REFERENCE · DIAGNOSIS

Functional Seizures

Refers to:

episodic convulsive or shaking events;
still or unresponsive events and episodes of altered awareness or responsiveness;
sensory, autonomic, memory or mixed seizure-like events; and
inability to move only when it forms part of the person’s stereotyped functional seizure.

Scope boundary: Isolated or persistent limb paralysis belongs on the paralysis page. A brief sudden fall without definite blackout and with rapid recovery may belong on the drop-attacks page. The diagnostic method below assesses the whole event, not one shared symptom such as shaking or immobility.

Featured technique: Careful event history followed, when feasible, by video-EEG recording of each typical event type.
Diagnostic method: Interpret the complete event, its clinical context and simultaneous video and EEG—not one movement viewed alone.
Media needed: A video-EEG process diagram or a consented clinical recording with specialist explanation; never provoke an event 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.

Typical-event video-EEG

A specialist interprets a familiar event’s video together with its EEG. A compatible event without the epileptic activity expected for that event can support documented functional seizures. Some epileptic seizures lack a clear scalp EEG correlate; a normal routine EEG is insufficient. [1][3]

Smartphone-video assessment

With consent, a safely recorded spontaneous event can supplement history. A prospective masked study found added diagnostic value when experts reviewed recordings. Missing onset, poor visibility and unfamiliar events limit interpretation; recording must never delay first aid. [4]

Ictal eye closure

Sustained or forceful eye closure during an event can support functional seizures in the appropriate semiological pattern. Primary studies and pooled evidence exist, but eye closure can also occur in epilepsy. Observation on video is more informative than recollection alone. [5][6]

Asynchronous limb movements

Out-of-step movements of the limbs during a convulsive-appearing event may support functional seizures. This is a studied semiological feature, not an absolute discriminator; frontal and hypermotor epileptic events can overlap. [6][7]

Fluctuating course

Repeated waxing and waning or pauses during an event can support a functional pattern. A blinded video study evaluated this feature alongside other movements. It must be assessed as part of the entire event, not from an isolated pause. [8]

Event duration

Clinicians time the event and its phases. Longer duration may shift diagnostic probability, but duration alone cannot identify the cause. An undiagnosed prolonged convulsive event still requires appropriate emergency assessment rather than a timing-based FND assumption. [9]

Side-to-side head movement

Repetitive head shaking is a descriptive clue studied in video-EEG cohorts. It occurs in both functional and epileptic seizures and has limited standalone value. It should never become a visual shortcut to diagnosis. [6][8]

Pelvic thrusting

Pelvic movements are recorded as part of the event sequence. Direct comparative research found overlap with epileptic seizures, including frontal presentations. This sign alone is insufficient and has no bearing on the person’s intent or sexual behaviour. [6][10]

Back arching

The examiner records trunk extension or arching without trying to reproduce or restrain it. Comparative video research did not establish it as a reliable independent discriminator. Arching cannot establish FND or rule out epilepsy. [8]

Ictal responsiveness

A clinician may assess whether a simple, non-distressing instruction is understood during an event. Preserved or changing responses can help characterize the episode, but some epileptic seizures preserve awareness. No response does not establish epilepsy either. [3][11]

Recall of the event

The clinician asks afterward what was heard or remembered. Recall can contribute to the event formulation alongside observed behaviour and EEG. It is not a test of honesty, and preserved memory alone cannot distinguish all seizure types. [3][6]

Postictal breathing and recovery

Breathing pattern, time to ordinary interaction and confusion after the event provide additional context. Comparative studies describe differences after convulsive events, but drugs, hypoxia, injury and seizure type affect recovery. These observations are not standalone tests. [12]

Ictal crying or weeping

Crying during an event has been reported in comparative research and may contribute to a pattern. It is not exclusive to functional seizures, does not reveal the cause of the event and does not mean the episode is an emotional choice. [6][13]

