Febrile Seizures

Essentials

• Effective first aid must be provided during the seizure Acute Care of Seizures of Cerebral Origin in Children.
• Severe infections must be excluded (central nervous system infection, sepsis).
• The benign nature of febrile seizures is explained to the parents and advice is given how to act in case of a recurring seizure; buccal midazolam or rectal diazepam can be given, as necessary, for home use.

Aetiology of seizures associated with fever

• A febrile seizure (simple or complex)
• A sign of a central nervous system infection (meningitis, encephalitis) or a severe bacterial infection (sepsis).
• A sign of an infection induced by a metabolic disturbance (hypoglycaemia, hyponatraemia etc.)
• An epileptic seizure provoked by fever in a patient with epilepsy
• A simple febrile seizure is by far the most common aetiology.

Criteria for febrile seizures

1. The child is 6 months to 6 years of age.
2. The child has a fever of over 38.0°C (an exact threshold for fever in relation to febrile seizures has not been specified, but the fever is often high, over 38.5°C).
   • The fever has not necessarily been noticed prior to the seizure, and the seizure may therefore be the first sign of a fever.
   • Any infection that raises a fever can trigger a febrile seizure.
3. A simple febrile seizure http://www.dynamed.com/condition/febrile-seizure#OTHER_DIAGNOSTIC_TESTING is of a short duration; usually it lasts for 1-2 minutes and no longer than 15 minutes. The seizure activity itself is typically tonic-clonic during which the child loses consciousness and the upper and/or lower limbs jerk and stiffen symmetrically, i.e. on both sides of the body. In some cases no convulsions are observed but the child only becomes floppy.
4. In a complex febrile seizure http://www.dynamed.com/condition/febrile-seizure#OTHER_DIAGNOSTIC_TESTING, the duration is longer than 15 minutes and/or the convulsions are asymmetrical and/or recur within 24 hours and/or they are followed by asymmetrical limb pareses (Todd's paralysis).

• 2-5% of children experience febrile seizures; more than two thirds of these are short lasting simple febrile seizures.

Indications for additional investigations

• If the parents telephone to report a febrile seizure that occurred at home and from which the child has already recovered it is essential to ascertain that the seizure really was of short duration and symmetrical and that the child became fully contactable once the seizure activity had stopped.
• A seizure in a febrile child may be a sign of bacterial meningitis, encephalitis or sepsis, and therefore a child who has had a seizure for the first time should be examined by a doctor on an emergency basis, even if the seizure was of short duration and the child has recovered from it.
• If the child appears to be in good condition during a few hours of monitoring after the seizure and nothing abnormal is noted during the physical examination, there is no need to admit the child to hospital, but the parents must be given detailed instructions as how to monitor the child's condition.
• After the first aid has been provided, the child should always be sent to hospital on an emergency basis if
  • the seizure continues for more than 5 minutes
  • the seizure recurs several times during the same febrile illness
  • the child's level of consciousness remains decreased after the seizure
  • the seizure is clearly asymmetric and/or an asymmetric limb paresis remains after the seizure (Todd's paralysis), or
  • a central nervous system infection or sepsis is suspected.
• EEG or imaging studies are not required as further investigations in normally developed and otherwise healthy children who have simple febrile seizures http://www.dynamed.com/condition/febrile-seizure#OTHER_DIAGNOSTIC_TESTING, even if the seizures recur during later febrile illnesses. These investigations are indicated if the child also experiences seizures without fever.
• Additional investigations are not required if a child between 6 months and 6 years of age has simple attacks of unconsciousness and convulsions only during a fever and the child recovers normally from them.

Prevention and first aid of febrile seizures at home Preventive Treatments for Recurrences of Febrile Seizures

• It is important to tell the parents about the natural course of febrile seizures and about their good prognosis.
• In 20-30% of children who have had a febrile seizure it will recur with new febrile infections.
• Prophylactic medication should not be used, since prophylactic drugs that were both effective and safe are not available http://www.dynamed.com/condition/febrile-seizure#TOPIC_SLN_J1J_XGB.
• Subsequent febrile episodes are treated in the same way as fever in any other child since there is no evidence that even an effective treatment of fever would prevent the occurrence of febrile seizures.
• The initial treatment of febrile seizures is carried out in the same way as the initial treatment of epileptic seizures. Most febrile seizures are short in duration, lasting 1-2 minutes, and they cease without any special measures.
• First aid medication is not prescribed routinely for home use to all febrile seizure patients.
  • It is good, however, to have first aid medication available especially for patients whose febrile seizure has been prolonged or whose lengthy febrile seizure is related to e.g. a delay caused by distance in getting to a unit giving first aid.
  • The guardians should be given detailed instructions in the use of the first aid medication http://www.dynamed.com/condition/febrile-seizure#TOPIC_AMH_H1J_XGB for febrile seizures lasting over 5 minutes - either buccal midazolam (dose 0.20-0.25 mg/kg) or rectal diazepam (dose 0.5[-0.75] mg/kg) is used, as deemed appropriate - and they should be advised about the general first aid measures in seizure attacks.
• If a single dose of the first aid medication administered at home does not help or if the child does not recover from the febrile seizure quickly, he/she must be taken to hospital care on an emergency basis in an ambulance.