Pediatric First Seizure

Population-based estimates suggest that every year 25,000–40,000 children in the United States experience a first unprovoked seizure. ^[1] Using the International League Against Epilepsy (ILAE) definition, this includes multiple seizures within a 24-hour period if the child returns to baseline consciousness between episodes. ^[2]

Most of these children never experience a recurrence .  However, a seizure may be the initial presentation of a more serious medical condition or subsequent epilepsy. Historically, epilepsy has been defined as a condition in which a child has 2 or more seizures without a proximal cause for the seizures (unprovoked seizures). In 2013, the ILAE also accepted these 2 alternative conditions: 1) one unprovoked or reflex seizure plus a recurrence risk of at least 60% over the next 10 years; or 2) a diagnosis of an epilepsy syndrome. ^[3]

When evaluating a child who has experienced a first seizure, the clinician needs to address the following:

• An identifiable etiology

• The most appropriate therapy

• The prognosis

For more information, see the following:

• Epilepsy and Seizures

• Benign Childhood Epilepsy

• First Adult Seizure

• EEG in Status Epilepticus

• Epileptiform Normal Variants on EEG

• EEG Video Monitoring

Identification of the underlying seizure etiology helps to identify appropriate treatment options and the prognosis for the child. In evaluating the child after a first seizure, the first consideration should be determining if the seizure was provoked or unprovoked. In the case of provoked seizures, treatment should include identifying and treating the underlying etiology.

Provoked seizures

Some etiologies of provoked (symptomatic) childhood seizures include central nervous system (CNS) infections, metabolic alterations, head trauma, and structural abnormalities.

CNS infections, such as meningitis, encephalitis, and empyema, can present with seizures. Identifying and treating the underlying infection is imperative.

Metabolic alterations can precipitate seizures and can be directly treatable targets. In children who are receiving intravenous (IV) fluids, are diabetic, or who may otherwise be prone to electrolyte abnormalities, consider evaluating glucose, sodium, and calcium levels. For patients with chronic hyponatremia, rapid sodium correction should be avoided to prevent central pontine myelinolysis. Also consider obtaining toxicology screens to evaluate for medication or toxic exposures.

Head trauma can precipitate seizures and requires immediate evaluation with appropriate neuroimaging studies to rule out hemorrhage, contusion, or other serious injuries.

Structural abnormalities, such as congenital cerebral malformations, ischemic or hemorrhagic strokes, tumors or other mass lesions are less common etiologies of seizures, but can be ruled out with appropriate neuroimaging studies. Focal cortical dysplasias are a frequent cause of medically-refractory epilepsy.

Febrile seizures

Febrile seizures are convulsions in infants and children triggered by a fever in the absence of CNS infection. Febrile seizures affect 4–5% of children aged 6 months to 6 years. These occur in association with a high fever, typically above 38.5°C (101.3°F), although some believe the rate of change in body temperature is more provoking than the absolute temperature in febrile seizures. There is often a positive family history of febrile seizures in other family members. A second episode occurs in 33% of children, and only 50% of those have a third episode. Few children, approximately 3–6%, with febrile seizures develop afebrile seizures or epilepsy. Electroencephalography (EEG) and neuroimaging are generally not warranted. ^[4] Further evaluation may be required for complex febrile seizures, which include seizures that are greater than 15 minutes in duration, have focal onset, or occur multiple times within 24 hours or within a febrile illness.

Epileptic syndromes

An exhaustive list of seizure types and pediatric epilepsy syndromes is beyond the scope of this article. However, familiarity with some of the most common seizure syndromes can aid the clinician in obtaining an appropriate workup and evaluation.

Infantile spasms typically begin in infants aged 4–8 months (although earlier and later presentations do occur) and consist of clusters of myoclonic spasms, typically upon awakening or falling asleep. The presentations can be more subtle and include slight eye flutter or head drop. If infantile spasms are suspected, appropriate diagnosis and swift management is essential to improve developmental outcome.

Absence epilepsy, also known as petit mal epilepsy, is manifested by frequent (as many as 100 times per day or more) episodes of brief staring spells, often with fluttering of the eyelids, lasting only a few seconds (typically up to 15 seconds) at a time. Following a typical absence seizure, patients return immediately to their baseline mental status. Absence seizures are primarily generalized in onset. The diagnosis can be assisted by classic EEG features and hyperventilation trial, which often provokes the seizures.

Benign rolandic epilepsy occurs in children aged 3–13 years. ^[5] The typical presentation is a seizure characterized by perirolandic or perisylvian sensorimotor features including speech arrest or guttural sounds and facial numbness or twitching, which may progress to generalized tonic-clonic activity. The majority of seizures occur during sleep or upon awakening. Classic EEG features can aid in the diagnosis of this syndrome.

