REFERENCE · DIAGNOSTIC TECHNIQUE

Semiology and the Whole Event Sequence

Clinician-focused educational reference. Other readers are welcome; this is not a home diagnostic test.

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

Semiology is the description of how an event begins, unfolds and ends. This assessment asks whether the combined pattern supports functional seizures, epilepsy, another explanation or continuing uncertainty. It should be carried out by a clinician with relevant seizure expertise. [1][2]

Semiology: The symptoms and observable signs of an event, including their order and timing.

It is a reasoning process, not a home checklist. A feature may alter diagnostic probability without being necessary or sufficient for diagnosis.

Anatomy and Physiology

Movement, awareness, responsiveness and later recall are different observations. Motor behaviour may be visible while the person’s experience remains inaccessible to an observer. Conversely, stillness does not tell us whether the person can hear or remember.

Different seizure types affect different functions. Scalp EEG and video contribute complementary information; clinical interpretation must consider the expected electrical pattern and recording limitations. [2][3]

Asynchronous movements: Limbs moving out of step with each other. Hypermotor: Prominent, often vigorous movements involving several body regions.

Some hypermotor epileptic events overlap with features described in functional seizures. Unusual appearance is not a mechanism or a diagnosis.

Preparation and Safety

Observe safely and obtain the person’s and witness’s accounts. During an acute episode, assess urgent care needs before collecting diagnostic detail. Describe the natural event; never request a more dramatic version or prolong it.

Do not apply pain, force eyelids open, restrain movement to see what happens, or drop an arm toward the face. Existing descriptive literature about such manoeuvres is not robust validation and does not make them appropriate home tests. A trained team may use simple non-distressing spoken instructions when suitable. [3]

Note hearing, language, speech and motor limitations before interpreting a missed response. Agree accessible communication for the recovery discussion.

Performing the Assessment

Describe the start: position, activity, warning, first observable change and whether the witness saw it.
Follow the sequence: eyes, movement timing, symmetry, pauses, responsiveness, breathing and colour, without reducing it to a single sign.
Separate the event from recovery. Ask about confusion, speech, movement, memory and return to the usual baseline.
Compare with other habitual types and note uncertainty in accounts or recording.
Integrate the pattern with the differential and relevant EEG, cardiovascular or other assessment. [1][3]

This is an editorial structure for documentation, not a validated five-step test. Duration is useful information, but no timing threshold alone makes an undiagnosed prolonged convulsive event functional.

Interpreting Findings

Observed eye closure and asynchronous limb movements have stronger discriminative evidence than many other individual features, but still require context. Their absence does not exclude functional seizures, and their presence does not remove the need to assess alternatives. Pelvic thrusting and side-to-side movements overlap with epileptic events. [2]

Recall, partial response or a pause in movements must be related to the event type and timing. A feature recorded after the event cannot automatically be assigned to the seizure itself. A new pattern needs reassessment even when previous events were functional. [1][3]

Use three possible conclusions: supportive pattern, pattern supporting another explanation, or insufficient/discordant evidence. Document why. Avoid “looks functional” as the whole explanation.

Neither dramatic movement nor apparent stillness measures the full disability. Ask separately about injuries, recovery, repeated interruptions and assistance. See the symptom overview.

Explaining the Result

An editorial example:

“I am looking at the order and combination of changes, rather than deciding from one movement. Some findings support a functional seizure, but I also need to consider other seizure types and the part of the event we did not see.”

Explain which findings apply to this person. If the evidence is sufficient, give a specific diagnosis and rationale; if it is not, give a specific next step. The person should not have to infer certainty from a vague reassurance.

Evidence and Limitations

The 2022 meta-analysis included 14 studies, 800 people with epileptic seizures and 452 with functional/psychogenic nonepileptic seizures. Eye closure and asynchronous limb movements were the strongest pooled discriminators for functional events. Each estimate rested on only three studies. [2]

Definitions varied, most studies lacked blinded sign assessment, and epilepsy-monitoring-unit selection limits transfer to community practice. The analysis did not establish equivalent performance for subjective-only or still/unresponsive events, intellectual-disability populations or nonexpert observers. No sign was exclusive to either diagnosis. [2]

These findings support careful observation; they do not validate a universal sign-count rule. We have not reproduced accuracy estimates as a bedside calculator. The remaining inventory features retain their original citations and await separate detailed appraisal where needed.

Targeted update: October 1, 2026. Full-text methods, results and limitations of the synthesis were checked; its constituent primary studies were not all independently reappraised.

Media and Accessibility

A text timeline is the preferred teaching aid: onset → event → recovery, with missing observations labelled. Any illustrative scene should avoid suggesting that one posture or facial expression diagnoses FND.

Real recordings require consent, a text alternative and contextual explanation. Do not use flashing or looping seizure demonstrations. No media has been added.

Research and Sources

Current recommendations support event-level assessment. The synthesis addresses selected observed features; video-EEG guidance explains why those features must be interpreted with the recording and differential.

Citation	Figure	Full citation
[1]	—	Tolchin B, Goldstein LH, Reuber M, et al. Management of functional seizures practice guideline executive summary: report of the AAN Guidelines Subcommittee. Neurology. 2026;106(1):e214466. FND-CIT-0010. https://doi.org/10.1212/WNL.0000000000214466 AAN clinician summary.
[2]	—	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.
[3]	—	Whitehead K, Kane N, Wardrope A, Kandler R, Reuber M. Proposal for best practice in the use of video-EEG when psychogenic non-epileptic seizures are a possible diagnosis. Clinical Neurophysiology Practice. 2017;2:130–139. DOI. Full text. FND-CIT-0233.