Identifying the cause of fever should be the top priority when evaluating infants or young children after a simple febrile seizure, and the differential diagnosis should always include meningitis, according to a new clinical practice guideline published by the American Academy of Pediatrics.
In most situations, however, “a simple febrile seizure does not usually require further evaluation, specifically electroencephalography, blood studies, or neuroimaging,” the AAP Subcommittee on Febrile Seizures wrote.
The new guideline replaces the 1996 AAP practice parameter for the neurodiagnostic evaluation of healthy infants and children 6–60 months of age who have had a simple febrile seizure and who present for evaluation within 12 hours of the event (Pediatrics 1996;97:769–72).
The new document is based on a comprehensive review of the evidence-based literature published from 1996 to February 2009, with an emphasis on research that differentiated simple febrile seizures from other seizure types. The final recommendations, presented as action statements relating to the use of lumbar puncture, electroencephalography, laboratory testing, and neuroimaging, were developed based on the quality of supporting evidence and the balance of benefit and harm if the given policy is carried out, said lead author Dr. Patricia K. Duffner, professor of neurology and pediatrics at the State University of New York at Buffalo, and her associates (Pediatrics 2011;127:389–94).
Dr. Duffner noted in an interview that the biggest change is in the recommendation regarding lumbar punctures. In the prior guideline, lumbar punctures were strongly considered for children aged 6–12 months and considered for those aged 12–18 months. With the advent of routine immunizations for Haemophilus influenzae and Streptococcus pneumoniae, the risk of simple febrile seizures being caused by bacterial meningitis is much reduced, she said. The caveat is the child who has not been immunized and the child who is on antibiotics which may mask the infection. In those cases, the physician will need to be more cautious in his/her evaluation of the child.
According to the document:
▸ Lumbar puncture. It is strongly recommended for children who present with febrile seizure and have meningeal signs and symptoms, including neck stiffness, Kernig signs, or Brudzinski signs, or those whose history or exam suggests possible meningitis or intracranial infection. The procedure is optional for infants between 6 and 12 months who have not received scheduled Haemophilus influenzae type b (Hib) or S. pneumoniae immunizations or when immunization status is unknown, and for children with febrile seizure who have been pretreated with antibiotics, which could potentially mask the signs and symptoms of meningitis.
Since the previous practice parameter was published, there has been widespread immunization in the United States for two of the most common causes of bacterial meningitis in this age range: Hib and S. pneumoniae. Compliance with all recommended immunizations does not completely eliminate the possibility of bacterial meningitis from the differential diagnosis, but “current data no longer support routine lumbar puncture in well-appearing, fully immunized children who present with a simple febrile seizure. Moreover, although approximately 25% of young children with meningitis have seizures as the presenting sign of the disease, some are either obtunded or comatose when evaluated by a physician for the seizure, and the remainder most often have obvious clinical signs of meningitis (focal seizures, recurrent seizures, petechial rash, or nuchal rigidity),” the guideline says.
▸ Electroencephalography (EEG). It should not be used routinely in the evaluation of simple febrile seizures in otherwise neurologically healthy children. “There is no evidence that EEG readings performed either at the time of presentation after a simple febrile seizure or within the following month are predictive of either recurrence of febrile seizures or the development of afebrile seizures/epilepsy within the next 2 years,” the authors wrote.
▸ Measurement of serum electrolytes, calcium, phosphorus, magnesium, blood glucose, or complete blood cell count. Such measurements should not be performed routinely for the sole purpose of identifying the cause of a simple febrile seizure. “When fever is present, the decision regarding the need for laboratory testing should be directed toward identifying the source of the fever rather than as part of the routine evaluation of the seizure itself,” Dr. Duffner and her associates concluded.
▸ Neuroimaging. It is not recommended for the routine evaluation of children who present with simple febrile seizures. “The literature does not support the use of skull films in evaluation of the child with a febrile seizure,” they explained, nor have data been published that support or negate the need for CT or MRI in this population.
Data do show that “CT scanning is associated with radiation exposure that may escalate future cancer risk. MRI is associated with risks from required sedation and high cost,” the authors said.