Clinical Approach to Seizures
Pediatric Comprehensive Framework1. Symptom Overview
Understanding the clinical significance and classification of seizures in children
Seizures are among the most common neurological emergencies in pediatric practice, affecting approximately 4-10% of children by age 16. Febrile seizures alone occur in 2-5% of children between 6 months and 5 years of age, making them the most common type of childhood seizure. Epilepsy, defined as recurrent unprovoked seizures, affects approximately 0.5-1% of children worldwide, with the highest incidence occurring in the first year of life. Seizures account for approximately 1-2% of all pediatric emergency department visits and represent a significant source of parental anxiety and healthcare utilization.
Definition
A seizure is a transient occurrence of signs and/or symptoms resulting from abnormal excessive or synchronous neuronal activity in the brain. It represents a sudden, uncontrolled electrical disturbance that can cause changes in behavior, movements, feelings, and levels of consciousness. In children, the clinical manifestation varies significantly based on age, brain maturation, and the location and extent of abnormal neuronal discharge.
Key Epidemiology
- Incidence: 25-60 per 100,000 children per year
- Febrile seizures: 2-5% of children aged 6 months to 5 years
- Epilepsy prevalence: 0.5-1% of children
- Peak incidence: First year of life
- Status epilepticus: 10-40 per 100,000 children per year
- First unprovoked seizure: 30% risk of recurrence within 2 years
Classification by Seizure Type (ILAE 2017)
The International League Against Epilepsy (ILAE) 2017 classification provides a standardized framework for categorizing seizures based on onset, awareness, and motor versus non-motor manifestations.
| Onset Type | Subcategory | Key Features | Common Pediatric Examples |
|---|---|---|---|
| Focal Onset | Aware (simple partial) | Consciousness preserved; motor, sensory, autonomic, or psychic symptoms | Benign rolandic epilepsy, focal motor seizures |
| Impaired awareness (complex partial) | Altered consciousness; automatisms common | Temporal lobe epilepsy, mesial temporal sclerosis | |
| Focal to bilateral tonic-clonic | Begins focally, then generalizes | Structural lesions, focal cortical dysplasia | |
| Motor vs Non-motor | Clonic, tonic, myoclonic, or sensory, cognitive, emotional | Various focal epilepsy syndromes | |
| Generalized Onset | Tonic-clonic (grand mal) | Bilateral stiffening then rhythmic jerking; postictal confusion | Juvenile myoclonic epilepsy, genetic generalized epilepsies |
| Absence (petit mal) | Brief staring spells; abrupt onset and offset; minimal postictal state | Childhood absence epilepsy (4-8 years peak) | |
| Myoclonic | Brief, shock-like jerks; may be single or repetitive | Juvenile myoclonic epilepsy, Dravet syndrome | |
| Atonic (drop attacks) | Sudden loss of muscle tone; falls | Lennox-Gastaut syndrome, myoclonic-atonic epilepsy | |
| Unknown Onset | Unclassified | Insufficient information to classify | Unwitnessed seizures, incomplete history |
Classification by Duration
| Category | Duration | Clinical Significance | Management Implications |
|---|---|---|---|
| Self-limited seizure | Less than 5 minutes | Most seizures terminate spontaneously; low risk of neuronal injury | Supportive care; rescue medication typically not required |
| Prolonged seizure | 5-30 minutes | Increased risk of progression to status epilepticus; may require intervention | Administer rescue benzodiazepine after 5 minutes of continuous seizure activity |
| Status epilepticus | Greater than 5 minutes (operational) or greater than 30 minutes (traditional) | Medical emergency; risk of permanent neuronal injury increases with duration | Emergency treatment protocol; IV access; escalating antiseizure therapy |
| Refractory status epilepticus | Persists despite two appropriate antiseizure medications | High morbidity and mortality; may require ICU admission | Continuous infusion of anesthetic agents; EEG monitoring |
Updated Definition of Status Epilepticus
The operational definition of status epilepticus has been revised to 5 minutes of continuous seizure activity or recurrent seizures without return to baseline. This earlier threshold reflects evidence that seizures lasting beyond 5 minutes are unlikely to self-terminate and that earlier treatment improves outcomes. In children, the 5-minute rule should prompt administration of first-line benzodiazepine therapy.
Classification by Etiology
Provoked (Acute Symptomatic) Seizures
Seizures occurring in close temporal relationship to an acute central nervous system insult or systemic disturbance:
- Febrile seizures — most common provoked seizure in children
- Metabolic disturbances — hypoglycemia, hyponatremia, hypocalcemia
- Central nervous system infections — meningitis, encephalitis
- Traumatic brain injury — within 7 days of injury
- Toxic exposures — medications, drugs, environmental toxins
- Acute stroke or intracranial hemorrhage
Unprovoked Seizures
Seizures occurring without an identifiable acute precipitant:
- Genetic/Idiopathic epilepsy — childhood absence, juvenile myoclonic epilepsy
- Structural — cortical malformations, tumors, mesial temporal sclerosis
- Metabolic — inborn errors of metabolism (chronic)
- Immune — autoimmune encephalitis
- Infectious — post-infectious epilepsy
- Unknown — no identifiable cause despite workup
Age-Specific Seizure Patterns
The clinical manifestation of seizures varies dramatically with age due to differences in brain maturation, myelination, and neuronal connectivity.
| Age Group | Common Seizure Types | Typical Presentations | Important Considerations |
|---|---|---|---|
| Neonates (0-28 days) | Subtle, tonic, clonic, myoclonic | Lip smacking, eye deviation, bicycling movements, apnea, desaturation | Often subtle and difficult to recognize; high index of suspicion needed; EEG confirmation often required |
| Infants (1-12 months) | Infantile spasms, focal seizures, febrile seizures (after 6 months) | Clusters of brief flexor or extensor spasms; subtle behavioral arrest | Infantile spasms are a medical emergency requiring urgent EEG; West syndrome triad |
| Toddlers (1-3 years) | Febrile seizures, generalized tonic-clonic, focal seizures | Generalized stiffening and shaking with fever; focal motor activity | Peak age for febrile seizures; distinguish simple from complex febrile seizures |
| Preschool (3-5 years) | Febrile seizures, absence seizures emerging, focal epilepsies | Staring spells; brief unresponsiveness; generalized convulsions | Absence seizures may be mistaken for inattention; upper age limit for febrile seizures |
| School age (6-12 years) | Childhood absence epilepsy, benign rolandic epilepsy, focal seizures | Frequent brief staring spells; nocturnal focal motor seizures with drooling | Childhood absence epilepsy peaks at 4-8 years; benign rolandic epilepsy peaks at 7-10 years |
| Adolescents (12-18 years) | Juvenile myoclonic epilepsy, juvenile absence epilepsy, focal epilepsies | Morning myoclonic jerks; generalized tonic-clonic seizures on awakening | Sleep deprivation and alcohol are common triggers; lifelong treatment often needed for juvenile myoclonic epilepsy |
Febrile Seizures: Special Considerations
Febrile seizures deserve special attention given their high prevalence and the anxiety they cause families.
| Feature | Simple Febrile Seizure | Complex Febrile Seizure |
|---|---|---|
| Duration | Less than 15 minutes | Greater than 15 minutes |
| Seizure type | Generalized | Focal features present |
| Recurrence in 24 hours | Does not recur | May recur within 24 hours |
| Postictal state | Brief (less than 1 hour) | Prolonged or focal deficits (Todd paralysis) |
| Age | 6 months to 5 years | Any age with fever, but features suggest underlying pathology |
| Recurrence risk | Approximately 30% overall | Higher recurrence risk; increased epilepsy risk |
| Epilepsy risk | Approximately 1-2% (slightly above general population) | 4-15% depending on features |
Key Concept: The “3 Cs” of Pediatric Seizure Evaluation
- Characterize — Define the seizure type (focal vs generalized, motor vs non-motor, awareness)
- Cause — Identify provoked versus unprovoked; determine underlying etiology
- Consequences — Assess risk of recurrence, impact on development, and need for treatment
2. Pathophysiology and Mechanisms
Understanding the underlying mechanisms of seizures in the developing brain
Seizures result from an imbalance between excitatory and inhibitory neurotransmission in the brain, leading to abnormal hypersynchronous neuronal firing. In the developing pediatric brain, unique maturational factors create increased seizure susceptibility compared to adults. Understanding these mechanisms is essential for rational diagnostic and therapeutic approaches.
The Seizure Threshold Concept
Every brain has an inherent “seizure threshold” — the point at which the balance between excitation and inhibition tips toward uncontrolled neuronal firing. Seizures occur when factors lower this threshold (proconvulsant) or when excitatory inputs exceed the threshold capacity.
Factors That Lower Seizure Threshold
- Fever (most significant in children)
- Sleep deprivation
- Metabolic disturbances (hypoglycemia, hyponatremia)
- Certain medications (tramadol, bupropion, fluoroquinolones)
- Alcohol or benzodiazepine withdrawal
- Photic stimulation (in susceptible individuals)
- Hyperventilation
- Stress and emotional factors
Factors That Raise Seizure Threshold
- Antiseizure medications
- Adequate sleep
- Metabolic homeostasis
- Ketogenic diet (increases GABA, decreases glutamate)
- Vagus nerve stimulation
- Normal body temperature
- Avoidance of known triggers
Neuronal Excitation and Inhibition
| Component | Mechanism | Clinical Relevance |
|---|---|---|
| Glutamate (Excitatory) | Primary excitatory neurotransmitter; acts on NMDA, AMPA, and kainate receptors; causes neuronal depolarization via sodium and calcium influx | Excessive glutamatergic activity leads to seizures; excitotoxicity causes neuronal injury in prolonged seizures; NMDA receptor antagonists (ketamine) can terminate refractory status epilepticus |
| GABA (Inhibitory) | Primary inhibitory neurotransmitter; GABA-A receptors cause chloride influx and hyperpolarization; GABA-B receptors cause potassium efflux | Benzodiazepines and barbiturates enhance GABA-A function; first-line treatment for status epilepticus; GABA-A receptor internalization occurs with prolonged seizures, reducing benzodiazepine efficacy |
| Voltage-gated sodium channels | Responsible for action potential generation and propagation; mutations cause channelopathies | Target of many antiseizure medications (phenytoin, carbamazepine, lamotrigine); SCN1A mutations cause Dravet syndrome |
| Voltage-gated calcium channels | T-type calcium channels involved in thalamocortical oscillations generating absence seizures | Ethosuximide blocks T-type calcium channels; first-line for childhood absence epilepsy |
| Potassium channels | Responsible for repolarization; mutations cause neonatal epilepsies | KCNQ2/KCNQ3 mutations cause benign familial neonatal seizures; ezogabine opens potassium channels |
The Immature Brain: Why Children Are More Susceptible
The pediatric brain has several developmental features that increase seizure susceptibility compared to the mature adult brain.
| Developmental Factor | Mechanism | Clinical Implication |
|---|---|---|
| Excitatory GABA in early life | GABA is depolarizing (excitatory) in neonates due to high intracellular chloride; switches to inhibitory by 2-3 months | Benzodiazepines may be less effective in neonates; phenobarbital (enhances chloride conductance regardless of gradient) may be preferred |
| Increased NMDA receptor expression | Higher density of NMDA receptors in developing brain for synaptic plasticity and learning | Greater excitability; increased susceptibility to excitotoxic injury during prolonged seizures |
| Incomplete myelination | Myelination continues until early adulthood; incomplete insulation of axons | Altered seizure propagation patterns; different semiology by age; “subtle” seizures more common in neonates |
| Immature blood-brain barrier | More permeable blood-brain barrier in young infants | Increased vulnerability to systemic metabolic disturbances; some medications penetrate better |
| Temperature sensitivity | Immature thermoregulation; rapid temperature changes affect neuronal excitability | Febrile seizures are unique to childhood; fever dramatically lowers seizure threshold in young children |
| Ongoing synaptogenesis | Rapid synaptic formation and pruning during critical periods | Seizures during development may disrupt normal brain wiring; potential for cognitive impact |
Clinical Pearl: GABA Paradox in Neonates
In neonates, GABA acts as an excitatory neurotransmitter because the chloride gradient is reversed (high intracellular chloride due to immature potassium-chloride co-transporter KCC2). This explains why benzodiazepines may paradoxically worsen neonatal seizures in some cases and why phenobarbital is often preferred as first-line treatment in this age group. The switch from excitatory to inhibitory GABA signaling occurs around 2-3 months of age.
