Paediatrics chapters
Epilepsy and antiepileptic drugs
Recurrent unprovoked seizures in children: how seizures are classified, the main childhood epilepsy syndromes with their EEG patterns, how to investigate, which drug suits which seizure, side effects and when to stop treatment.
- Epilepsy is recurrent unprovoked seizures (not due to fever or an acute brain insult); seizures are focal (simple if awake, complex if consciousness is impaired) or generalised (tonic-clonic, absence, myoclonic, atonic); EEG classifies them.
- Key syndromes: absence epilepsy (school age, many brief stares, 3 Hz spike-wave, ethosuximide), West syndrome (spasms, regression, hypsarrhythmia, ACTH or vigabatrin), Lennox-Gastaut (many seizure types, slow spike-wave, intellectual disability), juvenile myoclonic epilepsy (morning jerks, valproate for life), benign rolandic (sleep, face, outgrown).
- Use one drug matched to the seizure type (carbamazepine/oxcarbazepine for focal, valproate for generalised); most children can stop after 2 years without seizures.
On this page
Overview
A seizure is a sudden, short-lived disturbance of brain function from abnormal, excessive neuronal discharge, causing changes in movement, behaviour, sensation, autonomic function or consciousness. Epilepsy is recurrent unprovoked seizures, that is, seizures not caused by fever or an acute cerebral insult. Seizures affect about 4-10% of children at some time; about 0.5-2% have epilepsy, and most epilepsy begins in childhood.
Causes
- In about half of children no cause is found (idiopathic or genetic).
- Symptomatic epilepsy follows a fixed brain injury: hypoxic-ischaemic injury, intracranial haemorrhage, meningitis or encephalitis, head trauma, brain malformations (cortical dysplasia, lissencephaly).
- Neurocutaneous syndromes: tuberous sclerosis, neurofibromatosis, Sturge-Weber.
- Brain tumours, degenerative and metabolic diseases (including pyridoxine dependency).
- Acute symptomatic seizures (low glucose, calcium, sodium or magnesium; poisoning; infection; trauma) are not epilepsy.
Classification
| Group | Types | Consciousness |
|---|---|---|
| Focal (partial) | Simple partial (motor, sensory, autonomic, psychic) | Preserved |
| Complex partial | Impaired | |
| Focal with secondary generalisation | Lost when it spreads | |
| Generalised | Tonic-clonic, absence (typical, atypical), myoclonic, atonic, tonic, clonic, spasms | Lost (or brief lapse in absence) |
Generalised tonic-clonic (grand mal)
- The commonest convulsive seizure after infancy.
- May begin with an aura (in under a third); sudden loss of consciousness, fall, a cry as air is forced past the closed glottis, tonic stiffening with eyes rolled up, then clonic rhythmic jerking (usually under 5 minutes).
- Tongue biting, frothing, incontinence.
- Postictal sleep, confusion and headache; transient weakness of one side (Todd paralysis) implies a focal onset.
- In infancy seizures are mostly tonic.
Absence (petit mal)
- Usually begins at 4-6 years (rare before 5 in Akbar's account), commoner in girls, often outgrown by adolescence.
- Brief stares (under 15-30 seconds) with eyelid flutter, blinking, head nodding or simple automatisms; the child does not fall, may drop objects, then instantly resumes activity.
- Many attacks a day; parents or teachers notice day-dreaming and falling school work.
- Hyperventilation for 3-4 minutes or flashing lights provoke an attack.
- EEG: generalised 3 Hz (3 per second) spike-and-wave; neurological examination and imaging are normal.
Focal seizures
- Simple partial: awake throughout, usually motor (clonic jerks of face or limb), brief (10-20 seconds), no postictal phase; may spread steadily, for example face then arm then leg (Jacksonian march).
- Complex partial (temporal lobe or psychomotor): altered awareness, often an aura (fear, odd smell or taste, déjà vu), automatisms (lip smacking, chewing, swallowing, picking at clothes) in about half to three quarters; last 1-2 minutes; postictal tiredness; EEG shows anterior temporal spikes; MRI may show mesial temporal sclerosis.
- An aura always means a focal onset.
Absence versus complex partial seizure
| Feature | Absence | Complex partial |
|---|---|---|
| Duration | Seconds | Minutes |
| Frequency | Many per day | Infrequent |
| Aura | None | Common |
| Postictal state | None | Confusion, sleepiness |
| Provoked by | Hyperventilation, photic stimulation | Usually nothing |
| EEG | 3 Hz generalised spike-wave | Focal temporal discharges |
| First drug | Ethosuximide or valproate | Carbamazepine or oxcarbazepine |
Carbamazepine and oxcarbazepine can worsen absence seizures. Always distinguish absence from complex partial seizures before choosing a drug.
