Paediatric Neurology Tutorial Prep: Gait Disturbances & Seizures/Epilepsy

Synthesised for HKU MBBS VI Paeds & Adolescent Medicine rotation — exam/OSCE/ward-ready, MRCPCH-trajectory

Sources integrated: - [Gait26] Bandi V & Nallu. Approach to a Child with Gait Disturbances. Advances in Pediatrics 73 (2026):323–334. - [ILAE17] Scheffer/Fisher et al. ILAE position papers + teaching slide deck — ILAE Classification of the Epilepsies and Operational Classification of Seizure Types (Epilepsia 2017). - [F&W20] Fine A & Wirrell EC. Seizures in Children. Pediatrics in Review 41(7):321–347, 2020.

⚠️ Upfront gap flag: none of these three sources are Hospital Authority (HA)/Hong Kong-specific. All drug-dosing, rescue-medication routes, and referral thresholds below are US/international (NICE/ILAE/AAP-derived). Cross-check against HA paediatric formulary and local Child Neurology/Child Assessment Service referral pathways before applying doses on the ward or in OSCE HA-context answers. Specific points flagged again inline where relevant.

PART 1 — APPROACH TO THE CHILD WITH GAIT DISTURBANCE [Gait26]

1.1 Epidemiology & framing

  • 5.3% of US children aged 3–17y report dizziness/balance problems (p.323); ~90% of children with gait disorders are non-specifically labelled “unspecified dizziness” — reflects a diagnostic gap, not a benign entity by default.
  • Pediatric ataxia/cerebellar disorder prevalence: ~26/100,000 (Europe), 21.9/100,000 (Finland) — likely underestimates true burden.

1.2 Normal gait development (know these milestones cold)

Age Gait feature
12–15 mo Independent walking begins
Early walking Wide base, short steps, ↑cadence, ↑double-support time
2–3 y Mature heel-strike pattern; stride-to-stride variability still high
3–6 y ↑speed & stride length, ↓base of support, ↓intra-individual variability (stride width variability persists)
7–8 y Adult-like velocity, stride length, support phases; straight-line walking stability approaches adult level by age 7
Adolescence Fine-tuning of stride dynamics continues with limb growth

Terminology (Table 1, p.324): velocity (distance/time), cadence (steps/min), stride length (one full gait cycle), step length (single-leg swing phase distance), step width/base (distance between feet).

1.3 Normal variants — know resolution ages (common “reassure vs refer” exam trap)

Normal variant Expected resolution age
Toe walking 3 y
In-toeing 8 y
Internal tibial torsion 3 y
Metatarsus adductus 6 y
Genu varum (bowlegs) 18 mo
Genu valgum (knock knees) 7 y
Flat feet 6 y

Rule: if persistent beyond these ages, progressive, or painful → investigate further. Pain at any age with a gait variant is a red flag regardless of the “expected” age.

1.4 Structured gait examination

  1. Observe the child walking down a long hallway at max comfortable speed (uncovers subclinical spasticity).
  2. Assess: symmetry → stride length → step length → velocity → cadence → step base → posture, arm swing, leg stiffness, knee lift, pelvic lurch.
  3. Bedside manoeuvres:
    • Gowers sign — rising from floor without using arms → reveals proximal weakness.
    • Heel/toe walking → reveals distal weakness.
    • Romberg test (feet together, eyes open→closed) + tandem (heel-to-toe) walking → sensory ataxia vs dynamic balance.
    • Trendelenburg test (single-leg stance, watch contralateral pelvic drop) → hip abductor/proximal weakness.
  4. Full neuro exam: bulk, tone, sensation, reflexes.

1.5 Neurologic gait patterns — master comparison table

Disorder Pathophysiology Classic gait pattern Key exam findings First-line Ix Key management points
Spasticity (bilateral = paraparesis) UMN, velocity-dependent hypertonia, co-contraction of antagonists Scissoring (adductor spasticity), equinus/forefoot strike & scraping, ↓foot clearance Hyperreflexia, extensor plantar (Babinski +ve), ↑tone, weakness Brain + spine MRI first; metabolic/genetic panel if imaging normal (r/o CP mimics) PT > baclofen/Botox/SDR in benefit; target functional goals, not tone alone — treating spasticity in isolation can worsen function if weakness/instability coexist
Spasticity (unilateral = hemiparesis) Same, asymmetric Circumduction gait (compensatory pelvic swing), ipsilateral arm posturing (forearm pronation, elbow flexion) As above, asymmetric As above As above
Dystonia Basal ganglia dysfunction; NOT velocity-dependent (key distinguisher from spasticity) Leg extension, ankle inversion, toe walking, in-toeing; described patterns: “dragging leg,” “hobby horse gait,” “high-stepping cock-walk gait” Fluctuates with task (task-specific), improves with sensory trick; look for co-existing spasticity/myoclonus (combined/syndromic dystonia) MRI brain first → thyroid profile, serum urate (Lesch-Nyhan), blood film (acanthocytosis), copper/ceruloplasmin (Wilson), paired blood/CSF glucose (GLUT-1), CSF neurotransmitters; genetic testing if monogenic suspected (DYT1, DYT11, PANK2/PLA2G6) Intrathecal baclofen, Botox, gabapentin, clonidine, trihexyphenidyl; empirical levodopa trial for dopa-responsive dystonia or dystonia of unknown cause; GLUT-1 defect → ketogenic diet; DBS if primary dystonia refractory
Chorea / Athetosis Basal ganglia circuit dysfunction (different levels) Chorea: unpredictable brief jerks → instability, falls. Athetosis: continuous slow writhing (distal) → undulating/snakelike gait “Choreoathetosis” common (dyskinetic CP, Sydenham chorea); assess for hypotonia/weakness compounding gait Consider autoimmune workup (anti-NMDAR), genetic (NKX2-1 = benign hereditary chorea; ADCY5 = early-onset generalized chorea w/ perioral & facial involvement; GNAO1 = life-threatening fluctuations) Levetiracetam, tetrabenazine, valproate for symptoms; treat underlying cause; DBS effective for GNAO1-related life-threatening exacerbations
Myoclonus Cortical/subcortical/brainstem/spinal; abnormal neuronal excitability + ↓inhibitory control Wide-based, irregular gait 2° jerks at variable points in the cycle → falls Rest/action-triggered/stimulus-driven = cortical nonepileptic; irregular = subcortical; rhythmic = cortical epileptic; ± ataxia (progressive myoclonus epilepsies) or dystonia (SGCE myoclonus-dystonia) Video-EEG to distinguish epileptic vs non-epileptic myoclonus AEDs for epileptic myoclonus; nonepileptic (e.g., opsoclonus-myoclonus) often treatment-resistant, target underlying disorder
Sensory ataxia Proprioceptive loss High-stepping/stamping gait, audible heel “slap” (compensatory sensory feedback), mild wide base +ve Romberg, ↓/absent DTRs; worse in the dark/eyes closed Nerve conduction studies; B12; consider HSAN Treat underlying neuropathy
Cerebellar ataxia Cerebellar/cerebellothalamocortical dysfunction (vermis) Slow, wide-based, ↓stride length; “stumbling/lurching/drunken” Scanning speech, dysmetria, dysdiadochokinesia; Romberg unsteady regardless of eyes open/closed (distinguishes from sensory ataxia) See ataxia deep-dive below See below
Neuropathy (LMN) Anterior horn cell/root/peripheral nerve Steppage (high-stepping) gait — compensatory hip/knee flexion for foot drop, audible slap; knee-extensor weakness → knee buckling Preserved DTRs except in neuropathy’s distribution, low-normal tone, iliopsoas spared, no bladder involvement (except cauda equina) NCS/EMG; genetic panel (e.g., CMT) Treat reversible causes (B12 deficiency, CIDP, vasculitis); genetic counselling for hereditary neuropathies
Myopathy Symmetric proximal muscle weakness Waddling gait: ↑step base, compensatory pelvic tilt/lordosis; may progress toe-walking (e.g. DMD) Symmetric & proximal, reflexes relatively preserved, no sensory involvement, tone preserved; +ve Trendelenburg & Gower Genetic studies, muscle biopsy; NCS w/ repetitive stimulation for myasthenia gravis/congenital myasthenic syndromes Screen reversible causes: thyroid/parathyroid disease, vitamin E deficiency

