What Evaluation is Appropriate for Complex Febrile Seizures?
A 4.5-year-old male was transported to the emergency room with a history of a generalized tonic-clonic seizure for 10-15 minutes. He had been given one dose of lorazepam during transport but he continued to seize. He was given two more doses in the emergency room and a loading dose of phenobarbital. He stopped seizing after 20-25 minutes. He was febrile to 39° Celsius. The patient had no previous infectious symptoms. The past medical history revealed a healthy male who had been a full-term infant and was developing normally. He had two previous simple febrile seizures. The first last 10 minutes and had stopped by the time he was seen in the emergency room. He had an upper respiratory tract infection at that time. The second febrile seizure lasted 5 minutes and the parents had him seen by his physician who treated him for an ear infection. The family history was negative for genetic or neurological problems. The review of systems was negative.
The pertinent physical exam showed an arousable but sleepy male, with stable vital signs and growth parameters in the 10-50%. HEENT examination found a supple neck and mild tonsilar erythema. The rest of his examination was normal including a complete neurological examination. The laboratory evaluation included a complete blood count that was normal except for elevated platelets at 337,000. Electrolytes, calcium, magnesium and phosphorous were also normal. Chest x-ray and urinalysis were normal. Rapid strep test was negative as was the throat culture later. Lumbar puncture was normal. The diagnosis of a complex febrile seizure was made and the patient was given Ceftriaxone and transported to a regional children’s hosptial for evaluation by a child neurologist. The patient’s clinical course showed that he had no more seizures and his repeated examination revealed development of rhinorrhea. His neurological examination remained normal and the neurologist felt that although this was a complicated febrile seizure because of duration, the child did not need further evaluation as he had no other risk factors. His maximum temperature was 37.8° Celsius over 24 hours and he was discharged. His grandparents lived close by and the family was going to remain with them for at least 24 hours as they wanted to be close to the children’s hospital if another seizure occurred.
Febrile seizures are the most common type of seizures in children. They affect about 2-5% of all children. Febrile seizures are characterized into two groups: simple febrile seizures and complex febrile seizures. Basically, if the child does not meet the criteria for a simple febrile seizure it is called a complex febrile seizure. The main characteristics are outlined below:
Simple Febrile Seizure Complex Febrile Seizure Age 6-60 months < 6 months or > 60 months Duration < 15 minutes > 15 minutes Type Generalized Focal seizures tonic-clonic Tonic and/or clonic Partial seizure with/without generalization Head or eye deviation to one side Unilateral transient paralysis after seizure Loss of muscle tone Recurrence None in 24 hours Recurring in 24 hours Exam No signs of infectious disease or postictal pathology Previous No Yes or No Neurological Problem Underlying No No CNS-Infectious Disease
The risk of having another febrile seizure after the first episode is 29-35%. The risk of epilepsy following a simple febrile seizure is 1-2.4% and following a complex febrile seizure is 4.1-6%. Overall risks depend on many factors including genetics. Linkages for febrile seizures have been found on 2q, 5q, 5, 8q, 19p and 19q chromosomes. The strongest linkages have been found on 2q with genes associated with sodium channels.
Evaluation and treatment for simple febrile seizures and complex febrile seizures are debated. In general, simple febrile seizures are usually diagnosed by thorough history and physical examination. Laboratory testing should be directed toward evaluating appropriate possible underlying infectious disease or metabolic problem.
Recommendations for evaluation of simple febrile seizures from the American Academy of Pediatrics and the International League Against Epilepsy include:
- Lumbar puncture is strongly recommended for < 12 months olds, should be considered in 12-18 month olds. Lumbar puncture is always recommended if there are meningeal signs in patients of any age. Previously antibiotic treatment could mask meningeal signs and lumbar puncture should be strongly considered in those cases.
- EEG is not recommended to be performed for first simple febrile seizure.
- Routine electrolytes, calcium, phosphorous, magnesium are not recommended for first simple febrile seizure unless indicated for other reason such as acute diarrhea that may predispose to electrolyte abnormalities.
- Glucose is recommended to be obtained if the patient has a prolonged period of obtundation.
- A complete blood count is useful in the evaluation of fever and possible bacteremia particularly in children < 2 years but is not routinely recommended.
- Neuroimaging is not recommended for first simple febrile seizure.
Because of the diversity of potential underlying problems with a complex febrile seizure, more evaluation may or may not need to be completed based upon the circumstances. EEG is probably more helpful if the child continues to have seizures and the actual seizures can then be documented. Neuroimaging would also be more helpful if the child has a focal seizure or has neurodevelopmental abnormalities before or after the complex febrile seizure. Some clinicians like to obtain the blood chemistry tests because although they are very often normal, they also exclude some metabolic problems as the cause of the seizure.
Recommendations for evaluation of complex febrile seizures from the International League Against Epilepsy include:
- Evaluation for a source of possible infection including a lumbar puncture for any patient with suspected meningeal signs
- Routine chemistry tests are not recommended but should be considered based upon clinical conditions
- EEG is recommended
- Neuroimaging is highly recommended
Questions for Further Discussion
1. What are the possible treatment options for simple febrile seizures?
2. What are the possible treatment options for complex febrile seizures?
3. What are indications for an evaluation by a pediatric neurologist?
- Disease: Complex Febrile Seizure | Seizures
- Age: Preschooler
To Learn More
To view pediatric review articles on this topic from the past year check PubMed.
Information prescriptions for patients can be found at MedlinePlus for this topic: Seizures
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American Academy of Pediatrics Guideline. Febrile Seizures: Clinical Practice Guideline for the Long-term Management of the Child with Simple Febrile Seizures. Pediatrics. 2008:121;1281-1286.
Dube CM, Brewster AL, Baram TZ. Febrile seizures: mechanisms and relationship to epilepsy.
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Capovilla G, Mastrangelo M, Romeo A, Vigevano F. Recommendations for the management of “febrile seizures”: Ad Hoc Task Force of LICE Guidelines Commission.
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ACGME Competencies Highlighted by Case
1. When interacting with patients and their families, the health care professional communicates effectively and demonstrates caring and respectful behaviors.
2. Essential and accurate information about the patients’ is gathered.
3. Informed decisions about diagnostic and therapeutic interventions based on patient information and preferences, up-to-date scientific evidence, and clinical judgment is made.
4. Patient management plans are developed and carried out.
8. Health care services aimed at preventing health problems or maintaining health are provided.
9. Patient-focused care is provided by working with health care professionals, including those from other disciplines.
10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.
13. Information about other populations of patients, especially the larger population from which this patient is drawn, is obtained and used.
23. Differing types of medical practice and delivery systems including methods of controlling health care costs and allocating resources are known.
24. Cost-effective health care and resource allocation that does not compromise quality of care is practiced.
Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa Children’s Hospital