The Seizing Child - An Age-Based Approach to Pediatric Seizure Management

Shortly after putting their son to bed, the parents of an 8-year-old boy rushed to his room after hearing loud gurgling sounds. When they entered the room, they found their son asleep but noticed he had left-sided facial twitching, was making lip-smacking movements and gurgling noises from his throat, and drooling. They called-out his name and attempted to rouse him, but the child did not respond. The movements continued for approximately 30 seconds before spontaneously resolving.

Immediately following this episode, the parents took their son to the ED for evaluation. He was afebrile with normal vital signs. The physical examination, which included a neurological examination, was normal, and both parents noted that the child appeared to be completely back to his normal behavior. The patient’s past medical and surgical histories were unremarkable. His parents stated that he had not been on any medication and denied a family history of seizures.

Overview

Seizures, the most common pediatric neurological disorder, are a frequent presentation in the ED. It is estimated that between 4% and 10% of children will have at least one seizure before age 16 years.^1,2 The highest incidence of occurrence is seen in children younger than age 3 years; this frequency decreases in older children.²

Seizures are the resulting clinical manifestations of abnormal excessive synchronized neuronal activity within the cerebral cortex. Most seizure activity is stereotypical and self-limited³ and can be divided into two main types: generalized and partial. Generalized seizures involve both cerebral hemispheres and impairment of consciousness, while partial (or focal) seizures involve a single area of one hemisphere. Generalized seizures are usually classified as convulsive or nonconvulsive and include the following subtypes: tonic-clonic, atonic, absence, and myoclonic. Partial seizures can be subdivided into simple or complex, depending on whether consciousness is impaired.

Initial Management

As with critically ill patients, the first and most vital step in managing a seizing patient is to assess the airway, breathing, and circulation. Although the airway is the most frequently compromised component, simple interventions such as jaw thrust, suctioning, or the insertion of an oral or nasopharyngeal airway are usually sufficient to maintain adequate airway. If intubation is required, use of a short-acting paralytic agent should be considered so as not to mask ongoing seizure activity.¹ Patients actively seizing at presentation should be assumed to be in status epilepticus, which is defined as seizure activity lasting longer than 5 minutes or as repetitive seizure episodes without return of consciousness between episodes.

Treatment

The benzodiazepines are the first-line treatment for status epilepticus in pediatric patients. Although intravenous (IV) lorazepam has long been the standard for seizure termination, intramuscular midazolam has been shown to be as safe and effective in patients weighing more than 13 kg in whom IV access is either not available or is difficult to obtain.⁴

Many other forms of benzodiazepines exist for seizure cessation, such as diazepam gel, which is administered rectally. Intranasal and buccal administration of midazolam also has proved effective for pediatric seizure termination.^5,6 Second-line therapies include IV fosphenytoin, levetiracetam, phenobarbital, and valproic acid.^1,7,8 In infants, phenobarbital is usually the primary second-line therapy after benzodiazepines.

History and Behavioral Observation

Given both the significant number of causes of pediatric seizures and events that can mimic childhood seizure activity, obtaining a thorough history and detailed description of the seizure episode and any preceding events are essential. It is also important to note nonseizure-related activities unique to the pediatric population (eg, Moro reflex in young infants, back-arching with gastroesophageal reflux [Sandifer syndrome], breath-holding spells, daydreaming).

Differentiating normal movements from seizures can be particularly difficult with infants. For example, repetitive bicycling movements of the legs are a common sign of seizure activity in an infant but may be mistaken as normal by parents or inexperienced observers.

West Syndrome.
West syndrome (infantile spasms) is a rare severe seizure syndrome consisting of spasmodic flexural movements of the extremities and trunk that usually presents between ages 4 to 18 months. Subtle episodes can be misinterpreted as Moro reflex, the normal sudden extension of an infant’s extremities and arching of the back occurring from birth to approximately ages 3 to 5 months.⁹

Breath-holding.
An episode of loss of consciousness with associated cyanosis, pallor, rigidity, limpness, or even twitching that was immediately preceded by vigorous crying in a child ages 6 months to 5 years should prompt the physician to strongly consider a breath-holding spell.

Attention Deficit Disorder Versus Seizure Activity.
Children, especially those with attention deficit disorder, have a propensity for daydreaming. These children will often stare and not respond to voice at times; however, if these episodes are associated with facial movements or a sudden pause in activity (also known as behavior arrest), the possibility of absence or complex partial seizures should be suspected.²

 

Physical Examination

Along with the patient’s history, the physical examination should focus primarily on determining a possible seizure etiology. The entire body should be thoroughly evaluated for evidence of trauma. The head should be carefully evaluated for signs of deformity or swelling; the fullness of the anterior fontanel should be carefully assessed; and the pupils should be examined for signs of increased intracranial pressure (ICP). In the older pediatric patient with closed fontanelles in whom a cervical spine injury has been ruled out, assessment of the neck for evidence of meningeal irritation should be performed. Stigmata of underlying medical disease, along with the presence of dysmorphic features associated with particular genetic syndromes, also should be evaluated. In addition, signs of common toxidromes should be sought.

