Febrile Convulsion

The direct cause of a febrile seizure is not known; however, it is normally precipitated by a recent upper respiratory infection or gastroenteritis. A febrile seizure is the effect of a sudden rise in temperature (>39°C/102°F) rather than a fever that has been present for a prolonged length of time.

Febrile seizures represent the meeting point between a low seizure threshold (genetically and age-determined; some children have a greater tendency to have seizures under certain circumstances) and a trigger, which is fever. The genetic causes of febrile seizures are still being researched. Some mutations that cause a neuronal hyperexcitability (and could be responsible for febrile seizures) have already been discovered.

Several genetic associations have been identified. These include:

Certain forms are considered channelopathies.

The diagnosis is one that must be arrived at by eliminating more serious causes of seizure and fever: in particular, meningitis and encephalitis must be considered. However, in locales in which children are immunized for pneumococcal and Haemophilus influenzae, the prevalence of bacterial meningitis is low. If a child has recovered and is acting normally, bacterial meningitis is very unlikely. The diagnosis of a febrile seizure should not prevent evaluation of the child for source of fever, although this is usually limited to evaluation of the urine in the younger age groups.

There are two types of febrile seizures.

The simple seizure represents the majority of cases and is considered to be less of a cause for concern than the complex.

Simple febrile seizures do not cause permanent brain injury; do not tend to recur frequently (children tend to outgrow them); and do not make the development of adult epilepsy significantly more likely (about 3–5%), compared with the general public (1%) Template:Shinnar S, Glauser TA: Febrile Seizures. J Child Neurol 17S:S44, 2002. Children with febrile convulsions are more likely to suffer from afebrile epileptic attacks in the future if they have a complex febrile seizure, a family history of afebrile convulsions in first-degree relatives (a parent or sibling), or a preconvulsion history of abnormal neurological signs or developmental delay. Similarly, the prognosis after a simple febrile seizure is excellent, whereas an increased risk of death has been shown for complex febrile seizures, partly related to underlying conditions.

During simple febrile seizures, the body will become stiff and the arms and legs will begin twitching. The patient loses consciousness, although their eyes remain open. Breathing can be irregular. They may become incontinent (wet or soil themselves); they may also vomit or have increased secretions (foam at the mouth). The seizure normally lasts for less than five minutes.

The vast majority of patients do not require treatment for either their acute presentation with a seizure or for recurrences. The best way to manage is to control the temperature with acetaminophen (Paracetamol) or by sponging. When anticonvulsant therapy is judged by a doctor to be indicated, anticonvulsants can be prescribed. Sodium valproate or clonazepam are active against febrile seizures, with sodium valproate showing superiority over clonazepam.