Mechanisms by Condition
| Condition | Pathophysiological Mechanism | Treatment Implication |
|---|---|---|
| Febrile seizures | Fever increases neuronal excitability through temperature-sensitive ion channels and inflammatory cytokines (interleukin-1β); immature thermoregulation and myelination contribute | Antipyretics do not prevent febrile seizures (temperature change rate matters more than peak); benzodiazepines for prolonged febrile seizures |
| Infantile spasms (West syndrome) | Dysfunction of the hypothalamic-pituitary-adrenal axis; excess corticotropin-releasing hormone (CRH) in immature brain causes spasms; multiple etiologies converge on this pathway | ACTH or vigabatrin are first-line treatments (ACTH suppresses CRH); vigabatrin especially effective for tuberous sclerosis |
| Childhood absence epilepsy | Abnormal thalamocortical circuit oscillations; T-type calcium channels in thalamic relay neurons generate 3 Hz spike-and-wave discharges | Ethosuximide blocks T-type calcium channels; valproate also effective; carbamazepine and phenytoin may worsen absences |
| Benign rolandic epilepsy | Focal hyperexcitability in centrotemporal (rolandic) cortex; age-dependent expression related to cortical maturation; genetic predisposition | Often does not require treatment; resolves by adolescence; if treated, levetiracetam or carbamazepine are options |
| Dravet syndrome | SCN1A mutation causes loss of function in sodium channels of inhibitory interneurons, leading to disinhibition and hyperexcitability; fever-sensitive | Sodium channel blockers (carbamazepine, phenytoin, lamotrigine) are contraindicated; valproate, clobazam, stiripentol, cannabidiol, fenfluramine are used |
| Hypoglycemic seizures | Glucose is the brain’s primary energy substrate; hypoglycemia causes neuronal energy failure and membrane depolarization; also impairs GABA synthesis | Immediate glucose administration (2 mL/kg of D10W in infants); investigate underlying cause; seizures resolve with normoglycemia |
| Hyponatremic seizures | Rapid decrease in serum sodium causes water shift into neurons (cerebral edema); neuronal swelling and membrane instability trigger seizures | Hypertonic saline (3%) to raise sodium 4-6 mEq/L acutely; avoid overcorrection (osmotic demyelination syndrome) |
| Hypocalcemic seizures | Calcium stabilizes neuronal membranes; hypocalcemia increases membrane excitability and lowers seizure threshold | IV calcium gluconate 10% (1-2 mL/kg); monitor for cardiac effects; investigate underlying cause (hypoparathyroidism, vitamin D deficiency) |
| Pyridoxine-dependent epilepsy | ALDH7A1 mutation causes accumulation of toxic metabolites that inactivate pyridoxal phosphate (active vitamin B6), which is essential for GABA synthesis | Pyridoxine trial (100 mg IV) for any treatment-resistant neonatal seizures; lifelong pyridoxine supplementation required |
Phases of a Seizure
| Phase | Description | Clinical Features |
|---|---|---|
| Prodrome | Hours to days before seizure; may reflect building excitability | Mood changes, irritability, headache, sleep disturbance (not all patients experience this) |
| Aura | Focal seizure onset with preserved awareness; represents localized cortical activation | Epigastric rising sensation, déjà vu, fear, visual or auditory phenomena (valuable for localization) |
| Ictal phase | Active seizure; hypersynchronous neuronal discharge | Motor activity (tonic, clonic, myoclonic), altered awareness, autonomic changes, behavioral arrest |
| Postictal phase | Recovery period; neuronal exhaustion and active inhibition | Confusion, sleepiness, headache, focal weakness (Todd paralysis), amnesia; duration varies (minutes to hours) |
Consequences of Prolonged Seizures
Understanding why prolonged seizures cause harm guides the urgency of treatment.
0-5 Minutes
Compensated phase:
- Increased cerebral blood flow
- Increased glucose delivery
- Metabolic demands met
- Most seizures self-terminate
5-30 Minutes
Transitional phase:
- GABA-A receptor internalization begins
- Decreasing benzodiazepine efficacy
- Increasing NMDA receptor expression
- Emerging metabolic acidosis
Beyond 30 Minutes
Decompensated phase:
- Cerebral metabolic failure
- Excitotoxic neuronal injury
- Systemic complications (hyperthermia, rhabdomyolysis)
- Pharmacoresistance established
Time-Dependent Pharmacoresistance
As seizure duration increases, benzodiazepine efficacy decreases dramatically due to GABA-A receptor internalization. Studies show that benzodiazepines terminate approximately 80% of seizures when given within the first 5 minutes, but only 40% when given after 30 minutes. This underscores the critical importance of early treatment — “time is brain” applies to status epilepticus just as it does to stroke.
Seizure Propagation Patterns
Focal to Bilateral Spread
Seizure begins in one hemisphere
Spreads via corpus callosum
Results in bilateral tonic-clonic activity
May have lateralizing features early
Generalized from Onset
Bilateral hemispheric involvement from start
Thalamocortical circuits often involved
Absence and myoclonic seizures
No focal features or aura
Focal Remaining Focal
Seizure activity confined to one region
May have preserved awareness
Motor, sensory, or autonomic symptoms
Localizing value for etiology
Multifocal
Multiple independent seizure foci
Often seen in severe epileptic encephalopathies
Lennox-Gastaut syndrome
Poor prognosis; treatment-resistant
Clinical Pearl: Fever and Seizure Threshold
The rate of temperature rise, rather than the peak temperature, appears to be more important in triggering febrile seizures. This explains why antipyretics do not prevent febrile seizures — by the time fever is detected, the rapid temperature rise has already occurred. Inflammatory cytokines, particularly interleukin-1β, directly enhance neuronal excitability through effects on glutamate receptors and ion channels, independent of temperature itself.
3. History Taking
A comprehensive approach to eliciting the seizure history in children
Red Flags — Require Urgent Evaluation
- Prolonged seizure (greater than 5 minutes) — status epilepticus; immediate treatment needed
- Focal neurological deficits persisting beyond 1 hour — structural lesion, stroke
- Signs of increased intracranial pressure — headache, vomiting, papilledema, altered consciousness
- Meningeal signs — fever with neck stiffness, photophobia; CNS infection
- Seizure in neonate — always warrants full septic and metabolic workup
- First seizure with fever in infant less than 6 months — meningitis must be excluded
- Developmental regression — neurodegenerative disorder, epileptic encephalopathy
- Infantile spasms pattern — clusters of flexor/extensor spasms; West syndrome emergency
- Signs of non-accidental injury — bruising, retinal hemorrhages, inconsistent history
- Seizure following head trauma — intracranial hemorrhage, diffuse axonal injury
- Known cardiac disease with syncope/seizure — arrhythmogenic cause
- Toxic ingestion suspected — immediate toxicology evaluation needed
The history is the cornerstone of seizure diagnosis — in most cases, the diagnosis is made based on a detailed eyewitness account rather than investigations. Since the child often has no memory of the event, obtaining a thorough history from caregivers and any witnesses is essential. Video recordings of events, if available, are invaluable.
Systematic History: The “SEIZURES” Approach
Use the mnemonic “SEIZURES” to ensure comprehensive history taking:
- S — Start and Setting: What was the child doing? Where were they? Were they awake or asleep? Any warning signs or aura?
- E — Event Description: What exactly happened? Eye deviation? Limb movements (tonic, clonic, asymmetric)? Color change? Automatisms? Incontinence?
- I — Ictal Duration: How long did it last? Was it timed? Did it stop on its own or require medication?
- Z — Zone of Onset: Did it start in one part of the body? Which side? Did it spread? (Lateralization helps localize)
- U — Unresponsiveness: Was the child aware during the event? Could they respond to voice or commands? Any memory of the event?
- R — Recovery (Postictal): How long until back to normal? Confusion? Sleepiness? Weakness on one side (Todd paralysis)? Headache?
- E — Episodes Before: Is this the first event? Previous similar episodes? Staring spells? Myoclonic jerks? Sleep-related events?
- S — Surrounding Factors: Fever? Sleep deprivation? Illness? Medications? Possible ingestion? Recent head injury? Triggers?
Detailed Event Description
The most critical aspect of seizure history is obtaining a precise, moment-by-moment description of the event from an eyewitness.
| Aspect | Key Questions | Why It Matters |
|---|---|---|
| Prodrome/Warning | “Did your child say they felt strange beforehand? Any behavior change in the hours/minutes before?” | Aura suggests focal onset; prodrome may help with seizure anticipation and safety planning |
| Initial manifestation | “What was the very first thing you noticed? Which part of the body moved first?” | Focal onset localizes seizure origin; helps distinguish seizure types |
| Eye position | “Were the eyes open or closed? Were they looking in any particular direction? Did the eyes roll up?” | Eyes typically deviate toward seizure focus; eyes closed suggests psychogenic event |
| Motor activity | “Was there stiffening (tonic)? Rhythmic jerking (clonic)? Whole body or one side? Did it change over time?” | Characterizes seizure type; asymmetry suggests focal onset; progression pattern is diagnostic |
| Breathing and color | “Did they stop breathing? Did they turn blue (cyanosis) or pale? Where did the color change occur?” | Central cyanosis common in generalized tonic-clonic seizures; pallor suggests syncope |
| Automatisms | “Were there any repetitive movements like lip smacking, chewing, hand fumbling, or picking at clothes?” | Automatisms suggest focal seizure with impaired awareness (temporal lobe common) |
| Responsiveness | “Did they respond when you called their name? Could they follow commands during the event?” | Preserved awareness suggests focal aware seizure; impaired awareness has different implications |
| Duration | “Exactly how long did the shaking/staring last? Did you time it? It often feels longer than it is.” | Duration greater than 5 minutes requires intervention; parental estimates often inaccurate |
| Termination | “How did it stop? Gradually or suddenly? Did it stop on its own or was medication given?” | Abrupt offset typical for absence seizures; gradual for generalized tonic-clonic seizures |
| Postictal state | “After it stopped, was your child confused? Sleepy? How long until completely back to normal? Any weakness?” | Prolonged postictal state suggests generalized tonic-clonic seizure; Todd paralysis localizes focus |
Clinical Pearl: Ask for Video
Always ask: “Did anyone take a video on their phone?” Home video recordings have revolutionized seizure diagnosis. A video can provide more diagnostic information than the most detailed verbal description and can distinguish seizures from seizure mimics. Encourage families to safely record future events if possible (ensuring the child is in a safe position first).
