FND Education Project

REFERENCE · DIAGNOSIS

Functional Paralysis

Refers to:

  • complete or near-complete loss of voluntary movement in one or more limbs;
  • functional hemiplegia or paraplegia diagnosed from positive clinical evidence; and
  • persistent or episodic severe limb immobility outside, or continuing beyond, a functional-seizure event.

Scope boundary: This page treats paralysis as the severe end of a functional limb-weakness presentation, not as a separate proven mechanism. Facial weakness belongs on the facial symptoms page. Immobility that occurs only within a stereotyped functional seizure belongs on the functional-seizures page. Sleep paralysis, cataplexy, postictal weakness and structural neurological causes are different presentations requiring appropriate assessment.

Quick Reference

Presentation: Demonstrate a reproducible difference between voluntary access and movement recruited in another task, interpreted with the history, complete examination and appropriate investigation. No one sign covers bilateral or widespread paralysis.

More techniques: See the full list below.

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For the Person With FND

You may be unable to move an arm or leg when you try, or have so little available movement that ordinary tasks need help. The loss may persist or occur in episodes. This page concerns complete or near-complete limb movement loss; the appearance alone does not establish its cause.

Functional paralysis is usually considered a severe presentation of functional weakness. It is real and can be profoundly disabling. The diagnosis depends on positive clinical evidence of altered movement function; it does not guarantee that no other neurological disease or injury is present. This separate page exists because complete movement loss raises particular safety, care and rehabilitation questions. [1]

The diagnosis should be supported by positive features in the person’s own movement pattern. A clinician may compare movement produced while directly trying with movement recruited automatically during a different task. The relevant comparison depends on which limb and movement are affected. Hoover’s sign and the hip-abductor sign concern selected unilateral leg presentations; a finger-abduction sign has been described for unilateral arm paralysis. These signs are not tests of honesty, and none is a universal test for paralysis. [1][2][3][4]

Do not ask somebody at home to force a limb or repeatedly reproduce these signs. Pain, injury, comprehension, severe bilateral symptoms, neglect and coexisting neurological or musculoskeletal conditions may make a comparison unsafe or uninterpretable.

Persistent, episodic and seizure-associated immobility

Paralysis may be persistent, fluctuate or occur in episodes. The word alone does not establish the category. An isolated limb that remains unable to move between events is assessed as a motor presentation. Whole-body or limb immobility confined to a familiar seizure-like event is assessed as part of that event. If both occur, each appearance needs its own plan.

Some people report marked weakness or paralysis around functional seizures or periods of severe fatigue. Timing is useful context, but it does not decide the category or mechanism. Seizure-confined immobility follows the seizure-event pathway; limb paralysis outside the event follows the motor pathway; and severe fatigue needs assessment of fatigue, load and other contributors rather than being treated as proof of either diagnosis.

When familiar paralysis begins or worsens, stop driving, standing, transferring, carrying dangerous objects or using machinery; get into a safe position; and use the support or mobility plan already agreed. New paralysis, a sudden changed pattern or paralysis with facial droop, new speech or understanding difficulty, severe headache, new bladder or bowel change, saddle numbness, fever, injury or altered consciousness needs urgent assessment rather than automatic attribution to FND. [13][14]

What the assessment should include

Tell the team what happens during ordinary tasks, what help you need and what happens after activity. A brief movement seen on examination does not settle whether you can move safely, repeatedly or for long enough to meet daily needs. You can ask for an accessible summary explaining the positive evidence, any other condition being considered and the follow-up plan.

The assessment and care guide includes questions about transfers, positioning, toileting, communication and participation. These are care questions, not tests you have to pass. Worry, frustration or dependence on help can be discussed without assuming they caused the paralysis.

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For Family, Friends, and Other Supporters

Complete movement loss can vary without being voluntary. Do not pull the person upright, force a limb, remove an aid or demand that they demonstrate a previously observed movement. Ask what help is wanted, use trained transfer methods and bring the person’s usual aid or communication device.

