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ESSENTIALS OF DIAGNOSIS
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ESSENTIALS OF DIAGNOSIS
A febrile seizure is defined as a seizure occurring in the setting of fever (temperature ≥100.4°F or 38°C by any method), without other cause (eg, central nervous system infection, epilepsy), in children 6 through 60 months of age.1
Febrile seizures are categorized as simple or complex. Complex febrile seizures are characterized by 1 or more of the following features: (1) semiology focality, (2) duration of more than 15 minutes, or (3) more than 1 seizure in 24 hours.
The prognosis is excellent in children with simple febrile seizures, and additional neurologic investigations are typically not indicated. However, children with complex febrile seizures or febrile status epilepticus often require further evaluation.
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GENERAL CONSIDERATIONS
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Febrile seizures are common, occurring in 2% to 5% of children.1,2 The peak incidence is around 2 years of age, with the vast majority of first-time febrile seizures occurring before 3 years of age.2 Febrile seizures represent a typically benign, self-limited condition with an excellent prognosis. This chapter will discuss the diagnosis, complications, and management of febrile seizures, with careful attention paid to identifying instances in which further workup is necessary to differentiate febrile seizures from alternate diagnoses. Seizures in the setting of fever occurring in children less than 6 months of age are generally managed differently and will not be discussed here.
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Many have questioned whether prophylactic antipyretic medication can be used in the setting of febrile illness to prevent seizure recurrence in children with a history of febrile seizures. A meta-analysis of randomized controlled trials showed no benefit to antipyretics in seizure prevention during future febrile episodes when compared to placebo.3
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DIFFERENTIAL DIAGNOSIS
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Intracranial infection: In children who have a decreased level of consciousness or who are not returning to their baseline mental status after a seizure and in those who have meningeal signs on an exam, intracranial infection as the source of fever and cause of subsequent seizure (eg, meningitis, encephalitis, or intracranial abscess) should be considered.
Shaking chills/rigors: Tremulous movements occur commonly with fevers and can be mistaken for a seizure.
Epilepsy: Fever can lead to a decreased seizure threshold in children with epilepsy. Therefore, a seizure in the setting of a fever may be the first presentation of a child’s underlying epilepsy. Genetic epilepsy with febrile seizures plus (GEFS+) is typically inherited with autosomal dominance and variable penetrance, and therefore, a history of family members with variable presentations of seizures is commonly present. GEFS+ is caused by various genetic mutations, predominantly SCN1A mutation but also mutations in several other genes such as SCN2A, SCN1B, GABRG2, and GABRD.4 GEFS+ shows marked phenotypic heterogeneity within families. The most common manifestation is febrile seizures, which sometimes recur well beyond 5 to 6 years of age (febrile ...