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Table 1 Main semiological details distinguishing PNES from ES

From: The first-line management of psychogenic non-epileptic seizures (PNES) in adults in the emergency: a practical approach

Characteristic details

PNES

ES

Comments

General characteristics of the conversation analysis

Main theme of the seizure description

Patient emphasizes on the context of occurrence and the consequences of the episodes [22, 24]

Patient emphasizes on the description of the signs [22, 24]

Value is dependent of the patient’s level of cooperation

Answer when questioned about the most memorable event

Patient skipping the question or providing evasive answers [22]

Usually 2–3 memorable episodes are reported [22]

Value is dependent of patient’s level of cooperation

Emotional component of the conversation

Catastrophizing [24]

Tendency to dedramatize [24]

More valuable when the patient has a good social situation

Ictal features

Duration of the episodes

Usually, suspicious events longer than 5 min are PNES [40]

ES are usually shorter than 1–2 min

Consider the usual length of seizures thoroughly

Sleep occurrence (ES Sp = 100% [9])

No [9]

Episodes occurring during sleep are usually ES (or sleep disorders)

Low reliability of details based on history. V-EEG proof is important

Fluctuating intensity of the manifestations during a seizure (PNES Sp = 96% [9])

Usual for prolonged episodes (i.e. lasting more than 2 min) [9, 27]

Not usual, except in some cases of status epilepticus

In prolonged PNES, the patient is often able to respond to a gesture or word

Pelvic or whole-body thrusting (PNES Sp = 96–100% [9])

Yes, for episodes mimicking FBTCS [9, 10]

No for FBTCS. Could be seen in hyperkinetic ES (often frontal or anterior insular).

Here, the occurrence during sleep could help to eliminate PNES if this detail is reliable

Eye closure (PNES Sp = 74–100% [9])

If yes, most likely PNES [9, 10]

Eyes usually opened

Very good indicator, easily identifiable

Ability to respond to a gesture or a word during a seemingly convulsive episode

Could be able to answer

Unable to respond during focal with impaired awareness seizure or FBTCS

Relevant for bilateral convulsive events. Non-response state does not exclude PNES

Side to side head or body movement (PNES Sp = 96–100% [9])

Highly suggestive of PNES [9, 26, 40]

Usually, ictal turning in ES occur once or twice

Relevant for convulsion-like episodes

Ictal crying (PNES Sp = 100% [9])

Yes, sometimes (then combined with frustration gestures

Usually no. If they occur, they are noted prior to the convulsions

Could very rarely occur during ES but not during the convulsive phase

Post-ictal characteristics

Memory recall after a FBTCS-like episode (PNES Sp = 96% [9])

Typically preserved [21]

Usually, total amnesia of the episode or transient confusion [43]

Relevant for FBTCS and focal seizures with impaired awareness

Post-ictal confusion (ES Sp = 84–88% [9])

No (post-PNES fatigue may be confuse with confusion)

If yes, likely ES. May be surprisingly absent in frontal seizures with hypermotor semiology

Details often difficult to evaluate based on history

Breathing (ES Sp = 100% [9])

Tachypnea or apnea [44]

Bradypnea [44]

Stertorous breathing [44]

Relevant semiological value for bilateral convulsive episodes

Physical examination details

Induction test by nocebo effect

High value if positive. However, may be negative

Usually negative. May be positive by induction of PNES. However, true reflex ES may be triggered! [28]

A good suggestion is required. Rarely, the induction test may trigger PNES or ES in patients previously presenting only spontaneous ES [28]

Inhibition test by placebo effect

Possible intense response if experienced physician

Usually negative

The quality of the suggestion is crucial. Relevant in prolonged episodes

Paraclinical investigations

EEG

Interictal: normal

Ictal: normal

Inter-ictal: normal or epileptiform activity

Ictal: abnormal

Physiologic spikes can be wrongly interpreted and thus lead to a wrong diagnosis. Epileptiform spikes do not exclude PNES (mixed PNES/ES patients)

Prolactin level

Usually normal [32, 33]

High sensitivity for FBTCS (up to 100%) [33]

Relevant for bilateral convulsive episodes

  1. ES epileptic seizure, PNES psychogenic non-epileptic seizure, SE status epilepticus, FBTCS focal to bilateral tonic-clonic seizure, Sp specificity (%) for PNES or ES