Febrile seizures are the most common seizures in children. They occur in 2–5 % of all children less than 5 years of age [4]. A febrile seizure is defined as a seizure in infancy or childhood, between 6 months and 6 years of age, that is associated with fever but without any evidence of intracranial infection. The peak onset is 18 months. There are two types of febrile seizures: simple and complex, and the difference is important for prognostication. Simple febrile seizures occur as isolated events, are generalized in onset, and are less than 15 min. Complex febrile seizures, in distinction, have one or more of the following features: a duration longer than 15 min, more than one episode occurring within a 24 h period, or symptoms that point to a focal part of the brain.

There is a clear genetic predisposition for febrile seizures in some families: 10–20 % of first-degree relatives of children with febrile seizures will have experienced febrile seizures. A variety of genetic loci have been identified, and serious genetic epilepsy syndromes such as severe myoclonic epilepsy of infancy, or Dravet’s syndrome , may initially present with complex febrile seizures. Febrile seizures have also been associated with several viral and bacterial antigens including influenza, human herpes virus 6, adenovirus, and Para influenza [5].

The typical presentation of a febrile seizure is a generalized tonic-clonic seizure during the early phase of a febrile illness. Postictal lethargy is common and the majority of febrile seizures last less than 15 min. If there are atypical features such as a prolonged event or other associated neurocognitive deficits, it is imperative that more concerning etiologies such as central nervous system infections are ruled out. In the older child, signs and symptoms of a CNS infection may be more easily detected by neurological exam, whereas in the younger child, this can be more of a diagnostic dilemma. Other etiologies to consider in the differential diagnosis of febrile seizures are rigors in a child with fevers or breath-holding spells within the correct clinical context.

The emergency department of intensive care unit evaluation includes a lumbar puncture for any child presenting with meningismus, bulging fontanelle, prolonged lethargy, recurrent seizures, or status epilepticus. Additionally, in children less than 1 year of age, lumbar puncture is recommended if they are considered to be deficient in Haemophilus influenzae type b or Streptococcus pneumoniae immunizations. In otherwise healthy children over 1 year of age, a simple febrile seizure alone does not require significant workup. There is limited utility for performing a head CT in a child presenting with febrile seizures, especially when considering the negative side effects of ionizing radiation. EEGs are not indicated with initial presentation of a febrile seizure, but consideration may be given to perform an EEG in children with febrile seizure if the child is known to have a neurodevelopmental abnormality and a strong family history of childhood epilepsy or if they manifest with frequently recurring febrile seizures. Brain MRI may have utility in children who present with complex febrile seizures, but are typically performed only in children with other neurologic deficits and focal seizures or in whom focal EEG findings suggest that searching for a subtle brain malformation or lesion may be higher yield [5].

When a child recovers rapidly to their neurologic baseline after a febrile seizure, an underlying CNS infection is very unlikely. Therefore, a child presenting with first time febrile seizure warrants medical observation, but their admission to the hospital is usually not indicated. Though most febrile seizures are less than 15 min, if a seizure becomes prolonged, it will require symptomatic treatment with a benzodiazepine (see acute seizure management section below.) It is important to counsel family that the risk of recurrence is high. Approximately 33 % of children with a first febrile seizure will have a recurrence at some point. Sixteen percent will occur within 24 h of their first and 10 % will have more than three febrile seizures following the first one [5]. The main risk factors for recurrence are a positive family history and an early age of presentation. Though the risk of recurrence is high, the risk of developing future epilepsy in children with simple febrile seizure is 1 %, which is the same risk as in the general population. For complex seizures, the risk is minimally higher, 2–4 % that the child will proceed to develop epilepsy.

Given that the risk of epilepsy is not significantly greater than the general population and because febrile seizures are a benign, self-limited age-dependent response to fever, long-term prophylactic treatment with an antiepileptic medication is not indicated. Controlling the fever with antipyretic is a logical solution; however, in studies of children with febrile seizures, treatment with an antipyretic medication does not actually decrease the risk of febrile seizure. In fact, research has shown that 50 % of children with febrile seizures had already received an antipyretic medication prior to the seizure [5]. For children with prolonged seizures, the option of administering rectal diazepam at home exists, and for children with frequent febrile seizures, rectal or oral diazepam at the onset of a febrile illness has been demonstrated to decrease the risk of having a seizure by 50 % [6].

Every year, about 25,000–40,000 children in the USA experience their first nonfebrile seizure. Nonfebrile seizures are by definition not associated with a fever and therefore should eliminate any concern over CNS infection. It is important to establish that the child experienced a true seizure because children can present with seizure-like symptoms that may not represent seizures, also known as nonepileptic events. A detailed history from a reliable observer will usually help distinguish between seizures and other nonepileptic events such as breath-holding spells, syncope, gastroesophageal reflux, migraines, and psychogenic nonepileptic seizures.

After determining the patient had an epileptic event, the next management question is whether it was provoked . Again, history and physical exam are the most important as to whether there has been an ingestion, trauma, or metabolic derangement. Based on the history, the appropriate diagnostic workup should be completed within the context of a referral to a pediatric neurologist. Studies of children older than 6 months who present with a nonfebrile seizure in the absence of suggestive history or symptoms have shown that abnormalities on standard laboratory evaluations are rare. Therefore, laboratory tests are recommended only when there is clinical concern including vomiting, diarrhea, dehydration, pregnancy, or possible drug exposure or failure to return to baseline after the event. Additionally, there is no evidence to support performing a lumbar puncture unless the child is less than 6 months, has persistent alteration in mental status, or has concerning meningeal signs. If there is any suspicion for an increase in intracranial pressure, imaging of the brain prior to the LP may be warranted [7].

Many researches have looked into the utility of ordering a routine head CTs and MRIs in identifying a brain abnormality in a child with their first nonfebrile seizure. While there is some variability in results, up to one-third of children with first seizure have been shown to have abnormalities on imaging studies; however, only about 2 % have clinically significant findings that contribute to further clinical management. Routine neuroimaging for a child presenting with their first nonfebrile seizure is therefore not recommended unless warranted by the clinical scenario. Emergent neuroimaging should be performed in a child who has not returned to baseline within several hours after the seizure and in a child with a persistent focal neurological deficit. Nonurgent studies, which may be performed several days after the seizure, should be considered in a child with a focal seizure onset and a history of cognitive or motor impairment of unknown etiology [7]. In general, if a study is obtained, an MRI is the preferred study and should be scheduled in a facility with expertise in pediatric sedation, on a high-strength (3 T) magnet and with pediatric epilepsy protocols (including coronal T2 and FLAIR sequences). Head CTs are only indicated in the emergent setting if there is concern for hemorrhage, cerebral edema, mass effect, or hydrocephalus.

Multiple studies have confirmed that an EEG is not required prior to leaving the emergency department, but certainly is an important part of the evaluation of a child recovering from an initial unprovoked seizure. Routine EEGs read as normal can certainly be seen in patients with epilepsy, but an abnormal EEG can help diagnosis the type of seizure, and epileptiform discharges on the EEG may aid an epileptologist in predicting seizure recurrence. In general, the standard approach to a first time, nonfebrile seizure is an outpatient routine EEG [7]. Long-term video-EEG monitoring is indicated for patients with further seizures, patients with unclear events, and patients whose events are unresponsive to medications. Whenever children with epilepsy warrant further evaluation for changes in their conditions or for considerations of possible surgical therapies, repeat long-term video-EEG evaluation is often helpful in capturing both ictal and non-ictal electrographic events.