Seizures account for 1% of all emergency department visits for children, and the etiologies range from benign to life-threatening. The challenge for emergency clinicians is to diagnose and treat the life-threatening causes of seizures while avoiding unnecessary radiation exposure and painful procedures in patients who are unlikely to have an emergent pathology. When treating patients in status epilepticus, emergency clinicians are also faced with the challenge of choosing anticonvulsant medications that will be efficacious while minimizing harmful side effects. Unfortunately, evidence to guide the evaluation and management of children presenting with new and breakthrough seizures and status epilepticus is limited. This review summarizes available evidence and guidelines on the diagnostic evaluation of first-time, breakthrough, and simple and complex febrile seizures. Management of seizures in neonates and seizures due to toxic ingestions is also reviewed.
Keywords: emergency medicine CME, seizure, simple febrile seizure, complex febrile seizure, nonfebrile seizure, unprovoked seizure, status epilepticus, epilepsy, lumbar puncture, electrolyte panels, neuroimaging, electroencephalography, toxicology screening, benzodiazepines, lorazepam, midazolam, diazepam, hydantoins, phenytoin, fosphenytoin, barbiturate, valproic acid, levetiracetam, lacosamide, propofol, carbamazepine, oxcarbazepine, eslicarbazepine, pyridoxine
You are working a busy morning shift with a new medical student. You are reviewing the nursing notes for the 12-year-old boy who had a 2-minute generalized tonic-clonic seizure just after waking up. Just then, a 7-month-old girl is rushed in by panicked parents who say they were driving near the hospital when their daughter became unresponsive and was shaking in all her extremities for 1 minute. By the time you see her, she is awake and alert, and only wants to be held by her mother. Her temperature in triage is 40.5˚C. Your charge nurse comes to tell you that an ambulance is bringing in a 6-year-old boy with a known seizure disorder who is actively seizing. You ask the triage nurse to give the 7-month-old acetaminophen while you prepare for the 6-year-old patient. As you are running through medication dosing in for the 6-year-old, the medical student asks what laboratory tests you would order for each patient and if he should call for a CT scan for any of the patients…
Seizures account for 1% of all emergency department (ED) visits for patients aged < 18 years and account for an even higher percentage of visits in some tertiary referral hospitals.1,2 Each year, approximately 25,000 to 40,000 children in the United States experience their first nonfebrile seizure.3,4 Seizures are especially common in infants and children aged < 5 years.1 Infants aged < 1 year have the highest incidence of new unprovoked seizures in any age group.5 Seizures present special diagnostic and treatment challenges because the etiologies of seizures range from benign to life-threatening. Evaluation and treatment of seizures must be individualized based on the patient's presentation and the likely etiology. Management of a patient in status epilepticus requires simultaneous attention to respiratory and circulatory status, vascular access, and investigation into and treatment of reversible or life-threatening causes of seizure. However, well-appearing patients with self-resolved recurrent seizures or simple febrile seizures may not require any further investigation after a reassuring history and physical examination is completed. Unnecessary laboratory testing and radiation exposure should be avoided in these patients.
A literature search was performed in PubMed using combinations of the search terms pediatric, child, children, neonatal, neonate, seizure, febrile seizure, complex febrile seizure, status epilepticus, neuroimaging, and anticonvulsant. The references of articles were reviewed to identify relevant publications. The National Guideline Clearinghouse and the Cochrane Library were also searched.
Searches of the clinical policies and guidelines of the American Academy of Pediatrics (AAP), the American College of Emergency Physicians (ACEP), the American Academy of Neurology (AAN), the Child Neurology Society, and the American Epilepsy Society were conducted. The only relevant ACEP clinical policy was a 2014 policy on evaluation and management of seizures in adults. Applicable AAP clinical policies dealt only with febrile seizures. Available guidelines do not address many questions that arise in the evaluation and treatment of seizures. Specific issues not addressed in published guidelines are the appropriate evaluation of complex febrile seizures and the role of newer anticonvulsants (such as levetiracetam) in the ED setting.
