on the patient's experience and on the cost of the condition: saying the diagnosis, and saying it well. A physiotherapist is not the one who makes the diagnosis, but they are almost always the one who has to explain it again.

What the explanation must contain

The 2015 physiotherapy consensus makes it a treatment step in its own right, before any technique. An effective explanation has four elements: naming the disorder, affirming that the symptoms are real, explaining how they arise (a problem of functioning and not of structure), and saying that it is reversible⁹.

Demonstrating the positive sign to the patient is the most powerful tool in that explanation. Showing someone that their leg contracts normally when they are not looking at it turns an assertion into something they can feel. It is the opposite of “your tests are normal”, which leaves the patient with an absence in place of a diagnosis.

“Your tests are normal” is not a diagnosis, it is a statement of emptiness. The patient goes off to look elsewhere, and the cost starts again.

What the explanation avoids

The systematic review of economic cost concludes that interventions, including the simple act of making a firm diagnosis, reduce the cost of the condition by 9 to 90.7 %¹⁴. And the prognosis review shows that diagnostic delay is negatively correlated with outcome¹⁵. Those two results meet: time spent without a name costs, in money as in recovery.

The vocabulary to use in a session

Wordings to prefer and to avoid when explaining a functional neurological disorder.
To avoid	Why	Say instead
“Your tests are normal”	States an absence, not a diagnosis. The patient concludes that nothing has been found yet.	“Your examination shows something specific, and I am going to show it to you.”
“It's psychological”, “it's stress”	Assigns a cause the diagnosis has not assumed since DSM-5, and which is often wrong.	“It is a disorder of movement control. The circuit is intact, the command is not getting through properly.”
“There's nothing wrong”	Contradicts the patient's experience, since something is indeed wrong.	“There is a real disorder, and it has a name.”
“You could do it if you wanted to”	Implies feigning. It is the most destructive error in their care.	“This is not voluntary. That is exactly what the sign demonstrates.”
“We'll see if it passes”	Diagnostic delay is a documented unfavourable prognostic factor.	“We start now, and here is what with.”

The explanation has four steps: name it, validate the reality of the symptom, explain the mechanism, affirm that it is reversible.
Showing the positive sign to the patient is the most convincing demonstration available.
Making a firm diagnosis brings the cost of the condition down by 9 to 90.7 % depending on the study.
Diagnostic delay correlates with a poorer outcome. Waiting is not neutral.

Which rehabilitation, and on what level of evidence?

The content of physiotherapy for FND is described in an international consensus, and it differs markedly from usual neurological rehabilitation. This chapter describes what is recommended, then says exactly where that recommendation comes from.

The 2015 consensus, and what it is

Fourteen authors, physiotherapists, neurologists and neuropsychiatrists, produced a consensus recommendation in 2015 published in the Journal of Neurology, Neurosurgery and Psychiatry. The frame is explicitly biopsychosocial, and treatment turns on four axes: working on illness beliefs, correcting self-directed attention towards the limb, retraining movement patterns that have become habitual, and passing on self-managementstrategies, all in a positive and non-blaming context. The authors themselves write that the data were then insufficient to produce evidence-based recommendations⁹.

What that changes concretely in a session

Three principles set this rehabilitation apart from classic neurological rehabilitation.

Divert attention away from the limb, instead of bringing it back to it. In neurological rehabilitation after a stroke, the patient is asked to watch their movement, to feel it, to control it. Here it is the opposite: self-directed attention is part of the mechanism. We work through automatic tasks, rhythmic movements, indirect instructions.

Look for the moments when the movement works. The patient almost always has situations in which the symptom disappears: a step backwards, walking sideways, a movement made without thinking about it. Those moments are the starting point for retraining, and demonstrating them to the patient is in itself therapeutic.

Set a frame and an end point. The consensus insists on constructing the pathway: referral criteria, content, and how it ends. Rehabilitation with no planned end sustains the idea of an irreversible chronic disease.

