Seizures (Convulsions, Fits), Febrile and Pediatric
Parents who are frightened and concerned bring in their child who has just had a generalized seizure with jerking tonic-clonic movements and loss of consciousness, followed by a period of postictal obtundation that gradually resolves within 30 minutes. The patient has completely recovered by the time he is brought to your attention. The parents may have been horrified by the sight of their child becoming cyanotic with breathing difficulty, unresponsiveness, and jerking eye movements during the seizure. The child may be found to have a fever, and there may be a family history of febrile seizures. A vaccination with diphtheria and tetanus toxoids and whole-cell pertussis vaccine may have been administered earlier in the day or 1 to 2 weeks following a measles, mumps, and rubella vaccination.
What To Do:
Obtain a history of possible precipitating factors, such as trauma or toxin or drug ingestion. Inquire into recent condition(s) and medical history, as well as any family history of seizure disorders.
Have witnesses describe the event in detail, including the type of motor and eye movements, changes in breathing and skin color, and whether or not there was complete loss of consciousness or incontinence. Determine the duration of the seizure and the length of the postictal period.
Perform a physical examination that includes evaluation of pupil size and reactivity, along with funduscopy to look for retinal hemorrhage, which would suggest intentional injury. After the patient has experienced full recovery from the postictal state, the physical examination should be entirely normal.
In children older than 6 months of age, in the absence of a history of illness, vomiting or diarrhea, or suspected ingestion, routine laboratory testing is not needed.
Infants younger than 6 months of age require immediate glucose testing to rule out hypoglycemia. Serum sodium, calcium, and magnesium levels should also be determined to rule out low levels of these electrolytes. Toxicology screening should be considered if there is suspicion of toxin exposure.
A computed tomography (CT) scan should be obtained if there are findings of head trauma, focal (partial) seizure, seizure longer than 5 minutes, focal postictal deficits not rapidly resolving (Todd paralysis), persistently altered level of consciousness, sickle cell disease, bleeding disorders, malignancy, or human immunodeficiency virus (HIV) infection. For most children, immediate neuroimaging is not indicated.
Children who have just one unprovoked seizure—for whom there is no suspicion of trauma, infection, or intoxication—and who have returned to their baseline state, may be discharged with appropriate medical follow-up. Antiepileptic drugs are usually not prescribed.
Parents should be appropriately reassured and informed that 60% of such children never have a recurrence. Discharge instructions should describe what to do if the seizure recurs.
If seizure activity persists for more than 5 minutes, consider bag-valve-mask ventilation or intubation if there is significant respiratory compromise. An IV line should be placed, and a bedside glucose test should be performed. If the patient is hypoglycemic, 0.5 to 1 g/kg of glucose should be given as a bolus (2 mL/kg of 25% dextrose in water or, in neonates, 5 mL/kg of 10% dextrose in water).
With IV or IO (intraosseous) access:
— give lorazepam (Ativan), 0.1 mg/kg IV over 2 to 5 minutes; may repeat in 5 to 10 minutes up to a 4-mg dose (recommended treatment)
— or give diazepam (Valium), 0.2 to 0.5 mg/kg IV every 15 to 30 minutes to a maximum 5-mg dose.
Without IV or IO access:
— give lorazepam, 0.1 mg/kg rectally up to a 4-mg dose
— or give diazepam gel (Diastat), 0.5 mg/kg rectally up to a 10-mg dose
— or give midazolam (Versed), 0.1 to 0.2 mg/kg IM × 1 up to a 10-mg dose.
All children who present in status epilepticus should be considered for treatment with a long-acting antiepileptic drug, such as:
— phenytoin (Dilantin), 20 mg/kg IV at less than 1 mg/kg/min up to 1000 mg
— or fosphenytoin (Cerebyx), 20 mg/kg PE (phenytoin sodium equivalents) up to 1000 mg at less than 3 mg/kg/min (safety and efficacy not established for pediatric patients)
— or phenobarbital, 10 to 20 mg/kg IV up to 1000 mg at less than 1 to 2 mg/kg/min.
A careful history and physical examination should be done to identify a possible source of the fever and to rule out any evidence of trauma.
Children between the ages of 6 months and 5 years who have simple febrile seizures (generalized, lasting less than 5 minutes and occurring only once in a 24-hour period) carry few risks for complications and do not require any routine diagnostic studies.
Children with fever without an identifiable source should be evaluated for urinary tract infection.