Common Etiologies and Diagnostic Evaluation by Age

Since seizure etiologies and diagnostic evaluation vary greatly along the pediatric age spectrum, it is helpful to divide this population into three main groups: neonates and infants (ages 0-12 months), toddlers and young children (ages 12 months-10 years), and preadolescents and teenagers (ages 11-18 years).

In patients with known seizure disorders, the majority of cases are due to subtherapeutic antiepileptic medications either from a patient “outgrowing” his or her weight-based dose or from medication noncompliance. For the purposes of this article, we have limited our discussion to patients with first-time seizures.

Neonates and Infants.
In infants, hypoxic ischemic encephalopathy (HIE) due to perinatal asphyxia is the most common cause of seizures, the vast majority of which present within the first 24 to 48 hours of life.² Although EPs may encounter children with seizures caused by HIE, it is rare that these represent an initial seizure. Far more common etiologies of first-time seizures in infants are infection (eg, meningitis, encephalitis, sepsis) and nonaccidental trauma.

Electrolyte Imbalance. Although electrolytes are frequently checked in all age groups with seizures, infants are by far the most likely to experience seizures secondary to electrolyte abnormalities. Therefore, this is the only group in which routine evaluation of electrolytes is recommended. Common conditions associated with electrolyte imbalance include hyponatremia, hypocalcemia and hypomagnesemia, as well as errors of metabolism.

Hyponatremia in infants can be secondary to congenital adrenal hyperplasia or formula overdilution. Hypocalcemia and hypomagnesemia, associated with hypoparathyroidism may be the initial presentation in infants with DiGeorge syndrome. In addition, inborn errors of metabolism frequently lead to hypoglycemic seizures. Thus, in all patients with ongoing seizures refractory to medication, electrolyte abnormalities should be strongly considered.

Computed Tomography. A computed tomography (CT) scan of the head should be highly considered in this patient population as it is often difficult to determine if the patient has returned to neurological baseline. Since the fontanelles are open in infants, they can tolerate larger increases in intracranial volume (whether from blood or mass lesion) before evidence of increased ICP becomes clinically evident.

Lumbar Puncture. A lumbar puncture (LP) to analyze the cerebrospinal fluid (CSF) for infection should be considered in all afebrile infants with seizures, though some recent evidence shows a relatively low yield in such testing.^10,11

Toddlers and Young Children.
Within this age group, febrile seizures tend to predominate. A febrile seizure is defined as a seizure occurring between ages 6 months and 5 years that is associated with fever (temperature >38˚C [100.4˚F]) but without evidence of intracranial infection, neurological disease, or another defined cause.1 These seizures can be simple or complex. Simple febrile seizures last less than 15 minutes, have generalized clinical features, and occur only once in a 24-hour period. In contrast, complex febrile seizures last longer than 15 minutes, have focal manifestations, or recur multiple times in 24 hours.³

Simple Febrile Seizures.  The vast majority of patients presenting with simple febrile seizures require very limited diagnostic evaluation. If the patient has no evidence of intracranial infection, a normal neurological examination, and is back to baseline mental status, then no further evaluation is necessary. Serum electrolytes should only be checked if the patient does not quickly return to neurological baseline, at which point checking a serum glucose level would be prudent. Any further laboratory testing should be for the sole purpose of determining the source of the patient’s fever.

Most patients do not require CSF testing. In the consensus statement on the neurodiagnostic evaluation of patients with simple febrile seizures, the American Academy of Pediatrics listed only being younger than 6 months of age as a strong indicator to perform an LP. An LP should, however, be considered in patients aged 6 to 12 months who are deficient in their immunizations (especially Haemophilus influenza type B and Streptococcus pneumoniae) and in all patients pretreated with antibiotics as this could mask the signs of meningitis and encephalitis.¹²

 

Complex Febrile Seizures. Firm recommendations regarding the management of complex febrile seizures are currently lacking. These seizures carry a higher risk of intracranial infections and therefore warrant a low-threshold for both neuroimaging and CSF evaluation, especially in those patients younger than age 18 months.