Targeted Questions by Suspected Cause
| Suspected Cause | Key Features | Ask This Question |
|---|---|---|
| Febrile seizure | Age 6 months to 5 years; fever; generalized; brief | “Did your child have a fever? How high? Was this the first sign of illness or had they been sick for a while?” |
| Absence epilepsy | Brief staring; multiple daily episodes; school-age child | “Does your child have frequent brief ‘blank spells’ where they stare and don’t respond? How many per day? Can you interrupt them?” |
| Juvenile myoclonic epilepsy | Morning myoclonic jerks; adolescent; sleep deprivation trigger | “Does your teenager have sudden jerking movements, especially in the morning? Do they drop things at breakfast? Any seizures after a late night?” |
| Infantile spasms | Clusters of brief spasms; developmental regression; infant | “Does your baby have clusters of sudden movements where they flex forward or extend? How many in a cluster? Have you noticed any change in development?” |
| Benign rolandic epilepsy | Nocturnal focal motor seizures; drooling; speech arrest; school age | “Do the seizures happen during sleep? Does one side of the face twitch? Is there drooling or difficulty speaking during the event?” |
| Temporal lobe epilepsy | Aura (rising sensation, déjà vu); automatisms; impaired awareness | “Does your child describe any warning before the seizure — like a funny feeling in the stomach or a sense that something strange is happening?” |
| Hypoglycemia | Pallor, sweating, shakiness before event; diabetic or fasting child | “Was your child pale or sweaty before the seizure? When did they last eat? Do they have diabetes? Were they sick and not eating well?” |
| Meningitis/Encephalitis | Fever, headache, altered consciousness, neck stiffness | “Has your child complained of severe headache? Are they more sleepy or confused than usual? Is there neck stiffness or sensitivity to light?” |
| Toxic ingestion | Access to medications or substances; altered mental status | “Could your child have gotten into any medications, cleaning products, or other substances? Are there any medications missing from the house?” |
| Syncope (seizure mimic) | Upright position; prodrome (lightheadedness, vision changes); rapid recovery | “Was your child standing when this happened? Did they say they felt lightheaded or that their vision went dark? How quickly did they recover?” |
| Breath-holding spell (infant/toddler) | Triggered by crying/upset; color change precedes stiffening; rapid recovery | “Did this happen after your child was upset and crying? Did they stop breathing and turn blue or pale before the stiffening?” |
Past Medical History
Birth and Perinatal History
- Gestational age: Prematurity increases seizure risk
- Birth weight: Small for gestational age associated with increased risk
- Delivery complications: Hypoxic-ischemic encephalopathy, birth trauma
- NICU admission: Duration, intubation, seizures in neonatal period
- Neonatal infections: Meningitis, sepsis, TORCH infections
- Congenital anomalies: Associated with certain epilepsy syndromes
- Maternal factors: Infections, medications, substance use during pregnancy
Developmental History
- Gross motor milestones: Head control, sitting, walking — delays may indicate underlying pathology
- Fine motor milestones: Reaching, grasping, pincer grasp
- Language milestones: Babbling, first words, sentences — regression is a red flag
- Social milestones: Smiling, eye contact, interactive play
- Current developmental level: School performance, learning difficulties
- Any regression: Loss of previously acquired skills is highly concerning
- Behavioral concerns: Autism spectrum features, attention difficulties
Family History
Key Family History Questions:
- Epilepsy in first-degree relatives: Increases risk 2-4 fold; specific syndromes have strong heritability
- Febrile seizures in family: Strong genetic component; 10-20% of children with febrile seizures have affected family members
- Sudden unexplained deaths: May indicate inherited cardiac arrhythmia (long QT syndrome) or epilepsy (SUDEP)
- Neurodevelopmental disorders: Intellectual disability, autism spectrum disorder in family
- Neurodegenerative diseases: Progressive conditions with seizures as a feature
- Consanguinity: Increases risk of autosomal recessive metabolic and genetic conditions
- Specific epilepsy syndromes: Some have clear inheritance patterns (benign familial neonatal seizures, genetic generalized epilepsies)
Medication and Social History
Medications That Can Cause Seizures
- Antihistamines (diphenhydramine overdose) — anticholinergic toxicity
- Tramadol — lowers seizure threshold significantly
- Bupropion — dose-dependent seizure risk
- Isoniazid — pyridoxine depletion; treat with IV pyridoxine
- Fluoroquinolones — GABA antagonism
- Beta-lactam antibiotics (high doses) — especially with renal impairment
- Theophylline/Caffeine toxicity — adenosine antagonism
- Stimulant medications (overdose) — amphetamines, methylphenidate
- Tricyclic antidepressants — sodium channel blockade in overdose
- Withdrawal: Benzodiazepines, barbiturates, alcohol (adolescents)
Social and Environmental History
- Household medications: Potential for accidental ingestion
- Substance use (adolescents): Alcohol, recreational drugs, energy drinks
- Sleep habits: Sleep deprivation is a major seizure trigger
- Screen time: Photosensitive epilepsy; video game induced seizures
- School performance: Cognitive effects of seizures or medications
- Childcare/School setting: Witnessed events; seizure action plan needed
- Home safety: Supervision, water safety, heights
- Psychosocial stressors: May trigger psychogenic non-epileptic events
- Travel history: Neurocysticercosis in endemic areas
Immunization Status
| Vaccine | Seizure Association | Clinical Notes |
|---|---|---|
| DTaP (Pertussis component) | Febrile seizures may occur 0-3 days post-vaccination | Risk is approximately 1 in 14,000 doses; simple febrile seizures; no long-term consequences; vaccination should continue |
| MMR | Febrile seizures may occur 7-14 days post-vaccination | Corresponds to vaccine-induced immune response; risk approximately 1 in 3,000; benefits far outweigh risks |
| Influenza | Small increased risk of febrile seizures when co-administered with pneumococcal vaccine | Absolute risk remains very low; vaccination recommended especially for children with epilepsy |
Important Note on Vaccines and Seizures
While vaccines can rarely trigger febrile seizures in susceptible children, they do not cause epilepsy. Children with epilepsy should receive all routine vaccinations. The risks of vaccine-preventable diseases (including encephalitis and seizures from infections like measles) far outweigh the small risk of vaccine-associated febrile seizures.
Review of Systems — Seizure-Relevant
| System | Symptoms to Ask About | Relevance |
|---|---|---|
| Neurological | Headaches, vision changes, weakness, numbness, gait problems | Structural lesion, increased intracranial pressure, progressive condition |
| Cardiovascular | Palpitations, syncope, exercise intolerance, chest pain | Arrhythmia-induced syncope can mimic seizures; long QT syndrome |
| Infectious | Fever, neck stiffness, photophobia, rash, recent illness | CNS infection (meningitis, encephalitis) |
| Gastrointestinal | Vomiting (especially morning), poor feeding, abdominal pain | Increased intracranial pressure; metabolic disturbance |
| Endocrine/Metabolic | Excessive thirst/urination, weight changes, sweating, shakiness | Diabetes (hypoglycemia); electrolyte disturbances; inborn errors of metabolism |
| Dermatological | Skin lesions, birthmarks, café-au-lait spots, hypopigmented macules | Neurocutaneous syndromes (tuberous sclerosis, neurofibromatosis, Sturge-Weber) |
4. Physical Examination
A systematic approach to examining the child with seizures
Systematic Framework: Use a comprehensive “Head to Toe” approach for every child presenting with seizures. The examination serves to: (1) identify signs of ongoing seizure activity, (2) detect underlying etiology, (3) recognize complications, and (4) establish baseline neurological status.
Initial Rapid Assessment (If Actively Seizing)
Immediate Assessment During Active Seizure
- Airway: Position child safely; suction if needed; do NOT put anything in mouth
- Breathing: Observe respiratory effort; provide oxygen if cyanotic; prepare for bag-mask ventilation
- Circulation: Assess heart rate and perfusion; obtain IV/IO access
- Disability: Note seizure type, duration, and evolution; check glucose immediately
- Exposure: Look for trauma, rash, needle marks, medical alert jewelry
Time the seizure! Start treatment if seizure duration exceeds 5 minutes.
Vital Signs
Vital signs must be interpreted using age-appropriate normal values. Abnormalities may indicate underlying cause or seizure complications.
| Age | Heart Rate (bpm) | Respiratory Rate (/min) | Systolic BP (mmHg) | Temperature |
|---|---|---|---|---|
| Neonate (0-28 days) | 100-160 | 30-60 | 60-90 | Normal: 36.5-37.5°C Fever: ≥38°C Post-ictal hyperthermia may occur |
| Infant (1-12 months) | 100-150 | 25-40 | 80-100 | |
| Toddler (1-3 years) | 90-140 | 20-30 | 90-105 | |
| Preschool (3-5 years) | 80-120 | 20-25 | 95-110 | |
| School age (6-12 years) | 70-110 | 18-22 | 100-120 | |
| Adolescent (13-18 years) | 60-100 | 12-20 | 110-130 |
| Vital Sign Abnormality | Clinical Significance | Consider |
|---|---|---|
| Fever | Most common seizure trigger in children; may indicate infection | Febrile seizure (if age 6 months-5 years); CNS infection; systemic infection triggering seizure |
| Tachycardia | Common immediately post-ictal; may persist with fever, dehydration, or ongoing seizure | Autonomic response; dehydration; sepsis; arrhythmia as cause |
| Bradycardia | May occur ictally; concerning if persistent post-ictally | Ictal bradycardia; increased intracranial pressure; medication effect |
| Hypertension | Common post-ictal finding; may indicate increased intracranial pressure if persistent | Autonomic response; increased intracranial pressure; hypertensive encephalopathy |
| Hypotension | Unusual; suggests severe systemic illness | Sepsis; toxic ingestion; prolonged status epilepticus with systemic compromise |
| Oxygen desaturation | Common during and immediately after generalized tonic-clonic seizure | Ictal apnea; aspiration; airway obstruction; prolonged postictal depression |
Growth Parameters
| Parameter | What to Assess | Abnormalities and Significance |
|---|---|---|
| Weight | Plot on age-appropriate growth chart; compare to previous measurements | Failure to thrive may indicate chronic illness, metabolic disorder, or neglect |
| Height/Length | Plot on growth chart; assess proportionality | Short stature may be associated with certain genetic/metabolic syndromes |
| Head circumference | Essential in children under 2 years; plot on growth chart | Macrocephaly: hydrocephalus, megalencephaly, storage disorders; Microcephaly: congenital infection, genetic syndromes, perinatal injury |
General Inspection
- Level of consciousness: Alert, drowsy, obtunded, comatose; use pediatric Glasgow Coma Scale; postictal drowsiness is expected but should improve
- General appearance: Well versus ill-appearing; toxic appearance suggests serious infection
- Respiratory effort: Work of breathing; stridor; grunting (may indicate aspiration or infection)
- Color: Pallor, cyanosis (central versus peripheral), flushing
- Posture: Decorticate or decerebrate posturing indicates severe brain injury; asymmetric posture suggests focal pathology
- Movement: Spontaneous movements; asymmetry; abnormal movements (ongoing subtle seizure activity)
- Dysmorphic features: May suggest genetic syndrome associated with epilepsy
- Nutritional status: Wasting may indicate chronic illness or neglect
Skin Examination
The skin examination is crucial in pediatric seizures as it may reveal neurocutaneous syndromes or signs of underlying conditions.
| Finding | Description | Associated Condition |
|---|---|---|
| Hypopigmented macules (ash leaf spots) | Oval or leaf-shaped white patches; best seen with Wood lamp | Tuberous sclerosis complex — infantile spasms, focal seizures, intellectual disability |
| Facial angiofibromas (adenoma sebaceum) | Red papules on face, especially nasolabial folds; appear after age 3-4 | Tuberous sclerosis complex |
| Shagreen patch | Thickened, orange-peel textured plaque, usually on lower back | Tuberous sclerosis complex |
| Café-au-lait spots | Flat, uniformly hyperpigmented macules; ≥6 spots >5mm (prepubertal) is diagnostic | Neurofibromatosis type 1 — seizures in 4-7% of patients |
| Axillary/inguinal freckling | Multiple freckles in skinfolds | Neurofibromatosis type 1 |
| Port-wine stain (facial) | Unilateral facial capillary malformation in V1 distribution | Sturge-Weber syndrome — focal seizures, hemiparesis, glaucoma |
| Petechiae/Purpura | Non-blanching red/purple spots | Meningococcal sepsis; other causes of DIC; trauma (non-accidental injury) |
| Bruising in unusual locations | Bruises on ears, neck, trunk, buttocks in non-mobile child | Non-accidental injury — consider abusive head trauma |
| Linear hypopigmentation (lines of Blaschko) | Whorled or linear hypopigmented streaks following developmental lines | Hypomelanosis of Ito — seizures, developmental delay |
Clinical Pearl: Wood Lamp Examination
In children with infantile spasms or unexplained seizures, always perform a Wood lamp examination of the skin in a darkened room. Ash leaf spots of tuberous sclerosis may be subtle and only visible under ultraviolet light, especially in fair-skinned children. Finding even one ash leaf spot in an infant with spasms should prompt urgent evaluation for tuberous sclerosis complex and consideration of vigabatrin as first-line treatment.
