Paroxysmal Non-Epileptic Events

1. Definition

• Paroxysmal Non-Epileptic Events (PNEEs): Episodes of behavioral, motor, or sensory changes that resemble epileptic seizures but are not generated by abnormal cortical electrical discharges.
• Misdiagnosis: Occurs in ~20–30% of children referred to epilepsy centers.
• Terminology: “Pseudoseizures” is an outdated term typically referring to Psychogenic Non-Epileptic Seizures (PNES). PNEEs encompass both psychogenic and physiologic mimics.

2. Classification and Etiology (Age-Dependent Approach)

A. Neonates and Early Infancy (< 6 Months)

• Jitteriness: Stimulus-sensitive, high-frequency tremor; ceases with passive flexion/restraint. No autonomic changes or eye deviation.
• Benign Neonatal Sleep Myoclonus: Rhythmic jerks of limbs only during sleep (NREM). Ceases immediately upon arousal. EEG is normal.
• Sandifer Syndrome: Spasmodic torsional dystonia with arching of the back (opisthotonos) associated with Gastroesophageal Reflux (GERD). Often mistaken for infantile spasms.
• Hyperekplexia (Startle Disease): Exaggerated startle response to tactile/auditory stimuli followed by generalized stiffness.

B. Infancy and Toddlers (6 Months – 3 Years)

• Breath-Holding Spells (BHS):
  • Cyanotic Type (60%): Triggered by anger/frustration $\to$ expiratory apnea $\to$ cyanosis $\to$ loss of consciousness $\to$ generalized stiffening/jerks.
  • Pallid Type: Triggered by pain/fear $\to$ vagal bradycardia/asystole $\to$ pallor $\to$ collapse (syncope).
• Shuddering Attacks: Rapid, shivering-like movements of head/shoulders; child is fully conscious. Often familial; associated with Essential Tremor trait.
• Infantile Masturbation (Gratification Disorder): Stereotyped tonic posturing of lower limbs, rocking, grunting, flushing. No loss of consciousness; distractible.

C. Childhood and Adolescence (> 3 Years)

• Syncope (Neurocardiogenic/Vasovagal):
  • Most common mimic. Triggered by standing, heat, pain.
  • Prodrome: Lightheadedness, visual blurring (“tunnel vision”), pallor, diaphoresis.
  • Convulsive Syncope: Brief tonic stiffening or myoclonus due to cerebral hypoperfusion (not epilepsy). Rapid recovery.
• Psychogenic Non-Epileptic Seizures (PNES):
  • Subconscious conversion disorder (somatoform) or malingering.
  • Common in adolescents; female predominance; history of sexual/physical abuse or psychosocial stress.
• Sleep Disorders (Parasomnias):
  • Night Terrors: NREM sleep (first 1/3 of night). Screaming, autonomic arousal, inconsolable, amnesia of event.
  • Narcolepsy-Cataplexy: Sudden loss of tone triggered by emotion (laughter).
• Migraine Variants: Confusional migraine, Alice-in-Wonderland syndrome (visual distortions), cyclical vomiting.

3. Clinical Features: Differentiating PNES from Epilepsy

Feature	Epileptic Seizures (ES)	Psychogenic Non-Epileptic Seizures (PNES)
Eyes	Usually OPEN; deviated	Usually CLOSED; resistance to opening
Movements	Stereotyped, synchronous, rhythmic clonic jerking	Asynchronous, thrashing, waxing/waning, pelvic thrusting, side-to-side head shaking
Duration	Typically < 2 minutes	Often prolonged (> 5–10 minutes)
Vocalization	Ictal cry (initial); otherwise quiet	Stuttering, weeping, shouting, intelligible speech
Incontinence	Common	Rare
Injury	Tongue biting (lateral), falls	Tongue biting (tip/lip), rare severe injury
Post-ictal	Confusion, sleep, lethargy	Rapid return to baseline; memory of event often preserved
Induction	Rare by suggestion	Can often be induced by suggestion (e.g., hyperventilation, photic)

4. Investigations

• History (The Diagnostic Cornerstone): Detailed description of the event, triggers, eye position, and recovery. Home video recording (smartphone) is invaluable.
• Electroencephalogram (EEG):
  • Interictal EEG: Normal in PNEEs (though incidental anomalies occur in 5% of normals).
  • Video-EEG Telemetry (Gold Standard): Capturing the event confirms diagnosis. In PNES, background remains normal alpha rhythm during “unresponsiveness” or violent movements (absence of muscle artifact allows visualization).
• ECG: Mandatory to rule out Long QT syndrome or arrhythmia (cardiac syncope).
• Laboratory:
  • Serum Prolactin: Elevated 10–20 mins after true GTCS; normal in PNES (low sensitivity).
  • Iron profile: Iron deficiency anemia associated with severe Breath-Holding Spells.
• Neuroimaging (MRI): Usually normal; indicated if structural pathology suspected.

5. Management

• General Principles:
  • Avoid unnecessary Antiepileptic Drugs (AEDs) – can cause side effects and reinforce the “sick role.”
  • Compassionate communication of the diagnosis (do not say “faking it”).
• Specific Therapies:
  • Breath-Holding Spells: Reassurance (benign, self-limiting by age 4–5). Oral Iron therapy ($6mg/kg/day$) reduces frequency even in non-anemic children.
  • Syncope: Hydration, salt intake, counter-pressure maneuvers, recognition of prodrome.
  • Sandifer Syndrome: Anti-reflux medication (PPIs), positioning.
  • PNES:
    • Referral to Psychology/Psychiatry.
    • Cognitive Behavioral Therapy (CBT): Mainstay of treatment.
    • Identification and relief of underlying stressors (school, family, abuse).
    • Weaning of AEDs if previously started.