Afebrile Seizures. Types of afebrile seizure disorders presenting in this age group include juvenile myoclonic epilepsy (JME) and benign rolandic epilepsy (BRE), both of which tend to present between ages 5 and 15 years. The majority of patients with first-time afebrile seizures do not require emergent neuroimaging; however, they should be referred to a pediatric neurologist for outpatient magnetic resonance imaging (MRI) of the brain and an electroencephalogram (EEG). Patients requiring emergent neuroimaging with either CT or MRI include those with signs or symptoms of elevated ICP, a focal seizure or focal findings on neurological examination, failure to return to neurological baseline, and a seizure in the setting of head trauma.¹

Juvenile Myoclonic Epilepsy. Also known as Janz syndrome, JME is one of most common types of idiopathic generalized epilepsy in childhood. It presents most commonly in otherwise healthy teenagers with one or more of the following seizure types: myoclonic jerks, generalized tonic-clonic seizures (GTCS), or absence seizures. Myoclonic jerks are unique in that they occur during the morning hours, usually the first hour after awakening. They consist of rapid muscle contractions which are most often symmetric and bilateral. The GTCS occur in about 90% of patients with JME, typically just after awakening or during sleep. Both myoclonic jerks and GTCS are exacerbated by sleep deprivation.

Absence seizures are the least common type of seizure in JME. Intelligence in these patients is normal and there is often a family history of similar seizures. Most patients respond well to treatment with antiepileptic drugs, which are usually required for life.^3,13

Benign Rolandic Epilepsy. This is the most common form of partial epilepsy in childhood. The name is derived from the central sulcus of the cerebral cortex (the rolandic fissure) around which these seizures originate. Onset of BRE typically occurs between ages 5 and 15 years, with a peak incidence of initial seizures occurring between ages 8 and 9 years. Males are more commonly affected than females (approximate distribution of 1.5:1).²

Simple partial seizures are the hallmark of this type of epilepsy, with the majority of these seizures occurring during sleep. Cardinal features include unilateral facial sensory-motor symptoms, oropharyngeal symptoms, speech arrest, and hypersalivation. Although all of these manifestations are often present, seizures may be marked by only a single symptom. Although it is uncommon, partial seizures may progress to generalized tonic-clonic activity. The hallmark finding on EEG is centrotemporal spikes. Most children do not require treatment, and the vast majority (98%) outgrow the seizures by age 18 years.³ Children with BRE have normal development and intelligence.

Early Adolescents and Teenagers.
Among this cohort, toxic ingestion and overdose tend to be the most common etiologies of first-time seizures presenting to the ED. Oral hypoglycemics (especially sulfonylureas), tricyclic antidepressants, and isoniazid are the most common prescription medications leading to seizures. Others drugs include salicylates, lithium, anticholinergic medications, and bupropion.¹ With respect to nonprescription drugs, alcohol can cause seizures via hypoglycemia; cocaine and amphetamines also have a propensity to induce seizures.¹⁴ It is paramount to evaluate serum glucose levels and consider toxicologic etiology early in the management of seizures in this age group.

Case Conclusion

Given the focal nature of this patient’s probable seizures, a CT scan of the brain was ordered without contrast to rule out an intracranial mass lesion. Based on negative findings, no further testing was ordered. The patient remained at neurological baseline throughout the course of his stay in the ED, and was discharged home with a prescription for rectal diazepam and instructions on its use for seizures lasting longer than 5 minutes. He was referred to a pediatric neurologist for further evaluation, which included an EEG study that confirmed a diagnosis of BRE.

Dr. Schneider is a pediatric emergency medicine fellow, Eastern Virginia Medical School, Children’s Hospital of the King’s Daughters, Norfolk.

Dr. Clingenpeel is a fellowship director, pediatric emergency medicine, and associate professor of pediatrics, Eastern Virginia Medical School, Norfolk.

Shortly after putting their son to bed, the parents of an 8-year-old boy rushed to his room after hearing loud gurgling sounds. When they entered the room, they found their son asleep but noticed he had left-sided facial twitching, was making lip-smacking movements and gurgling noises from his throat, and drooling. They called-out his name and attempted to rouse him, but the child did not respond. The movements continued for approximately 30 seconds before spontaneously resolving.

Immediately following this episode, the parents took their son to the ED for evaluation. He was afebrile with normal vital signs. The physical examination, which included a neurological examination, was normal, and both parents noted that the child appeared to be completely back to his normal behavior. The patient’s past medical and surgical histories were unremarkable. His parents stated that he had not been on any medication and denied a family history of seizures.

Overview

Seizures, the most common pediatric neurological disorder, are a frequent presentation in the ED. It is estimated that between 4% and 10% of children will have at least one seizure before age 16 years.^1,2 The highest incidence of occurrence is seen in children younger than age 3 years; this frequency decreases in older children.²

Seizures are the resulting clinical manifestations of abnormal excessive synchronized neuronal activity within the cerebral cortex. Most seizure activity is stereotypical and self-limited³ and can be divided into two main types: generalized and partial. Generalized seizures involve both cerebral hemispheres and impairment of consciousness, while partial (or focal) seizures involve a single area of one hemisphere. Generalized seizures are usually classified as convulsive or nonconvulsive and include the following subtypes: tonic-clonic, atonic, absence, and myoclonic. Partial seizures can be subdivided into simple or complex, depending on whether consciousness is impaired.