What the prospective series show

Before the phase 3 randomised trial, several cohorts had documented clear results. The intensive 5-day programme described by the same team included 47 patients whose mean symptom duration was 5.5 years and of whom 64 % were out of work for health reasons: 65 % reported themselves “much” or “very much” improved at the end of the programme, 55 % at three months, with significant gains on the physical domains of the SF-36, the Berg Balance Scale and the 10-metre walk test. Mental health measures, on the other hand, did not move¹⁶.

In the United States, the hospital multidisciplinary programme Motor Retraining (one week, with daily physiotherapy, occupational therapy, speech therapy and psychotherapy) reported across 32 consecutive patients 86.7 % reporting improvement at discharge and 69.2 % at six months, with a 59.1 % fall in the PMDRS score rated by a physician on standardised video. A notable result: neither symptom duration, nor a history of abuse, nor psychiatric comorbidity predicted failure¹⁷.

Finally, the 2017 randomised feasibility study, which preceded Physio4FMD, produced clear figures: across 57 patients analysed, 72 % of the intervention group reported themselves improved at six months against 18 % of controls, with an adjusted difference of 19.8 points (95 % CI 10.2 to 29.5) on SF-36 physical function, and a cost per QALY of £12,087¹⁸.

Rehabilitation modalities for FND and the associated level of evidence

Each card carries the source that supports it, and the study type. The level does not judge clinical usefulness: it says what the literature allows us to state.

No rehabilitation modality for FND today reaches the level of a recommendation based on high-quality evidence. Saying so to the patient is part of the care.

The content of physiotherapy for FND is described by an international consensus from 2015, and it differs from classic neurological rehabilitation.
Diverting attention away from the limb instead of bringing it back to it: that is the central principle.
The prospective cohorts show 55 to 69 % improved at three and six months, without a control group.
The 2017 randomised feasibility trial was clearly positive : 72 % against 18 %.
Neither symptom duration nor psychiatric comorbidity predicted failure in the MoRe series.

What does the Physio4FMD trial change in practice?

It is the most important trial in the field, and its primary result is negative. Passing over it would be dishonest; reading it as a condemnation of physiotherapy would be wrong. This chapter reads it line by line.

The protocol

A pragmatic, multicentre, phase 3 trial conducted in 11 hospitals in England and Scotland. Adults with a clinically established diagnosis of functional motor disorder, made by a neurologist. Randomisation 1:1 between protocolised specialist physiotherapy (nine sessions plus a follow-up) and usual care (referral to local neurological physiotherapy). Primary outcome: the “physical function” domain of the SF-36 at 12 months. Recruitment from October 2018 to March 2020, interrupted by the pandemic, resumed from August 2021 to January 2022¹⁰.

The result

355 patients included, 179 in specialist physiotherapy and 176 in usual care. 89 patients had to be excluded from the primary analysis because the suspension of care during the pandemic prevented them from receiving the allocated treatment (27 in the specialist arm, 62 in the control arm). The primary analysis finally covered 241 patients.

Adjusted difference on SF-36 physical function at 12 months: 3.5 points (95 % CI −2.3 to 9.3; p = 0.23). Not significant. No serious adverse events related to the interventions; 35 serious events in 24 patients in the specialist arm (17.0 %) and 24 in 18 patients in the control arm (17.0 %), all judged unrelated to physiotherapy¹⁰.

What this result allows us to say, and what it does not

What it allows. The specialist nine-session protocol did no better, on self-reported physical function at one year, than referral to the neurological physiotherapy available locally. The comparator was not doing nothing: both arms received physiotherapy.

What it does not allow. Concluding that physiotherapy is of no use in FND. There was no arm without physiotherapy. The authors themselves write that more patients in the specialist arm rated their motor symptoms as improved and scored better on subjective mental health measures, and that both forms of physiotherapy appear safe and are valued in selected patients. They call for the interventions to be refined and for evidence-based referral methods to be built¹⁰.