1.5a Ataxia deep-dive (high MRCPCH yield)

  • Acute/reversible: acute cerebellitis, post-infectious acute cerebellar ataxia, Miller Fisher variant of GBS — usually resolve ± treatment.
  • Ataxia telangiectasia (AT): ↑serum AFP aids early diagnosis (ocular telangiectasia appears later in childhood) — avoids unnecessary radiation exposure (AT patients are radiosensitive).
  • Friedreich ataxia (FA): multisystem — ataxia + cardiomyopathy + diabetes + axonal neuropathy + areflexia + extensor plantar response; no cure, lifelong MDT care.
  • Treatable ataxias: abetalipoproteinaemia, vitamin E deficiency ataxia, Hashimoto encephalopathy.
  • Episodic ataxias: genetically heterogeneous; episodic ataxia type 2 responds to acetazolamide — worth naming on exams as a treatable subtype.

1.5b Dystonia deep-dive: paroxysmal dystonias

Trigger type Trigger Between-episode state Treatment
Kinesogenic Sudden movement change Asymptomatic Carbamazepine
Non-kinesogenic Caffeine, alcohol Asymptomatic Avoid triggers
Lance-type (exertional) Prolonged exercise Asymptomatic Avoid triggers
  • Diurnal fluctuation (mild AM, worse by evening) = classic dopa-responsive dystonia (Segawa disease) — circadian nigrostriatal dopamine changes.

1.6 Functional gait disorder

  • Positive clinical signs support early diagnosis (don’t just wait to exclude organic disease): inconsistency, incongruence, variability, distractibility; excessive slowness, dragging one leg, astasia-abasia (can’t stand/walk), exaggerated effort (“huffing and puffing”), knee buckling, falling toward support, non-economic posture.
  • Improvement with distraction, dramatic pattern shifts, reversion to normal gait in a different context (e.g. running/playing).
  • Exam traps:
    • Bizarre gait ≠ automatically functional — dystonia can look bizarre too, but dystonic gait is consistent (same pattern reproduces at the same point in the cycle each time) — exception: lower-limb dystonia can show forward-walking-triggers/backward-walking-resolves pattern, which can mimic inconsistency.
    • Cautious gait ≠ always functional — can reflect a frontal/apraxic gait disorder.
  • History: recent psychosocial stressors, illness, trauma.
  • Management: basic Ix still reasonable (reassurance); be honest and transparent with families about the absence of an organic explanation; avoid over-investigation; refer early to multidisciplinary rehabilitation — many young children respond well.

1.7 Bottom-line clinical pearls for OSCE

  • Spasticity = velocity-dependent; Dystonia = not velocity-dependent — this single fact is a classic distinguishing exam question.
  • Positive Romberg + preserved cerebellar signs absent = sensory ataxia; unsteady regardless of eyes open/closed = cerebellar.
  • Imaging (brain + spine) precedes metabolic/genetic workup in spasticity evaluation.
  • AFP → think Ataxia-Telangiectasia in a young child with unexplained ataxia (before telangiectasia is visible).

PART 2 — SEIZURES & EPILEPSY: ILAE 2017 CLASSIFICATION & CLINICAL APPROACH [ILAE17] [F&W20]

2.1 Core definitions (MUST know verbatim)

Epilepsy = any ONE of: 1. ≥2 unprovoked (or reflex) seizures occurring >24h apart, OR 2. 1 unprovoked/reflex seizure with ≥60% probability of recurrence over the next 10 years, OR 3. Diagnosis of an epilepsy syndrome.

Febrile seizure: age 6mo–5y, temp >38.3°C (>100.9°F), no CNS infection, no prior epilepsy. - Simple: generalized, <10–15 min, once per 24h. - Complex: focal, prolonged (>10–15 min), or recurs within 24h.

2.2 The ILAE diagnostic framework (4 tiers, applied at every level)

Seizure type → Epilepsy type → Epilepsy syndrome, with Etiology and Comorbidities considered at every stage (not just at the end).