Initial Management

As with critically ill patients, the first and most vital step in managing a seizing patient is to assess the airway, breathing, and circulation. Although the airway is the most frequently compromised component, simple interventions such as jaw thrust, suctioning, or the insertion of an oral or nasopharyngeal airway are usually sufficient to maintain adequate airway. If intubation is required, use of a short-acting paralytic agent should be considered so as not to mask ongoing seizure activity.¹ Patients actively seizing at presentation should be assumed to be in status epilepticus, which is defined as seizure activity lasting longer than 5 minutes or as repetitive seizure episodes without return of consciousness between episodes.

Treatment

The benzodiazepines are the first-line treatment for status epilepticus in pediatric patients. Although intravenous (IV) lorazepam has long been the standard for seizure termination, intramuscular midazolam has been shown to be as safe and effective in patients weighing more than 13 kg in whom IV access is either not available or is difficult to obtain.⁴

Many other forms of benzodiazepines exist for seizure cessation, such as diazepam gel, which is administered rectally. Intranasal and buccal administration of midazolam also has proved effective for pediatric seizure termination.^5,6 Second-line therapies include IV fosphenytoin, levetiracetam, phenobarbital, and valproic acid.^1,7,8 In infants, phenobarbital is usually the primary second-line therapy after benzodiazepines.

History and Behavioral Observation

Given both the significant number of causes of pediatric seizures and events that can mimic childhood seizure activity, obtaining a thorough history and detailed description of the seizure episode and any preceding events are essential. It is also important to note nonseizure-related activities unique to the pediatric population (eg, Moro reflex in young infants, back-arching with gastroesophageal reflux [Sandifer syndrome], breath-holding spells, daydreaming).

Differentiating normal movements from seizures can be particularly difficult with infants. For example, repetitive bicycling movements of the legs are a common sign of seizure activity in an infant but may be mistaken as normal by parents or inexperienced observers.

West Syndrome.
West syndrome (infantile spasms) is a rare severe seizure syndrome consisting of spasmodic flexural movements of the extremities and trunk that usually presents between ages 4 to 18 months. Subtle episodes can be misinterpreted as Moro reflex, the normal sudden extension of an infant’s extremities and arching of the back occurring from birth to approximately ages 3 to 5 months.⁹

Breath-holding.
An episode of loss of consciousness with associated cyanosis, pallor, rigidity, limpness, or even twitching that was immediately preceded by vigorous crying in a child ages 6 months to 5 years should prompt the physician to strongly consider a breath-holding spell.

Attention Deficit Disorder Versus Seizure Activity.
Children, especially those with attention deficit disorder, have a propensity for daydreaming. These children will often stare and not respond to voice at times; however, if these episodes are associated with facial movements or a sudden pause in activity (also known as behavior arrest), the possibility of absence or complex partial seizures should be suspected.²

 

Physical Examination

Along with the patient’s history, the physical examination should focus primarily on determining a possible seizure etiology. The entire body should be thoroughly evaluated for evidence of trauma. The head should be carefully evaluated for signs of deformity or swelling; the fullness of the anterior fontanel should be carefully assessed; and the pupils should be examined for signs of increased intracranial pressure (ICP). In the older pediatric patient with closed fontanelles in whom a cervical spine injury has been ruled out, assessment of the neck for evidence of meningeal irritation should be performed. Stigmata of underlying medical disease, along with the presence of dysmorphic features associated with particular genetic syndromes, also should be evaluated. In addition, signs of common toxidromes should be sought.

Common Etiologies and Diagnostic Evaluation by Age

Since seizure etiologies and diagnostic evaluation vary greatly along the pediatric age spectrum, it is helpful to divide this population into three main groups: neonates and infants (ages 0-12 months), toddlers and young children (ages 12 months-10 years), and preadolescents and teenagers (ages 11-18 years).

In patients with known seizure disorders, the majority of cases are due to subtherapeutic antiepileptic medications either from a patient “outgrowing” his or her weight-based dose or from medication noncompliance. For the purposes of this article, we have limited our discussion to patients with first-time seizures.

Neonates and Infants.
In infants, hypoxic ischemic encephalopathy (HIE) due to perinatal asphyxia is the most common cause of seizures, the vast majority of which present within the first 24 to 48 hours of life.² Although EPs may encounter children with seizures caused by HIE, it is rare that these represent an initial seizure. Far more common etiologies of first-time seizures in infants are infection (eg, meningitis, encephalitis, sepsis) and nonaccidental trauma.

Electrolyte Imbalance. Although electrolytes are frequently checked in all age groups with seizures, infants are by far the most likely to experience seizures secondary to electrolyte abnormalities. Therefore, this is the only group in which routine evaluation of electrolytes is recommended. Common conditions associated with electrolyte imbalance include hyponatremia, hypocalcemia and hypomagnesemia, as well as errors of metabolism.