An important methodological reservation. The 89 pandemic-related exclusions are heavily unbalanced: 62 out of 176 in the control arm against 27 out of 179 in the specialist arm. A loss of that size and that asymmetry affects the initial comparability, whatever the quality of the analysis plan.

A trial that is negative on its primary outcome is not a trial that proves uselessness. It says that against this comparator, on this outcome, at this time point, the expected difference was not found.

Physio4FMD compares specialist physiotherapy with local physiotherapy, not with nothing.
Primary outcome not significant : 3.5 points (95 % CI −2.3 to 9.3; p = 0.23).
Favourable secondary results on self-rated motor symptoms and mental health.
No serious adverse events related to the interventions in either arm.
The imbalance in pandemic-related exclusions (62 against 27) is a limitation to keep in mind.

Functional seizures: what changes for the physiotherapist?

Psychogenic non-epileptic seizures (ICD-11 6B60.4) are the subtype the physiotherapist meets least and dreads most. Two things to know: what the best available trial says, and what to do when a seizure happens in a session.

The CODES trial

CODES is a pragmatic multicentre randomised trial conducted in 27 neurology or epilepsy services in the United Kingdom, then 17 liaison psychiatry services. 368 adults who had had dissociative seizures in the preceding eight weeks and no epileptic seizure for twelve months were randomised between specific cognitive behavioural therapy plus standardised medical care and standardised medical care alone.

Primary outcome, monthly seizure frequency at 12 months: not significant (median 4 seizures against 7; estimated IRR 0.78; 95 % CI 0.56 to 1.09; p = 0.144). Several secondary outcomes were, by contrast, favourable: seizures rated less bothersome, a longer seizure-free period over the last six months (IRR 1.64; 1.22 to 2.20; p = 0.001), better quality of life, better psychosocial functioning, less psychological distress and fewer somatic symptoms¹⁹.

The transferable lesson is the same as for Physio4FMD: in this field, the “hard” primary outcomes hold out, and the outcomes describing daily life move.

A seizure during a session

The physiotherapist does not have to make the diagnosis, but it is in their interest to know what to do. The principles taken from management guidance are simple: make the environment safe, do not restrain, do not apply painful stimulation, speak calmly and briefly, let the seizure end, resume the session when the patient can. A known and documented seizure does not call for routine emergency services; a new picture, or a seizure unlike the previous ones, does.

In a seizure in the clinic, call the emergency services

A first seizure, or a seizure whose presentation differs markedly from those the patient usually describes.
Injury during the fall, particularly a head injury, or lateral tongue biting.
Persisting impairment of consciousness after the movements have stopped, or abnormally long recovery.
A new focal neurological sign immediately afterwards.
Cyanosis, respiratory distress, haemodynamic abnormality.
A diagnosis of functional seizures in the record does not protect against an epileptic seizure: the two coexist in some patients.

What prognosis, and what shifts it?

The prognosis of FND is often presented in two opposite and equally false ways: “it goes away on its own” or “it is permanent”. The data say something else, and above all they point to levers.

The reference systematic review retained 24 studies and 10,491 patients with functional motor symptoms, with a weighted mean follow-up of 7.4 years. The result is bleak and has to be given as it is: on average, 39 % of patients are the same or worse at follow-up, with considerable spread across studies (10 to 90 %). Levels of physical disability and of psychological comorbidity at follow-up remain high¹⁵.

The prognostic factors identified are few but clinically usable. Associated with a better outcome: a short duration of symptoms, an early diagnosis, and high satisfaction with the care received. Associated with a poorer outcome: diagnostic delay and a personality disorder. Sex has no effect. Other factors (age, comorbid anxiety and depression, IQ, education, marital status, ongoing litigation) varied from one study to another¹⁵.

What weighs on prognosis, and what makes no difference

Prognostic factors for functional motor symptoms. Systematic review of 24 studies, 10,491 patients, weighted mean follow-up 7.4 years. After Gelauff 2014 (PMID 24029543).

