REFERENCE · DIAGNOSTIC TECHNIQUE

Differential Assessment of Drop Attacks

Clinician-focused educational reference. Use within professional competence and an agreed assessment plan.

Purpose and Suitability
Anatomy and Physiology
Preparation and Safety
Performing the Assessment
Interpreting Findings
Explaining the Result
Evidence and Limitations
Media and Accessibility
Research and Sources

Purpose and Suitability

Use this guide to select the next clinical pathway after reconstructing the event. Syncope, epilepsy, cataplexy, vestibular events, mechanical falls and functional symptoms can require different investigations and can coexist. 1

Syncope: A brief loss of consciousness caused by reduced blood flow to the brain.

NICE guidance cited here concerns suspected transient loss of consciousness in people over 16; it is adjacent guidance, not a protocol for every fall. 2

Anatomy and Physiology

A sudden fall may reflect loss of postural support, disturbed balance or loss of consciousness. These possibilities are not interchangeable. “No definite blackout” leaves room for an incomplete account; it must not be translated automatically into “conscious throughout”. The history and examination determine which body systems need assessment.

Preparation and Safety

New chest pain, sustained palpitations, breathlessness, a new neurological deficit, serious injury or delayed recovery needs urgent assessment. Follow local emergency pathways. For any standing assessment, use suitable staff, support and equipment; do not expose the person to an avoidable fall to obtain a measurement.

Performing the Assessment

Clinical questions and routes

Finding or question	Assessment route	Interpretation boundary
Possible blackout or circulatory symptoms	Cardiovascular history/examination; ECG and postural blood pressure as indicated; specialist monitoring when needed	A normal resting ECG cannot exclude every intermittent event
Stereotyped seizure-like events	Neurology assessment and selected epilepsy investigations	A routine normal test is not a functional diagnosis
Weakness episodes with sleep symptoms or emotion-related events	Sleep/neurology assessment for cataplexy and related disorders	Preserved awareness alone does not distinguish causes
Vertigo, hearing symptoms or vestibular history	Vestibular assessment matched to the presentation	A normal general gait test does not answer every vestibular question
Buckling, pain, trips, medication or environmental factors	Gait, strength, musculoskeletal, medication and environmental review	Several contributors may coexist

These routes expand the original differential inventory; they are not a mandatory test panel. 1 NICE recommends a 12-lead ECG during initial suspected-blackout assessment. Use its current pathway and local guidance for test selection rather than using this table as a standing or tilt-test protocol. 2

Interpreting Findings

Document what each investigation answers and what it leaves unresolved. Abnormal findings may be relevant, incidental or coexist with functional symptoms. Negative investigations narrow particular possibilities; they do not establish FND by subtraction. If a finding concerns gait or weakness, explain its actual scope and link it to the event account.

Explaining the Result

Authored explanation example: “We are checking several possible contributors to these falls. This test addresses one of them. Whatever the result, we still need to explain the event pattern and make a safe plan.”

Give the person a named follow-up route and reasons to seek earlier reassessment.

Evidence and Limitations

The drop-attack cohort is descriptive and cannot validate a differential-testing algorithm. NICE supplies a separate clinical pathway for suspected blackouts; it should not be applied as if it were a positive functional-drop-attack test. Full recommendation-page retrieval was unavailable during this check; the indexed official recommendation was verified. Detailed protocols remain with the guideline and treating service. 1, 2

Media and Accessibility

A diagram may begin with “sudden fall” and branch by clinical questions. Label branches as possibilities, not diagnoses decided by one symptom. Provide a full text equivalent; do not depict a staged collapse or unsafe standing test.

Research and Sources

Citation	Full citation and evidence limit
[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]	NICE. Transient loss of consciousness (‘blackouts’) in over 16s. Clinical guideline CG109. Recommendations. Accessed October 7, 2026. Adjacent guidance for suspected transient loss of consciousness; not functional-drop-attack diagnostic criteria. FND-CIT-0263.

Continue: Falls, Everyday Function and Follow-Up

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