If the established episode plan identifies an automatic movement cue, offer it once and only when the person is safe. When the person cannot use a cue, practical care—safe positioning, pressure relief, warmth, toileting access, hydration and a way to call for help—may matter more than active retraining. Record duration, distribution, associated symptoms and recovery if the person wants this information kept.

A previous functional diagnosis does not determine the cause of every new paralysis episode. Follow the person’s emergency plan and seek reassessment for a new, markedly changed, prolonged or injured presentation.

Preparing for review

With consent, help describe what was observed, what the person reported, which help was needed and how the episode ended. Bring the agreed transfer and episode plans if available. Ask how the person wants to communicate during immobility; do not assume that an inability to move means they cannot understand.

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For Clinicians and the Care Team

Primary techniques: Phenotype-specific comparison of attempted movement with automatic or synergistic movement—for example Hoover’s or the hip-abductor sign for unilateral leg paralysis, and the finger-abduction sign for unilateral arm paralysis.
Diagnostic method: Demonstrate a reproducible difference between voluntary access and movement recruited in another task, interpreted with the history, complete examination and appropriate investigation. No one sign covers bilateral or widespread paralysis.
Media needed: Clinician-led video with separate upper- and lower-limb examples plus a diagram explaining why the selected sign applies only to that movement pattern.

Match the sign to the phenotype

The assessment sequence is described in Severe Immobility: Assessment and Care Needs. Detailed leg and arm guides distinguish their respective comparisons and evidence limits.

No single validated bedside sign for bilateral or widespread functional paralysis is established by the sources reviewed here. In those presentations, document the complete pattern, positive evidence actually observed, limitations of the examination and the work-up of plausible alternatives. Normal investigations alone do not make the diagnosis.

Diagnosis and daily support are separate questions

Document diagnostic evidence, observed task performance and everyday support needs separately. A positive sign does not determine the safety of an unsupervised transfer, the duration of useful movement or the person’s capacity for work or self-care. Ask about repeated activity, pain/fatigue, aids, assistance and recovery rather than inferring these from an examination-bed comparison.

The authored care record supports coordination across neurology, rehabilitation, OT, physiotherapy, nursing and primary care. It is not a validated scale. Agree care and reassessment while uncertainty remains; severe or persistent disability does not imply failure of effort.

For new bladder/bowel or saddle-sensation symptoms, use the appropriate urgent assessment. The scan-negative cauda equina page explains why a negative scan and an FND diagnosis are not interchangeable. [14]

Media contributor brief

The original filming brief is preserved in the assessment guide, including continuous comparisons, consent and safety requirements.

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Research and Sources

Diagnostic techniques at a glance

The preserved nine-entry inventory retains every original description and source association. Detailed guides expand selection and interpretation; not every entry has a fully reviewed standalone protocol.

Hoover’s sign in suitable unilateral paralysis

Use the existing guide for the suitable one-sided leg presentation.

Hip-abductor sign

Assess related sideways forces with the opposite-leg limitations in view.

Abduction-finger sign

Interpret associated finger spreading only in its appropriate severe-unilateral context.

Spinal Injuries Center test

Keep the severe-weakness and mechanical-support restrictions explicit.

Elbow flex-ex comparison

Compare opposite-direction arm force in an appropriate unilateral presentation.

Preserved automatic or task-linked movement

Establish that the same capacity is being compared.

Tone, reflexes and plantar responses

Use findings for localization without treating normality as proof of FND.

Motor and sensory pathway investigations

Select investigations to answer a clinical question.

Tests that require residual voluntary movement

Do not count an impossible starting task as a positive sign.

Research and Sources

Evidence notes

  • The 2025 technique review brings the leg and arm comparisons together, including their movement requirements and study limitations. Use it alongside the original studies; it does not establish a single test for widespread paralysis. [15]
  • Functional paralysis is treated here as a severe presentation of functional limb weakness. A separate reference page improves findability and permits phenotype-specific safety and rehabilitation guidance; it does not assert a distinct mechanism. [1]
  • Hoover’s sign has moderate sensitivity and high specificity in one prospective suspected-stroke cohort, but only eight participants had functional weakness. The upper-limb finger-abduction and lower-limb hip-abductor publications concern unilateral presentations and do not establish a universal sign. [2][3][4]