Three of the five factors identified depend on how care is conducted, not on the patient. That is what makes this table usable.

39 % the same or worse at 7.4 years on average, with a very wide spread across studies.
Favourable: short duration, early diagnosis, satisfaction with care. Three levers, all partly in our hands.
Unfavourable: diagnostic delay, personality disorder.
Sex has no effect. Many other frequently cited factors vary from one study to another.
The studies included are mostly retrospective and selective: the figure of 39 % describes populations seen in specialist centres.

How do you apply this in the clinic?

This chapter summarises the course of care, from first contact to discharge, distinguishing what falls to the physiotherapist from what must be referred on.

At the first session

Check that the diagnosis has been made and that it has been explained. Ask the patient to say, in their own words, what they were told. The answer “they didn't find anything” signals that the explanation did not take place, whatever the report said.
Look for one or two positive signs yourself, and show them to the patient. Hoover's and the abductor sign take two minutes, on an examination couch.
Look for the moments when the movement works : walking backwards, walking sideways, climbing stairs, an automatic movement. Note them, they will be the starting point.
Set the frame: aims, the number of sessions envisaged, criteria for finishing. A stated duration is itself a message about prognosis.

Over the sessions

Work with attention diverted : indirect instructions, dual tasks, an external rhythm, whole-body rather than analytical movements.
Avoid aids that sustain the symptom when they are not necessary: the consensus insists on this point, and gradual weaning is part of the plan.
Keep visual feedback and conscious control of the limb for the situations where they are indispensable.
Document progress with measurements : gait speed, the 10-metre walk test, the Berg Balance Scale, measures the cohorts used and which do move.

When to refer

To the neurologist : anything on the red flag list, a picture that changes in nature, or the absence of a formal diagnosis.
To the psychiatrist or psychologist : when an anxiety, depressive or post-traumatic comorbidity is prominent, or when the patient asks. It is not a precondition for rehabilitation.
To a multidisciplinary programme : long-standing symptoms, severe disability, failure of well-conducted outpatient care. The intensive programme series included patients whose mean symptom duration exceeded five years.

The first session serves to check the explanation and to show a sign, before any technique.
The working principle is diverted attention, the opposite of classic neurological rehabilitation.
A stated end point is part of the treatment: rehabilitation with no planned end sustains the idea of chronicity.
Psychiatric comorbidity is not a precondition to be treated before starting: it did not predict failure in the MoRe series.

Frequently asked questions

Is the patient feigning?

No. Feigning exists, it is rare, and it belongs to another diagnosis (factitious disorder or malingering in the medico-legal sense). FND denotes involuntarysymptoms. That is exactly what a positive sign demonstrates: the movement happens when the patient is not commanding it, which no one feigning would set out to produce.

Is a stress factor needed to make the diagnosis?

No, and that is a fundamental change in DSM-5 and then ICD-11. A psychological factor may exist and matter in management, but its absence in no way rules out the diagnosis. Looking for it in order to validate the diagnosis leads to interviews that are pointless and sometimes hurtful.

Does a positive Hoover's sign rule out a stroke?

No. It establishes that a functional component is present. The two can coexist, and McWhirter's cohort was precisely made up of patients referred with suspected stroke. Faced with a sudden deficit, the emergency pathway takes priority, whatever functional signs are observed.

How many sessions?

No number is validated. The Physio4FMD protocol had nine sessions plus a follow-up; the published intensive programmes last five days. What is documented is the value of stating a frame and an end point, not an optimal duration.

Should you wait for the psychiatrist's opinion before starting?

No. The physiotherapy consensus describes care that starts as soon as the diagnosis is made, within a multidisciplinary frame where one exists. The Motor Retraining series showed that psychiatric comorbidity did not predict failure of the motor programme.

What do you answer to “so it's all in my head”?