Head and Fontanelle Examination
| Finding | Assessment | Clinical Significance |
|---|---|---|
| Anterior fontanelle (infants) | Assess with child calm and upright; should be soft and flat | Bulging: increased intracranial pressure, meningitis, hydrocephalus; Sunken: dehydration |
| Head circumference | Measure occipitofrontal circumference; plot on growth chart | Macrocephaly or microcephaly as discussed above |
| Skull shape | Assess for asymmetry, ridging along sutures | Craniosynostosis; positional plagiocephaly; may be associated with increased intracranial pressure |
| Scalp | Inspect for bruising, swelling, lacerations | Traumatic injury; subgaleal hematoma; non-accidental injury |
| Cranial bruits | Auscultate over anterior fontanelle, temples, orbits | Arteriovenous malformation; increased intracranial blood flow |
Eye Examination
| Component | Assessment | Abnormal Findings and Significance |
|---|---|---|
| Pupils | Size, symmetry, reactivity to light | Asymmetric pupils: structural lesion, herniation; Fixed dilated: severe brain injury, anticholinergic toxicity; Pinpoint: opioid toxicity, pontine lesion |
| Eye movements | Conjugate gaze; nystagmus; eye deviation | Tonic eye deviation during/after seizure (eyes deviate toward seizure focus in early ictal phase); Nystagmus may indicate ongoing subtle seizure or medication toxicity |
| Fundoscopy | Optic disc, retina, vessels | Papilledema: increased intracranial pressure (may take hours-days to develop); Retinal hemorrhages: abusive head trauma (highly specific), severe hypertension |
| Visual fields | Confrontation testing if cooperative | Homonymous hemianopia suggests occipital or optic tract lesion |
| Iris | Look for Lisch nodules (iris hamartomas) | Neurofibromatosis type 1 (seen in >90% of adults with NF1, less common in young children) |
Neurological Examination
A thorough neurological examination is essential but should be adapted to the child’s age and level of cooperation.
Mental Status
- Level of alertness: Use pediatric Glasgow Coma Scale for objective assessment
- Orientation: To person, place, time (age-appropriate)
- Attention: Ability to focus and follow commands
- Language: Comprehension and expression; dysphasia suggests focal lesion
- Interaction: Eye contact, social responsiveness (especially in young children)
| Component | Assessment (Age-Adapted) | Abnormal Findings |
|---|---|---|
| Cranial Nerves | Facial symmetry, eye movements, pupillary responses, gag reflex, tongue movement | Facial weakness (CN VII), eye movement abnormalities (CN III, IV, VI), absent gag (CN IX, X), tongue deviation (CN XII) |
| Motor — Tone | Passive movement of limbs; compare sides; assess for spasticity, rigidity, hypotonia | Hypotonia: post-ictal, metabolic, neuromuscular; Increased tone: upper motor neuron lesion, cerebral palsy |
| Motor — Strength | Observe spontaneous movement; formal strength testing if cooperative (graded 0-5) | Hemiparesis: focal lesion contralateral to weakness; may be Todd paralysis (resolves within 48 hours) |
| Deep tendon reflexes | Biceps, triceps, brachioradialis, patellar, Achilles; compare sides | Asymmetry suggests focal pathology; hyperreflexia suggests upper motor neuron lesion; hyporeflexia may be post-ictal |
| Plantar response | Stroke lateral sole from heel to toe | Extensor (Babinski) is normal up to 12-18 months; in older children, suggests upper motor neuron lesion |
| Coordination | Finger-to-nose, rapid alternating movements, gait observation | Ataxia: cerebellar lesion, medication toxicity (phenytoin), post-ictal |
| Gait | Observe walking, running, heel-to-toe walking (if developmentally appropriate) | Hemiplegic gait, ataxic gait, or refusal to walk may indicate focal pathology |
| Sensory | Light touch, pinprick, proprioception (limited in young children) | Hemisensory loss suggests thalamic or cortical lesion |
Meningeal Signs
| Sign | How to Assess | Interpretation |
|---|---|---|
| Neck stiffness | Passive flexion of neck with patient supine; resistance or pain indicates stiffness | Positive in meningitis, subarachnoid hemorrhage; may be absent in infants and immunocompromised |
| Kernig sign | Flex hip to 90°, then attempt to extend knee; positive if painful or resisted | Meningeal irritation |
| Brudzinski sign | Passive neck flexion causes involuntary hip and knee flexion | Meningeal irritation |
Important: Meningeal Signs in Infants
Classic meningeal signs (neck stiffness, Kernig, Brudzinski) are often absent in infants with meningitis. In young infants, signs of meningitis may be subtle and non-specific: irritability, poor feeding, bulging fontanelle, altered consciousness, or fever without source. Maintain a low threshold for lumbar puncture in febrile infants with seizures, especially those under 6-12 months of age.
Cardiovascular Examination
- Heart rate and rhythm: Arrhythmia may cause syncope mimicking seizure
- Murmurs: May indicate structural heart disease; endocarditis can cause embolic stroke with seizures
- Peripheral pulses: Assess for coarctation (femoral pulse delay); emboli
- Perfusion: Capillary refill, skin color, temperature
Abdominal Examination
- Hepatomegaly: Metabolic storage disorders, inborn errors of metabolism
- Splenomegaly: Metabolic disorders, infection
- Organomegaly: Consider glycogen storage diseases, lysosomal disorders
Summary: Expected Findings by Etiology
| Condition | General | Neurological | Other Key Findings |
|---|---|---|---|
| Simple febrile seizure | Febrile, may appear unwell from underlying infection | Normal post-ictal examination; no focal deficits | Source of fever (otitis, pharyngitis, viral illness); normal fontanelle |
| Meningitis | Ill-appearing, febrile, may be irritable or lethargic | Meningeal signs (may be absent in infants); altered consciousness | Bulging fontanelle; petechial rash (meningococcal); photophobia |
| Encephalitis | Febrile, altered mental status | Focal deficits; altered consciousness; may have movement disorders | Behavioral changes; memory impairment; may progress rapidly |
| Intracranial mass/tumor | May have signs of increased intracranial pressure | Focal deficits; papilledema; sixth nerve palsy | Morning headache and vomiting; personality changes; gait disturbance |
| Abusive head trauma | Variable; may appear well or critically ill | Variable; may have focal deficits; bulging fontanelle | Retinal hemorrhages; bruising in unusual locations; inconsistent history |
| Tuberous sclerosis | May be normal | May be normal or have developmental delay | Hypopigmented macules; facial angiofibromas; cardiac rhabdomyomas |
| Childhood absence epilepsy | Normal | Completely normal between seizures | May be able to induce absence with hyperventilation (3 minutes) |
| Benign rolandic epilepsy | Normal | Normal examination | Normal; diagnosis based on history and characteristic EEG |
| Hypoglycemia | May be pale, sweaty, tremulous | Altered consciousness; seizure resolves with glucose | Confirm with bedside glucose; look for signs of underlying cause |
| Toxic ingestion | Variable depending on toxin | May have altered pupils, tone abnormalities, movement disorders | Toxidrome pattern; medication bottles; characteristic findings |
Important Teaching Point: Normal Examination is Common
Many children with epilepsy, including those with common syndromes like childhood absence epilepsy, benign rolandic epilepsy, and juvenile myoclonic epilepsy, have completely normal physical examinations between seizures. A normal examination does not exclude epilepsy. The diagnosis is primarily clinical, based on the history and characteristic semiology of events, supported by EEG findings.
Developmental Assessment
Formal developmental assessment is important in children with seizures, as developmental delay may indicate underlying etiology or be a consequence of seizures/epileptic encephalopathy.
| Age | Gross Motor | Fine Motor | Language | Social |
|---|---|---|---|---|
| 2 months | Lifts head prone | Hands unfisted | Coos | Social smile |
| 4 months | Head control, rolls front to back | Reaches for objects | Laughs, squeals | Enjoys social interaction |
| 6 months | Sits with support | Transfers objects hand to hand | Babbles | Stranger anxiety emerging |
| 9 months | Sits independently, crawls | Pincer grasp developing | Says “mama/dada” non-specifically | Waves bye-bye |
| 12 months | Pulls to stand, cruises | Pincer grasp | 1-2 words with meaning | Separation anxiety; points |
| 18 months | Walks independently | Stacks 2-3 blocks; scribbles | 10-20 words; follows simple commands | Parallel play |
| 2 years | Runs, kicks ball | Stacks 6 blocks; turns pages | 2-word phrases; 50+ words | Imaginative play |
5. Differential Diagnosis
Systematic approach organized by probability, age, and clinical features
The differential diagnosis of seizures in children requires consideration of both true seizures (epileptic events) and seizure mimics (non-epileptic paroxysmal events). The approach varies significantly by age, as certain conditions are age-specific. Always consider whether the event is a provoked seizure (acute symptomatic), an unprovoked seizure (suggesting epilepsy), or a non-epileptic event.
Diagnostic Framework for Pediatric Seizures:
- Step 1: Is this a seizure or a seizure mimic? (History and video are key)
- Step 2: If seizure, is it provoked (acute symptomatic) or unprovoked?
- Step 3: What is the seizure type? (Focal vs generalized; specific semiology)
- Step 4: What is the underlying etiology? (Genetic, structural, metabolic, immune, infectious, unknown)
- Step 5: Does this fit a recognized epilepsy syndrome?