Combined semiology tools

Structured scores combine several observed features rather than relying on one movement. Published development and validation work exists, but accuracy depends on the setting, reference diagnosis and population. These tools support trained assessment and do not replace video-EEG when indicated. [14]

ILAE diagnostic-certainty framework

History, witnessed events, specialist observation and EEG evidence support different levels of diagnostic certainty. These are consensus criteria, not several interchangeable positive tests. Record which level is supported and whether all habitual event types have been assessed. [3]

Hand/arm-drop avoidance during unresponsiveness

A hand changing course during release has been described in apparent unresponsiveness, including the context of a seizure-like event. Evidence is descriptive, not a validated standalone seizure test. Never deliberately drop a limb toward the face; avoidance does not prove FND or conscious control. [15][16]

Modified hand-drop and eyelid observations

Specialist descriptions include a modified hand-drop observation and assessment of eyelid opening intended to avoid injury. These may contribute to assessment of functional unresponsiveness, which is not identical to every functional seizure. Robust diagnostic-accuracy validation is lacking. [16]

Suggestion and induction protocols

Some services use consented activation or suggestion during monitoring to capture a typical event. An induced event must be verified as habitual and interpreted with EEG and clinical context. Inducibility alone is not diagnostic; deception, painful stimuli and unsafe provocation are inappropriate. [1][17]

Prolactin, lactate and creatine kinase

Selected post-event blood tests may help answer a differential question, but timing, seizure type and other causes limit them. Neither normal nor abnormal values establish functional seizures. These are ancillary investigations, not positive FND signs. [1][18]

Tilt testing for apparent blackouts

When the phenotype suggests syncope or apparent unresponsiveness, specialist tilt assessment with blood pressure, heart rate and sometimes EEG can distinguish mechanisms. Evidence for psychogenic pseudosyncope does not automatically apply to convulsive functional seizures; the diagnoses can coexist. [19]

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Functional seizures are real episodes that may include changes in movement, awareness, sensation, responsiveness or memory. They can resemble epileptic seizures, fainting and other episodic conditions. No single behaviour—closed eyes, shaking, crying, a long event or remembering part of it—proves that an event is functional.

The most reliable assessment begins with a detailed account from you and anyone who witnessed the event. A clinician may review a safely obtained home video. When it is feasible, the diagnostic standard is to record a typical event using video-EEG, so the person’s behaviour and the brain’s electrical activity can be interpreted together. More than one type of event may need to be recorded. [1][2]

A normal routine EEG between events does not rule out epilepsy. Some people have both functional seizures and epilepsy, so the diagnosis should identify which event type was recorded and how certain the team is.

The seizure is episodic, but the surrounding symptoms may last longer

Functional seizures are episodic by definition, but their duration and recovery can vary. Some people have a recognizable warning; some have clusters; some take substantial time to recover. Other functional symptoms—such as jerking, gait change, weakness, speech difficulty or altered sensation—may appear before, during or after a seizure-like event and may last for a different amount of time. Those associated symptoms should be described separately rather than assuming the entire period is one seizure.

At a familiar warning or onset, follow the person’s established safety plan: move away from traffic, water, stairs, heat or other hazards; get into the safest practical position; and use a pre-agreed grounding, attention or breathing strategy only if the person remains able to use it. A first event, a substantially different event, serious injury, unusual breathing or colour change, or prolonged/repeated events outside the person’s plan need appropriate urgent assessment.

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During an event, follow the person’s safety plan, protect them from injury and seek urgent help when the situation calls for it. Recording is secondary to care. If a spontaneous event can be filmed safely, record the whole person and surrounding context, note the time, and do not restrain them, test their response in painful ways or try to make the episode continue.

Describe what you observed in ordinary language: what happened first, whether the person responded, how breathing and colour looked, how long the event lasted and what recovery was like. Do not decide the diagnosis from a video yourself.

