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.

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. No validated single bedside sign for functional drop attacks was located.
Media needed: An event-classification flow diagram and clinician-led history example; never provoke a fall for filming.

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 longer explanations already on this page remain below. Individual technique pages will be developed and reviewed separately.

Structured event reconstruction

The clinician maps the sequence before, during and after the fall, including posture, warning, awareness, movement and recovery. A retrospective cohort describes a common functional phenotype, but no validated single bedside sign was established. [1]

Witness account or safe video

A consensual account or existing recording may clarify whether there was blackout, knee buckling or a longer seizure-like event. This supports classification, not diagnosis from appearance alone. Never provoke a fall or withhold an aid for recording. [1]

Awareness and recovery profile

No definite loss of consciousness with relatively rapid recovery may fit the described phenotype. It also occurs in other disorders, including cataplexy and vestibular falls. Missing memory of impact does not by itself establish or exclude a functional cause. [1]

Associated positive functional signs

Matching weakness, gait or seizure findings may support a wider functional formulation. The drop-attack cohort showed overlap, but a functional diagnosis elsewhere does not prove the cause of each fall. [1]

Cardiovascular and orthostatic assessment

History, examination, ECG and selected monitoring or tilt testing address syncope and arrhythmia when indicated. These are differential investigations; normal results alone do not classify a fall as functional. [1]

Epilepsy and sleep assessment

Event characteristics guide seizure investigation or assessment for cataplexy and narcolepsy. These are differential pathways, not positive FND techniques. Preserved awareness is compatible with cataplexy and some epileptic events. [1]

Vestibular, gait and mechanical assessment

The clinician evaluates vestibular drop attacks, leg buckling, medications and environmental or musculoskeletal causes as appropriate. No single normal balance or gait test proves functional drop attacks. [1]

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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.

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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.

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Structured diagnostic approach

Define the event from standing or walking through impact and recovery, including warning, recall, awareness, motor pattern, autonomic features, injury and duration.
Obtain witness description or consensual video when available, recognizing selection and interpretation limits.
Examine gait, strength, movement, cardiovascular and vestibular features as guided by the history.
Consider syncope and orthostatic causes, epilepsy including atonic events, cataplexy or narcolepsy, vestibular or Tumarkin attacks, medication effects, mechanical falls and other neurological, cardiac or musculoskeletal causes.
Identify whether the event is better formulated as functional gait/weakness, a functional seizure or a functional drop attack. Record overlap rather than forcing one label when two established phenotypes coexist.
Explain the basis and limits of the formulation and provide an injury-response plan while diagnostic work continues where needed.

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]

Media contributor brief

Preferred format: A narrated flow diagram beginning with “sudden fall” and separating definite blackout, prolonged seizure-like features, gait or weakness-related buckling, and the no-definite-blackout/rapid-recovery presentation. Keep differential branches non-exhaustive and direct viewers to assessment.

Clinical example: Use a fictional consultation or actor. Show the questions asked before, during and after an event, what a witness can report, and why no single normal test proves the diagnosis.

Do not stage a fall, withdraw an aid, provoke an event or use injury footage. Captions should distinguish “drop attack” as an event description from “functional drop attack” as a clinical formulation.

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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 September 2, 2026. FND-CIT-0061. https://neurosymptoms.org/en/symptoms/fnd-symptoms/functional-drop-attacks/

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

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