Seize the moment
Updated: Jan 28, 2020
Approach to first time unprovoked seizures in children
Everyone is entitled to one seizure. This is what I tell all my first time seizures in the Emergency Department. But pediatric seizures always feel more complicated than those in adults. Maybe it has to do with the terrified parent in the room or maybe our own terror in missing “something bad” in a kid. Here we will try and make the workup less confusing. The approach to febrile seizures is fairly straight forward and will be discussed at a later date on this website.
The initial evaluation of first time seizure in children should focus on determining whether this is a provoked, e.g. there is an identifiable cause, or unprovoked (classically thought of as epilepsy). Epilepsy is defined as two or more unprovoked seizures, and therefore is not the diagnosis after first time seizure (1).
I think the easiest way to determine next steps in workup is to ask yourself one question: Is the child back to their normal mental status baseline after normal period of post-ictal state? If no – look for causes: signs of trauma, ill appearing, signs of infection, exam findings consistent with rickets, etc; then workup should be done based on those findings. If the answer is yes, they are back to baseline, then this is when the workup becomes more difficult; what should you do now? Labs? Imaging? Admission?
In pediatric patients who have returned to their baseline, whom the provider has determined has had a first time seizure, laboratory evaluation is not necessary unless the history or physical exam indicates a possibility of abnormal electrolytes, e.g. history of vomiting, diarrhea, signs of rickets. According to the practice parameters published by Neurology laboratory evaluation rarely changes management, except for in the case of infants under 6 months of age, in patients with signs of focal seizure, or ongoing mental status changes (1). Hyponatremia has been shown to be present in up to 70% of infants younger than 6 months presenting with seziures (2). Therefore, laboratory evaluation is warranted in children 6 months of age and under with a first time unprovoked seizure. However, in children older than 6 months, laboratory evaluation can be reserved when clinical evaluation is suggestive of electrolyte abnormality as long as child is back to their mental baseline.
Lumbar puncture (LP) should not be performed in first time, non-febrile seizures, unless there is clinical concern for meningitis. The seizure alone is not an indication for LP (1).
EEG is likely warranted as part of the evaluation of first time unprovoked seizure, both to help direct imaging as well as prognostic stratification. This study discusses the role of EEG in predicting rate of seizure recurrence (3). However, the ideal timing of EEG has not been well established. Current recommendations do not endorse admission for EEG alone and it can be done as an outpatient (1). Which is probably good, as getting an EEG tech to the ED to set a patient up, usually feels like asking for a flying unicorn to bring you a moon rock.
Now the real kicker – Do I need to CT scan this child? As both emergency physicians and pediatricians, we are always hoping to limit radiation exposure, so it’s important to judiciously decide which patients need imaging following their first time seizure.
Multiple studies have shown that a small percentage of new onset seizure patient’s CT imaging (about 2-4%) will have results that change immediate medical management (1,4). CT scan of the brain should be reserved for unstable patients when a space-occupying lesion is suspected, or a focal seizure has occurred. These are the most likely to yield a result that will change immediate management (4). MRI brain has consistently been shown to be more sensitive than CT in the workup of pediatric seizures. However, it is not always readily available, and often requires sedation in the pediatric population. Nonurgent neuroimaging has been shown to change ongoing management of seizures in children, as well as provide prognostic information moving forward. Therefore, if you’ve determined that the child does not need urgent imaging (unstable, signs of trauma, not at baseline, focal seizure, etc.), than outpatient neurology follow-up to determine next imaging modality is warranted (1).
GET THE POINT:
- If child is back to their baseline mental status after a first time seizure, laboratory tests only need to be ordered if you clinically suspect electrolyte abnormality, e.g vomiting, diarrhea, dehydration, or if child is under 6 months of age or signs of focal seizure.
- EEG should be part of the workup of first time unprovoked seizure, but can be done as an outpatient if patient at their baseline.
- Emergent Lumbar puncture is rarely indicated.
- CT brain indicated in unstable patients or patients with signs of trauma, not at their baseline, focal seizure, or concern for space-occupying lesion.
1. Freeman JH. Practice parameter: evaluating a first nonfebrile seizure in children: Report of the Quality Standards Subcommittee of the American Academy of Neurology, the Child Neurology Society, and the American Epilepsy Society. Neurology. 2001;56(4):574.
2. Farrar HC, Chande VT, Fitzpatrick DF, Shema SJ. Hyponatremia as the cause of seizures in infants: a retrospective analysis of incidence, severity, and clinical predictors. Ann Emerg Med. 1995;26(1):42-8.
3. Appleton RE. Significance of the EEG after the first afebrile seizure. Arch Dis Child. 1999;80(1):100-1.
4. Garber B. Tips for Updating Your Approach to Pediatric Seizures. https://www.acepnow.com/article/tips-for-updating-your-approach-to-pediatric-seizures/?singlepage=1&theme=print-friendly. Accessed January 27, 2020.