Before, during and after an episode

The visible seizure-like event may be only one part of a longer period of symptoms. If the person develops their familiar speech, gait, jerking, weakness or sensory changes before or after events, follow the separate safety and recovery plan for those symptoms rather than repeatedly asking whether another seizure is starting. Reduce unnecessary crowding and instructions if that is part of the agreed plan.

Time the event when practical, but do not let timing or filming interfere with safety. Note whether the person returned to their usual baseline between repeated events; that information can be important to the emergency plan and clinical review.

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Episodic pattern and longer surrounding flares

For each event type, document warning/prodrome, ictal sequence, duration, frequency, clustering, recovery and return to baseline. Also document motor, speech, cognitive, sensory or gait symptoms that occur around the event but have a different time course. Do not automatically label the entire symptomatic period as one prolonged functional seizure.

Provide a written onset and emergency plan with thresholds that account for the person’s established pattern, coexisting epilepsy and other medical risks. If the patient has a usable warning, adapt one or two treatment skills for that short window; if awareness is lost too quickly, the plan should rely on environmental safety and supporter response instead. A changed semiology or recovery pattern requires renewed differential assessment.

Technique outline: typical-event assessment with video-EEG

Create an event inventory. Ask whether there is one recurring type or several, and document the sequence, duration, frequency, triggers, injuries, recovery and treatment already given for each.
Obtain the patient’s account and, with permission, a factual witness account. Review an available home video only if it was recorded without delaying care or provoking the event.
Consider epilepsy, syncope, sleep disorders, migraine, movement disorders, metabolic causes and cardiac causes according to the presentation. Do not let an established FND diagnosis end this differential.
When feasible and clinically appropriate, arrange video-EEG monitoring intended to capture every typical event type under consideration. Record whether the patient and witness recognize the captured event as typical.
Interpret clinical semiology and simultaneous EEG together. An event without an ictal EEG correlate is not automatically functional; some epileptic seizures have limited or obscured scalp-EEG changes.
State the level of diagnostic certainty, which event type the conclusion applies to, and whether coexisting epilepsy remains present or possible.
Explain the positive evidence clearly and provide a practical event-management and follow-up plan.

Media contributor brief

The preferred first contribution is an annotated process diagram:

Patient and witness describe each usual event type.
Video and EEG are recorded at the same time.
The captured event is confirmed as typical.
A specialist interprets behaviour, EEG and clinical context together.

If an authentic clinical recording is used, it must come from an event that occurred during clinically indicated monitoring and have separate, specific permission for public use. Show the synchronized video and EEG context before any short excerpt. Never induce, prolong or repeat a seizure solely to create educational media, and never present an isolated gesture as diagnostic.

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Research and Sources

Evidence notes

The American Academy of Neurology guideline emphasizes respectful communication, evaluation for coexisting epilepsy and other disorders, and video-EEG of all typical event types where feasible. [1]
The general clinical review describes video-EEG as the diagnostic gold standard while recognizing that access and certainty vary. [2]

Citation table

Citation	Full citation
[1]	Tolchin B, Baslet G, Dworetzky BA, et al. Management of functional seizures practice guideline executive summary: report of the AAN Guidelines Subcommittee. Neurology. 2026. FND-CIT-0010. https://doi.org/10.1212/WNL.0000000000214466
[2]	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