That the symptom is real, that it comes from a problem in the way motor control works, and that the structure of the nervous system is intact. The clearest comparison is software and hardware: nothing is broken, something is running badly, and that can be retrained.

Do functional seizures justify stopping rehabilitation?

No, outside the seizure itself. They do mean knowing what to do if a seizure happens in a session, and referring on to specific care, which the CODES trial documents on its secondary outcomes.

Can we talk about cure?

With caution. The long-term prognostic data are unfavourable (39 % the same or worse at more than seven years), and the available studies cover populations seen in specialist centres, so severe ones. It is, on the other hand, accurate and documented to say that the disorder is reversible and that an early diagnosis improves the chances.

References

Twenty-two references, resolved one by one through the PubMed E-utilities API. For each of them the abstract was read in full and the figures cited in the article checked at source. The year kept is that of the issue, re-read on the XML record: the first “year” field of a PubMed record is sometimes a revision date, and shifts the citation by a year.

Epidemiology and nosological frame (5)

Finkelstein SA, Diamond C, Carson A, Stone J. Incidence and prevalence of functional neurological disorder: a systematic review. J Neurol Neurosurg Psychiatry. 2025;96(4):383-395. PMID 39663114.
Stone J, Carson A, Duncan R, Roberts R, Warlow C, Hibberd C, Coleman R, Cull R, Murray G, Pelosi A, Cavanagh J, Matthews K, Goldbeck R, Smyth R, Walker J, Sharpe M. Who is referred to neurology clinics? The diagnoses made in 3781 new patients. Clin Neurol Neurosurg. 2010;112(9):747-751. PMID 20646830.
Espay AJ, Aybek S, Carson A, Edwards MJ, Goldstein LH, Hallett M, LaFaver K, LaFrance WC, Lang AE, Nicholson T, Nielsen G, Reuber M, Voon V, Stone J, Morgante F. Current concepts in diagnosis and treatment of functional neurological disorders. JAMA Neurol. 2018;75(9):1132-1141. PMID 29868890.
Hallett M, Aybek S, Dworetzky BA, McWhirter L, Staab JP, Stone J. Functional neurological disorder: new subtypes and shared mechanisms. Lancet Neurol. 2022;21(6):537-550. PMID 35430029.
Aybek S, Perez DL. Diagnosis and management of functional neurological disorder. BMJ. 2022;376:o64. PMID 35074803.

Positive diagnosis and clinical signs (6)

Daum C, Hubschmid M, Aybek S. The value of 'positive' clinical signs for weakness, sensory and gait disorders in conversion disorder: a systematic and narrative review. J Neurol Neurosurg Psychiatry. 2014;85(2):180-190. PMID 23467417.
McWhirter L, Stone J, Sandercock P, Whiteley W. Hoover's sign for the diagnosis of functional weakness: a prospective unblinded cohort study in patients with suspected stroke. J Psychosom Res. 2011;71(6):384-386. PMID 22118379.
Sonoo M. Abductor sign: a reliable new sign to detect unilateral non-organic paresis of the lower limb. J Neurol Neurosurg Psychiatry. 2004;75(1):121-125. PMID 14707320.
Horn D, Galli S, Berney A, Vingerhoets F, Aybek S. Testing head rotation and flexion is useful in functional limb weakness. Mov Disord Clin Pract. 2017;4(4):597-602. PMID 30363481.
van der Veen S, Klamer MR, Elting JWJ, Koelman JHTM, van der Stouwe AMM, Tijssen MAJ. The diagnostic value of clinical neurophysiology in hyperkinetic movement disorders: a systematic review. Parkinsonism Relat Disord. 2021;89:176-185. PMID 34362669.
Stone J, Smyth R, Carson A, Lewis S, Prescott R, Warlow C, Sharpe M. Systematic review of misdiagnosis of conversion symptoms and "hysteria". BMJ. 2005;331(7523):989. PMID 16223792.