Hyponatremia in infants can be secondary to congenital adrenal hyperplasia or formula overdilution. Hypocalcemia and hypomagnesemia, associated with hypoparathyroidism may be the initial presentation in infants with DiGeorge syndrome. In addition, inborn errors of metabolism frequently lead to hypoglycemic seizures. Thus, in all patients with ongoing seizures refractory to medication, electrolyte abnormalities should be strongly considered.

Computed Tomography. A computed tomography (CT) scan of the head should be highly considered in this patient population as it is often difficult to determine if the patient has returned to neurological baseline. Since the fontanelles are open in infants, they can tolerate larger increases in intracranial volume (whether from blood or mass lesion) before evidence of increased ICP becomes clinically evident.

Lumbar Puncture. A lumbar puncture (LP) to analyze the cerebrospinal fluid (CSF) for infection should be considered in all afebrile infants with seizures, though some recent evidence shows a relatively low yield in such testing.^10,11

Toddlers and Young Children.
Within this age group, febrile seizures tend to predominate. A febrile seizure is defined as a seizure occurring between ages 6 months and 5 years that is associated with fever (temperature >38˚C [100.4˚F]) but without evidence of intracranial infection, neurological disease, or another defined cause.1 These seizures can be simple or complex. Simple febrile seizures last less than 15 minutes, have generalized clinical features, and occur only once in a 24-hour period. In contrast, complex febrile seizures last longer than 15 minutes, have focal manifestations, or recur multiple times in 24 hours.³

Simple Febrile Seizures.  The vast majority of patients presenting with simple febrile seizures require very limited diagnostic evaluation. If the patient has no evidence of intracranial infection, a normal neurological examination, and is back to baseline mental status, then no further evaluation is necessary. Serum electrolytes should only be checked if the patient does not quickly return to neurological baseline, at which point checking a serum glucose level would be prudent. Any further laboratory testing should be for the sole purpose of determining the source of the patient’s fever.

Most patients do not require CSF testing. In the consensus statement on the neurodiagnostic evaluation of patients with simple febrile seizures, the American Academy of Pediatrics listed only being younger than 6 months of age as a strong indicator to perform an LP. An LP should, however, be considered in patients aged 6 to 12 months who are deficient in their immunizations (especially Haemophilus influenza type B and Streptococcus pneumoniae) and in all patients pretreated with antibiotics as this could mask the signs of meningitis and encephalitis.¹²

 

Complex Febrile Seizures. Firm recommendations regarding the management of complex febrile seizures are currently lacking. These seizures carry a higher risk of intracranial infections and therefore warrant a low-threshold for both neuroimaging and CSF evaluation, especially in those patients younger than age 18 months.

Afebrile Seizures. Types of afebrile seizure disorders presenting in this age group include juvenile myoclonic epilepsy (JME) and benign rolandic epilepsy (BRE), both of which tend to present between ages 5 and 15 years. The majority of patients with first-time afebrile seizures do not require emergent neuroimaging; however, they should be referred to a pediatric neurologist for outpatient magnetic resonance imaging (MRI) of the brain and an electroencephalogram (EEG). Patients requiring emergent neuroimaging with either CT or MRI include those with signs or symptoms of elevated ICP, a focal seizure or focal findings on neurological examination, failure to return to neurological baseline, and a seizure in the setting of head trauma.¹

Juvenile Myoclonic Epilepsy. Also known as Janz syndrome, JME is one of most common types of idiopathic generalized epilepsy in childhood. It presents most commonly in otherwise healthy teenagers with one or more of the following seizure types: myoclonic jerks, generalized tonic-clonic seizures (GTCS), or absence seizures. Myoclonic jerks are unique in that they occur during the morning hours, usually the first hour after awakening. They consist of rapid muscle contractions which are most often symmetric and bilateral. The GTCS occur in about 90% of patients with JME, typically just after awakening or during sleep. Both myoclonic jerks and GTCS are exacerbated by sleep deprivation.

Absence seizures are the least common type of seizure in JME. Intelligence in these patients is normal and there is often a family history of similar seizures. Most patients respond well to treatment with antiepileptic drugs, which are usually required for life.^3,13

Benign Rolandic Epilepsy. This is the most common form of partial epilepsy in childhood. The name is derived from the central sulcus of the cerebral cortex (the rolandic fissure) around which these seizures originate. Onset of BRE typically occurs between ages 5 and 15 years, with a peak incidence of initial seizures occurring between ages 8 and 9 years. Males are more commonly affected than females (approximate distribution of 1.5:1).²

Simple partial seizures are the hallmark of this type of epilepsy, with the majority of these seizures occurring during sleep. Cardinal features include unilateral facial sensory-motor symptoms, oropharyngeal symptoms, speech arrest, and hypersalivation. Although all of these manifestations are often present, seizures may be marked by only a single symptom. Although it is uncommon, partial seizures may progress to generalized tonic-clonic activity. The hallmark finding on EEG is centrotemporal spikes. Most children do not require treatment, and the vast majority (98%) outgrow the seizures by age 18 years.³ Children with BRE have normal development and intelligence.