[3]	LaFrance WC, Baker GA, Duncan R, et al. Minimum requirements for the diagnosis of psychogenic nonepileptic seizures: a staged approach: a report from the International League Against Epilepsy Nonepileptic Seizures Task Force. Epilepsia. 2013;54(11):2005-2018. DOI. PMID: 24111933. FND-CIT-0146.
[4]	Tatum WO, Hirsch LJ, Gelfand MA, et al. Assessment of the Predictive Value of Outpatient Smartphone Videos for Diagnosis of Epileptic Seizures. JAMA neurology. 2020;77(5):593-600. DOI. PMID: 31961382. FND-CIT-0168.
[5]	Chung SS, Gerber P, Kirlin KA. Ictal eye closure is a reliable indicator for psychogenic nonepileptic seizures. Neurology. 2006;66(11):1730-1731. DOI. PMID: 16769949. FND-CIT-0139.
[6]	Muthusamy S, Seneviratne U, Ding C, Phan TG. Using Semiology to Classify Epileptic Seizures vs Psychogenic Nonepileptic Seizures: A Meta-analysis. Neurology. Clinical practice. 2022;12(3):234-247. DOI. PMID: 35747545. FND-CIT-0165.
[7]	Gates JR, Ramani V, Whalen S, Loewenson R. Ictal characteristics of pseudoseizures. Archives of neurology. 1985;42(12):1183-1187. DOI. PMID: 3933461. FND-CIT-0144.
[8]	Duncan AJ, Peric I, Boston R, Seneviratne U. Predictive semiology of psychogenic non-epileptic seizures in an epilepsy monitoring unit. Journal of neurology. 2022;269(4):2172-2178. DOI. PMID: 34550469. FND-CIT-0161.
[9]	Seneviratne U, Minato E, Paul E. How reliable is ictal duration to differentiate psychogenic nonepileptic seizures from epileptic seizures? Epilepsy & behavior : E&B. 2017;66:127-131. DOI. PMID: 28039841. FND-CIT-0133.
[10]	Geyer JD, Payne TA, Drury I. The value of pelvic thrusting in the diagnosis of seizures and pseudoseizures. Neurology. 2000;54(1):227-229. DOI. PMID: 10636155. FND-CIT-0157.
[11]	Wardrope A, Wong S, McLaughlan J, et al. Peri-ictal responsiveness to the social environment is greater in psychogenic nonepileptic than epileptic seizures. Epilepsia. 2020;61(4):758-765. DOI. PMID: 32154929. FND-CIT-0163.
[12]	Azar NJ, Tayah TF, Wang L, et al. Postictal breathing pattern distinguishes epileptic from nonepileptic convulsive seizures. Epilepsia. 2008;49(1):132-137. DOI. PMID: 17651411. FND-CIT-0159.
[13]	Walczak TS, Bogolioubov A. Weeping during psychogenic nonepileptic seizures. Epilepsia. 1996;37(2):208-210. DOI. PMID: 8635432. FND-CIT-0184.
[14]	De Paola L, Terra VC, Silvado CE, et al. Improving first responders’ psychogenic nonepileptic seizures diagnosis accuracy: Development and validation of a 6-item bedside diagnostic tool. Epilepsy & behavior : E&B. 2016;54:40-46. DOI. PMID: 26645799. FND-CIT-0167.
[15]	Marcus H, Aldam P, Lennox G, Laing R. Medically unexplained neurological symptoms. JRSM short reports. 2010;1(3):25. DOI. PMID: 21103117. FND-CIT-0153.
[16]	Bacchi S, Slee M. Physical examination in functional unresponsiveness. Practical neurology. 2023;23(1):54-56. DOI. PMID: 36717206. FND-CIT-0119.
[17]	Popkirov S, Grönheit W, Wellmer J. A systematic review of suggestive seizure induction for the diagnosis of psychogenic nonepileptic seizures. Seizure. 2015;31:124-132. DOI. PMID: 26362389. FND-CIT-0148.
[18]	Chen DK, So YT, Fisher RS, Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology. Use of serum prolactin in diagnosing epileptic seizures: report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology. Neurology. 2005;65(5):668-675. DOI. PMID: 16157897. FND-CIT-0123.
[19]	Tannemaat MR, van Niekerk J, Reijntjes RH, et al. The semiology of tilt-induced psychogenic pseudosyncope. Neurology. 2013;81(8):752-758. DOI. PMID: 23873974. FND-CIT-0174.

Technique outline created: August 24, 2026 · Epileptology and emergency-care review pending

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