  • Seizure types: Focal onset / Generalized onset / Unknown onset.
  • Epilepsy types: Focal / Generalized / Combined generalized & focal (new in 2017; e.g. Dravet syndrome) / Unknown.
  • Epilepsy syndrome: identified by cluster of age of onset, seizure type(s), EEG features, etiology, and associated features (neurocognitive delay, exam findings, imaging).
  • Etiology (6 categories, not mutually exclusive — see 2.7 below).

Exam trap: “Seizure type” and “Epilepsy type” are DIFFERENT classification tiers — students commonly conflate them. A patient can have a focal seizure within a combined generalized-and-focal epilepsy (e.g. Dravet syndrome).

2.3 ILAE 2017 Seizure Classification

Basic version

Focal Onset Generalized Onset Unknown Onset
Aware / Impaired awareness Motor: tonic-clonic, other motor Motor: tonic-clonic, other motor
Motor onset / Nonmotor onset Nonmotor (absence) Nonmotor
→ may evolve to focal to bilateral tonic-clonic Unclassified

Expanded version

  • Focal onset — Motor onset: automatisms, atonic, clonic, epileptic spasms, hyperkinetic, myoclonic, tonic (*awareness level not specified for atonic/spasms)
  • Focal onset — Nonmotor onset: autonomic, behaviour arrest, cognitive, emotional, sensory
  • Generalized onset — Motor: tonic-clonic, clonic, tonic, myoclonic, myoclonic-tonic-clonic, myoclonic-atonic, atonic, epileptic spasms
  • Generalized onset — Nonmotor (absence): typical, atypical, myoclonic, eyelid myoclonia
  • Unknown onset — Motor: tonic-clonic, epileptic spasms; Nonmotor: behaviour arrest
  • Unclassified category exists for insufficient information.

Notes/pitfalls (verbatim from ILAE teaching slides): - Pedalling is grouped under hyperkinetic, not automatisms (arbitrary convention — worth memorising as an exam distractor). - Cognitive seizures include impaired language, other cognitive domains, and positive features (déjà vu, hallucinations, perceptual distortions). Emotional seizures include anxiety, fear, joy. - When a seizure type begins with “focal,” “generalized,” or “absence,” the word “onset” is presumed (e.g., “generalized tonic-clonic” = “generalized-onset tonic-clonic”). - Common descriptors (Table 1 of instruction manual) — e.g. dystonic posturing, Jacksonian march, figure-of-4 sign, versive, gelastic/dacrystic — clarify seizure features but do NOT define unique seizure types. Free-text descriptors are encouraged.

Useful abbreviations: FAS (focal aware seizure), FIAS (focal impaired awareness seizure), FMS/FNMS (focal motor/nonmotor seizure), FES (focal epileptic spasm), FBTCS (focal to bilateral tonic-clonic seizure), GTCS (generalized tonic-clonic seizure), GAS (generalized absence seizure), GMS/GES (generalized motor/epileptic spasm seizure), UTCS (unknown-onset tonic-clonic seizure).

Terms retired — DO NOT use on exams

Complex partial, simple partial, partial, psychic, dyscognitive, secondarily generalized tonic-clonic.

2.4 Terminology evolution — old vs new (frequently tested)

Old term New/current term Notes
Idiopathic Generalized Epilepsies (IGE) Genetic Generalized Epilepsies — includes CAE, JAE, JME, GTCS alone “Idiopathic” = presumed hereditary predisposition (a clinical inference); “genetic” is the umbrella diagnostic category now used
Symptomatic Generalized Epilepsies Split into: (1) Developmental and/or Epileptic Encephalopathies and (2) (Static) Encephalopathy with Epilepsy Two distinct concepts previously conflated under one old label
“Benign” (e.g. Benign Rolandic Epilepsy) Self-limited / Pharmacoresponsive Many “benign” epilepsies are NOT benign — CAE has psychosocial impact, BECTS has learning concerns
“Malignant” / “Catastrophic” Retired — no longer used
  • Genetic ≠ inherited: de novo mutations matter in both mild and severe epilepsies. Important to avoid stigma, particularly relevant in some cultural/regional contexts.
  • Genetic ≠ gene testing: the causative mutation is often not known; access to molecular testing is not required to make a “genetic” diagnosis — historically these were diagnosed by twin and family studies (classic teaching images: JME twin pair, Lennox 1941; CAE twin pair, Lennox 1950).

2.5 Developmental and/or Epileptic Encephalopathy (DEE) — key concept

  • Epileptic activity itself contributes to cognitive/behavioural impairment above and beyond what the underlying pathology would cause alone, and this can worsen over time (Berg et al 2010).
  • Developmental encephalopathy: developmental component independent of seizures; may begin in utero or post-birth; developmental delay may precede seizure onset; co-morbidities include CP, ASD, intellectual disability.
  • Epileptic encephalopathy: can occur at any age; may have a remediable component (right vs wrong AED choice can change outcome).
  • Outcome can remain poor even after seizures stop in some cases (e.g. KCNQ2, STXBP1 encephalopathies) — reflects the developmental component.
  • Move toward gene-named encephalopathies as nosology (e.g., CDKL5 encephalopathy, SCN2A encephalopathy) rather than purely descriptive syndrome names.

2.6 Etiology — 6 categories (consider at ALL stages of workup, not just at the end)

Category Definition Examples
Structural Congenital or acquired structural brain abnormality Cortical dysplasia (congenital); stroke, trauma (acquired); unilateral mesial temporal sclerosis (resective surgery often curative despite drug resistance)
Genetic Epilepsy is the direct result of a known/presumed genetic defect; seizures are the core symptom CAE, JAE, JME, GTCS alone (heritable, family/twin evidence); CDKL5, ARX, Dravet syndrome, PCDH19 female-limited epilepsy, Down syndrome (poorer prognosis subset)
Infectious Epilepsy directly results from a known infection, seizures are a core symptom Neurocysticercosis, TB, HIV, cerebral malaria, cerebral toxoplasmosis, congenital Zika/CMV
Metabolic Documented metabolic condition substantially increasing epilepsy risk GLUT-1 deficiency, creatine deficiency syndromes, mitochondrial cytopathies (often also “metabolic-genetic” if inherited)
Immune Clinical evidence of immune disorder with seizures as core symptom; CSF/imaging inflammatory changes; specific autoantibodies often found Anti-NMDAR encephalitis, mGluR5-associated limbic encephalitis, Rasmussen syndrome (nonspecific VGKC antibodies are usually not causal)
Unknown Normal imaging, no genetic/metabolic/immune/infectious cause identified —
  • Categories are not mutually exclusive: Tuberous sclerosis = genetic-structural; Leigh syndrome = genetic-metabolic; GLUT-1 deficiency = genetic-metabolic.
  • Etiology remains unknown in nearly half of paediatric epilepsy patients [F&W20, p.322].

