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 ~20β30% 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- Terminology: "Pseudoseizures" is an outdated term typically referring to Psychogenic Non-Epileptic Seizures (PNES).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 β 3 Years)
- Breath-Holding Spells (BHS):
- Cyanotic Type (60%): Triggered by anger/frustration
expiratory apnea cyanosis loss of consciousness generalized stiffening/jerks. - Pallid Type: Triggered by pain/fear
vagal bradycardia/asystole pallor collapse (syncope).
- Cyanotic Type (60%): Triggered by anger/frustration
- 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 (> 5β10 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 10β20 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) β 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 4β5). Oral Iron therapy (
) 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.
- Breath-Holding Spells: Reassurance (benign, self-limiting by age 4β5). Oral Iron therapy (