Nonepileptic seizures

Definition

Paroxysmal events that appear similar to an epileptic seizure but do not involve abnormal, rhythmic discharges of neurons in the brain.

Types

Pseudo-seizure

Psychogenic seizures

Psychogenic seizures are real events and may not be under voluntary control

Differentiating NES from epileptic seizures

Feature	Epileptic seizure	NES
% males	72%	20%
Clonic UE movement	- In-phase: 96% - Out-of-phase: 0	- In-phase: 20% - Out-of-phase: 56%
Clonic LE movement	- In-phase: 88% - Out-of-phase: 0	- In-phase: 16% - Out-of-phase: 56%
Vocalizations	- None: 16% - Start of seizure: 24% - Middle: 60% “epileptic cry” - Types: only sounds of tonic/clonic respiratory muscle contraction	- None: 56% - Start of seizure: 44% - Middle: 0 - Types: moans, screams, grunts, snorts, gagging, retching, understandable statements, gasps
Head turning	- Unilateral: 64% - Side-to-side: 8% (slow, low amplitude)	- Unilateral: 16% - Side-to-side: 36% (violent, high amplitude)

Features often associated with NES

Frequent seizures despite therapeutic AEDs

Before

Suggestible or inducible seizures
Provoked with stimuli that would not cause a seizure (e.g. tuning fork to the head, alcohol pad to the neck, IV saline…)
Multiple or variable seizure types (ES is usually stereotypical), fluctuating level of consciousness, denial of correlation of seizure with stress

During

Arching of the back: 90% specific for NES
Fluctuating intensity and severity during seizure
Side-to-side rolling, pelvic thrusting, wild movements
Bilateral motor activity with preserved consciousness
Non-physiologic spread of neurologic signs
Disproportionate postictal mental status changes
Expression of relief or indifference
Crying or whimpering
Asynchronous movement

Intermittent arrhythmic and out-of-phase convulsive activity

Stop & go: seizures usually build and then gradually subside
Forced eye closing during entire seizure
Weeping (whining): highly specific
Bilateral shaking with preserved awareness.

Exception: supplementary motor area seizures (mesial frontal area)—these seizures are usually tonic (not clonic)

After

Absence of laboured breathing or drooling after generalized convulsion
No postictal confusion or lethargy

Multiple different-physician visits

Lingering prodrome or gradual ictal onset (over minutes)

Prolonged seizure duration (> 5 mins)

Manifestations altered by distraction

Features common to both

Verbal unresponsiveness,

Rarity of automatisms

Whole-body flaccidity

Rarity of urinary incontinence

More definitive findings

If any two of the following are demonstrated, 96% of time this will be NES:

Out-of-phase clonic UE movement
Out-of-phase clonic LE movement
No vocalization or vocalization at start of event

Lateral tongue laceration: very specific for seizures.

Tests

Minnesota Multiphasic Personality Inventory (MMPI) scales in hypochondriasis, depression hysteria, and schizophrenia

Chen 2005

Elevated serum prolactin assay, when measured in the appropriate clinical setting at 10 to 20 minutes after a suspected event, is a useful adjunct for the differentiation of generalized tonic–clonic or complex partial seizure from psychogenic nonepileptic seizure among adults and older children
Serum prolactin assay does not distinguish epileptic seizures from syncope
The use of serum PRL assay has not been established in the evaluation of status epilepticus, repetitive seizures, and neonatal seizures