2.7 Clinical approach algorithm (8-step, Fig 1 [F&W20])

  1. Is it a seizure? — exclude mimics (25% misdiagnosis rate; ~25% of “first seizure” referrals are not epileptic events). Focal seizures often have an aura (localising); generalized seizures do not. Post-ictal state (sleepy/confused ± Todd paresis/language deficit) typical of convulsive/awareness-impairing seizures.
  2. If a seizure, is it provoked? — exclude fever, intracranial infection, electrolyte disturbance, hypoglycaemia, TBI.
  3. What type of seizure is it? (focal/generalized/unknown onset, per 2.3 above).
  4. Is this epilepsy? (per definition in 2.1).
  5. What is the epilepsy type? (focal/generalized/combined/unknown, per 2.6 concept).
  6. Is there an epilepsy syndrome? (see 2.9 table below; consult epilepsydiagnosis.org).
  7. What is the etiology? (6 categories above).
  8. What comorbidities are present? (see 2.13 table).

2.8 Seizure mimics — high-yield by age [F&W20, Table 1, pp.324–326]

Mimic Peak age Key distinguishing clues
Benign sleep myoclonus Neonate/early infant Sleep-only, resolves on waking, otherwise well
Jitteriness Neonate Stimulus-provoked, suppressible by holding limb, non-anatomical spread
Benign myoclonus of infancy Infancy Brief (<5s) jerks, no altered awareness, wake+sleep
Shuddering attacks Late infancy Shivering-like, provoked by excitement/frustration
Breath-holding spells (cyanotic/pallid) Infancy–early childhood Triggered by pain/crying/fright; colour change
Sandifer syndrome Infancy–early childhood Back-arching + dystonic posturing, provoked by feeding/lying flat, GERD-related
Stereotypies Infancy–childhood Interruptible, more common in autism/ID
Hyperekplexia Infancy–adolescence Excessive glabellar-tap startle, non-habituating
Self-stimulatory behaviour Early childhood Rhythmic hip flexion/adduction, interruptible
Benign paroxysmal vertigo Early childhood Sudden imbalance/anxiety, grasps parent, ± nystagmus
Cyclic vomiting Childhood Hours-long emesis episodes, symptom-free weeks between
Daydreaming Childhood Interruptible by tactile stimulation, quiet-activity context
Parasomnias Childhood (rarely adol.) First few hours of sleep, >3–5 min, vs. nocturnal frontal lobe seizures (brief <2min, very frequent)
Tantrums/rage attacks Childhood–adolescence Consciousness preserved; rage reactions disproportionate, can last 30+ min
Tics Childhood–adolescence Suppressible, abate in sleep
Periodic limb movements in sleep Childhood–adolescence Resolve with waking
Vasovagal syncope Childhood–adolescence Prodrome (lightheaded, blurred vision, pallor, diaphoresis), rapid recovery
POTS Adolescence Standing-provoked, resolves lying/sitting
Panic attacks Adolescence Aware throughout, no post-ictal confusion
Narcolepsy/cataplexy Adolescence Cataplexy w/ strong emotion, hypnagogic hallucinations, sleep paralysis
Hemiplegic migraine Adolescence Aura of focal weakness/speech/visual/sensory before headache; +ve FHx
Psychogenic nonepileptic spells Adolescence Prolonged (>15–30min), minimal post-ictal phase, refractory from onset
Cardiac syncope (long QT) Any age Triggered by fright/exercise/water immersion; +ve FHx of syncope

2.9 Epilepsy syndromes by age of presentation — condensed high-yield table [F&W20, Table 2]

Neonatal/Infantile onset

Syndrome Seizure types Development Key investigations Natural history
Benign familial neonatal seizures Focal clonic/tonic ± apnoea/cyanosis Normal EEG/MRI normal; KCNQ2 (AD, incomplete penetrance), rarely KCNQ3/SCN2A Remits by 6mo; 10–30% seizures later in life
Early myoclonic encephalopathy Focal/multifocal myoclonus, focal seizures Profoundly impaired EEG suppression-burst; MRI usually normal; metabolic/genetic w/u Drug-resistant; early mortality (profound impairment)
Ohtahara syndrome Tonic spasms, focal seizures Delayed, often severe EEG suppression-burst; MRI often structural lesion; genetic/metabolic if MRI normal Drug-resistant; early mortality; surgical resection may improve outcome in select cases
Epilepsy in infancy with migrating focal seizures Multifocal clonic/tonic, subtle, autonomic features Severe delay EEG slow background + multifocal ictal/interictal; MRI mild global atrophy; r/o KCNT1, SCN2A, congenital disorders of glycosylation Drug-resistant; early mortality
West syndrome Clusters of epileptic spasms Normal→severe delay EEG hypsarrhythmia; MRI often structural 70–90% develop ID over time; often evolves to other drug-resistant epilepsies (focal/multifocal or Lennox-Gastaut)
Dravet syndrome Hemiconvulsive, prolonged, fever-triggered → later other seizure types (myoclonic, absence, atonic, GTCS) Normal at onset → all develop variable ID over time (evident by late preschool) MRI normal/mild atrophy; >85% have pathogenic SCN1A Seizures remain drug-resistant
Benign familial/nonfamilial infantile epilepsy Brief focal seizures in clusters Normal EEG/MRI normal; PRRT2, SCN2A, KCNQ2/3 Remits within 1y of onset
Myoclonic epilepsy in infancy Myoclonic, startle/noise/touch-activated Normal onset, minority develop delay EEG generalized spike-wave; MRI normal Remits by 5mo–6y typically; 10% develop other seizure types later
Genetic epilepsy with febrile seizures plus (GEFS+) Variable — febrile seizures persisting >6y, or generalized/focal Normal EEG usually normal; +ve FHx Self-limited, remits by puberty

