FND Education Project

REFERENCE · DIAGNOSIS

Functional Drop Attacks

Refers to:

  • sudden falls from standing or walking, usually with little or no warning;
  • events without definite loss of consciousness and often with rapid recovery; and
  • functional, idiopathic or historically “cryptogenic” drop attacks after appropriate assessment.

Scope boundary: “Drop attack” is a description, not a diagnosis, and not every unexplained fall is functional. Knee buckling without a fall may fit the gait or weakness page. Prolonged altered awareness, convulsive movement or another stereotyped seizure-like event belongs on the functional-seizures page. Syncope, epileptic seizures, cataplexy, vestibular events and mechanical or structural causes require their own assessment.

Quick Reference

Presentation: Establish the event phenotype and positive clinical formulation rather than inferring FND from normal tests. Assessment rests on the event history and clinical formulation; there is no single established bedside test.

More techniques: See the full list below.

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For the Person With FND

A drop attack is a sudden fall while standing or walking. In the presentation covered here, there is no definite blackout and recovery is often quick. Some people describe no warning; others later identify a very brief change in awareness, sensation or body control. Injuries can be significant even when the event itself is brief. [1][2][3]

Many conditions can cause sudden falls. The diagnosis is therefore based on the exact sequence, witness information, examination and tests chosen for plausible alternatives—not on the label “drop attack” or on normal results alone. Community members may use the phrase for fainting, seizures, knee buckling, paralysis or any collapse; a clinician may classify those events differently because their diagnostic and recovery plans differ.

If an event is new, changing, associated with definite loss of consciousness, chest pain, sustained palpitations, new neurological symptoms, prolonged confusion or injury, seek appropriate medical assessment. Do not deliberately recreate a fall or walk without needed support to obtain a recording.

What assessment should also cover

Tell the team about injuries, help needed after an event, activities affected and access to daily life. A brief walk in clinic does not show how safely you can manage a whole day. The falls and follow-up guide explains how to record this separately from diagnosis.

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For Family, Friends, and Other Supporters

Ask the person what they want others to do after a familiar event. Make the area safe, check for injury and allow recovery without rapidly lifting them or demanding an explanation. If moving them is necessary because of immediate danger, follow first-aid guidance and use trained help where possible.

Useful witness observations include posture and activity before the fall; warning or behavioural change; whether the body stiffened, went limp or buckled; eye and limb movements; responsiveness; colour or breathing change; injury; and time to ordinary interaction. A recording may help only when it can be made without delaying care, compromising dignity or creating danger.

Do not assume that every fall in a person with FND is another functional drop attack. Follow emergency guidance for a changed event, serious injury, definite blackout, breathing difficulty or delayed recovery.

For the Person With FND
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For Clinicians and the Care Team

Featured technique: Specialist structured event and falls history, witness account or safely obtained recording when available, examination, and targeted differential assessment.
Diagnostic method: Establish the event phenotype and positive clinical formulation rather than inferring FND from normal tests. Assessment rests on the event history and clinical formulation; there is no single established bedside test.
Media needed: An event-classification flow diagram and clinician-led history example; never provoke a fall for filming.

Structured diagnostic approach

Read the six-step clinical outline and event record.

The retrospective “cryptogenic drop attack” cohort showed substantial overlap with dissociative symptoms, functional limb weakness and nonepileptic attacks, but it did not establish that all unexplained drop attacks are functional. The later qualitative study of seven people proposed a cognitive-behavioural model; it was not a diagnostic-accuracy or treatment trial. [1][2]

The broader drop-attack literature uses the term for several kinds of collapse, sometimes including blackouts. Establish what actually happened before selecting cardiovascular, vestibular, neurological or sleep assessment. [5]

Targeted investigations: Suspected blackouts require their own assessment pathway; the differential guide explains the scope of the over-16 NICE guidance. [4]

Media contributor brief

Read the preserved media brief.

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Diagnostic techniques at a glance

These brief entries describe signs, observations, criteria and investigations clinicians may consider. They are not a checklist of tests everyone needs. Evidence and limitations differ for each entry; a positive sign must fit the whole clinical picture, including possible coexisting disease.

The detailed guides above cover the main assessment questions. Every original entry is linked below and preserved in the separate inventory; an entry is not necessarily a validated test.

Structured event reconstruction

Read the preserved assessment description.

Witness account or safe video

Read the preserved assessment description.

Awareness and recovery profile

Read the preserved assessment description.

Associated positive functional signs

Read the preserved assessment description.

Cardiovascular and orthostatic assessment

Read the preserved assessment description.

Epilepsy and sleep assessment

Read the preserved assessment description.

Vestibular, gait and mechanical assessment

Read the preserved assessment description.

Research and Sources

Evidence notes

  • In a retrospective cohort of 83 people diagnosed with idiopathic or cryptogenic drop attacks, 43% reported prodromal dissociative symptoms; 31% had functional limb weakness and 28% had nonepileptic attacks. These overlaps support careful functional assessment but do not classify every drop attack as FND. [1]
  • A qualitative interview-and-diary study of seven people proposed a cognitive-behavioural account involving threat, dissociation and conditioned responses. It generated a model rather than validating a diagnostic sign or treatment. [2]
  • Specialist educational guidance describes the usual no-blackout, little-warning and rapid-recovery presentation while emphasizing multiple possible causes. [3]

Citation table

Citation Full citation
[1] Hoeritzauer I, Carson AJ, Stone J. “Cryptogenic drop attacks” revisited: evidence of overlap with functional neurological disorder. Journal of Neurology, Neurosurgery & Psychiatry. 2018;89(7):769–776. FND-CIT-0059. https://doi.org/10.1136/jnnp-2017-317396
[2] Revell ER, Gillespie D, Morris PG, Stone J. Drop attacks as a subtype of FND: a cognitive behavioural model using grounded theory. Epilepsy & Behavior Reports. 2021;16:100491. FND-CIT-0060. https://doi.org/10.1016/j.ebr.2021.100491
[3] Stone J. Functional drop attacks. Neurosymptoms.org. Accessed October 12, 2026. FND-CIT-0061. https://neurosymptoms.org/en/symptoms/fnd-symptoms/functional-drop-attacks/
[4] NICE. Transient loss of consciousness (‘blackouts’) in over 16s. Clinical guideline CG109. Recommendations. Accessed October 12, 2026. Adjacent guidance for suspected transient loss of consciousness; not functional-drop-attack diagnostic criteria. FND-CIT-0263.
[5] Manford E, Garg A, Manford M. Drop attacks: a practical guide. Practical Neurology. 2024;24(2):106–113. DOI. FND-CIT-0272.

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

For the Person With FND
For Family, Friends, and Other Supporters
For Clinicians and the Care Team
Research and Sources