Pediatric Epilepsy Syndromes & Paroxysmal Events
Age, semiology, and EEG name the syndrome — and the syndrome picks the drug
Thinking in syndromes
Why syndromes matter. Pediatric epilepsy syndromes are defined by age at onset, seizure type, EEG pattern, and developmental course. Naming the syndrome predicts prognosis and selects the drug. Sodium-channel blockers (carbamazepine, oxcarbazepine, phenytoin) help focal epilepsies but can worsen absence, myoclonic, and Dravet seizures.
| Syndrome | Onset and clues | EEG | Treatment |
|---|---|---|---|
| Infantile spasms (West) | 3–12 months; clustered spasms on waking, regression | Hypsarrhythmia | ACTH or high-dose prednisolone; vigabatrin for TSC |
| Childhood absence | 4–10 years; many 5–10-second stares | Generalized 3-Hz spike-and-wave | Ethosuximide |
| Juvenile myoclonic | 12–18 years; morning jerks, GTCs | 4–6-Hz polyspike-and-wave, photosensitive | Levetiracetam, lamotrigine, or valproate; lifelong |
| Centrotemporal spikes | ~4–10 years; nocturnal facial seizures, drooling | Sleep-activated centrotemporal spikes | Often none; remits by adolescence |
| Lennox-Gastaut | 1–8 years; tonic, atonic, atypical absence seizures; intellectual disability | Slow (<2.5-Hz) spike-and-wave | Valproate, rufinamide, clobazam, cannabidiol; diet, VNS, callosotomy |
| Dravet | First year; prolonged febrile seizures; SCN1A | Often normal early | Valproate, clobazam, stiripentol, fenfluramine; no sodium-channel blockers |
Infantile spasms
Presentation. Spasms begin at 3–12 months as brief, symmetric flexion ("jackknife") or extension of the neck, trunk, and limbs in clusters, often on waking. They are easily mistaken for colic, reflux, or startles. West syndrome is the triad of spasms, hypsarrhythmia (a chaotic, high-voltage EEG with multifocal spikes), and developmental arrest or regression. Suspected spasms warrant an urgent EEG, because delayed treatment worsens developmental outcome.
Causes and work-up. Tuberous sclerosis is a leading identifiable cause; others include hypoxic-ischemic injury, brain malformations, perinatal stroke, Down syndrome, infections, and metabolic or genetic disorders such as CDKL5. Evaluate with brain MRI, a Wood lamp skin exam for ash-leaf macules, genetic and metabolic testing, and an echocardiogram for cardiac rhabdomyomas when tuberous sclerosis (TSC1/TSC2) is suspected.
Treatment. ACTH or high-dose oral prednisolone is first-line; vigabatrin, an irreversible GABA transaminase inhibitor, is preferred for tuberous sclerosis and requires monitoring for irreversible peripheral visual field loss. Success means cessation of spasms and resolution of hypsarrhythmia. Many children go on to other epilepsies, including Lennox-Gastaut, and intellectual disability.
Absence and juvenile myoclonic epilepsy
Childhood absence epilepsy. Onset is at ages 4–10, more often in girls. Abrupt 5–10-second stares with eyelid fluttering occur many times a day without aura or postictal confusion, and are often mislabeled as daydreaming or ADHD. Hyperventilation for 3–5 minutes provokes a spell, and the EEG shows generalized 3-Hz spike-and-wave. Ethosuximide, which blocks T-type calcium channels in thalamic neurons, is first-line; in the NIH childhood absence trial it matched valproate for seizure control with fewer attention problems, and lamotrigine was least effective. Valproate is chosen when generalized tonic-clonic seizures coexist. Carbamazepine, oxcarbazepine, phenytoin, gabapentin, and vigabatrin can worsen absences. Most children outgrow the disorder by adolescence.
Absence vs focal impaired awareness seizure: absences last seconds, occur many times a day, and end abruptly; focal seizures last 1–2 minutes, often start with an aura, include automatisms, leave postictal confusion, and warrant MRI.
Juvenile myoclonic epilepsy. Onset is at ages 12–18 with myoclonic jerks of the arms within an hour of waking (a dropped toothbrush or spilled cereal), generalized tonic-clonic seizures in most patients, and sometimes absences. Sleep deprivation, alcohol, and flashing lights are triggers. The EEG shows generalized 4–6-Hz polyspike-and-wave with photosensitivity; the neurologic exam is normal.