First Seizure in Children: Differential by Probability
| Probability | Condition | Key Features | Red Flags |
|---|---|---|---|
| COMMON (approximately 70%) | Febrile seizure | Age 6 months-5 years; fever; generalized tonic-clonic; brief duration; rapid recovery | Complex features (focal, prolonged >15 min, recurrent in 24 hours); age <6 months or >5 years |
| Viral illness-associated | Concurrent viral infection (gastroenteritis, respiratory); may or may not have fever | Persistent altered consciousness; focal features; clustering | |
| First unprovoked seizure | No identifiable acute cause; may be first presentation of epilepsy | Focal features suggesting structural lesion; developmental regression | |
| Seizure mimic (not a seizure) | Breath-holding spell, syncope, sleep phenomena, behavioral event | Features atypical for mimics suggest true seizure | |
| LESS COMMON (approximately 20%) | Central nervous system infection | Fever, altered consciousness, meningeal signs; may have focal seizures | Rapid deterioration; petechial rash; bulging fontanelle |
| Metabolic disturbance | Hypoglycemia, hyponatremia, hypocalcemia; often in context of illness | Persistent seizures until corrected; signs of underlying disease | |
| Traumatic brain injury | History of head trauma; may have external signs of injury | Altered consciousness; focal deficits; signs of skull fracture | |
| Toxic ingestion | Access to medications/toxins; toxidrome features; altered consciousness | Cardiovascular instability; specific toxidrome; coma | |
| UNCOMMON BUT SERIOUS (approximately 10%) | Intracranial mass/tumor | Progressive headache, vomiting; focal seizures; papilledema | Rapid neurological deterioration; signs of herniation |
| Stroke (arterial ischemic or hemorrhagic) | Acute focal deficits; may present with seizure as first sign | Persistent focal deficits; altered consciousness | |
| Abusive head trauma | Infant with altered consciousness; retinal hemorrhages; inconsistent history | Any features of non-accidental injury; multiple injuries | |
| Autoimmune encephalitis | Behavioral changes, movement disorders, seizures; subacute onset | Rapid progression; psychiatric features; refractory seizures |
Age-Based Differential Diagnosis
The differential diagnosis varies significantly by age due to developmental factors and age-specific conditions.
Neonates (0-28 days)
| Category | Conditions | Key Features |
|---|---|---|
| Hypoxic-ischemic encephalopathy | Most common cause of neonatal seizures | History of perinatal distress; onset within first 24-72 hours; multifocal seizures |
| Intracranial hemorrhage | Intraventricular, subdural, subarachnoid hemorrhage | Prematurity (IVH); birth trauma; may have bulging fontanelle |
| Central nervous system infection | Bacterial meningitis, viral encephalitis (HSV), congenital infections (TORCH) | Fever or hypothermia; poor feeding; lethargy; may have rash or hepatosplenomegaly |
| Metabolic disturbances | Hypoglycemia, hypocalcemia, hypomagnesemia, hypo/hypernatremia | Jitteriness; poor feeding; may have underlying endocrine or metabolic cause |
| Inborn errors of metabolism | Pyridoxine-dependent epilepsy, maple syrup urine disease, urea cycle defects, non-ketotic hyperglycinemia | Treatment-resistant seizures; metabolic acidosis; unusual odor; encephalopathy |
| Brain malformations | Lissencephaly, polymicrogyria, cortical dysplasia, holoprosencephaly | May have dysmorphic features; microcephaly; developmental concerns |
| Neonatal epilepsy syndromes | Benign familial neonatal epilepsy, early myoclonic encephalopathy, Ohtahara syndrome | Family history (benign); burst-suppression on EEG (severe syndromes) |
| Drug withdrawal | Maternal opioid, benzodiazepine, SSRI use | Maternal history; onset 24-72 hours after birth; irritability, tremor |
Neonatal Seizure Emergency
All neonatal seizures are considered serious until proven otherwise. Key urgent considerations:
- Herpes simplex encephalitis: Start acyclovir empirically if any suspicion (fever, CSF pleocytosis, temporal lobe involvement)
- Bacterial meningitis: Empiric antibiotics after blood culture and LP
- Hypoglycemia: Check glucose immediately and treat if low
- Pyridoxine-dependent seizures: Give pyridoxine trial (100mg IV) for refractory seizures
Infants (1-12 months)
| Probability | Condition | Key Features |
|---|---|---|
| COMMON | Febrile seizures (after 6 months) | Fever with viral illness; generalized; brief; rapid recovery |
| Viral illness-associated seizures | Gastroenteritis (rotavirus), respiratory infections; may cluster | |
| LESS COMMON | Infantile spasms (West syndrome) | Clusters of flexor/extensor spasms; developmental regression; onset 4-8 months peak |
| CNS infection | Meningitis, encephalitis; fever, irritability, bulging fontanelle | |
| UNCOMMON | Dravet syndrome | Prolonged febrile seizures starting around 6 months; fever-sensitive; later myoclonic and absence seizures |
| Structural brain abnormalities | Cortical malformations, tuberous sclerosis, tumors |
Infantile Spasms: A Medical Emergency
Infantile spasms require urgent recognition and treatment to optimize neurodevelopmental outcomes. Key features:
- Clusters of brief spasms (flexor, extensor, or mixed), often upon awakening
- Developmental regression or stagnation
- EEG shows hypsarrhythmia (chaotic high-amplitude pattern)
- Treatment delay worsens prognosis — aim to start treatment within 1-2 weeks of diagnosis
- First-line: ACTH or vigabatrin (vigabatrin preferred if tuberous sclerosis)
Toddlers and Preschool (1-5 years)
| Probability | Condition | Key Features |
|---|---|---|
| COMMON | Febrile seizures | Peak incidence 12-18 months; most common cause of seizures in this age group |
| Viral illness-associated | Especially gastroenteritis; may occur without significant fever | |
| Breath-holding spells (mimic) | Triggered by upset/crying; cyanotic or pallid; brief stiffening; rapid recovery | |
| LESS COMMON | Genetic epilepsy syndromes emerging | Dravet syndrome progression; myoclonic-atonic epilepsy (Doose syndrome) |
| CNS infection | Meningitis, encephalitis; distinguish from febrile seizure | |
| UNCOMMON | Toxic ingestion | Peak age for accidental ingestion; access to medications |
| Brain tumors | Posterior fossa tumors common in this age; headache, vomiting, ataxia |
School Age (6-12 years)
| Probability | Condition | Key Features |
|---|---|---|
| COMMON | Childhood absence epilepsy | Peak 4-8 years; brief staring spells; multiple daily; 3 Hz spike-wave on EEG |
| Benign epilepsy with centrotemporal spikes (rolandic) | Peak 7-10 years; nocturnal focal motor seizures; drooling; speech arrest | |
| First unprovoked generalized tonic-clonic seizure | May be first presentation of genetic generalized epilepsy | |
| LESS COMMON | Focal epilepsies | Temporal lobe epilepsy; may have aura, automatisms, impaired awareness |
| Syncope (mimic) | Vasovagal; prodrome of lightheadedness; upright position; rapid recovery | |
| UNCOMMON | Autoimmune encephalitis | Behavioral changes, psychiatric symptoms, movement disorders, seizures |
| Brain tumors | Supratentorial tumors more common; focal seizures; headache |
Adolescents (12-18 years)
| Probability | Condition | Key Features |
|---|---|---|
| COMMON | Juvenile myoclonic epilepsy | Morning myoclonic jerks; generalized tonic-clonic on awakening; sleep deprivation trigger |
| Juvenile absence epilepsy | Less frequent absences than childhood form; more likely to have generalized tonic-clonic seizures | |
| Syncope (mimic) | Vasovagal common; orthostatic; situational (hair brushing, prolonged standing) | |
| LESS COMMON | Focal epilepsies | Temporal, frontal lobe epilepsy; may have psychiatric comorbidity |
| Psychogenic non-epileptic seizures | Atypical features; variable semiology; eyes closed; psychological stressors | |
| UNCOMMON | Substance-related | Alcohol withdrawal, illicit drugs (stimulants, synthetic cannabinoids), energy drinks |
| Cardiac arrhythmia (mimic) | Long QT syndrome; may present as “seizure” with syncope and convulsive movements |
Seizure Mimics: Non-Epileptic Paroxysmal Events
Approximately 20-30% of children referred for “seizures” have non-epileptic events. Accurate diagnosis prevents unnecessary antiseizure medication and directs appropriate treatment.
| Mimic | Age Group | Key Features | Distinguishing from Seizure |
|---|---|---|---|
| Breath-holding spells | 6 months – 6 years (peak 1-2 years) | Triggered by upset, pain, or startle; cyanotic or pallid; brief stiffening/limpness; rapid recovery | Always triggered by emotional upset or minor injury; color change PRECEDES stiffening; no postictal confusion |
| Syncope (vasovagal) | Any age (more common in adolescents) | Prodrome (lightheadedness, vision changes, nausea); upright position; pallor; brief convulsive movements possible | Upright position; prodrome present; pallor before event; rapid recovery (<1-2 minutes); brief tonic or myoclonic movements may occur but are not sustained clonic activity |
| Reflex anoxic seizures | Infants and toddlers | Triggered by pain, surprise; pallor; asystole; brief tonic posturing | Clear trigger (minor bump, cold food); pallid rather than cyanotic; may have brief asystole on ECG during event |
| Sleep phenomena | Any age | Night terrors, confusional arousals, hypnic jerks, sleep myoclonus | Occur only during sleep-wake transitions; stereotyped pattern; no postictal state; normal EEG |
| Benign neonatal sleep myoclonus | Neonates | Rhythmic jerking during sleep ONLY; stops when awakened | Exclusively during sleep; stops immediately with arousal; normal EEG |
| Infantile gratification disorder (masturbation) | Infants and toddlers | Rhythmic movements, flushing, sweating; may appear “zoned out”; easily distractible | Can be interrupted by distraction; no postictal state; video is diagnostic; normal EEG |
| Shuddering attacks | Infants | Brief shuddering/trembling episodes; associated with excitement or frustration | Very brief (seconds); no loss of awareness; associated with emotional state; normal EEG |
| Sandifer syndrome | Infants | Dystonic posturing of head/neck; associated with gastroesophageal reflux | Associated with feeds; relieved by treating reflux; no alteration of consciousness |
| Tics | School age and adolescents | Stereotyped movements; suppressible; preceded by urge; wax and wane | Can be suppressed (temporarily); preceded by premonitory urge; no loss of awareness |
| Stereotypies | Any age (common in autism) | Repetitive, patterned movements (hand flapping, rocking); interruptible | Occur when excited or focused; can be interrupted; awareness preserved; often associated with developmental disorders |
| Daydreaming/Inattention | School age | Staring, inattention; responsive to stimulation | Can be interrupted by calling name or touch; no automatisms; no postictal state; unlike absence seizures |
| Psychogenic non-epileptic seizures | Older children and adolescents | Variable semiology; often prolonged; eyes typically closed; suggestible | Eyes closed (seizures usually eyes open); out-of-phase limb movements; pelvic thrusting; responsiveness during “seizure”; normal ictal EEG |
| Cardiac arrhythmia (long QT syndrome) | Any age | Syncope with exercise, swimming, or startle; may have convulsive movements | Triggered by exercise, swimming, loud noise; family history of sudden death; prolonged QTc on ECG |
Anatomical/Etiological Approach
Genetic/Idiopathic
Childhood absence epilepsy
Juvenile myoclonic epilepsy
Benign rolandic epilepsy
Genetic generalized epilepsies
Benign familial neonatal seizures
Dravet syndrome (SCN1A)
Structural
Cortical dysplasia
Tuberous sclerosis
Brain tumors
Stroke (arterial or venous)
Traumatic brain injury
Hippocampal sclerosis
Metabolic/Toxic
Hypoglycemia
Electrolyte disturbances
Inborn errors of metabolism
Pyridoxine-dependent epilepsy
Toxic ingestions
Drug withdrawal
Infectious/Immune
Bacterial meningitis
Viral encephalitis (HSV, enterovirus)
Autoimmune encephalitis (anti-NMDA receptor)
Rasmussen encephalitis
Febrile infection-related epilepsy syndrome (FIRES)
Drug-Induced Seizures in Children
| Drug/Substance | Mechanism | Key Features | Management Notes |
|---|---|---|---|
| Antihistamines (diphenhydramine) | Anticholinergic toxicity; lowers seizure threshold | Tachycardia, mydriasis, flushing, urinary retention, delirium | Supportive care; benzodiazepines for seizures; physostigmine in severe cases |
| Tricyclic antidepressants | Sodium channel blockade; anticholinergic effects | Wide QRS, arrhythmias, seizures, altered consciousness | Sodium bicarbonate for cardiac toxicity; benzodiazepines; avoid class IA/IC antiarrhythmics |