Early Adolescents and Teenagers.
Among this cohort, toxic ingestion and overdose tend to be the most common etiologies of first-time seizures presenting to the ED. Oral hypoglycemics (especially sulfonylureas), tricyclic antidepressants, and isoniazid are the most common prescription medications leading to seizures. Others drugs include salicylates, lithium, anticholinergic medications, and bupropion.¹ With respect to nonprescription drugs, alcohol can cause seizures via hypoglycemia; cocaine and amphetamines also have a propensity to induce seizures.¹⁴ It is paramount to evaluate serum glucose levels and consider toxicologic etiology early in the management of seizures in this age group.

Case Conclusion

Given the focal nature of this patient’s probable seizures, a CT scan of the brain was ordered without contrast to rule out an intracranial mass lesion. Based on negative findings, no further testing was ordered. The patient remained at neurological baseline throughout the course of his stay in the ED, and was discharged home with a prescription for rectal diazepam and instructions on its use for seizures lasting longer than 5 minutes. He was referred to a pediatric neurologist for further evaluation, which included an EEG study that confirmed a diagnosis of BRE.

Dr. Schneider is a pediatric emergency medicine fellow, Eastern Virginia Medical School, Children’s Hospital of the King’s Daughters, Norfolk.

Dr. Clingenpeel is a fellowship director, pediatric emergency medicine, and associate professor of pediatrics, Eastern Virginia Medical School, Norfolk.

Shortly after putting their son to bed, the parents of an 8-year-old boy rushed to his room after hearing loud gurgling sounds. When they entered the room, they found their son asleep but noticed he had left-sided facial twitching, was making lip-smacking movements and gurgling noises from his throat, and drooling. They called-out his name and attempted to rouse him, but the child did not respond. The movements continued for approximately 30 seconds before spontaneously resolving.

Immediately following this episode, the parents took their son to the ED for evaluation. He was afebrile with normal vital signs. The physical examination, which included a neurological examination, was normal, and both parents noted that the child appeared to be completely back to his normal behavior. The patient’s past medical and surgical histories were unremarkable. His parents stated that he had not been on any medication and denied a family history of seizures.

Overview

Seizures, the most common pediatric neurological disorder, are a frequent presentation in the ED. It is estimated that between 4% and 10% of children will have at least one seizure before age 16 years.^1,2 The highest incidence of occurrence is seen in children younger than age 3 years; this frequency decreases in older children.²

Seizures are the resulting clinical manifestations of abnormal excessive synchronized neuronal activity within the cerebral cortex. Most seizure activity is stereotypical and self-limited³ and can be divided into two main types: generalized and partial. Generalized seizures involve both cerebral hemispheres and impairment of consciousness, while partial (or focal) seizures involve a single area of one hemisphere. Generalized seizures are usually classified as convulsive or nonconvulsive and include the following subtypes: tonic-clonic, atonic, absence, and myoclonic. Partial seizures can be subdivided into simple or complex, depending on whether consciousness is impaired.

Initial Management

As with critically ill patients, the first and most vital step in managing a seizing patient is to assess the airway, breathing, and circulation. Although the airway is the most frequently compromised component, simple interventions such as jaw thrust, suctioning, or the insertion of an oral or nasopharyngeal airway are usually sufficient to maintain adequate airway. If intubation is required, use of a short-acting paralytic agent should be considered so as not to mask ongoing seizure activity.¹ Patients actively seizing at presentation should be assumed to be in status epilepticus, which is defined as seizure activity lasting longer than 5 minutes or as repetitive seizure episodes without return of consciousness between episodes.

Treatment

The benzodiazepines are the first-line treatment for status epilepticus in pediatric patients. Although intravenous (IV) lorazepam has long been the standard for seizure termination, intramuscular midazolam has been shown to be as safe and effective in patients weighing more than 13 kg in whom IV access is either not available or is difficult to obtain.⁴

Many other forms of benzodiazepines exist for seizure cessation, such as diazepam gel, which is administered rectally. Intranasal and buccal administration of midazolam also has proved effective for pediatric seizure termination.^5,6 Second-line therapies include IV fosphenytoin, levetiracetam, phenobarbital, and valproic acid.^1,7,8 In infants, phenobarbital is usually the primary second-line therapy after benzodiazepines.

History and Behavioral Observation

Given both the significant number of causes of pediatric seizures and events that can mimic childhood seizure activity, obtaining a thorough history and detailed description of the seizure episode and any preceding events are essential. It is also important to note nonseizure-related activities unique to the pediatric population (eg, Moro reflex in young infants, back-arching with gastroesophageal reflux [Sandifer syndrome], breath-holding spells, daydreaming).

