Febrile Seizures

Abstract

Febrile seizures occur in children as an age-related phenomenon. In most cases they are not associated with adverse outcomes. They can be part of genetic syndromes and susceptibility to develop epilepsy is marginally increased compared to the general population.

As a result of different prognostic implications, febrile seizures are categorized into simple (SFS) and complex febrile seizures (CFS). The term “simple febrile seizures” is defined as a generalized convulsion precipitated by fever arising from infection outside the nervous system in a child, aged from 6 months to 60 months, who is otherwise neurologically normal, that occurs once in the course of the illness and is not associated with focal neurology and from which the child fully recovers.

It is vital to distinguish from seizures with fever, genetic epilepsy with febrile seizures plus, or manifestations of another genetically determined epileptic syndrome, e.g., Dravet syndrome or Doose syndrome. The investigations done on a child with a simple or complex seizure during a febrile illness should be directed by the degree of illness and the suspected underlying infection. Simple febrile seizures do not require any investigations if the diagnosis is certain on history taking and physical examination. For complex febrile seizures, the search for fever etiology, blood chemical tests, and search for possible underlying brain lesion are recommended. Management of febrile seizures is based mainly on the recommendations of the Task Force of the LICE Guidelines Commission. In most cases, SFS spontaneously cease within 2–3 min and do not require treatment. Occasionally SFS may last longer than 5 min; in these cases, pharmacologic treatment is recommended.

The best treatment for children with a first febrile seizure is education and reassurance for the parents. Simple febrile seizures do not need prophylactic antiepileptic drug treatment. The risks are small and the potential side effects of drugs outweigh the benefits. Prophylactic AED treatment may be considered if a child has complex febrile seizures, neurological abnormalities, age <1 year, or frequent recurrences. Recurrence risk of further febrile seizures is 10% in patients with no risk factors, 25–50% in the presence of 1–2 risk factors, and 50–100% in the presence of 3 or more risk factors. The risk of epilepsy is estimated at around 1–1.5% in patients with SFS, only slightly higher than incidence in the general population, which is approximately 0.5%. The risk of epilepsy in subjects with CFS is estimated between 4% and 15%.