| Isoniazid | Depletes pyridoxine (vitamin B6), reducing GABA synthesis | Refractory seizures, metabolic acidosis, coma | Pyridoxine 1g IV for each gram of isoniazid ingested (or 5g empirically) |
| Tramadol | Lowers seizure threshold; serotonergic effects | Seizures even at therapeutic doses; serotonin syndrome features | Benzodiazepines; avoid in patients with epilepsy |
| Bupropion | Lowers seizure threshold; dose-dependent | Seizures, tachycardia, agitation | Supportive care; benzodiazepines |
| Camphor | Direct CNS stimulant | Found in topical preparations (Vicks VapoRub); seizures with ingestion | Supportive care; benzodiazepines; decontamination if early |
| Theophylline/Caffeine | Adenosine antagonism; CNS stimulation | Tachycardia, vomiting, seizures; caffeine toxicity from energy drinks | Benzodiazepines; hemodialysis in severe cases |
| Sympathomimetics (amphetamines, cocaine) | CNS stimulation; hyperthermia | Hypertension, tachycardia, hyperthermia, agitation, seizures | Benzodiazepines; cooling; avoid beta-blockers |
| Synthetic cannabinoids | Variable; often unpredictable | Agitation, psychosis, seizures; may be severe | Supportive care; benzodiazepines |
| Withdrawal (benzodiazepines, alcohol) | Loss of GABA-ergic inhibition | Onset 24-72 hours after cessation; tremor, autonomic instability | Benzodiazepine replacement; gradual taper |
Quick Reference: “If You See This, Think This”
| Clinical Clue | Think This First | Key Next Step |
|---|---|---|
| Infant with clusters of brief spasms + regression | Infantile spasms (West syndrome) | Urgent EEG; start treatment within days if confirmed |
| 6-month-old with prolonged febrile seizures recurring | Dravet syndrome | Genetic testing (SCN1A); avoid sodium channel blockers |
| School-age child with multiple daily staring spells | Childhood absence epilepsy | EEG with hyperventilation; consider ethosuximide |
| Adolescent with morning myoclonic jerks + generalized tonic-clonic seizure | Juvenile myoclonic epilepsy | EEG; valproate or levetiracetam; lifelong treatment usually needed |
| Nocturnal focal seizures with drooling in school-age child | Benign rolandic epilepsy | EEG (centrotemporal spikes); may not need treatment; resolves by adolescence |
| Neonate with refractory seizures + metabolic acidosis | Inborn error of metabolism | Metabolic workup; pyridoxine trial; urgent genetics/metabolics consultation |
| Toddler with seizure triggered by crying and turning blue | Breath-holding spell (not a seizure) | Reassurance; check iron studies; no antiseizure medication needed |
| Adolescent with “seizure” during exercise + family history of sudden death | Long QT syndrome (cardiac syncope) | ECG; avoid QT-prolonging drugs; cardiology referral |
| Child with seizure + port-wine stain on face | Sturge-Weber syndrome | MRI brain with contrast; ophthalmology referral (glaucoma) |
| Infant with spasms + hypopigmented skin lesions | Tuberous sclerosis complex | MRI, echocardiogram, renal ultrasound; vigabatrin is first-line for spasms |
6. Diagnostic Investigations
A stepwise, evidence-based approach guided by clinical context
The investigation of pediatric seizures should be guided by the clinical presentation, age of the child, seizure type, and presence or absence of red flags. Not every child with a seizure requires extensive testing. The goals of investigation are to: (1) identify treatable causes, (2) classify the seizure/epilepsy type, (3) determine prognosis, and (4) guide treatment decisions.
Guiding Principles for Investigation:
- Clinical context determines the extent of workup — a simple febrile seizure requires minimal investigation
- Neonatal seizures always warrant comprehensive evaluation
- First unprovoked seizure in an otherwise well child may require EEG and MRI but not emergency labs
- Status epilepticus or seizures with red flags require urgent, comprehensive workup
- Consider radiation exposure when ordering CT scans in children
Immediate Bedside Testing
| Test | When to Perform | What to Look For | Clinical Notes |
|---|---|---|---|
| Point-of-care glucose | ALL patients with seizure or altered consciousness | Hypoglycemia (<60 mg/dL or <3.3 mmol/L); target varies by age (neonates: <45 mg/dL) | Most critical immediate test; treat before waiting for lab confirmation if clinically hypoglycemic |
| Temperature | All patients | Fever suggests febrile seizure or infection; hypothermia in neonates may indicate sepsis | Fever does not exclude CNS infection — maintain appropriate suspicion |
| Oxygen saturation | All patients | Desaturation during/after seizure; persistent hypoxia suggests ongoing seizure or aspiration | May be transiently low post-ictally; persistent hypoxia requires intervention |
| Heart rate and ECG rhythm | All patients; ECG if cardiac cause suspected | Arrhythmias; prolonged QTc (>460ms pediatric); bradycardia | Long QT syndrome can present as “seizure”; obtain formal 12-lead ECG if syncope features |
Laboratory Investigations
Baseline Laboratory Tests
| Test | Indications | What to Look For | Clinical Notes |
|---|---|---|---|
| Serum glucose (laboratory) | All patients with seizure (if not already confirmed normal) | Hypoglycemia; consider underlying cause if recurrent | Bedside glucose sufficient in most cases; lab confirmation if abnormal |
| Electrolytes (Na, K, Ca, Mg) | Neonates; ill-appearing children; prolonged/recurrent seizures; children on diuretics or with GI losses | Hyponatremia (<135 mmol/L); hypocalcemia; hypomagnesemia | Routine electrolytes NOT required for simple febrile seizure in well-appearing child |
| Complete blood count | Fever with seizure; suspected infection; ill-appearing | Leukocytosis (infection); anemia; thrombocytopenia | Guides infection workup; not routine for unprovoked seizure in well child |
| Blood gas (venous or arterial) | Prolonged seizure; status epilepticus; respiratory compromise; suspected metabolic disorder | Metabolic acidosis (lactic acidosis post-seizure; inborn error of metabolism); respiratory status | Transient lactic acidosis expected post-ictally; persistent acidosis concerning for metabolic disorder |
| Liver and renal function | Ill-appearing; suspected metabolic disease; before starting certain antiseizure medications | Elevated ammonia (urea cycle defects); hepatic dysfunction; renal impairment | Baseline before valproate; monitor with chronic antiseizure medication use |
| Ammonia | Neonatal seizures; encephalopathy; suspected urea cycle defect; recurrent unexplained vomiting | Elevated ammonia (>100 μmol/L concerning; >200 μmol/L urgent) | Must be collected and processed correctly (on ice, immediate analysis); false elevations common |
| Lactate | Suspected mitochondrial disease; recurrent metabolic decompensation; post-status epilepticus | Elevated lactate (>2.5 mmol/L); lactate:pyruvate ratio if mitochondrial disease suspected | Transient elevation expected after seizure; persistent elevation suggests metabolic etiology |
Toxicology Screening
| Test | Indications | Detects | Limitations |
|---|---|---|---|
| Urine drug screen | Altered mental status with seizure; adolescent; suspected ingestion; inconsistent history | Amphetamines, benzodiazepines, opioids, cannabinoids, cocaine, PCP | Does not detect synthetic cannabinoids, many prescription drugs; false positives/negatives occur |
| Serum drug levels | Suspected specific ingestion; therapeutic drug monitoring | Specific drug levels (acetaminophen, salicylates, antiseizure medications, digoxin, lithium) | Acetaminophen and salicylate levels should be checked in any intentional ingestion |
| Blood alcohol level | Adolescents; altered mental status; suspected alcohol involvement | Ethanol level | Consider ethylene glycol, methanol if osmolar gap present |
Lumbar Puncture
When is Lumbar Puncture Indicated?
Lumbar puncture should be performed when CNS infection is suspected. Specific indications include:
- Mandatory: Infants <6 months with first febrile seizure (meningeal signs unreliable)
- Strongly consider: Infants 6-12 months with febrile seizure (especially if unimmunized or on antibiotics)
- Consider: Any child with meningeal signs, prolonged postictal state, or persistent altered consciousness
- Consider: Complex febrile seizure, especially if child appears ill
- Required: Suspected encephalitis or meningitis regardless of age
Contraindications: Signs of increased intracranial pressure, hemodynamic instability, coagulopathy, skin infection at LP site. If LP contraindicated but infection suspected, start empiric antibiotics and image before LP.
| CSF Parameter | Normal Values | Bacterial Meningitis | Viral Meningitis/Encephalitis |
|---|---|---|---|
| Opening pressure | <20 cm H₂O | Often elevated | Normal or mildly elevated |
| Appearance | Clear, colorless | Cloudy/turbid | Usually clear |
| WBC count | <5 cells/μL (neonates <20) | >1000 cells/μL (neutrophil predominant) | 10-500 cells/μL (lymphocyte predominant) |
| Protein | <45 mg/dL (neonates <150) | Markedly elevated (>100 mg/dL) | Normal or mildly elevated |
| Glucose | >50% of serum glucose | Low (<40 mg/dL or <50% serum) | Usually normal |
| Gram stain | No organisms | May show bacteria (60-80% sensitive) | Negative |
Electroencephalography (EEG)
EEG is the most important investigation for characterizing seizures and diagnosing epilepsy. It records electrical activity of the brain and can identify epileptiform abnormalities.
| EEG Type | Indications | Advantages | Limitations |
|---|---|---|---|
| Routine EEG (20-40 minutes) | First unprovoked seizure; suspected epilepsy; classification of seizure type | Widely available; relatively quick; includes hyperventilation and photic stimulation | Brief recording; may miss interictal abnormalities (normal in 50% after first seizure) |
| Sleep-deprived EEG | Normal routine EEG with high suspicion for epilepsy; suspected sleep-related epilepsy | Increased yield for detecting epileptiform activity; captures sleep | Requires patient cooperation for sleep deprivation; may be difficult in young children |
| Prolonged EEG (1-24 hours) | Frequent events; need to capture typical event; suspected subclinical seizures | Greater chance of capturing events and interictal discharges | More resource-intensive; may require admission |
| Continuous EEG monitoring | Status epilepticus; ICU patients; coma; suspected non-convulsive seizures | Detects subclinical seizures; monitors treatment response | Resource-intensive; requires specialized interpretation |
| Video-EEG monitoring | Characterizing seizure semiology; presurgical evaluation; distinguishing epileptic from non-epileptic events | Correlates clinical events with EEG; gold standard for diagnosis | Requires admission; may need multiple days to capture events |
Key EEG Patterns in Pediatric Epilepsy
| EEG Pattern | Description | Associated Condition |
|---|---|---|
| 3 Hz generalized spike-and-wave | Regular, bilateral, synchronous spike-and-wave at 3 Hz; induced by hyperventilation | Childhood absence epilepsy (highly characteristic) |
| 4-6 Hz generalized polyspike-and-wave | Fast spike-and-wave; polyspikes; often on awakening | Juvenile myoclonic epilepsy |
| Centrotemporal spikes | High-amplitude spikes in central/temporal regions; activated by sleep | Benign epilepsy with centrotemporal spikes (rolandic epilepsy) |
| Hypsarrhythmia | Chaotic, high-amplitude, disorganized background with multifocal spikes | Infantile spasms (West syndrome) |
| Slow spike-and-wave (<2.5 Hz) | Slow, generalized spike-and-wave; often with background slowing | Lennox-Gastaut syndrome |
| Burst-suppression | Alternating bursts of activity with periods of suppression | Severe epileptic encephalopathy (Ohtahara syndrome); anoxic brain injury |
| Focal spikes or sharp waves | Localized epileptiform discharges in one region | Focal epilepsy; may indicate structural lesion |
| Generalized slowing | Diffuse slow-wave activity; loss of normal background rhythms | Encephalopathy (metabolic, infectious, post-ictal); may be non-specific |
Important: Normal EEG Does Not Exclude Epilepsy
A single routine EEG is normal in approximately 50% of children after a first unprovoked seizure. Interictal epileptiform discharges are not always present, and a normal EEG does not rule out epilepsy. If clinical suspicion is high and routine EEG is normal, consider sleep-deprived EEG, prolonged EEG, or repeat testing. Conversely, some epileptiform patterns (especially centrotemporal spikes) can be seen in children who never have clinical seizures.