Differentiating normal movements from seizures can be particularly difficult with infants. For example, repetitive bicycling movements of the legs are a common sign of seizure activity in an infant but may be mistaken as normal by parents or inexperienced observers.

West Syndrome.
West syndrome (infantile spasms) is a rare severe seizure syndrome consisting of spasmodic flexural movements of the extremities and trunk that usually presents between ages 4 to 18 months. Subtle episodes can be misinterpreted as Moro reflex, the normal sudden extension of an infant’s extremities and arching of the back occurring from birth to approximately ages 3 to 5 months.⁹

Breath-holding.
An episode of loss of consciousness with associated cyanosis, pallor, rigidity, limpness, or even twitching that was immediately preceded by vigorous crying in a child ages 6 months to 5 years should prompt the physician to strongly consider a breath-holding spell.

Attention Deficit Disorder Versus Seizure Activity.
Children, especially those with attention deficit disorder, have a propensity for daydreaming. These children will often stare and not respond to voice at times; however, if these episodes are associated with facial movements or a sudden pause in activity (also known as behavior arrest), the possibility of absence or complex partial seizures should be suspected.²

 

Physical Examination

Along with the patient’s history, the physical examination should focus primarily on determining a possible seizure etiology. The entire body should be thoroughly evaluated for evidence of trauma. The head should be carefully evaluated for signs of deformity or swelling; the fullness of the anterior fontanel should be carefully assessed; and the pupils should be examined for signs of increased intracranial pressure (ICP). In the older pediatric patient with closed fontanelles in whom a cervical spine injury has been ruled out, assessment of the neck for evidence of meningeal irritation should be performed. Stigmata of underlying medical disease, along with the presence of dysmorphic features associated with particular genetic syndromes, also should be evaluated. In addition, signs of common toxidromes should be sought.

Common Etiologies and Diagnostic Evaluation by Age

Since seizure etiologies and diagnostic evaluation vary greatly along the pediatric age spectrum, it is helpful to divide this population into three main groups: neonates and infants (ages 0-12 months), toddlers and young children (ages 12 months-10 years), and preadolescents and teenagers (ages 11-18 years).

In patients with known seizure disorders, the majority of cases are due to subtherapeutic antiepileptic medications either from a patient “outgrowing” his or her weight-based dose or from medication noncompliance. For the purposes of this article, we have limited our discussion to patients with first-time seizures.

Neonates and Infants.
In infants, hypoxic ischemic encephalopathy (HIE) due to perinatal asphyxia is the most common cause of seizures, the vast majority of which present within the first 24 to 48 hours of life.² Although EPs may encounter children with seizures caused by HIE, it is rare that these represent an initial seizure. Far more common etiologies of first-time seizures in infants are infection (eg, meningitis, encephalitis, sepsis) and nonaccidental trauma.

Electrolyte Imbalance. Although electrolytes are frequently checked in all age groups with seizures, infants are by far the most likely to experience seizures secondary to electrolyte abnormalities. Therefore, this is the only group in which routine evaluation of electrolytes is recommended. Common conditions associated with electrolyte imbalance include hyponatremia, hypocalcemia and hypomagnesemia, as well as errors of metabolism.

Hyponatremia in infants can be secondary to congenital adrenal hyperplasia or formula overdilution. Hypocalcemia and hypomagnesemia, associated with hypoparathyroidism may be the initial presentation in infants with DiGeorge syndrome. In addition, inborn errors of metabolism frequently lead to hypoglycemic seizures. Thus, in all patients with ongoing seizures refractory to medication, electrolyte abnormalities should be strongly considered.

Computed Tomography. A computed tomography (CT) scan of the head should be highly considered in this patient population as it is often difficult to determine if the patient has returned to neurological baseline. Since the fontanelles are open in infants, they can tolerate larger increases in intracranial volume (whether from blood or mass lesion) before evidence of increased ICP becomes clinically evident.

Lumbar Puncture. A lumbar puncture (LP) to analyze the cerebrospinal fluid (CSF) for infection should be considered in all afebrile infants with seizures, though some recent evidence shows a relatively low yield in such testing.^10,11

Toddlers and Young Children.
Within this age group, febrile seizures tend to predominate. A febrile seizure is defined as a seizure occurring between ages 6 months and 5 years that is associated with fever (temperature >38˚C [100.4˚F]) but without evidence of intracranial infection, neurological disease, or another defined cause.1 These seizures can be simple or complex. Simple febrile seizures last less than 15 minutes, have generalized clinical features, and occur only once in a 24-hour period. In contrast, complex febrile seizures last longer than 15 minutes, have focal manifestations, or recur multiple times in 24 hours.³

Simple Febrile Seizures.  The vast majority of patients presenting with simple febrile seizures require very limited diagnostic evaluation. If the patient has no evidence of intracranial infection, a normal neurological examination, and is back to baseline mental status, then no further evaluation is necessary. Serum electrolytes should only be checked if the patient does not quickly return to neurological baseline, at which point checking a serum glucose level would be prudent. Any further laboratory testing should be for the sole purpose of determining the source of the patient’s fever.