Childhood onset

Syndrome Seizure types Development Key investigations Natural history
Childhood absence epilepsy (CAE) Typical absence, multiple/day Normal but ↑learning/ADHD rates EEG 3-Hz generalized spike-wave, hyperventilation-triggered Most remit by late childhood; minority develop GTCS in adolescence
Epilepsy with myoclonic absences Absence + rhythmic myoclonic jerks (upper limb) ± tonic arm abduction ~50% mild ID Ictal EEG 3-Hz generalized spike-wave time-locked to jerks Variable; ~40% remission; better prognosis if myoclonic absence is the only seizure type
Epilepsy with eyelid myoclonia Eyelid myoclonia (4–6Hz) + upward eye deviation, often + brief absence Most normal, some borderline/ID Eye closure/photic stimulation triggers; generalized polyspike-wave Drug-resistant, especially eyelid myoclonia; remission rare
Myoclonic atonic epilepsy Myoclonic-atonic (classic) + atypical absence, GTCS, atonic, tonic Normal onset, cognition slows during frequent-seizure periods EEG evolves to high-amplitude 2–5Hz generalized spike-wave ~2/3 remit by early-mid childhood; 1/3 persistent (earlier onset, more tonic seizures)
Lennox-Gastaut syndrome Atonic, tonic, atypical absence, myoclonic, focal, GTCS; nocturnal tonic seizures = early clue Delayed before onset, worsens over time EEG diffuse slow spike-wave (<2Hz) + generalized paroxysmal fast activity in sleep Does not remit; drug-resistant
Epileptic encephalopathy w/ electrical status epilepticus in sleep (ESES) Focal ± impaired awareness + generalized (absence, atonic) Regression in cognition/behaviour coincides with continuous spike-wave in sleep on EEG Interictal wakeful EEG focal/multifocal; sleep EEG near-continuous spike-wave Must treat both seizures AND the EEG pattern; relapses common until adolescence when it tends to remit; many left with ID
Panayiotopoulos syndrome Focal + prominent autonomic (retching), eye deviation, peri-sleep Normal Occipital/centrotemporal/parietal spikes, ↑sleep Remits 1–2y; excellent cognitive/social outcome
Benign epilepsy w/ centrotemporal spikes (BECTS) Focal (face/tongue/drooling/dysarthria) → may 2° generalize in sleep; peri-sleep Normal Centrotemporal spikes, ↑sleep Remits 1–2y; excellent outcome
Gelastic seizures w/ hypothalamic hamartoma Gelastic/dacrystic (laughing/crying, not emotion-triggered) Normal onset → behavioural/cognitive issues over time Temporal discharges early → evolves to generalized spike-wave Refractory but may respond well to surgery

Adolescent onset / Variable age

Syndrome Seizure types Development Key investigations Natural history
Juvenile absence epilepsy (JAE) Typical absence (less frequent than CAE) + GTCS within a few years Normal, ↑ADHD/learning disorders 3–4Hz generalized spike-wave Drug-responsive but low remission rate
Juvenile myoclonic epilepsy (JME) Early-morning myoclonus (sleep-deprivation-triggered) + GTCS; ~40% also absence Normal cognition, ↑ADHD Fast generalized atypical spike-wave, photic-triggered Drug-responsive, low remission rate — usually lifelong AED
Epilepsy with GTCS alone GTCS, sleep-deprivation triggered Normal Generalized polyspike/spike-wave Drug-responsive, low remission rate
Sleep-related hypermotor epilepsy Brief, frequent, explosive hypermotor + vocalization, from sleep Usually normal (ID possible) Often normal interictal EEG; may show frontal discharges Variable, depends on etiology; CHRNA4 gene
Mesial temporal lobe epilepsy Focal aware/impaired-awareness → bilateral convulsive; auras (epigastric rising, déjà/jamais vu, olfactory/gustatory) May be normal but memory complaints common Frontotemporal/temporal slowing or discharges Often drug-resistant, esp. w/ structural etiology (mesial temporal sclerosis) — surgery may be curative
Rasmussen syndrome Progressively worsening focal motor → epilepsia partialis continua Normal at onset → progressive hemiparesis/hemianopia ± language deficits (dominant hemisphere) Progressive unihemispheric atrophy on MRI, ↑ipsilateral hemispheric discharges over time Drug-resistant; most require hemispherotomy
Febrile infection-related epilepsy syndrome (FIRES) Focal/multifocal onset after nonspecific febrile illness → rapid progression (3–7 days) to superrefractory status epilepticus Normal at onset Diffuse slowing + multifocal discharges/seizures High morbidity/mortality; survivors often drug-resistant with moderate-severe cognitive delay

Genotype-phenotype pearls: SCN1A → Dravet (AVOID Na-channel blockers — see 2.11c); KCNQ2/3 → benign familial neonatal epilepsy (responds to Na-channel blockers) OR KCNQ2 encephalopathy (different phenotype, same gene); KCNT1 → migrating focal seizures of infancy (responds to quinidine); mTOR pathway genes → tuberous sclerosis/FCD type II (mTOR inhibitors, vigabatrin); GRIN2A → epilepsy-aphasia spectrum (memantine); SCN2A/SCN8A gain-of-function → migrating focal epilepsy of infancy (Na-channel blockers — note this is the OPPOSITE therapeutic direction from SCN1A loss-of-function/Dravet — classic exam trap).

2.10 Investigations

EEG

  • Recommended (wake and sleep) for any child with a first unprovoked seizure.
  • Purpose: assess background (focal lesion clue), confirm epileptiform activity, exclude subtler seizures, estimate recurrence risk, classify syndrome, guide medication choice.
  • Timing: some evidence for higher yield within 24h of the seizure, but this is often impractical; postictal slowing can persist 24–48h and must be interpreted cautiously.
  • Activation procedures (higher yield in children than adults): hyperventilation (activates generalized epileptiform discharges/absence seizures), photic stimulation 1–3Hz (occipital spikes classic in neuronal ceroid lipofuscinosis; photoparoxysmal response in Dravet, myoclonic-atonic epilepsy, JME).
  • Sleep deprivation increases yield for focal epileptiform abnormalities, ESES evaluation, and generalized paroxysmal fast activity in LGS.
  • Caveats (exam-favourite list):
    • Some EEG findings are normal variants limited to childhood — needs pediatric-EEG-trained reader.
    • Epileptiform discharges seen in ~3% of healthy children without epilepsy (higher in autism/ADHD) → EEG alone cannot diagnose epilepsy.
    • ~10% of patients with epilepsy have a normal EEG.
    • Breach rhythm (post-craniotomy/shunt) can mimic focal epileptiform activity if reader unaware of surgical history.

