classification of febrile convulsion (seizure)

Last reviewed 01/2022

febrile seizure classification

Febrile seizures can be broadly divided into simple or complex based on duration, recurrence, and the presence of focal features

  • majority are generalised tonic-clonic seizures,

  • around 30-35% of cases have one or more complex features (focal onset, duration >10 minutes, or multiple seizures during the illness episode)

feature

simple febrile seizure

complex febrile seizures

duration

short (<15 minutes)

longer (>15 minutes)

focal features

generalised tonic-clonic features are typical (stiffening of muscles followed by rhythmical jerking or shaking)

focal seizures with or without secondary generalisation

recurrence

no recurrence within the next 24 hours

may present with repetitive seizures during the next 24 hours

postictal features

no postictal pathology

Todd’s paresis may be present (a period of paresis of affected limbs)

SA subgroup of complex febrile seizures known as febrile status epilepticus (FSE) - seizures lasting more than 30 minutes - is present in around 5% of cases (1)

  • responsible for 25% of all episodes of status epilepticus seen in children
    • around two thirds of status epilepticus cases seen in the second year of life are FSE
  •  is considered as a medical emergency (2)

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