Most patients do not require CSF testing. In the consensus statement on the neurodiagnostic evaluation of patients with simple febrile seizures, the American Academy of Pediatrics listed only being younger than 6 months of age as a strong indicator to perform an LP. An LP should, however, be considered in patients aged 6 to 12 months who are deficient in their immunizations (especially Haemophilus influenza type B and Streptococcus pneumoniae) and in all patients pretreated with antibiotics as this could mask the signs of meningitis and encephalitis.¹²

 

Complex Febrile Seizures. Firm recommendations regarding the management of complex febrile seizures are currently lacking. These seizures carry a higher risk of intracranial infections and therefore warrant a low-threshold for both neuroimaging and CSF evaluation, especially in those patients younger than age 18 months.

Afebrile Seizures. Types of afebrile seizure disorders presenting in this age group include juvenile myoclonic epilepsy (JME) and benign rolandic epilepsy (BRE), both of which tend to present between ages 5 and 15 years. The majority of patients with first-time afebrile seizures do not require emergent neuroimaging; however, they should be referred to a pediatric neurologist for outpatient magnetic resonance imaging (MRI) of the brain and an electroencephalogram (EEG). Patients requiring emergent neuroimaging with either CT or MRI include those with signs or symptoms of elevated ICP, a focal seizure or focal findings on neurological examination, failure to return to neurological baseline, and a seizure in the setting of head trauma.¹

Juvenile Myoclonic Epilepsy. Also known as Janz syndrome, JME is one of most common types of idiopathic generalized epilepsy in childhood. It presents most commonly in otherwise healthy teenagers with one or more of the following seizure types: myoclonic jerks, generalized tonic-clonic seizures (GTCS), or absence seizures. Myoclonic jerks are unique in that they occur during the morning hours, usually the first hour after awakening. They consist of rapid muscle contractions which are most often symmetric and bilateral. The GTCS occur in about 90% of patients with JME, typically just after awakening or during sleep. Both myoclonic jerks and GTCS are exacerbated by sleep deprivation.

Absence seizures are the least common type of seizure in JME. Intelligence in these patients is normal and there is often a family history of similar seizures. Most patients respond well to treatment with antiepileptic drugs, which are usually required for life.^3,13

Benign Rolandic Epilepsy. This is the most common form of partial epilepsy in childhood. The name is derived from the central sulcus of the cerebral cortex (the rolandic fissure) around which these seizures originate. Onset of BRE typically occurs between ages 5 and 15 years, with a peak incidence of initial seizures occurring between ages 8 and 9 years. Males are more commonly affected than females (approximate distribution of 1.5:1).²

Simple partial seizures are the hallmark of this type of epilepsy, with the majority of these seizures occurring during sleep. Cardinal features include unilateral facial sensory-motor symptoms, oropharyngeal symptoms, speech arrest, and hypersalivation. Although all of these manifestations are often present, seizures may be marked by only a single symptom. Although it is uncommon, partial seizures may progress to generalized tonic-clonic activity. The hallmark finding on EEG is centrotemporal spikes. Most children do not require treatment, and the vast majority (98%) outgrow the seizures by age 18 years.³ Children with BRE have normal development and intelligence.

Early Adolescents and Teenagers.
Among this cohort, toxic ingestion and overdose tend to be the most common etiologies of first-time seizures presenting to the ED. Oral hypoglycemics (especially sulfonylureas), tricyclic antidepressants, and isoniazid are the most common prescription medications leading to seizures. Others drugs include salicylates, lithium, anticholinergic medications, and bupropion.¹ With respect to nonprescription drugs, alcohol can cause seizures via hypoglycemia; cocaine and amphetamines also have a propensity to induce seizures.¹⁴ It is paramount to evaluate serum glucose levels and consider toxicologic etiology early in the management of seizures in this age group.

Case Conclusion

Given the focal nature of this patient’s probable seizures, a CT scan of the brain was ordered without contrast to rule out an intracranial mass lesion. Based on negative findings, no further testing was ordered. The patient remained at neurological baseline throughout the course of his stay in the ED, and was discharged home with a prescription for rectal diazepam and instructions on its use for seizures lasting longer than 5 minutes. He was referred to a pediatric neurologist for further evaluation, which included an EEG study that confirmed a diagnosis of BRE.

Dr. Schneider is a pediatric emergency medicine fellow, Eastern Virginia Medical School, Children’s Hospital of the King’s Daughters, Norfolk.

Dr. Clingenpeel is a fellowship director, pediatric emergency medicine, and associate professor of pediatrics, Eastern Virginia Medical School, Norfolk.