eMedicine Specialties > Neurology > Pediatric Neurology

First Seizure, Pediatric Perspective

Author: Catherine J Chu-Shore, MD,, Instructor in Neurology, Harvard Medical School, Massachusetts General Hospital
Coauthor(s): Brian S Tseng, MD, PhD, Assistant Professor, Department of Neurology, Division of Pediatric Neurology, Harvard Medical School, Massachusetts General Hospital
Contributor Information and Disclosures

Updated: Jan 14, 2010

Background

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 Many children who experience a first seizure may never experience a second seizure. However, a seizure may be the initial presentation of a more serious medical condition or subsequent epilepsy. Epilepsy is a condition in which a child has 2 or more seizures without a proximal cause for the seizures (unprovoked seizures).

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

Differential Diagnosis

Many disorders can mimic seizures in children and should be considered in the differential diagnosis of first seizure in a child. The most common nonepileptic paroxysmal disorders include the following:³

• Syncope or breath-holding spells
• Migraine
• Benign paroxysmal vertigo
• Behavioral events such as nonepileptic staring spells, jitteriness, self-stimulation, or stereotypies
• Gastrointestinal reflux (Sandifer syndrome)
• Movement disorders such tics, benign myoclonus, dyskinesias, or dystonias
• Sleep disorders such as night terrors or confusional arousals
• Psychogenic pseudoseizures or panic attacks

Potential Etiologies

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

Some etiologies of provoked (symptomatic) childhood seizures include the following situations:

• Central nervous system infections, such as meningitis, encephalitis, and empyema, can present with seizures and identifying and treating the underlying infection is imperative.
• Metabolic alterations can precipitate seizures and can be directly treatable targets. Consider evaluating glucose, sodium, and calcium levels in children with first seizures, particularly in those children who are receiving intravenous (IV) fluids, are diabetic, or may otherwise be prone to electrolyte abnormalities. 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, or tumors or other mass lesions are less common etiologies of seizures, but can be ruled out with appropriate neuroimaging studies.

Febrile seizures affect 2-5% of children aged 6 months to 6 years. These occur in association with a high fever, typically above 38.5° C, in the absence of central nervous system infection. There is often positive family history of febrile seizures in other family members. Some believe the rate of change in body temperature is more provoking than the absolute temperature. A second episode occurs in 33% of children, and only 50% of those have a third episode. Approximately 3-6% of patients with febrile seizures will develop afebrile seizures or epilepsy. 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.

Most children with a first afebrile seizure do not have a clear underlying etiology. Many of these children will not develop a second seizure.⁴ } In this case, identification of risk factors or a specific epilepsy syndrome may help with treatment decision and prognostication. Some childhood epilepsy syndromes include the following:

• Infantile spasms typically begin in infants aged 4-8 months (though earlier and later presentations do occur) and consist of clusters of myoclonic spasms that typically occur upon awakening or falling asleep. Presentations can be more subtle and include slight eye flutter or head drop. If 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 primary generalized in onset. Diagnosis can be assisted by hyperventilation trial, which often provokes the seizures and classic EEG features.
• 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 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 Panyiotopoulous syndrome in which autonomic symptoms are prominent.
• Juvenile myoclonic epilepsy (JME) occurs 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.

Clinical

History

Because medical personnel often do not witness the first seizure, the medical history may be the most important part of the evaluation. A thorough description of the event from start to finish from a primary witness should be obtained. In the history, collect information on what the patient was doing just before the seizure as well as postictal findings, such as confusion or hemiparesis. An accurate description of seizure semiology including whether consciousness was affected, lateralizing signs or automatisms, and other behaviors is important because different evaluations and treatments may be indicated (or contraindicated) for specific seizure types. An accurate description of seizure semiology at onset is particularly important, as this might give clues as to whether a generalized seizure actually had a partial onset.

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

Physical

A thorough general 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 age 6 months.)
• 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

Laboratory and Diagnostic Evaluation

Initial laboratory evaluation of a first seizure can include serum studies for glucose, electrolytes, calcium, and magnesium and toxicology studies. The American Academy of Neurology (AAN) recommends that clinicians use their clinical judgment.⁶

Perform a CT scan if the patient has had recent head trauma, significantly altered mental status, a significant headache, papilledema or a bulging fontanelle, or an abnormal neurologic examination.