Epilepsy syndromes
| Syndrome | Age | Features | EEG | Treatment and outlook |
|---|---|---|---|---|
| West syndrome (infantile spasms) | 3-9 months (peak 3-8) | Clusters of brief flexor (salaam) or extensor spasms, often on waking; developmental regression | Hypsarrhythmia: chaotic high-voltage slow waves and spikes | ACTH, oral steroids, vigabatrin (choice in tuberous sclerosis); poor outlook if symptomatic (80-90% intellectual disability), better if cryptogenic |
| Lennox-Gastaut | 2-7 years | Many seizure types (atonic drop attacks, tonic, atypical absence), frequent falls and injuries, intellectual disability | Slow (under 3 Hz) spike-wave | Valproate, clobazam, lamotrigine, topiramate, rufinamide; poor response; lifelong |
| Childhood absence epilepsy | School age | Many daily absences | 3 Hz spike-wave | Ethosuximide (valproate if tonic-clonic seizures too); usually remits |
| Juvenile myoclonic epilepsy (Janz) | 12-16 years | Myoclonic jerks on waking (drops things), later tonic-clonic and absence seizures; normal examination | Generalised discharges | Valproate, lamotrigine; responds well but lifelong treatment |
| Benign rolandic epilepsy (centrotemporal spikes) | 3-10 years | Focal seizures of the face and arm, mostly in sleep, drooling, speech arrest while awake | Centrotemporal (rolandic) spikes | Good response; normal intellect; outgrown by puberty |
| Benign neonatal convulsions | End of the first week | Focal fits in well newborns ("fifth-day fits") | Variable | Excellent outcome |
| Landau-Kleffner | Young children | Sudden loss of language (auditory agnosia) | Epileptiform in sleep | Treatable; consider in autistic-like regression |
Hypsarrhythmia = West syndrome; 3 Hz spike-wave = absence; slow spike-wave + drop attacks + intellectual disability = Lennox-Gastaut; morning jerks in a teenager = JME.
"West = Wake-up salaams, Worsening development, Wild EEG."
An aura always means focal onset, and Todd paralysis after a fit also points to a focal origin.
Vigabatrin is the drug of choice for infantile spasms caused by tuberous sclerosis.
Non-epileptic events to exclude
Breath-holding spells, syncope, cardiac arrhythmia (long QT), night terrors, tics, benign sleep myoclonus, Sandifer syndrome (reflux), migraine variants, and psychogenic non-epileptic seizures (eyes closed, pelvic thrusting, no injury, no incontinence, can be stopped by suggestion; EEG normal during the event).
Diagnosis and investigations
- Epilepsy is a clinical diagnosis: a careful eye-witness history is the most useful tool. Ask about age at onset, frequency, triggers, aura, focal onset, postictal Todd paralysis, development and previous drugs.
- Examine the head size, dysmorphic features, skin (café-au-lait spots, ash-leaf macules for neurocutaneous syndromes) and fundi.
| Test | Use |
|---|---|
| EEG | Best test to confirm and classify seizures; a normal interictal EEG does not exclude epilepsy; video-EEG for unclear events |
| MRI | Better than CT for structural lesions; not needed in typical absence epilepsy or JME |
| CT | Quick emergency test for bleeding |
| Blood tests | Glucose, calcium, sodium, magnesium, toxicology for a first seizure if unwell; not needed in a well child with a normal examination |
| Lumbar puncture | Only if infection is suspected |
Management
Whether to treat
- After a first unprovoked seizure with normal development, examination, EEG and MRI, the recurrence risk is low (about 25%) and treatment is usually not started.
- With abnormal EEG, examination or development, or a family history, the risk is higher (up to over 90% when both EEG and examination are abnormal), and treatment is offered. Absence seizures, infantile spasms, atypical absence and atonic seizures are always treated.
Principles
- Use the drug of choice for the seizure type, one drug at a time, increasing until seizures stop or side effects appear. About 60% are controlled by the first drug.
- If it fails, add a second and withdraw the first gradually; never stop suddenly (risk of status epilepticus).
- Check drug levels (trough) when control is poor, toxicity is suspected or compliance is doubtful.
- Ketogenic diet for resistant seizures; epilepsy surgery for drug-resistant focal epilepsy.