Citation table

Citation Figure Full citation
[1] — Bennett K, Diamond C, Hoeritzauer I, Gardiner P, McWhirter L, Carson A, Stone J. A practical review of functional neurological disorder (FND) for the general physician. Clinical Medicine. 2021;21(1):28–36. FND-CIT-0001. https://doi.org/10.7861/clinmed.2020-0987
[2] — 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. Journal of Psychosomatic Research. 2011;71(6):384–386. FND-CIT-0018. https://doi.org/10.1016/j.jpsychores.2011.09.003
[3] — Tinazzi M, Simonetto S, Franco L, et al. Abduction finger sign: a new sign to detect unilateral functional paralysis of the upper limb. Movement Disorders. 2008;23(16):2415–2419. FND-CIT-0057. https://doi.org/10.1002/mds.22268
[4] — Sonoo M. Abductor sign: a reliable new sign to detect unilateral non-organic paresis of the lower limb. Journal of Neurology, Neurosurgery & Psychiatry. 2004;75(1):121–125. FND-CIT-0058. DOI: 10.1136/jnnp.75.1.121
[5] — Yugué I, Shiba K, Ueta T, Iwamoto Y. A new clinical evaluation for hysterical paralysis. Spine. 2004;29(17):1910-3; discussion 1913. DOI: 10.1097/01.brs.0000137055.55350.37. PMID: 15534415. FND-CIT-0166.
[6] — Lombardi TL, Barton E, Wang J, et al. The elbow flex-ex: a new sign to detect unilateral upper extremity non-organic paresis. Journal of neurology, neurosurgery, and psychiatry. 2014;85(2):165-167. DOI. PMID: 23695497. FND-CIT-0134.
[7] — Stone J, Warlow C, Sharpe M. The symptom of functional weakness: a controlled study of 107 patients. Brain : a journal of neurology. 2010;133(Pt 5):1537-1551. DOI. PMID: 20395262. FND-CIT-0047.
[8] — Daum C, Gheorghita F, Spatola M, et al. Interobserver agreement and validity of bedside ‘positive signs’ for functional weakness, sensory and gait disorders in conversion disorder: a pilot study. Journal of neurology, neurosurgery, and psychiatry. 2015;86(4):425-430. DOI. PMID: 24994927. FND-CIT-0130.
[9] — Baker JH, Silver JR. Hysterical paraplegia. Journal of neurology, neurosurgery, and psychiatry. 1987;50(4):375-382. DOI: 10.1136/jnnp.50.4.375. PMID: 3585346. FND-CIT-0120.
[10] — Edwards MJ, Koens LH, Liepert J, et al. Clinical neurophysiology of functional motor disorders: IFCN Handbook Chapter. Clinical neurophysiology practice. 2024;9:69-77. DOI. PMID: 38352251. FND-CIT-0022.
[11] — Daum C, Aybek S. Validity of the “Drift without pronation” sign in conversion disorder. BMC neurology. 2013;13:31. DOI. PMID: 23548051. FND-CIT-0131.
[12] — Sonoo M. Paradoxical wrist flexion: A new test to detect functional weakness of the upper limb. eNeurologicalSci. 2021;22:100302. DOI. PMID: 33344786. FND-CIT-0185.
[13] — NHS. Symptoms of a stroke. Reviewed September 12, 2024; accessed September 17, 2026. Source. FND-CIT-0108.
[14] — Hoeritzauer I, Pronin S, Carson A, Statham P, Demetriades AK, Stone J. The clinical features and outcome of scan-negative and scan-positive cases in suspected cauda equina syndrome: a retrospective study of 276 patients. Journal of Neurology. 2018;265(12):2916–2926. https://doi.org/10.1007/s00415-018-9078-2 FND-CIT-0016.
[15] — Dolbow J, El-Azzouni S, Zhang Y, Geiger C. A practical guide to assessing functional motor weakness: a review of validated techniques. Journal of Neurology. 2025;272(6):427. DOI. FND-CIT-0183.

Technique outline created: September 2, 2026 · Neurology, rehabilitation, lived-experience and accessibility review pending

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