1. "I didn't think to check the patient's blood sugar. The patient isn't diabetic, and I was focused on stopping the seizure and managing the airway.”
Hypoglycemia is a dangerous but reversible cause of seizures. Children may be hypoglycemic for a number of reasons such as ingestion of oral hypoglycemic medications and undiagnosed metabolic disorders. A bedside glucose level should be checked immediately in patients with active seizures or altered mental status.
2. "I didn't consider eclampsia as a cause of seizures. The patient is only 14 years old.”
While rare in pediatric patients, eclampsia cannot be missed, as this diagnosis changes patient management drastically. For additional information on management of this condition, refer to the January 2015 Emergency Medicine Practice issue titled "Clinical Decision Making In Seizures And Status Epilepticus," available at: www.ebmedicine.net/EMPseizures.
3. "The 3-month-old girl had a single, brief, self-resolved generalized seizure. She looked great, so I diagnosed her with a simple febrile seizure.”
Febrile seizures are seen in children aged 6 months to 5 years. A fever and seizure in a younger infant is concerning for infections such as meningitis and encephalitis.
4. "I thought febrile seizures were a benign entity, so I didn't work up the 18-month-old child for meningitis.”
While simple febrile seizures are generally a benign entity, not all seizures associated with fever are febrile seizures. Encephalitis, brain abscess, and meningitis may all present with fever and seizure. While the vast majority of children with simple febrile seizures do not require a lumbar puncture, a careful history and physical examination is needed to evaluate for signs and symptoms of serious infection or other serious pathology.
5. "Witnesses said the patient had a seizure at school. I worked him up for a first-time seizure, but didn't see any reason to get an ECG.”
Dysrhythmia leading to syncope is a dangerous seizure mimic. Patients with a dysrhythmia may have twitching motions that are mistaken for seizure activity.
6. "I know chemistries are generally normal in seizure patients, so I didn't order one for the seizing 3-week-old.”
While electrolytes are likely to be normal in an older infant or child with a self-resolved seizure, status epilepticus in any child, or even a resolved seizure in a neonate, warrants further investigation. A neonate may have hypocalcemia due to undiagnosed DiGeorge syndrome or hyponatremia or hypernatremia from improper formula preparation.
7. "The pediatric neurologist said I should have given pyridoxine to the neonate with status epilepticus. I'd never even heard of pyridoxine-dependent seizures.”
Pyridoxine-dependent seizures are a diagnosis unique to pediatric patients. Pyridoxine should be administered to infants with seizures that do not resolve with first-line treatments.
8. "The pediatric intensive care unit attending just told me that I should have treated the 2-year-old in status epilepticus with pyridoxine because it turned out the child ingested isoniazid. I never thought to ask about isoniazid in the home.”
Isoniazid overdose and several other ingestions can cause seizures that are unlikely to be controlled with other treatments. Pyridoxine should be considered for difficult-to-control and otherwise unexplained seizures.
9. "I asked about a history of trauma in the baby, but the family denied it. They seemed trustworthy.”
Unfortunately, one diagnosis that must always be a consideration in pediatric patients is nonaccidental trauma, and caregivers are unlikely to volunteer this information or provide a reliable history.
10. ”I'm being sued because a teenager I saw for a first-time seizure was in a car accident during a second seizure and injured several people. I always report adults with seizures to the Department of Motor Vehicles, but I didn't know this teenager even had a driver's license."
Clinicians must report patients with seizures in some states. It is prudent to understand the laws of the state and remember that older teenagers are of driving age.
Evidence-based medicine requires a critical appraisal of the literature based upon study methodology and number of subjects. Not all references are equally robust. The findings of a large, prospective, randomized, and blinded trial should carry more weight than a case report.
To help the reader judge the strength of each reference, pertinent information about the study, such as the type of study and the number of patients in the study will be included in bold type following the references cited in this paper, as determined by the author, will be noted by an asterisk (*) next to the number of the reference.
Genevieve Santillanes, MD, FAAP, FACEP; Quyen Luc, MD
March 2, 2015