Strongly consider a lumbar puncture (LP) in patients who have fever and a stiff neck or who have fever and are unconscious. If increased intracranial pressure is suspected, obtain noncontrast head CT prior to LP, as there may be a risk of inducing cerebral herniation with space-occupying lesions or obstructive hydrocephalus. The AAN recommends lumbar puncture be performed in any child with persistent changes in mental status who is younger than age 6 months or any child with meningeal signs.⁶

If suspicion of CNS infection is high, appropriate empiric antibiotic and antiviral medications should begin promptly. Steroids are currently thought to improve outcome in some forms of CNS bacterial infection, in particular Haemophilus influenzae type b infection, and should be given before the antibiotics as a rapid infusion unless this would delay the initiation of antibiotic therapy. LP is best obtained prior to antibiotic administration, but LP can be obtained during or after, if technical factors would introduce a substantial treatment delay.

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.

Role of EEG After First Seizure

Electroencephalograms are an important tool in determining prognosis for future seizures and should be strongly considered for all children with a first seizure. If the child is clinically stable, it may not be necessary to perform the EEG on an emergent basis.

An EEG does not determine whether or not the patient had a seizure, as this is a clinical diagnosis. In healthy individuals, 10% have an abnormal EEG, whereas 50% of patients with epilepsy have a normal first EEG. Repeating the EEG a second time may increase the sensitivity to 80-90%.⁷ EEGs may be helpful in classifying seizure types and identifying particular epilepsy syndromes, 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.

If clinical concern arises for nonconvulsive status epilepticus following a clinical seizure, an EEG would determine if the patient is still having electrographic seizure activity. An EEG is 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.

Role of Neuroimaging After First Seizure

If the child has recent head trauma, recurrent seizures, focal or new neurologic deficits, and/or papilledema, neuroimaging should be obtained. Patients who have clearly defined epileptic syndromes, such as petit mal epilepsy or benign rolandic epilepsy, do not necessarily need a brain MRI. The role of neuroimaging in a child with new onset afebrile seizures is controversial.

Without stratifying based on history and neurologic examination findings, a recent meta-analysis reports that emergent head CT resulted in a change in acute management in 3-8% of children presenting to an emergency department with a seizure.⁸ 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 EEG can be helpful. For example, a focal EEG may increase suspicion for a structural abnormality.

Treatment

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.¹⁰

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 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.

In other conditions, such as the primary generalized epilepsies, absence epilepsy, or JME, the likelihood of a recurrent event is high; therefore, appropriate anticonvulsants (eg, lamotrigine or valproate) should be administered early to the patient.

The decision of whether or not to treat with chronic anticonvulsant therapy after a first unprovoked seizure in a neurologically normal child requires consideration of the risks of medication side effects and psychological stigma against the risk of recurrent seizure 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, mental retardation, 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.

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.

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.

Long-Term Prognosis

Giving a definitive prognosis after a single seizure is difficult, but some general rules do apply, based on epidemiological 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 EEG is found to be normal, 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 one year and 56% within 3 years.

Children with developmental problems, structural CNS lesions, or focal neurologic deficits have a 37% risk of having another seizure within one year and 60% risk of having another seizure within three 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.^13,14,15

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

Patient Education

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

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 more 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.

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 instance, 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.

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 CPR. CPR according to the AHA or American Red Cross are highly recommended to all families.

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

For excellent patient education resources, visit eMedicine's Brain and Nervous System Center. Also, see eMedicine's patient education article Epilepsy.

Keywords

epilepsy, febrile seizure, childhood seizure, infantile spasm, petit mal epilepsy, benign rolandic epilepsy, juvenile myoclonic epilepsy, JME, meningitis, encephalitis, absence epilepsy, complex partial seizures

The authors and editors of eMedicine gratefully acknowledge the contributions of previous author S Matthew Stead, MD, PhD, to the development and writing of this article.

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