In patients whose level of consciousness has not returned to baseline; who have a bulging fontanel, a positive Kernig or Brodzinski sign, photophobia, severe headache, or pretreatment with antibiotics; or who are lethargic or irritable, lumbar puncture should be performed to exclude meningitis. Children who are younger than 6 months of age must be evaluated for metabolic abnormalities, underlying neurologic disorders, meningitis, and encephalitis.
Antibiotics are only indicated for focal infections.
Antipyretics have not been found to be effective in preventing the recurrence of febrile seizures. Benzodiazepines are also probably of no practical benefit when used for prophylaxis.
There is no evidence that children with simple febrile seizures have any difference in cognitive outcomes than children without such seizures, and although these seizures appear frightening, they are generally harmless. Parents should be reassured and given written, detailed information about febrile seizures and then referred back to their primary care physician for follow-up.
Febrile seizures that are focal, last more than 10 minutes, or recur within 24 hours are complex febrile seizures that require a more intensive investigation and are associated with a greater risk for later epilepsy.
What Not To Do:
Do not perform a lumbar puncture on an afebrile child who has returned to normal mental status and has no meningeal signs.
Do not do routine neuroimaging on children with first-time afebrile seizures or febrile seizure patients who have a normal neurologic examination with full postseizure recovery.
Do not do routine laboratory testing on children who are older than 6 months of age who have not been ill without vomiting or diarrhea and where there is no suspicion of a toxic ingestion.
Do not start antiepileptic drugs on patients with simple febrile seizures or first-time, unprovoked, uncomplicated seizures.
Do not try using “around-the-clock” acetaminophen or ibuprofen to prevent the recurrence of febrile seizures. It may only contribute to the parents’ fever phobia.
Seizures are either generalized or partial (focal). Generalized seizures can be of several types: absence, atonic, tonic-clonic, tonic, myoclonic, or infantile spasms. Partial seizures are classified as simple (simple partial), in which consciousness is preserved, or complex (complex partial), in which consciousness is impaired. Secondarily generalized seizures are partial seizures that become generalized.
Paroxysmal nonepileptic disorders that may be mistaken for seizures include syncope (which may include a brief seizure with immediate awakening), breath-holding spells (which usually occur with crying until there is a noiseless state of expiration, color change, loss of consciousness, and postural tone with occasional body jerking and urinary incontinence), and night terrors (in which a 2- to 6-year-old child awakens suddenly within 4 hours of falling asleep, appears frightened or confused, cries, and becomes diaphoretic, tachycardic, and tachypneic and then falls asleep and is amnesic regarding the event the following morning). Other disorders that can mimic seizures are migraine headaches (which can be accompanied by an aura, motor dysfunction, and clouding of consciousness), apparent life-threatening events (ALTE) (which are episodes characterized by some combination of infant apnea, color change, choking, gagging, and loss of muscle tone), and pseudoseizures (most commonly occurring in teenage girls and usually consisting of bilateral, thrashing motor activity and rarely result in injury) (see Chapter 4).
Febrile seizures are defined as those that occur in febrile children who are 6 months to 5 years of age who do not have evidence of intracranial infection or known seizure disorder.
Because most febrile seizures occur during the first 24 hours of illness, the seizure is the first sign of a febrile illness in approximately 25% to 50% of cases. Although children with febrile seizures have high mean temperatures (39.8° C), they are not at high risk for serious bacterial illness.
Most clinicians now define status epilepticus to be continuous or repetitive seizure activity for longer than 5 minutes. Because almost all self-limited seizures stop within 5 minutes, antiepileptic drug therapy should be initiated for any patient with a seizure lasting longer than 5 minutes. Seizure duration of longer than 1 hour, especially with hypoxia, has been associated with permanent neurologic injury.
Overall, the risk for recurrent febrile seizures is increased in younger patients (younger than 12 months old) with a first-time febrile seizure, patients with lower temperatures (less than 40° C) on presentation of their first seizure, patients with shorter duration of fever before the seizure (less than 24 hours), and patients with a family history of febrile seizures.
In the general population, the risk for development of epilepsy by the age of 7 years is approximately 1%. Children who have had one simple febrile seizure have a slightly higher risk for developing epilepsy. Children who were younger than 12 months of age at their first simple febrile seizure or those who have had several simple febrile seizures have a 2.4% risk for developing epilepsy. The risk for developing epilepsy increases to 30 to 50 times that of the general population in patients who have had one or more complex febrile seizures, particularly seizures with focal features in a child with abnormal neurologic development.