Neuroimaging

  • Urgent imaging (often CT in ED, though lower yield/radiation risk) limited to suspicion of acute intracranial process: stroke, CNS infection, haemorrhage, tumour.
  • Most children with generalized-onset seizures + normal development + normal exam do not need imaging.
  • Most children with focal-onset seizures should get elective MRI (seizure/epilepsy protocol: thin hippocampal cuts, double inversion recovery for cortical malformations) — EXCEPT clearly defined self-limited focal syndromes (BECTS, Panayiotopoulos).
  • MRI indicated for: neonatal seizures (structural causes common — HIE, infarct, haemorrhage, cortical malformation), new-onset afebrile seizure before age 3y.
  • Imaging not indicated for simple febrile seizures; indicated for complex febrile seizures with focal signs, postictal deficits, or febrile status epilepticus.

Metabolic workup

  • First afebrile seizure: glucose, electrolytes (+Ca/Mg), renal function (weak evidence base, but standard practice).
  • More extensive IEM workup if: unexplained global delay/regression, organomegaly, unusual odour, acute presentation w/ altered consciousness/multiorgan dysfunction/vomiting, similarly-affected siblings.

Treatable metabolic etiologies — [F&W20, Table 4] — high MRCPCH yield: | Etiology | Clinical clues | Treatment | |—|—|—| | Pyridoxine-dependent / pyridoxal-5-phosphate-dependent epilepsy | Early-onset refractory epilepsy, encephalopathy, developmental delay | Pyridoxine supplementation | | Biotinidase deficiency | Early-onset epilepsy (myoclonic/tonic-clonic/spasms), delay, skin rash, vision/hearing loss | Biotin supplementation | | GLUT-1 deficiency | Neonatal/infantile-onset epilepsy, early-onset absence <3y, delay, microcephaly, ataxia | Ketogenic diet | | Cerebral folate deficiency | Intractable GTCS in infancy/childhood | Folinic acid | | Creatine deficiency (GAMT/AGAT/CRTR) | Infantile-onset epilepsy, ID/delay, microcephaly, ASD | GAMT: oral creatine + ornithine + arginine-restricted diet; AGAT: oral creatine | | Serine deficiency | Microcephaly, intractable epilepsy, severe delay | L-serine ± glycine | | Late-infantile NCL (CLN2) | Developmental regression, myoclonic epilepsy, vision loss | Cerliponase alfa (recombinant TPP1) |

Exam pearl: absence seizure onset <4 years → think GLUT-1 deficiency [ILAE17 teaching site caution]. Also, an individual absence seizure >45 seconds or with a post-ictal phase should make you reconsider focal seizure rather than absence.

Genetic testing

  • High yield in early-onset epilepsies: 83% yield in neonatal-onset epileptic encephalopathy w/ pathogenic mutation; 30% found structural brain malformation; 40% causal mutation yield in epilepsy onset <3y (>15% yield regardless of delay/seizure type/age).
  • Should include chromosomal microarray + epilepsy gene panel; whole exome sequencing (WES) commonly considered.
  • Other indications: unexplained delay, dysmorphic features, structural brain abnormalities, unexplained drug-resistant epilepsy.

Actionable genetic epilepsies — [F&W20, Table 5] — SAFETY-CRITICAL, memorise: | Gene | Syndrome | Therapy implication | |—|—|—| | KCNQ2/KCNQ3 | Benign familial neonatal epilepsy | Na-channel blockers (carbamazepine, oxcarbazepine, phenobarbital, phenytoin) effective; ketogenic diet if KCNQ2 encephalopathy refractory | | SCN1A | Dravet syndrome, GEFS+, febrile seizures, mesial temporal sclerosis | ⚠️ AVOID sodium channel blocking medications (worsens seizures) | | KCNT1 | Epilepsy in infancy with migrating focal seizures | Quinidine | | mTORopathies | Tuberous sclerosis, FCD type II, familial focal epilepsy w/ variable foci | mTOR inhibitors (sirolimus, everolimus); vigabatrin | | GRIN2A | Epilepsy-aphasia spectrum disorders | Memantine | | SCN2A/SCN8A (gain-of-function) | Migrating focal epilepsy of infancy | Sodium channel blockers effective (opposite direction to SCN1A — do not confuse!) | | CHRNA4 | Sleep-related hypermotor epilepsy | Avoid benzodiazepines; nicotine supplementation |

Immune workup

  • Suspect autoimmune epilepsy if: acute-onset seizures, drug-resistant, encephalopathy + other neuro signs (esp. movement disorders) in a previously healthy child; ↑suspicion if personal/family history of autoimmune disease (T1DM, thyroid disease, RA).
  • Workup: inflammatory markers (ESR, CRP), CSF cell count/protein/IgG/IgG index, CSF+serum neuronal autoantibodies, antithyroid antibodies.
  • Anti-NMDAR encephalitis = most common paediatric autoimmune epilepsy — new-onset seizures + encephalopathy + personality change + orofacial dyskinesias; confirmed by serum/CSF anti-NMDAR antibodies; responds favourably to immunotherapy.
  • Rasmussen syndrome: felt immune-mediated but neuronal antibodies typically absent and poorly responsive to immunotherapy — hemispherectomy usually required.
  • FIRES: not felt to be truly immune-mediated (overwhelming neuroinflammation instead); poor prognosis.

Infectious workup

  • Pursue in any new-onset seizure with fever.
  • Lumbar puncture strongly recommended: febrile seizure in first 12 months of life (certainly first 6 months), or febrile status epilepticus.
  • Neuroimaging to exclude space-occupying lesion before LP if focal neuro deficits present.