Muscle enzyme studies

Events in children that can stimulate epileptic seizure

Event	Description
Reflex anoxic seizure (pallid Breath holding spell)	Common in young children, especially under 2 years. Unexpected stimulus (pain, shock, fright) causes excessive vagal activity—heart and respiration stops transiently and child becomes pale
Cyanotic breath holding spell	Reflex expiration in response to anger/frustration causes child to become cyanotic
Cardiogenic syncope	Syncope resulting from structural or functional cardiac abnormality—no convulsive movements associated
Cough syncope	Prolonged cough spasms (e.g. asthmatic, infection) can reduce venous return and lead to syncope with incontinence
Gastroesophageal reflux	Can lead to paroxysmal dystonic posturing associated with meals due to discomfort
Narcolepsy	Sudden loss of muscular tone secondary to cataplexy, usually an emotional trigger, no postictal state or loss of consciousness, EEG shows recurrent attacks of REM sleep
Night terrors	Brief nocturnal episodes of terror without typical convulsive movements, common in ages 4–6
Paroxysmal dyskinesias	Precipitated by sudden movement or startle, no associated change in consciousness
Paroxysmal vertigo	Common in toddlers, triggered by fright/crying—seen to stagger, fall and possibly vomit
Non-epileptiform attack disorder (pseudoseizure)	No EEG changes except movement artefact during episode
Rage attacks/Tantrum	Common in children aged 6–12 years, outburst is explosive and out of proportion to trigger (tantrums are goal directed)
Shuddering attack	Shiver-like movement of the trunk with associated stiffening, neck flexion and arm adduction, each episode lasts seconds and there is no change in consciousness
Vasovagal syncope (neurally mediated syncope)	Loss of consciousness triggered by postural change, heat or emotion; there is presyncopal dizziness, clouded/tunnel vision before a slow collapse
Tic	Involuntary, non-rhythmic, repetitive movements not associated with impaired consciousness

Non-epileptic 'status'

Many different types

Lie still
Prolonged events, waxing and waning
Thrashing
Shaking/tremor all over (rarely jerking)
Back arching

Drug effect

Benzodiazepine use may disinhibit!

Other features

Resisting eye opening
Injuries can occur during an attack
Recovery rapid

Risk factors

LD, young/middle aged, prev head injury, female gender, sexual/physical abuse, FHx epilepsy, depression

Non-convulsive status epilepticus (NCSE)

Nonconvulsive seizures (NCSz)

Purely electrographic seizures
Subtle clinical signs:

Face and limb twitching
Nystagmus
Eye deviation
Pupillary abnormalities
Autonomic instability
Negative clinical features

Hippus can occur in NCSE

Differential diagnosis

Category	Subtypes / Examples
Psychologic disorders (psychogenic seizures)	- Somatoform disorders: especially conversion disorder - Anxiety disorders: especially panic attacks and PTSD - Dissociative disorders - Psychotic disorders - Impulse control disorders - Attention-deficit disorders¹ - Factitious disorders (including Munchausen's syndrome)
Cardiovascular disorders	- Syncope - Cardiac arrhythmias - Transient ischemic attacks - Breath-holding spells¹
Migraine syndromes	- Complicated migraines¹ - Basilar migraines
Movement disorders	- Tremors - Dyskinesias - Tics¹, spasms - Other (including shivering)
Parasomnias & sleep-related	- Night terrors¹, nightmares¹, somnambulism¹ - Narcolepsy, cataplexy - Rapid eye movement behavior disorder - Nocturnal paroxysmal dystonia
Gastrointestinal disorders	- Episodic nausea or colic¹ - Cyclic vomiting syndrome¹
Other	- Malingering - Cognitive disorders with episodic behavioral or speech symptoms - Medication effects or toxicity - Daydreams¹

¹usually encountered in children

Psychogenic:

20–90% of patients with intractable seizures referred to epilepsy centers.
These patients carry the diagnosis of seizures from 5–7 years.
Up to 50% of these may have legitimate seizures at some time as well.

Tic:

Can be suppressed, is not repetitive
If repetitive, may be hemifacial spasm

Movement disorder: myoclonus (can be epileptic or non-epileptic)

Cataplexy: sudden muscular weakness triggered by strong emotions such as laughter, anger and surprise.

e.g. with narcolepsy often provoked by laughter or other emotional stimulus (can rarely be caught on EEG, and when it is, it shows REM intrusion into wakefulness)

Parasomnia: a group of sleep disorders that involve unwanted events or experiences (abnormal movements, behaviours, emotions, perceptions or dreams) that occur while you are falling asleep, sleeping or waking up.

Experiences

Night terrors (occurs in slow wave sleep, vs. nightmare which occurs in REM),
Sleep walking,
REM behaviour disorders (usually occurs in older men)

There is a high probability they will go on to have degenerative brain disease (used to be called paroxysmal nocturnal PNT).

Syncope:

90% of the time people who faint have myoclonic jerks or shaking