Drug of choice
| Seizure type | First choice |
|---|---|
| Focal (simple, complex, secondarily generalised) | Carbamazepine or oxcarbazepine |
| Generalised tonic-clonic | Sodium valproate (also lamotrigine, levetiracetam) |
| Absence | Ethosuximide (valproate if tonic-clonic seizures coexist) |
| Juvenile myoclonic | Valproate, lamotrigine |
| Infantile spasms | ACTH or high-dose steroids; vigabatrin (tuberous sclerosis) |
| Lennox-Gastaut | Valproate, clobazam, lamotrigine, topiramate, rufinamide |
| Neonatal seizures | Phenobarbitone |
Common antiepileptic drugs
| Drug | Notes and side effects |
|---|---|
| Phenobarbitone | Cheap and effective; useful in neonates and status; drowsiness, hyperactivity, aggression, learning problems: avoid in school children |
| Phenytoin | Not sedating; gum hypertrophy, hirsutism, megaloblastic anaemia, agranulocytosis, rash, ataxia, diplopia, tremor; avoid long-term use in girls; good dental hygiene helps |
| Sodium valproate | Broad spectrum; raises brain GABA; nausea, weight gain, hair loss, low platelets, hepatotoxicity; avoid under about 18 months and in liver disease; monitor blood count and liver tests |
| Carbamazepine | Focal seizures; dizziness, diplopia, ataxia, rash, low white cells and platelets, SIADH; can worsen absence |
| Ethosuximide | Absence only |
| Lamotrigine | Broad spectrum; rash, dizziness, diplopia, ataxia; increase the dose slowly and use a lower dose with valproate |
| Clonazepam, clobazam, nitrazepam | Myoclonic seizures, infantile spasms, Lennox-Gastaut |
| Vigabatrin | Infantile spasms, especially tuberous sclerosis |
Phenobarbitone suits neonates but harms behaviour and learning in school-age children; phenytoin causes cosmetic problems in girls.
Stopping treatment
- Most children can be weaned after 2 years without seizures, tapering slowly; about 70-75% have no further seizures. An EEG is usually done first; an abnormal EEG may delay withdrawal.
- Juvenile myoclonic epilepsy, Lennox-Gastaut and progressive myoclonic epilepsy need lifelong treatment.
Living with epilepsy
- Explain the condition and the long course; encourage normal life and school.
- Supervised swimming and bathing only (drowning risk), helmets for cycling, no locked bathroom doors, avoid sleep loss.
- Do not stop drugs during fever or illness.
- Driving rules depend on national law and require a period without seizures.
Expect: definition of epilepsy; simple versus complex partial seizures; absence versus complex partial table; 3 Hz spike-wave and hyperventilation; West syndrome triad, hypsarrhythmia, ACTH and vigabatrin with tuberous sclerosis; Lennox-Gastaut triad; JME with morning jerks and lifelong valproate; benign rolandic epilepsy in sleep; drug of choice for each seizure type; side effects of phenytoin, valproate, carbamazepine and phenobarbitone; carbamazepine worsening absence; when to start and stop treatment; EEG as the key test.
Quick revision
- Epilepsy: recurrent unprovoked seizures; diagnosis is clinical, EEG classifies.
- Focal: simple (aware) or complex (impaired); aura means focal onset; Todd paralysis.
- Absence: brief, many daily, no postictal phase, 3 Hz spike-wave, ethosuximide.
- West: spasms, regression, hypsarrhythmia; ACTH, steroids, vigabatrin.
- Lennox-Gastaut: many seizure types, slow spike-wave, intellectual disability.
- JME: teenage morning jerks; valproate for life. Rolandic: sleep, face; outgrown.
- Focal: carbamazepine or oxcarbazepine; generalised: valproate.
- Phenytoin: gums, hair, ataxia. Valproate: liver, weight, hair loss, platelets.
- Stop after 2 years without seizures, slowly.
Written by The House Job from standard references (Basis of Paediatrics by Pervez Akbar; Nelson Essentials of Paediatrics).
FAQ
How do I tell an absence seizure from day-dreaming?
Absences start and stop suddenly, happen many times a day, cannot be interrupted by calling or touching the child, and are often brought on by hyperventilation. The EEG shows 3 Hz spike-and-wave.
Should every child be treated after a first seizure?
No. If development, examination, EEG and imaging are normal the recurrence risk is low and treatment is usually deferred. Treatment is advised when these are abnormal or seizures recur.
Which drug is used for infantile spasms?
ACTH or high-dose oral steroids, or vigabatrin. Vigabatrin is preferred when the spasms are due to tuberous sclerosis.
When can antiepileptic drugs be stopped?
Most children can taper off after two years without seizures, slowly and usually after an EEG. Juvenile myoclonic epilepsy and Lennox-Gastaut syndrome need lifelong treatment.