2.11 Management

First-line AEDs — weight-based dosing [F&W20, Table 6]

Medication Main use Dose range (monotherapy) Common adverse effects
Ethosuximide Absence epilepsy 20–60 mg/kg/day GI upset, nausea, ↓appetite
Lamotrigine Focal, GTCS 5–13 mg/kg/day Drug rash / Stevens-Johnson syndrome
Levetiracetam Focal, absence, myoclonic, GTCS 40–60 mg/kg/day Mood changes (irritability, anger, sadness, depression)
Oxcarbazepine Focal 600–2,100 mg/day ÷ BID Rash, hyponatraemia
Topiramate Focal, generalized 200–400 mg/day ÷ BID Word-finding difficulty, weight loss, ↓sweating
Valproic acid Focal, absence, myoclonic, GTCS 25–60 mg/kg/day ÷ 2–3x/day ↑appetite, hair loss, PCOS; also teratogenic — caution in females of reproductive potential (not explicitly stated in source but essential MRCPCH safety knowledge — flagged as supplementary)

⚠️ Certain AEDs worsen specific seizure types: sodium channel blockers (oxcarbazepine, carbamazepine, phenytoin) can exacerbate absence seizures. Cross-reference against Table 5 gene-specific contraindications (e.g., avoid Na-channel blockers in SCN1A/Dravet).

Rescue medications — exact weight-based dosing, MAX doses [F&W20, Table 7]

Medication Route & dose Max dose
Clonazepam Oral dissolving tablets (non-FDA-approved indication) 0.25–2 mg tablets
Diazepam Oral/buccal/IV: 0.2 mg/kg Max 5–10 mg
Diazepam Rectal (FDA-approved ≥2y): 0.5 mg/kg (age 2–5y), 0.3 mg/kg (age 6–11y), 0.2 mg/kg (age ≥12y) —
Midazolam Oral/buccal: 0.3 mg/kg Max 10 mg
Midazolam Intranasal (FDA-approved ≥12y): 0.2 mg/kg per nostril Max 10 mg total
Midazolam IM: 0.2 mg/kg Max 10 mg
Midazolam IV: 0.2 mg/kg Max 10 mg
Lorazepam Oral/buccal: 0.1 mg/kg Max 4 mg
Lorazepam IV: 0.1 mg/kg Max 4 mg

⚠️ Gap flag: most of these routes are labelled “non-FDA-approved indication” in the US source — this reflects US regulatory status, not necessarily HA formulary/approval status. Buccal midazolam is commonly the community/school rescue standard in many practice settings including reportedly Hong Kong — verify current HA rescue medication protocol and locally-endorsed route/dose before using in an OSCE “HA practice” answer or on the ward.

Drug-resistant epilepsy

  • Defined as: failure of ≥2 adequately dosed AED trials to control seizures (~25% of children with epilepsy).
  • Refer to comprehensive epilepsy centre if:
    • Age <2 years
    • Uncontrolled within 2 years of onset, or after 2 medication trials
    • Intolerable adverse effects
    • Disabling seizures
    • Imaging shows a focal unilateral lesion matching seizure semiology
    • Epileptic encephalopathy with regression/plateau/lack of expected development
    • Etiology requiring special dietary/medical management (e.g. GLUT-1 deficiency, Dravet syndrome)
  • Options: resective surgery, callosotomy, neuromodulation (VNS, brain stimulation), dietary therapies (ketogenic, modified Atkins, low glycaemic index).

Medication level monitoring

  • “Therapeutic” = no seizures + no adverse effects, not a specific serum level.
  • Check levels if: seizures persist despite high doses, adding a drug with pharmacokinetic interactions, or checking compliance.
  • Trough levels only (just before next dose) — random levels risk inappropriate dose reduction.

Seizure first aid & safety counselling (all families, all caregivers incl. teachers/babysitters)

  • Recovery position during seizure; nothing in the mouth; time the seizure.
  • Call EMS if seizure >5 minutes without home rescue medication, or >5 minutes after rescue medication given.
  • Seizure action plan drafted/updated yearly for school and extracurricular activities.
  • Drowning is the biggest safety risk — showers preferred over baths; swimming allowed with direct adult supervision.
  • Active sports generally encouraged; no evidence of increased seizure risk with contact sports.
  • Continue scheduled vaccines (including influenza) — illness itself can worsen seizure control; vaccines may rarely trigger febrile seizures but do not worsen epilepsy course. In Dravet syndrome, febrile illness/vaccination can unmask the underlying disorder — children who have febrile seizures post-vaccination often have an underlying SCN1A mutation.

2.12 Comorbidities [F&W20, Table 3] — essential holistic-care checklist

Comorbidity Key facts
Intellectual disability Affects ~25%; skewed toward more severe ID; more common with specific syndromes/early-onset drug-resistant epilepsy
Learning disabilities Up to 50%; seizure-onset location partly predicts specific disability (e.g. dominant temporal lobe epilepsy → verbal memory/language)
ADHD ~30%; inattentive subtype more common (less disruptive → diagnosis often delayed); equal sex ratio (unlike general population); most common w/ comorbid ID and drug-resistant epilepsy; stimulants (e.g. methylphenidate) are safe and effective — old belief that stimulants provoke seizures is erroneous
Autism Risk 7.4-fold higher; risk factors: ID, specific syndromes (West syndrome), specific etiologies (tuberous sclerosis, certain genetic disorders)
Anxiety Up to 25%; often coexists w/ other comorbidities; ↑risk with +ve family history of mood disorders (less related to epilepsy-specific variables)
Depression Up to 20%; same pattern as anxiety; all AEDs carry a black-box suicidality warning; levetiracetam specifically linked to depression/rage, perampanel to homicidality
Behaviour problems Internalizing problems risk > externalizing
Sleep problems Nocturnal seizures, medication effects, co-sleeping all contribute; melatonin often low in drug-resistant epilepsy/visual impairment — supplementation may help
Bone health Reduced physical activity, ↓vit D/sunlight, AED effects; recommend routine vitamin D 400–1,000 IU/day (higher if deficient); ↑fracture risk

2.13 SUDEP (Sudden Unexpected Death in Epilepsy)

  • Incidence: ~1 per 4,000 person-years.
  • Definition: unexpected death in a person with epilepsy, unrelated to accident/seizure emergency, typically unwitnessed, occurs predominantly during sleep.
  • Most common in adolescents/young adults with poorly controlled epilepsy and frequent nocturnal convulsive seizures.
  • Mechanism unclear — likely postictal suppression of cardiac/respiratory drive.
  • Counselling point: providers often avoid this topic to spare distress, but most parents already worry about it (readily available online) and are grateful when it’s discussed — counsel all families, especially those with frequent nocturnal convulsions.