Treating JME. Valproate is the most effective drug but is teratogenic (neural tube defects, lower IQ), so females of childbearing potential start levetiracetam or lamotrigine and take folic acid. Carbamazepine, oxcarbazepine, and phenytoin can aggravate myoclonus. Therapy is usually lifelong because relapse after withdrawal is common; regular sleep and limited alcohol reduce seizures.
Other childhood syndromes
Self-limited epilepsy with centrotemporal spikes. Formerly benign rolandic epilepsy, this is the most common focal epilepsy of childhood, beginning at about 4–10 years. Seizures arise from sleep with one-sided facial twitching, tingling, drooling, and speech arrest while awareness is preserved; some generalize. Development and MRI are normal, and it remits by adolescence. Because seizures are infrequent and nocturnal, many children need no daily medication.
Lennox-Gastaut syndrome. Onset is at 1–8 years (peak 3–5), often evolving from infantile spasms or brain injury. Hallmarks are multiple seizure types (tonic seizures in sleep, atonic drop attacks with injuries, atypical absences), slow spike-and-wave below 2.5 Hz, and intellectual disability. It is drug-resistant; options include valproate, lamotrigine, rufinamide, clobazam, cannabidiol, and fenfluramine, plus the ketogenic diet, vagus nerve stimulation, or corpus callosotomy for drop attacks.
Dravet syndrome. Usually a de novo SCN1A loss-of-function variant, which mainly silences inhibitory interneurons. It begins in the first year with prolonged febrile or hemiclonic seizures triggered by fever, warm baths, or vaccines, followed by myoclonic and other seizures, developmental slowing after age 1–2, and a high risk of sudden unexpected death in epilepsy. Treatment uses valproate, clobazam, stiripentol, cannabidiol, or fenfluramine with a rescue benzodiazepine plan.
Sodium-channel blockers (carbamazepine, oxcarbazepine, phenytoin, lamotrigine) worsen Dravet syndrome by further disinhibiting the cortex.
Neonatal seizures
Recognition. Neonatal seizures are often subtle: lip smacking, bicycling, eye deviation, or apnea, as well as clonic or tonic events. Jitteriness, by contrast, is stimulus-sensitive, stops with gentle restraint, and lacks eye deviation or autonomic change. Many neonatal seizures are electrographic only, so continuous video-EEG confirms them.
Causes. Hypoxic-ischemic encephalopathy is the most common, typically in the first 24–48 hours, followed by stroke or intracranial hemorrhage, hypoglycemia, hypocalcemia, hypomagnesemia, hyponatremia, meningitis or HSV, inborn errors of metabolism, and pyridoxine-dependent epilepsy.
- Point-of-care glucose, then Ca, Mg, NaCorrect whatever is low.
- Infection work-upBlood culture, lumbar puncture, HSV testing, empiric antimicrobials.
- Video-EEG and imagingConfirm seizures; MRI for HIE, stroke, or malformation.
- PhenobarbitalFirst-line antiseizure drug.
- Refractory seizuresIV pyridoxine trial during EEG for pyridoxine-dependent epilepsy.
Paroxysmal events that mimic seizures
| Event | Key features | Action |
|---|---|---|
| Cyanotic breath-holding | 6–18-month onset; anger → crying → expiratory apnea, cyanosis, limpness, brief jerks | Reassure; CBC and ferritin (iron reduces spells) |
| Pallid breath-holding | Pain or fright → vagal bradycardia, pallor | Reassure; iron studies; ECG to exclude long QT |
| Night terrors | Ages ~3–7; first third of night, deep non-REM; inconsolable, no recall | Reassure |
| Benign neonatal sleep myoclonus | Jerks only in sleep, stop on waking; normal EEG | Reassure; resolves within months |
| Syncope | Trigger and prodrome; seconds of jerking; rapid recovery | ECG; exertional syncope needs cardiac evaluation |
| Tics | Brief, stereotyped, suppressible; premonitory urge | Reassure; behavioral therapy if impairing |
| Sandifer syndrome | Back arching and neck twisting with feeds | Treat gastroesophageal reflux |