Treatment and clinical trials (7)

Nielsen G, Stone J, Matthews A, Brown M, Sparkes C, Farmer R, Masterton L, Duncan L, Winters A, Daniell L, Lumsden C, Carson A, David AS, Edwards M. Physiotherapy for functional motor disorders: a consensus recommendation. J Neurol Neurosurg Psychiatry. 2015;86(10):1113-1119. PMID 25433033.
Nielsen G, Stone J, Lee TC, Goldstein LH, Marston L, Hunter RM, Carson A, Holt K, Marsden J, Le Novere M, Nazareth I, Noble H, Reuber M, Strudwick AM, Santana Suarez B, Edwards MJ, Physio4FMD study group. Specialist physiotherapy for functional motor disorder in England and Scotland (Physio4FMD): a pragmatic, multicentre, phase 3 randomised controlled trial. Lancet Neurol. 2024;23(7):675-686. PMID 38768621.
Nielsen G, Buszewicz M, Stevenson F, Hunter R, Holt K, Dudziec M, Ricciardi L, Marsden J, Joyce E, Edwards MJ. Randomised feasibility study of physiotherapy for patients with functional motor symptoms. J Neurol Neurosurg Psychiatry. 2017;88(6):484-490. PMID 27694498.
Nielsen G, Ricciardi L, Demartini B, Hunter R, Joyce E, Edwards MJ. Outcomes of a 5-day physiotherapy programme for functional (psychogenic) motor disorders. J Neurol. 2015;262(3):674-681. PMID 25557282.
Jacob AE, Kaelin DL, Roach AR, Ziegler CH, LaFaver K. Motor retraining (MoRe) for functional movement disorders: outcomes from a 1-week multidisciplinary rehabilitation program. PM R. 2018;10(11):1164-1172. PMID 29783067.
Nicholson C, Edwards MJ, Carson AJ, Gardiner P, Golder D, Hayward K, Humblestone S, Jinadu H, Lumsden C, MacLean J, Main L, Macgregor L, Nielsen G, Oakley L, Price J, Ranford J, Ranu J, Sum E, Stone J. Occupational therapy consensus recommendations for functional neurological disorder. J Neurol Neurosurg Psychiatry. 2020;91(10):1037-1045. PMID 32732388.
Goldstein LH, Robinson EJ, Mellers JDC, Stone J, Carson A, Reuber M, Medford N, McCrone P, Murray J, Richardson MP, Pilecka I, Eastwood C, Moore M, Mosweu I, Perdue I, Landau S, Chalder T, CODES study group. Cognitive behavioural therapy for adults with dissociative seizures (CODES): a pragmatic, multicentre, randomised controlled trial. Lancet Psychiatry. 2020;7(6):491-505. PMID 32445688.

Prognosis and cost (2)

Gelauff J, Stone J, Edwards M, Carson A. The prognosis of functional (psychogenic) motor symptoms: a systematic review. J Neurol Neurosurg Psychiatry. 2014;85(2):220-226. PMID 24029543.
O'Mahony B, Nielsen G, Baxendale S, Edwards MJ, Yogarajah M. Economic cost of functional neurologic disorders: a systematic review. Neurology. 2023;101(2):e202-e214. PMID 37339887.

Classification (2)

World Health Organization. ICD-11 for Mortality and Morbidity Statistics, chapter 06, category 6B60 “Dissociative neurological symptom disorder” and its subcategories. Simple tabulation table, version 2025-01-24. icd.who.int.
American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5), criteria for functional neurological symptom disorder. Washington, 2013.

Three neighbouring articles in the corpus shed light on the pictures FND is most often discussed against. Complex regional pain syndrome is the other diagnosis on this site made on positive clinical criteria, with the same requirement of demonstration. Fibromyalgia shares the vocabulary of explanation and the same difficulty in delivering the diagnosis. Finally, faced with an isolated gait disturbance in an older person, normal pressure hydrocephalus is the diagnosis not to miss, and cerebellar ataxia the one that examination separates best from it.