Other benign partial epilepsies of childhood include benign occipital epilepsy of childhood (Gastaut syndrome), in which visual symptoms predominate, and Panayiotopoulos syndrome, in which autonomic changes, vomiting, sweating, and pallor are prominent ictal symptoms.

Juvenile myoclonic epilepsy (JME) may present in the teen years. In JME, individuals may present with generalized tonic-clonic seizures, myoclonic jerks (typically seen within hours of awakening), and staring spells.

For more information regarding specific pediatric epilepsy syndromes, please refer to the International League Against Epilepsy.

Because medical personnel often do not witness the first seizure, eyewitness accounts are a crucial step in evaluation. Collect information on what the patient was doing just before the seizure (eg, association with sleep onset or arousal from sleep). Seizure while watching television or flickering lights may suggest a photosensitive seizure.

An accurate description of seizure semiology can help differentiate between specific seizure types. One should ask about alteration of consciousness, lateralizing signs (eg, eye deviations, head turning, focal clonus) or automatisms (eg, lip smacking, picking at clothes, gestures such as fumbling or tapping). ^[6] An accurate description of seizure semiology at onset is particularly important, as this might give clues to whether a generalized seizure actually had a partial onset. ^[2]

If possible, getting the patient’s account of the event can provide further diagnostic clues. For example, olfactory or epigastric aura are suggestive of temporal lobe epilepsy, while visual hallucinations can occur with occipital lobe seizures.

In addition to events immediately surrounding the seizure, it is important to gather any history of recent illnesses, antibiotic treatment (which may raise suspicion for a partially treated meningitis), recent travel, recent head injury, chemical or toxin exposures, and intake of medications, supplements, alcohol, and/or illicit drugs.

Obtain a family history of epilepsy or febrile seizures, particularly among first-degree relatives. Elicit a history of fever, chronic medical conditions (eg, diabetes), medications, behavioral or dietary changes, and recent or remote history of head trauma or CNS infections. A developmental history is important in assessing possible etiologies and risk of future events.

A thorough general examination and detailed neurologic examination should be performed. In particular, the patient should be evaluated for the following:

• Fever or other abnormalities in vital signs

• Signs suggestive of trauma or the presence of an intracranial shunt

• Dysmorphic features and abnormal neurodevelopment

• Papilledema, suggesting increased intracranial pressure

• Nuchal rigidity or other signs of meningismus (specific signs of meningitis may be absent in children, particularly in neonates and infants younger than 6 mo)

• Skin features such as port-wine stain, facial angiofibromas, hypopigmented macules, or shagreen patch suggestive of neurocutaneous syndrome, or petechial rash suggestive of meningococcal infection

• Focal neurologic deficits, which may be indicative of an underlying focal structural lesion or postictal Todd paresis

Initial laboratory evaluation of a first seizure can include serum studies for levels of glucose, electrolytes, calcium, and magnesium and for toxicology. The American Academy of Neurology (AAN) recommends that clinicians use their clinical judgment. ^[5]

While it is not routinely tested, prolactin may help to distinguish seizures from nonepileptic events. ^[7]

Give particular attention to the laboratory evaluation of the neonate, as glucose and calcium abnormalities can be observed in the first week of life. When a metabolic abnormality is suspected in the neonate, consider a basic metabolic evaluation with serum ammonia, serum lactate and pyruvate, serum for amino acids, and urine for organic acids. Further metabolic studies should be guided by the history, examination, and clinical course.

Strongly consider a lumbar puncture (LP) in patients who have fever and either meningeal signs (neck pain, Kernig or Brudzinski sign) or altered mental status. If increased intracranial pressure is suspected, obtain rapid imaging before performing the lumbar puncture, as there may be a risk of inducing cerebral herniation with space-occupying lesions or obstructive hydrocephalus.

The American Academy of Neurology (AAN) recommends LP be performed in any child with persistent changes in mental status who is younger than 6 months or any child with meningeal signs. ^[5] For many years ,the role of lumbar puncture in infants aged 6–12 months has been controversial. These children are still too young to exhibit reliable meningeal signs. However, widespread immunization against Haemophilus influenzae type b (Hib) and Streptococcus pneumoniae has mitigated the risk of meningitis in this population.

In the American Academy of Pediatrics 2011 guidelines, LP is an option when an infant in this age-group is considered deficient in immunization and if immunization status cannot be determined. ^[8] Other elements of the presentation, such as failure to return to baseline, may also prompt LP in this age group.