Neuroimaging
When to Image
| Scenario | Imaging Urgency | Modality | Rationale |
|---|---|---|---|
| Simple febrile seizure | NOT indicated | None | Extremely low yield; no benefit; unnecessary radiation/sedation |
| Complex febrile seizure | Not routine; consider if focal or prolonged | MRI preferred (non-urgent) | Low yield but may identify structural abnormality in some |
| First unprovoked seizure (well child, back to baseline) | Non-urgent (can be outpatient) | MRI brain | Identifies structural etiology in 10-20%; helps classify epilepsy |
| Focal seizure | Indicated | MRI brain with epilepsy protocol | Higher yield for structural abnormality; guides management |
| Infantile spasms | Urgent | MRI brain | Identifies tuberous sclerosis, cortical malformations, other structural causes |
| Neonatal seizures | Urgent | Cranial ultrasound (bedside) followed by MRI | High yield for structural, ischemic, hemorrhagic lesions |
| Status epilepticus | Urgent (after stabilization) | CT initially if unstable; MRI when stable | Rule out mass lesion, hemorrhage; CT if herniation suspected |
| Focal neurological deficits | Urgent | CT emergently; MRI for definitive evaluation | Rule out mass lesion, stroke, hemorrhage |
| Signs of increased intracranial pressure | Emergent | CT head (non-contrast) | Rapid evaluation before LP; identify mass effect, hydrocephalus |
| Suspected non-accidental injury | Urgent | CT initially; MRI for detailed evaluation | Identify subdural hematoma, parenchymal injury; medicolegal implications |
CT versus MRI
CT Head
- Advantages: Rapid; widely available; no sedation usually needed; good for acute hemorrhage, fractures
- Disadvantages: Radiation exposure (significant concern in children); limited soft tissue detail; misses many epileptogenic lesions
- Use for: Emergent evaluation when hemorrhage, mass effect, or herniation suspected
MRI Brain
- Advantages: No radiation; superior soft tissue detail; detects cortical dysplasia, mesial temporal sclerosis, small tumors
- Disadvantages: Longer scan time; often requires sedation in young children; less available emergently
- Use for: Definitive imaging for all epilepsy evaluations; epilepsy protocol sequences recommended
Clinical Pearl: Epilepsy Protocol MRI
When ordering MRI for epilepsy evaluation, specifically request an “epilepsy protocol” which includes thin coronal and axial T2/FLAIR sequences through the temporal lobes to detect hippocampal sclerosis, and high-resolution 3D T1-weighted imaging for cortical malformations. A standard brain MRI may miss subtle epileptogenic lesions. Communication with neuroradiology about the clinical question improves yield.
Metabolic and Genetic Testing
When to Pursue Metabolic Workup
| Indication | Tests to Consider | Conditions Detected |
|---|---|---|
| Neonatal seizures (all) | Glucose, electrolytes, ammonia, lactate, amino acids, acylcarnitine profile, urine organic acids | Hypoglycemia, electrolyte disturbances, urea cycle defects, organic acidurias, fatty acid oxidation defects |
| Refractory neonatal seizures | Pyridoxine trial (100mg IV); pyridoxal phosphate trial; CSF neurotransmitters; genetic testing | Pyridoxine-dependent epilepsy, pyridoxal phosphate-responsive epilepsy, folinic acid-responsive seizures |
| Developmental regression with seizures | Lysosomal enzymes, urine glycosaminoglycans, very long chain fatty acids, CSF lactate | Lysosomal storage disorders, peroxisomal disorders, mitochondrial disease |
| Myoclonic epilepsy with developmental delay | Urine organic acids, plasma amino acids, biotinidase, genetic testing | Neuronal ceroid lipofuscinosis, biotinidase deficiency, genetic epileptic encephalopathies |
| Encephalopathy with seizures | Ammonia, lactate, glucose, amino acids, organic acids | Urea cycle defects, organic acidurias, mitochondrial disorders |
Genetic Testing
| Test | Indications | Examples of Conditions Detected |
|---|---|---|
| Epilepsy gene panel | Epileptic encephalopathy; early-onset epilepsy; specific syndrome suspected | Dravet syndrome (SCN1A), KCNQ2 epilepsy, CDKL5 deficiency, many others |
| Chromosomal microarray | Epilepsy with developmental delay, dysmorphic features, multiple congenital anomalies | Copy number variants; microdeletion/duplication syndromes (15q11-13, 1p36, etc.) |
| Whole exome/genome sequencing | Unexplained epileptic encephalopathy; negative targeted testing; research/diagnosis | Novel variants; atypical presentations of known disorders |
| Single gene testing | High suspicion for specific disorder based on phenotype | SCN1A (Dravet); TSC1/TSC2 (tuberous sclerosis); MECP2 (Rett syndrome) |
Investigation Pathways by Clinical Scenario
Simple Febrile Seizure
Minimal Investigation Needed:
- Identify and treat source of fever
- No routine blood work, EEG, or imaging required
- Consider LP only if: age <6 months, meningeal signs, prolonged postictal state, or child appears ill
- Educate family about febrile seizures and recurrence risk
First Unprovoked Seizure (Well Child, Back to Baseline)
Recommended
- EEG: Helps classify epilepsy type; predicts recurrence risk
- MRI brain: Can be done electively as outpatient
Not Routinely Needed
- Blood work (unless specific indication)
- Lumbar puncture (unless infection suspected)
- Emergency CT (unless focal deficits or not back to baseline)
Neonatal Seizure Workup
Comprehensive Neonatal Seizure Evaluation
All neonatal seizures require thorough investigation:
- Immediate: Glucose, electrolytes (Ca, Mg, Na), blood gas
- Infection workup: CBC, blood culture, LP (if stable), consider HSV PCR
- Metabolic: Ammonia, lactate, amino acids, acylcarnitine, urine organic acids
- EEG: Continuous EEG monitoring preferred; confirms seizures and guides treatment
- Imaging: Cranial ultrasound (bedside); MRI brain
- Consider: Pyridoxine trial for refractory seizures; genetic testing if cause unclear
Status Epilepticus Workup
| Phase | Investigations | Purpose |
|---|---|---|
| Immediate (while treating) | Point-of-care glucose; monitor vitals and oxygen saturation | Identify and treat reversible causes immediately |
| Early (once IV access) | Glucose, electrolytes, calcium, magnesium, CBC, blood gas, antiseizure medication levels (if applicable) | Identify metabolic causes; guide ongoing treatment |
| As indicated | Toxicology screen; ammonia; lactate; liver/renal function | Evaluate for toxic, metabolic, or organ dysfunction |
| After stabilization | CT head (if not returning to baseline or focal signs); LP (if infection suspected) | Rule out structural lesion; evaluate for CNS infection |
| Ongoing | Continuous EEG monitoring; MRI brain (when stable) | Detect ongoing subclinical seizures; identify underlying etiology |
Antiseizure Medication Levels
| Medication | Therapeutic Range | When to Check | Notes |
|---|---|---|---|
| Phenobarbital | 15-40 μg/mL | Trough level; after loading; suspected toxicity; breakthrough seizures | Long half-life; sedation common at higher levels |
| Phenytoin | 10-20 μg/mL (total); 1-2 μg/mL (free) | After loading; suspected toxicity; breakthrough seizures; altered albumin | Nonlinear kinetics; check free level if low albumin or renal failure |
| Valproic acid | 50-100 μg/mL | Trough level; suspected toxicity; breakthrough seizures | Free level if low albumin; monitor liver function and ammonia |
| Carbamazepine | 4-12 μg/mL | Trough level; suspected toxicity; breakthrough seizures | Auto-induction; levels may change over first weeks |
| Levetiracetam | 12-46 μg/mL (less established) | Generally not required; may check for compliance or toxicity | Levels correlate less well with efficacy; clinical response more important |
7. Clinical Decision-Making
Practical algorithms and decision pathways for pediatric seizures
Step 1: Is This Urgent?
The first priority is to identify patients requiring immediate intervention. Use this triage framework to guide urgency of response.
