History

A careful description of the event or events from beginning to end, including re-enactments by the parents of any unclear physical symptoms, is critical.

Pertinent questions include:

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  Was this the first such event, or have there been multiple events?

  
  
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  Is there a single type of event, or multiple events?

  
  
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  What was the child doing at the time of each spell—were they awake, asleep, playing, or sitting quietly?

  
  
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  If they were asleep, how long had they been asleep, or what time of day or night did the spell occur?

  
  
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  If abnormal tone or movements were involved, was the child rigid or limp, and which limbs were involved? Were the movements rhythmic and synchronous, or were they alternating, migratory, or stop-start?

  
  
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  If the child was unresponsive or had alteration of awareness, what did the parents do to ascertain their level of responsiveness? Did the parents try touching them to regain their attention, or merely call their name?

  
  
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  How long did the event last, and how did the child behave afterward?

  
  
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  Did the child describe any symptoms prior to the onset of the actual event, or was there any abnormal behavior that the parents witnessed prior to the event?

  
  
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  Were there any signs or symptoms of illness associated with the spell? Were any fevers documented?

  
  
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  Has there been any behavioral, developmental, or academic regression since the start of the events?

  
  
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  Is the child developmentally normal? If not, has the child’s development always been abnormal, or was there a regression at some point?

  
  
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  Were there any problems during pregnancy or the delivery?

  
  
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  Has the child ever had a significant head injury or central nervous system (CNS) infection?

  
  
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  Is there any family history of similar events, or any other neurologic disorders?

Parents frequently record videos of these spells on their mobile devices, which are ideal for the physician to review.

Physical Examination

The physician should compare vital signs, including blood pressure and head circumference, to previous measurements if possible. Elevated blood pressure can be indicative of pain, anxiety, increased intracranial pressure, or hypertensive encephalopathy. Hypotension may suggest syncopal events or sepsis. Dramatic increases in head circumference in infants may indicate intracranial pathology.

A general physical examination, including the cardiopulmonary and abdominal examinations, should be performed; abnormalities may indicate a nonneurologic cause for spells. Dysmorphic features or cutaneous findings can provide clues toward an underlying syndrome.

An ophthalmologic examination can be as simple as obtaining a red reflex and observation of eye movements in young children. Eye movements may be observed by having the patient track a moving object or toy; abnormalities such as deviation, nystagmus, or new-onset limitations in range of motion may indicate a structural cause for the spells such as hydrocephalus or a mass lesion. In cooperative older children, the physician should attempt a funduscopic examination. Papilledema is a clue to increased intracranial pressure but unfortunately is only readily appreciable after 2-3 weeks of increased intracranial pressure; it will not be present with acute disturbances leading to increased intracranial pressure.

The child will provide important information about their mental status and developmental status through simple conversation. Conversations about toys, school, or family members in the room can provide information about orientation, aphasia, dysarthria, and fund of knowledge for age. If there are any questions about whether any facial asymmetry is new-onset, parents may be able to provide old photographs; most people have some degree of facial asymmetry at baseline that may only be noticed after a frightening event causes the parents to observe the child more closely.

Muscle strength can be ascertained by manual testing in a cooperative older child, or observing natural play or strength of resistance to examination in a younger child. If a child can easily perform age-appropriate actions such as crawling, walking, running, climbing, or grabbing for objects, and strongly resists examination, they are fairly likely to have grossly normal strength in their major muscle groups. Tone can be checked by passively moving the patient’s limbs, or suspending an infant in your hands to check if they start to slide through your grip. Low tone (hypotonia) can also be detected by observing gait or observing how the child sits; “W”-sitting (sitting with knees together and heels outside of their hips) may be another clue. Low strength (weakness) should be distinguished from hypotonia or ataxia; an example of normal strength but low tone might be an infant with motor delays and head lag who vigorously opposes examination; a child with normal strength but ataxia might vigorously oppose examination but cannot accurately reach to push away the examiner.