The role of neuroimaging in a child with new-onset afebrile seizures is controversial. Emergent neuroimaging should be performed when there is a high clinical suspicion for a condition requiring immediate intervention, such as recent head trauma, recurrent seizures, focal or new neurologic deficits, and papilledema. Neuroimaging should also be considered if the patient has not returned to baseline. In marked distinction to the adult population seen in the emergency department, afebrile seizures in children are not commonly associated with abnormal neuroimaging.

Clinically significant neuroimaging abnormalities have been reported in 2% of children presenting with first afebrile seizure without focal features or predisposing conditions. ^[9] The decision of whether or not to obtain neuroimaging in these cases should be made on an individual basis, and an electroencephalogram (EEG) can be helpful. For example, a focal EEG may increase suspicion for a structural abnormality. Patients who have clearly defined epileptic syndromes, such as absence epilepsy or benign rolandic epilepsy, do not necessarily require neuroimaging. American Academy of Neurology (AAN) practice parameters recommend nonurgent imaging after initial seizure in situations in which there is a significant cognitive or motor impairment, unexplained abnormalities on the neurological examination, partial-onset seizures, an EEG inconsistent with a benign or primary generalized epilepsy, and in patients younger than 1 year. ^[5]

If neuroimaging is obtained, MRI is the preferred method of imaging to avoid radiation exposure while providing more detailed diagnostic information. ^[7] However, CT is still frequently obtained based on available resources.

According to one study, CT in the emergency department for children presenting with first seizure will change acute management in approximately 3 to 8% of patients. ^[10]

Electroencephalogram (EEG) can be useful in the acute setting if there is a concern for subclinical seizures (electrographic seizures without clinical correlate) or if the patient has persistent altered mental status. An EEG is also important if a nonreactive patient received paralytics for intubation and does not show awakening in the critical care unit after an expected timeframe. Clinical signs such as appropriate pupil reactivity and withdrawal to pain/stimulation can be helpful clues that the patient is not in continuous nonconvulsive status epilepticus. Long-term (24 h or greater) EEG monitoring should be considered to identify nonconvulsive seizures in at-risk patients, including infants or children with persistent unexplained altered mental status.

If the child is clinically stable, it may not be necessary to perform the EEG on an emergent basis. However, EEGs are an important tool in determining prognosis (see Long-Term Prognosis) for future seizures and should be strongly considered for all children with a first seizure on a nonurgent basis. ^[6] In the nonacute setting, there is still debate as to whether an EEG performed within the first 24 hours is more sensitive to identify epileptiform abnormalities. However, current practice does not mandate early EEG, as untreated patients with epilepsy tend to have persistent EEG abnormalities. EEG yield can be increased by including sleep and activating procedures, such as hyperventilation and photic stimulation. If there is a high suspicion for a seizure disorder and routine EEG is normal, repeat EEG or prolonged EEG monitoring can be obtained. Repeating the EEG a second time may increase the sensitivity to 80–90%. ^[8]

It is important to remember that an EEG does not determine whether the patient had a seizure, as this is a clinical diagnosis. EEGs may be abnormal in up to 10% of healthy individuals, and 50% of patients with epilepsy have a normal first EEG. EEGs can be helpful in classifying seizure types and identifying epilepsy syndromes with specific electroclinical features, such as benign rolandic epilepsy or juvenile myoclonic epilepsy. This classification system can help both with prognosis and determining appropriate anticonvulsant therapy. For more information regarding EEG findings in specific childhood epilepsy syndromes, see EEG in Common Epilepsy Syndromes.

As mentioned above, in the case of provoked seizures, treatment should include identifying and treating the underlying etiology. The aspects relevant to the decision of whether or not to initiate anticonvulsant drug therapy after first seizure is discussed.

Acute anticonvulsant therapy

The decision of whether or not to initiate anticonvulsant treatment after a first seizure must be based on the clinical scenario and risks and benefits determined for the individual patient. In general, anticonvulsant drugs are used to decrease the probability of recurrent seizures; however, they have not been found to prevent the development of epilepsy after first seizure. ^{[4, 11]}

In patients presenting in status epilepticus or in acutely ill children (eg, seizures associated with encephalitis), in which the chance of a recurrent seizure is high, medications that can be administered quickly through intravenous access (IV) access, such as benzodiazepines, fosphenytoin, phenobarbital, valproic acid, or levetiracetam are useful. A prescription for rectal diazepam (Diastat) for use at home if patients have a recurrent prolonged seizure in the future may be useful.

In some situations, such as simple febrile seizures, the risks and potential side effects of chronic anticonvulsant therapy may outweigh the benefits, and treatment is not typically offered.

