AAP Guidelines for Evaluating a First Simple Febrile Seizure in a Child
Febrile seizures—primary generalized seizures that last less than 15 minutes and do not recur within 24 hours—are the most common convulsive event in children under age 5. Between 2% and 5% of all children experience one or more such seizures during early childhood.1
For which children with a first simple febrile seizure should you consider a lumbar puncture? Are an electroencephalogram (EEG), blood studies, and neuroimaging studies routinely indicated in this setting?
In updated guidelines on neurodiagnostic imaging of children with a first simple febrile seizure—the highlights of which are summarized here—the American Academy of Pediatrics (AAP) offers help with these and other related questions. A caveat: The AAP recommendations do not pertain to children who have had complex febrile seizures (prolonged, focal, and/or recurrent) or who have a history of neurologic insults, central nervous system abnormalities, or afebrile seizures. Also, these practice parameters are intended only for children between 6 months and 5 years of age.
LUMBAR PUNCTURE
A key change from the previous AAP guidelines2 is that lumbar puncture is no longer routinely recommended for well-appearing, fully immunized children who present with a simple febrile seizure. Since the publication of the earlier guidelines, there has been widespread immunization in the United States for Haemophilus influenzae type b (Hib) and Streptococcus pneumoniae, which are two of the most common causes of bacterial meningitis in young children.
A lumbar puncture should be performed when meningeal signs and symptoms, such as neck stiffness and Kernig and Brudzinski signs, are present or when the history or examination findings suggest intracranial infection. Lumbar puncture is an option for a child aged 6 to 12 months with a simple febrile seizure if the immunization status is unknown or insufficient for Hib or S pneumoniae. It is also an option for a child with a febrile seizure who has had previous antibiotic therapy, since such treatment can mask meningeal signs. Furthermore, keep in mind that a recognized source of fever, such as otitis media, does not exclude meningitis.
The Table lists characteristics most likely to be associated with abnormal cerebrospinal fluid findings in children who initially present with febrile seizure.
ELECTROENCEPHALOGRAPHY
The AAP recommends that an EEG should not be obtained in a neurologically healthy child with a first simple febrile seizure. No evidence exists that an EEG can predict recurrent febrile seizures, the development of afebrile seizures, or the onset of epilepsy within the following 2 years.
BLOOD STUDIES
Routine measurement of the complete blood cell (CBC) count or of serum electrolyte, calcium, phosphorus, magnesium, or glucose levels is not recommended. Although some children with febrile seizures have abnormal serum electrolyte values, a careful history taking and physical examination usually identify the cause.
If the decision has been made to perform a lumbar puncture, blood culture and serum glucose testing should be ordered as well. These studies can increase the sensitivity for detecting bacteria and can aid in identifying the presence of hypoglycorrhachia, which is frequently associated with bacterial meningitis.
NEUROIMAGING
Skull films and CT and MRI scans are not usually helpful in the routine evaluation of a young child’s first simple febrile seizure. Clinically important intracranial structural abnormalities are uncommon in infants and toddlers.
Moreover, CT scans expose the child to radiation that may increase the risk of cancer in the future. MRI scans are expensive, and the required sedation may pose a risk to the child.
REFERENCES:
1. Subcommittee on Febrile Seizures, American Academy of Pediatrics. Neurodiagnostic evaluation of the child with a simple febrile seizure. Pediatrics. 2011;127(2):389-394.
2. Provisional Committee on Quality Improvement, Subcommittee on Febrile Seizures. Practice
parameter: the neurodiagnostic evaluation of the child with a first simple febrile seizure. Pediatrics. 1996;97:769-772.