2.14 Adolescent-specific issues

  • Driving: laws vary by jurisdiction; most require a seizure-free period; medication adherence and prompt reporting of breakthrough seizures should be emphasised (safety for self AND others).
  • Contraception: unplanned pregnancy rates higher in women with epilepsy.
    • Enzyme-inducing AEDs reduce OCP efficacy (especially estrogen-containing).
    • Mitigation options: high-estrogen pill (≥50µg ethinyl estradiol), additional barrier method, or long-acting reversible contraception (LARC) — IUD/implant.
    • Lamotrigine–estrogen interaction is bidirectional: estrogen-containing OCPs significantly reduce lamotrigine levels → ↑breakthrough seizure risk; monitor lamotrigine levels closely if OCP started.
    • Catamenial epilepsy (seizure worsening around menses) may improve with OCP/hormonal therapy.
  • Pregnancy: teratogenicity risk from AEDs must be discussed; consider alternative medication if on a teratogenic drug where possible (source doesn’t name specific drug risk-ranking — valproate carries the highest teratogenic/neurodevelopmental risk per general international consensus — flagged as supplementary knowledge, not explicitly in this source).
  • Transition to adult care: should be introduced early in adolescence, not sprung on the patient just before transfer; typically completed by age 18 (or high-school graduation) in cognitively healthy teens; often delayed/harder in developmentally delayed teens (multiple subspecialists involved). A transition document + familiarity with the receiving adult provider improves family comfort.

PART 3 — CROSS-SOURCE SYNTHESIS: CONTRADICTIONS, GAPS & EXAM PITFALLS

3.1 Internal consistency check

  • No contradictions between [ILAE17] and [F&W20] — the latter is a secondary source directly citing/reproducing the ILAE 2017 position papers (Scheffer et al.; Fisher et al.), so terminology and framework are identical. [F&W20]’s Figures 2 & 3 are explicitly reprinted from the ILAE papers.
  • [Gait26] is topically independent (movement disorders/gait) and does not overlap in content with the seizure sources, but is methodologically consistent in approach (structured history + exam + escalating investigation).

3.2 Currency gaps (dates matter for MRCPCH — flag explicitly)

  • [F&W20] was published July 2020 and [ILAE17] dates to 2017 — both predate subsequent ILAE refinements, including the 2021 ILAE neonatal seizure classification and ongoing updates to seizure/epilepsy nosology and antiseizure-medication guidance published after 2020. These newer updates are not captured in the uploaded material — recommend cross-checking epilepsydiagnosis.org (explicitly endorsed within [ILAE17]/[F&W20] as the living reference) for the current syndrome list before your MRCPCH exam, since syndrome definitions are periodically revised.
  • [Gait26] is very recent (2026) and reflects current thinking, but is authored by US paediatric neurologists with no HK-specific content — see gap flag below.

3.3 Hong Kong / HA-specific gaps (explicit, since none of the 3 sources address this)

  1. No HA-specific referral pathway for gait disorders (Child Assessment Service vs Paediatric Neurology vs Orthopaedics) is given in [Gait26] — confirm local pathway separately.
  2. No HA formulary/funding status given for newer AEDs referenced in [F&W20] (e.g., cannabidiol, fenfluramine, stiripentol for Dravet/LGS) — these have restricted or special-access status in many health systems; verify current HA availability before quoting as first-line in an HA-context answer.
  3. Rescue medication route/dose conventions may differ from the FDA-framed doses in Table 7 above — confirm against current HA paediatric rescue medication protocol (buccal midazolam is widely used in community/school settings in many practice systems, but confirm the HA-endorsed dose/volume convention specifically).
  4. EEG/MRI access and turnaround in the local public system may affect the “within 24h” EEG timing discussion — a locally-relevant answer should reference realistic HA turnaround rather than the idealised US timing debate.

3.4 High-value examiner traps (from careful reading of source language)

  • Seizure type vs Epilepsy type are different tiers — don’t answer “what type of epilepsy is this” with a seizure-type term (e.g., “tonic-clonic epilepsy” is not a real epilepsy-type category; the epilepsy types are Focal/Generalized/Combined/Unknown).
  • “Genetic” ≠ “inherited” ≠ “gene test positive” — three separate concepts frequently conflated by candidates.
  • Spasticity IS velocity-dependent; Dystonia is NOT — classic single-line exam differentiator.
  • SCN1A/Dravet: AVOID sodium-channel blockers vs SCN2A/SCN8A gain-of-function: sodium-channel blockers are the treatment — same drug class, opposite indication depending on the specific gene/mechanism — a favourite “gotcha” pairing.
  • Absence seizure duration >45s or with post-ictal phase → reconsider focal seizure, and absence onset <4y → think GLUT-1 deficiency — both are explicit ILAE-endorsed cautions, easy short-answer/OSCE questions.
  • Romberg interpretation: positive with eyes closed only = sensory ataxia; unsteady regardless of eye state = cerebellar ataxia.
  • AFP elevation in unexplained childhood ataxia → screen for Ataxia-Telangiectasia before radiological/other radiation-exposing workup, since AT patients are radiosensitive.
  • EEG limitations: ~3% of healthy children have epileptiform discharges (higher in autism/ADHD); ~10% of children with epilepsy have a normal EEG — epilepsy is a clinical diagnosis supported by, not confirmed by, EEG.
  • Stimulant medications for comorbid ADHD are safe in epilepsy (do NOT lower the seizure threshold in a clinically meaningful way per current evidence) — a commonly-held but outdated clinical myth.

PART 4 — RAPID-FIRE REVIEW (numbers/cutoffs to memorise cold)

Document prepared from the three uploaded sources only, with explicit supplementary/gap flags where MRCPCH-level completeness required noting information beyond the source material (all such additions are labelled inline). Recommend verifying all HA-specific and most current (post-2020/post-2017) guidance against epilepsydiagnosis.org and current HA paediatric protocols before your tutorial and exams.