Chronic anticonvulsant therapy

The decision of whether to treat with long-term anticonvulsant therapy after a first unprovoked seizure requires consideration of the risks of medication adverse effects and psychological stigma against the risk of recurrent seizure. Decisions must be made on an individualized basis and should involve discussions with the patient and family.

As a care guideline, most pediatric neurologists would not start chronic anticonvulsants after a first-time seizure, unless prominent risk factors for epilepsy (eg, cerebral palsy, intellectual disability, brain structural lesions, abnormal EEG) are known to exist. ^{[11, 12]} Even if increased recurrence risk is determined, many neurologists would delay starting chronic anticonvulsants until a second unprovoked seizure occurred, establishing adequate frequency of seizures to warrant medication.

This general practice is guided by data from both adult and pediatric studies, which show that delayed treatment of seizure disorders does not reduce the likelihood of seizure freedom and may spare some individuals from long-term antiepileptic drug treatment. ^{[1, 13]}

If anticonvulsant medications are initiated, the choice of medication should be made based on seizure type. Some medications have been shown to be highly efficacious for some types of seizures but worsen other types. For example, carbamazepine can be helpful against partial seizures but can exacerbate generalized absence seizures.

In most childhood epilepsies, anticonvulsant prophylaxis is maintained until the child is seizure-free for 1-2 years or until an appropriate age when the child would no longer be expected to be at risk of having seizures.

Patients at risk of seizures or lapses of consciousness who are old enough to drive must be carefully evaluated and reported to state authorities per mandates of individual state laws. Find out more information at the Epilepsy Foundation.

Giving a definitive prognosis after a single seizure is difficult, but some general rules do apply, based on epidemiologic data.

In general, children who have a single, short, generalized seizure along with normal neurologic development and normal findings on neurologic examination are estimated to have a 24% risk of having another seizure within 1 year and a 36% chance of having a second seizure within 3 years. In these children, if the electroencephalogram (EEG) is found to be normal, the risk of seizure recurrence is estimated to decrease to approximately 15% within 1 year and 26% within 3 years. If the EEG is found to be abnormal, approximately 41% will have another seizure within 1 year and 56% within 3 years.

Children with developmental problems, structural central nervous system (CNS) lesions, or focal neurologic deficits have a 37% risk of having another seizure within 1 year and 60% risk of having another seizure within 3 years.

If a child has a second unprovoked seizure, the risk for further seizures is greater than 50%, even among children without other risk factors. ^{[12, 14, 15]} Identifying the seizure as part of a syndrome has additional predictive value. For example, patients with simple febrile seizures will likely have spontaneous remission as they enter school-age years; however, patients with juvenile myoclonic epilepsy are likely to have lifelong seizure recurrence. ^[16]

Inform the patient's family about the following:

• Steps to be taken in the event of a second seizure

• Seizure precautions

• Appropriate follow-up

• Organizations that can provide more information

In the event of a second seizure

If a child has a second seizure, place the child in a lateral decubitus position to allow gravity to pull secretions and the tongue out of the airway. Attempt to keep the neck straight to keep the airway most open. Place no objects in the child's mouth.

Most seizures last for less than 2 minutes; however, if a seizure lasts longer than 5 minutes, the child should be transported to an emergency department for administration of medications to stop the seizures. If the seizure is the second unprovoked seizure (eg, no fever, drug exposure, or proximate head trauma), contact the patient's primary physician or neurologist, because anticonvulsant therapy is frequently indicated.

Seizure precautions

Children with the possibility of a having a second seizure should not engage in activities that are potentially harmful. They should not be allowed to take unsupervised baths (because of the risk of drowning) or to climb higher than 5 feet. Supervised swimming, bike riding (helmeted), and playing video games are considered by most neurologists to be safe activities.

Driving age patients should refrain from driving until deemed safe and seizure-free, according to the laws of their state. For example, in the State of Wisconsin, patients need to be seizure-free for 3 months before they can resume driving, whereas in Arkansas, patients need to be seizure-free for 1 year. For individual state regulations, see the Epilepsy Foundation Web site.

Follow-up

After a single seizure, an appointment should be made with the child's primary care physician or a neurologist. This is useful to address any further questions the family has, review the need for further diagnostic testing, and discuss any further therapy. Families should also be encouraged to learn basic cardiopulmonary resuscitation (CPR). CPR training according to the American Heart Association (AHA) or American Red Cross is highly recommended to all families.

Organizations

Direct families of patients to reliable sources of information. The Epilepsy Foundation provides comprehensive information.

For patient education information, see Brain and Nervous System Center, as well as Epilepsy.