Febrile seizure

Background

• 2-3% chance of developing epilepsy (1% for general population)
• 50% of pts never have temp >39
• 50% of pts <12 mo will have another simple febrile seizure
• 30% of pts >12 mo will have another simple febrile seizure

Clinical Presentation

• Seizure + fever

Differential Diagnosis

• Meningitis
  • More likely if status epilepticus
• Seizure due to identifiable cause (e.g. intracranial mass, trauma, ingestion)
• Epidural/subdural infection or hematoma
• Toxic Ingestion
• Pyridoxine Responsive Seizure

Diagnosis

Simple versus Complex

• Simple
  • Generalized tonic-clonic seizure
  • <15 min in duration
  • Age 6mo - 6yr
  • Occurs only once in 24hr period
  • No focal features
• Complex
  • Any exception to above

Work-Up

• Glucose in all pts
• Simple febrile seizure
  • Neither labs nor neuroimaging are absolutely necessary
  • Normal pediatric fever workup
• Complex febrile seizure
  • Consider CBC, blood cx, UA, Ucx, CSF studies
• Consider CT if:
  • Persistently abnormal neuro exam (esp w/ focality)
  • Signs/symptoms of increased ICP
  • pt has VP shunt
• Routine EEG not indicated
  • Consider only if developmental delay or for focal symptoms

Treatment

• Treat if initial seizure persists >5 min or for subsequent seizures
  • Benzodiazepines
    • Lorazepam 0.1mg/kg IV
    • Diazepam 0.2 mg/kg IV or 0.5 mg/kg PR (choice if difficult or no access)
    • Midazolam 0.1 mg/kg IV or IM or IN
      • If persists try one additional dose (risk of resp. depression incr if >2 doses)
  • Fosphenytoin (15-20 mg PE/kg IV) or Phenytoin (10-20 mg/kg IV up to 1g @ 1mg/kg/min)
    • Treat if seizure persists despite benzo treatment
    • Onset of action may take as long as 30 minutes
    • Can cause hypotension and dysrhythmias
  • Barbituates
    • Phenobarbital 15-20 mg/kg IV
    • Consider only if benzos and phenytoin have failed
    • May lead to respiratory depression, especially when preceded by a benzo
  • Valproic acid 10-15 mg/kg IV (20 mg/min)
    • Has been shown to be effective when benzos, phenytoin, and barbituates have failed
    • Can be used as 2nd or 3rd-line treatment
  • Keppra 20 mg/kg IVP
  • Propofol 2-3 mg/kg IVP; maintenance 0.125-0.3 mg/kg/min IV
  • Consider Pyridoxine (vitamin B6) 1g per g of INH ingested (in D5W IV over 30 min)
  • Consider Pyridoxine Responsive Seizure Disorder - 100mg/pyridoxine is generally effective
• Treat underlying infection

Disposition

• Discharge
  • Simple febrile seizure if pt at baseline
    • Follow-up in 1-2d
  • Complex febrile seizure if pt well-appearing, work-up normal
    • Follow-up in 24hr
• Admit:
  • Ill-appearing
  • Lethargy beyond postictal period

See Also

• Seizure
• Fever (Peds)