Febrile Seizures

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Febrile Seizures: Basics - Fever's Jittery Intro

  • Definition: Seizure with fever ($T \ge \textbf{38}^\circ C$) in children aged 3 months to 6 years, without CNS infection, metabolic disturbance, or prior afebrile seizures.

  • Epidemiology:

    • Peak age: 6 months - 5 years.
    • Incidence: 2-5% of children.

    ⭐ Most common seizure disorder in childhood, affecting 2-5% of children.

  • Types: Classified based on clinical presentation.

    FeatureSimple Febrile Seizure (SFS)Complex Febrile Seizure (CFS)
    Duration<15 minutes (typically brief)$\ge$15 minutes (can be serial)
    SemiologyGeneralized (usually tonic-clonic)Focal onset or features during seizure
    Recurrence (24h)One seizure per febrile illness>1 seizure within 24 hours / same illness
    PostictalRapid recovery, non-focalMay have transient focal deficit (Todd's)

Febrile Seizures: Etiopathogenesis & Features - Hot Brain Shakes

  • Etiology:
    • Viral infections (common): HHV-6, Influenza.
    • Post-vaccination (rare): DTP, MMR.
  • Pathophysiology:
    • Fever (>38°C) acts as a trigger.
    • Cytokine release (e.g., IL-1β).
    • Immature neuronal networks & genetic susceptibility.
  • Clinical Features:
    • Simple (SFS): Generalized, duration <15 min, single episode/24h, no postictal focality.

      Simple febrile seizures are generalized, last <15 minutes, occur once in 24 hours, and have no focal features; they do not cause brain damage.

    • Complex (CFS): Meets ≥1 of: 📌 Focal (features during seizure or postictal deficit like Todd's paresis), Long (duration >15 min), Recurrent (≥2 episodes in 24h or same illness).

Febrile Seizures: Diagnosis & DDx - Seizure Sleuthing

  • Diagnosis: Clinical, history (fever + seizure). Exclude CNS infection.
  • Key Investigations:
    • Lumbar Puncture (LP):
      • Strongly consider: age <12 months.
      • Indicated: signs of meningitis/intracranial infection.
      • Consider if on antibiotics (masks meningitis).
-   **EEG**: Not routine for simple FS; consider for complex/atypical.
-   **Neuroimaging (CT/MRI)**: Not routine; consider for focal deficit, ↑ICP signs.
  • Differential Diagnosis (DDx):
    • Meningitis/Encephalitis.
    • Epilepsy triggered by fever.
    • Electrolyte imbalance (hypoglycemia).
    • Toxic ingestion.

⭐ According to AAP guidelines, LP is strongly considered for infants aged 6-12 months with a first simple febrile seizure if immunization status for Hib or S. pneumoniae is deficient or undetermined.

Febrile Seizures: Management & Prognosis - Cool Down Care

  • Acute Management:
    • ABCs, recovery position.
    • Antipyretics (paracetamol/ibuprofen) for comfort.
    • Seizure >5 min: Rescue Benzodiazepines (Rectal Diazepam $0.5 \text{ mg/kg}$, IN/Buccal Midazolam $0.2 \text{ mg/kg}$).
  • Parental Counseling & Education:
    • Reassurance, fever control for comfort (not prevention), seizure first aid.
    • Low risk of epilepsy.
  • Prophylaxis: Generally not recommended (side effects vs. benign nature).
  • Prognosis:
    • Recurrence risk: ~30%.
      • Risk factors: Young age at first FS (<18 months), family history of FS, fever <39°C, short fever-seizure interval. 📌
    • Epilepsy risk: Simple FS ~1-2%; higher for complex FS or other risks.

⭐ Antipyretics (paracetamol, ibuprofen) are used for child's comfort during fever but do not prevent the recurrence of febrile seizures.

High‑Yield Points - ⚡ Biggest Takeaways

  • Age: Common between 6 months to 5 years, triggered by fever (often >38°C).
  • Simple FS: Generalized, <15 min, single episode/24h, quick recovery.
  • Complex FS: Focal, >15 min, multiple episodes/24h, or postictal deficit.
  • Acute Care: Antipyretics; diazepam (rectal/IV) if seizure >5 min.
  • Prognosis: Generally excellent; low risk of future epilepsy.
  • EEG: Not routine for first simple febrile seizure.
  • LP: Consider in infants <12 months, or if meningitis suspected_._
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Practice Questions: Febrile Seizures

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Which of the following is not typical of Simple Febrile Seizures?

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_____ due to fever in tonsillitis, is an indication for tonsillectomy.

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_____ due to fever in tonsillitis, is an indication for tonsillectomy.

Febrile seizures

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