| Clinical Scenario | Urgency Level | Immediate Action |
|---|---|---|
| Active seizure (ongoing or >5 minutes) | EMERGENT | ABCs; position safely; check glucose; administer benzodiazepine; call for help; start timer |
| Post-ictal with respiratory compromise | EMERGENT | Airway management; suction; oxygen; recovery position; prepare for possible recurrence |
| Signs of increased intracranial pressure | EMERGENT | Elevate head of bed; urgent CT; neurosurgery consultation; treat seizure if present |
| Suspected meningitis/encephalitis | EMERGENT | IV access; blood cultures; empiric antibiotics and acyclovir; LP when safe |
| Suspected abusive head trauma | EMERGENT | Stabilize; CT head; full trauma evaluation; child protection team; do not discharge |
| Infantile spasms (clusters of spasms) | URGENT | Urgent EEG (within 24-48 hours); pediatric neurology referral same day; early treatment critical |
| Neonatal seizure (any) | URGENT | Full septic and metabolic workup; continuous EEG monitoring; treat underlying cause |
| First febrile seizure with complex features | URGENT | Evaluate for CNS infection; consider LP especially if <12 months; observation |
| Focal neurological deficits persisting >1 hour | URGENT | Urgent neuroimaging (CT then MRI); stroke protocol if appropriate; neurology consultation |
| Simple febrile seizure (well child, back to baseline) | ROUTINE | Identify fever source; parental education; discharge with safety netting |
| First unprovoked seizure (well child, normal exam) | ROUTINE | EEG and MRI (can be outpatient); neurology referral; seizure safety education |
| Known epilepsy with typical breakthrough seizure | ROUTINE | Review adherence and triggers; check medication levels if indicated; adjust therapy if needed |
Step 2: Classify the Event
Provoked Seizure
Acute symptomatic seizure with identifiable trigger:
- Febrile seizure
- Metabolic (hypoglycemia, electrolyte)
- CNS infection
- Toxic ingestion
- Acute head trauma
Action: Treat underlying cause; antiseizure medication usually not needed long-term
Unprovoked Seizure
No identifiable acute precipitant:
- First unprovoked seizure
- Epilepsy (recurrent unprovoked)
- Remote symptomatic (prior brain injury)
Action: EEG and MRI; consider antiseizure medication; neurology referral
Non-Epileptic Event
Paroxysmal event that is not a seizure:
- Breath-holding spell
- Syncope
- Sleep phenomena
- Movement disorder
- Psychogenic event
Action: Correct diagnosis; reassurance; treat underlying condition; no antiseizure medication
Step 3: Age-Based Decision Algorithms
Algorithm A: Neonatal Seizures (0-28 days)
| Step | Action | Key Considerations |
|---|---|---|
| 1. Stabilize | ABCs; IV access; check glucose immediately | Treat hypoglycemia (D10W 2 mL/kg) before anything else |
| 2. Confirm seizure | Continuous EEG monitoring if available; clinical observation | Neonatal seizures can be subtle; EEG confirmation ideal |
| 3. Laboratory workup | Glucose, electrolytes (Ca, Mg, Na), blood gas, ammonia, lactate, infection workup | Correct electrolyte abnormalities; start antibiotics if infection possible |
| 4. Treat seizure | Phenobarbital 20 mg/kg IV first-line | May repeat 10 mg/kg x2; max 40 mg/kg loading dose |
| 5. Consider treatable causes | Pyridoxine trial 100 mg IV if refractory; acyclovir if HSV possible | Do not miss pyridoxine-dependent epilepsy or herpes encephalitis |
| 6. Neuroimaging | Cranial ultrasound (bedside); MRI when stable | Identifies HIE, hemorrhage, malformations |
| 7. Metabolic/genetic workup | Amino acids, acylcarnitine, urine organic acids; consider genetic testing | Early diagnosis of inborn errors can guide specific treatment |
Algorithm B: Febrile Seizures (6 months – 5 years)
| Question | If Yes | If No |
|---|---|---|
| Is the child still seizing or was seizure >5 minutes? | Treat as status epilepticus; benzodiazepine; full workup | Proceed to next question |
| Are there signs of meningitis or CNS infection? | LP mandatory; empiric antibiotics; consider acyclovir | Proceed to next question |
| Is the child <6 months old? | This is NOT a simple febrile seizure; full workup including LP | Proceed to next question |
| Is the child 6-12 months AND unimmunized or on antibiotics? | Strongly consider LP (meningeal signs unreliable at this age) | Proceed to next question |
| Were there complex features? (focal, >15 min, recurrent in 24 hours, prolonged postictal) | Complex febrile seizure; period of observation; consider workup based on features | Simple febrile seizure |
| Simple febrile seizure confirmed? | Identify fever source; educate family; discharge with safety netting; no EEG/imaging/labs needed | Re-evaluate classification |
Key Points for Febrile Seizure Management
- No routine blood tests, EEG, or neuroimaging for simple febrile seizures
- Antipyretics do not prevent febrile seizures (but can be used for comfort)
- Recurrence risk: ~30% overall; higher if first seizure at younger age or lower fever threshold
- Epilepsy risk: ~1-2% for simple febrile seizures (only slightly above baseline)
- Parent education is the most important intervention — provide written information
Algorithm C: First Unprovoked Seizure (Any Age)
| Step | Action | Rationale |
|---|---|---|
| 1. Ensure back to baseline | Complete neurological examination; confirm return to normal function | Persistent deficits require urgent imaging and evaluation |
| 2. Detailed history | Event description; prodrome; postictal state; possible triggers; family history | Determines seizure type and guides further workup |
| 3. Obtain EEG | Routine EEG (ideally within 24-48 hours; captures sleep if possible) | Epileptiform abnormalities predict higher recurrence risk; helps classify epilepsy type |
| 4. Obtain MRI | MRI brain with epilepsy protocol (can be scheduled outpatient) | Identifies structural etiology in 10-20%; guides prognosis and treatment |
| 5. Decision: Treat or observe? | Discuss with family; consider recurrence risk and individual factors | After single seizure, recurrence risk ~30% over 2 years; treatment decision is individualized |
| 6. Seizure safety counseling | Water safety, heights, driving restrictions (adolescents), first aid | Essential for all patients regardless of treatment decision |
| 7. Neurology referral | Arrange follow-up with pediatric neurology | For ongoing management, EEG interpretation, treatment decisions |
Algorithm D: Status Epilepticus Protocol
Time-Based Status Epilepticus Protocol
Start the clock when seizure begins (or when you arrive if already seizing)
| Time | Stage | Actions |
|---|---|---|
| 0-5 minutes | Stabilization |
|
| 5 minutes | First-line therapy |
|
| 15-20 minutes | Second-line therapy |
|
| 30-40 minutes | Refractory status epilepticus |
|
| >40-60 minutes | Super-refractory status |
|
“What Do I Do If…” Decision Reference
| Clinical Situation | Immediate Action | Next Steps |
|---|---|---|
| Parent reports “staring spells” multiple times daily | Detailed history; attempt hyperventilation for 3 minutes in office to provoke event | EEG (looking for 3 Hz spike-wave); if absence epilepsy confirmed, ethosuximide or valproate |
| Infant with clusters of brief spasms, especially on waking | Urgent EEG (same day or next day); video if possible | If infantile spasms confirmed (hypsarrhythmia), start treatment within days; do not wait for MRI |
| 6-month-old with recurrent prolonged febrile seizures | Consider Dravet syndrome; avoid sodium channel blockers | Genetic testing for SCN1A; prescribe rescue benzodiazepine; neurology referral |
| Adolescent with morning jerks who drops things at breakfast | High suspicion for juvenile myoclonic epilepsy; history of sleep deprivation as trigger | EEG; counsel on sleep hygiene and avoiding alcohol; valproate or levetiracetam |
| Child has “seizure” with exercise; family history of sudden death | This may be cardiac syncope, not seizure; obtain ECG immediately | If prolonged QTc (>460 ms), cardiology referral urgently; genetic testing for long QT syndrome |
| Child has seizure and port-wine stain on face | Suspect Sturge-Weber syndrome | MRI with contrast (leptomeningeal angioma); ophthalmology referral (glaucoma risk); antiseizure medication |
| Neonate with seizures refractory to phenobarbital | Give pyridoxine 100 mg IV while monitoring EEG | If seizures stop, continue pyridoxine and test for pyridoxine-dependent epilepsy; comprehensive metabolic workup |
| Child with known epilepsy having more frequent seizures | Check medication adherence; recent illness; sleep deprivation; medication levels | Optimize current medication before adding second agent; review diagnosis if atypical |
| School reports child is “daydreaming” but child is interruptible | Likely not absence seizures (absences cannot be interrupted); consider ADHD or normal daydreaming | EEG if doubt remains; ADHD evaluation if appropriate |
| Toddler has event with crying, turning blue, then brief stiffening | Classic cyanotic breath-holding spell (NOT a seizure) | Reassurance; check iron studies (iron deficiency may increase spells); no antiseizure medication needed |
When to Start Antiseizure Medication
Generally START Treatment
- Two or more unprovoked seizures (meets criteria for epilepsy)
- Single seizure with high recurrence risk:
- Epileptiform EEG abnormalities
- Structural brain abnormality on MRI
- Significant neurological deficit
- Status epilepticus as first presentation
- Epilepsy syndrome diagnosed (e.g., juvenile myoclonic epilepsy)
- Infantile spasms (urgent treatment)
- High-risk occupation/activity (adolescent drivers)
May DEFER Treatment
- Single unprovoked seizure with:
- Normal EEG
- Normal MRI
- Normal neurological examination
- Benign rolandic epilepsy (may not require treatment)
- Childhood absence epilepsy with very infrequent seizures
- Patient/family preference after informed discussion
- Provoked seizures (treat underlying cause instead)
When to Refer to Pediatric Neurology
| Urgency | Indications |
|---|---|
| EMERGENT (same day) | Suspected infantile spasms; neonatal seizures; status epilepticus; new focal deficits; suspected epileptic encephalopathy |
| URGENT (within 1-2 weeks) | First unprovoked seizure; frequent seizures; suspected epilepsy syndrome; abnormal EEG requiring interpretation |
| ROUTINE (within 1-2 months) | Stable epilepsy for ongoing management; complex febrile seizures for counseling; medication adjustment |
Troubleshooting: Seizures Not Controlled
Ask These Questions When Seizures Persist Despite Treatment
- Is the diagnosis correct? Could these be non-epileptic events (psychogenic, cardiac, other)?
- Is the epilepsy syndrome correctly identified? Some medications worsen certain epilepsy types (e.g., carbamazepine worsening absence seizures)
- Is medication adherence adequate? Check levels; discuss barriers to adherence
- Is the dose optimized? Has the medication been titrated to adequate levels before adding another?
- Are there ongoing triggers? Sleep deprivation, illness, alcohol (adolescents), stress
- Is there a structural lesion amenable to surgery? Consider epilepsy surgery workup for drug-resistant focal epilepsy
- Has genetic testing been done? May identify precision therapy options
- Have dietary therapies been considered? Ketogenic diet effective for many refractory epilepsies
8. Clinical Pearls and Pitfalls
Practical wisdom — learn from experience and avoid common mistakes
Must-Know Clinical Pearls
Critical Pitfalls to Avoid
Key Takeaways
- Seizures are common in children — febrile seizures alone affect 2-5% of children, and most have an excellent prognosis.
- The diagnosis is clinical — a detailed history from an eyewitness is the most valuable diagnostic tool. Always ask for video.
- Status epilepticus is a time-sensitive emergency — give a benzodiazepine after 5 minutes of continuous seizure activity; do not wait.
- Age matters — the differential diagnosis, clinical presentation, and management vary significantly by age group.
- Not all paroxysmal events are seizures — breath-holding spells, syncope, and psychogenic events are common mimics.
- Simple febrile seizures require minimal workup — education and reassurance are the main interventions.
- Infantile spasms are a medical emergency — early treatment (within days) improves neurodevelopmental outcomes.
- Some medications can worsen certain epilepsy types — know which drugs are contraindicated in which syndromes.
- Normal examination and normal EEG do not exclude epilepsy — the diagnosis is primarily clinical.
- Seizure safety counseling is essential for every patient and family — this includes first aid, water safety, and activity restrictions.
Quick Reference Algorithm
Systematic Approach to Pediatric Seizures:
- Stabilize: If actively seizing, ensure ABCs, check glucose, give benzodiazepine if >5 minutes, time the seizure.
- Characterize: Was this truly a seizure? If so, what type? Obtain detailed eyewitness history and video if available.
- Classify: Is this a provoked seizure, unprovoked seizure, or non-epileptic event? Age and context are key.
- Investigate: Tailor workup to clinical scenario — simple febrile seizure needs little; neonatal seizure needs comprehensive evaluation.
- Identify: Look for underlying etiology (genetic, structural, metabolic, infectious, immune) and specific epilepsy syndrome.
- Treat: Address underlying cause if present; decide on antiseizure medication based on recurrence risk and syndrome.
- Educate: Provide seizure first aid training, safety counseling, and written information to all families.
- Refer: Involve pediatric neurology for unprovoked seizures, epilepsy diagnosis, or any diagnostic uncertainty.
- Follow up: Ensure appropriate monitoring, medication adjustment, and ongoing support for children with epilepsy.