A normal physical examination does not rule out the presence of a neurologic disorder, but generally indicates a disorder that does not require immediate intervention and that more time can be spent carefully evaluating all diagnostic possibilities. In children with baseline neurologic abnormalities, such as children with cerebral palsy, knowledge of their base line physical examination, abilities, and behavior is critical in deciding how urgently they need to be evaluated further. Parents can be very helpful in determining a child’s baseline behavior in this case.

Increased Intracranial Pressure or Large Intracranial Mass

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  Hypertension and bradycardia

  
  
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  3rd or 6th nerve palsy; anisocoria, ptosis, diploplia

  
  
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  Forced-seeming and persistent downward deviation of both eyes (tonic downward gaze deviation)

  
  
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  Papilledema

  
  
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  Severe vomiting that is exquisitely positional (i.e., strongly provoked by the transition from lying to sitting)

  
  
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  Engorged scalp veins

  
  
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  Bulging fontanel or split cranial sutures in an infant

  
  
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  Presence of a ventriculoperitoneal shunt (VP shunt) with any of the above symptoms should prompt concern about shunt malfunction

Ongoing Status Epilepticus

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  Waxing and waning responsiveness after a convulsive seizure has ended, particularly with periods of complete unresponsiveness

  
  
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  Persistent eye deviation after a convulsive seizure has ended

  
  
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  Persistent tachycardia after a convulsive seizure has ended

  
  
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  Persistent confusion or delirium, even if the child is able to speak and walk

Stroke or Complicated Migraine

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  Focal weakness or numbness, particularly if accompanied by slurred speech or confusion (if the spell is remote and the patient has returned to a normal baseline, suggest expedited referral to a neurologist)

Meningitis

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  Fever

  
  
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  Nuchal rigidity

  
  
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  Positive Kernig or Brudzinski signs

  
  
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  Bulging fontanel

The following red flags should prompt an urgent or even emergent referral to a pediatric neurologist, including direct communication with a neurologist for proper triaging:

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  Infantile spasms

  
  
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  Clusters of abdominal “crunches” or “startles,” particularly when the child is falling asleep or waking up from sleep

  
  
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  Developmental plateau or regression

  
  
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  Loss of visual attentiveness

Any developmental regression in infants or toddlers that has been present for more than 1 month (or sooner, for dramatic or progressive regressions) is concerning; change in handedness after 4-5 years of age is also a red flag.

Localization-Related Seizures, Partial Seizures

Focal seizures are seizures in which the first clinical and electroencephalogram (EEG) changes indicate initial activation of a system of neurons limited to part of 1 cerebral hemisphere. The clinical symptoms and signs of focal seizures reflect the functional anatomy of the region of the brain undergoing the abnormal neuronal discharge.

When consciousness is impaired, this was historically known as a complex partial seizure; if there is no apparent loss of consciousness, this was known as a simple partial seizure. These terms have been replaced by the more descriptive terms focal seizure with impairment of consciousness or focal dyscognitive seizure in the case of complex partial seizures, and focal seizure without impairment of consciousness for simple partial seizures.

An aura is the portion of a seizure that is experienced before any loss of consciousness. Some auras can be difficult for a patient to describe; asking them if they know a seizure will happen before it happens, even if they cannot articulate precisely what they are experiencing, is one way to approach the topic. Examples of auras include an epigastric rising sensation; nausea; visual, auditory, or olfactory hallucinations; or limbic symptoms such as fear or a sensation of déjà vu. An aura may be suspected in very young children if there is a change in behavior before seizures, such as interrupting an activity to seek out parents, or complaining of abdominal pain. The presence of an aura is traditionally thought to be indicative of a focal seizure without impairment of consciousness, as it implies focal cortical dysfunction, but some studies have reported that up to 64% of patients with documented idiopathic generalized epilepsy experience some form of aura, possibly due to asymmetric propagation of the discharges through the thalamocortical networks.

Nonepileptic events such as migraines or syncope may also have a prodrome, further highlighting the value of a comprehensive history in distinguishing types of events.

The progressive symptoms of some seizures after the initial aura reflect the spread of the abnormal electrical discharge beyond the region of onset, which is why a detailed history is critical for evaluating paroxysmal spells and determining the likelihood that they represent seizure activity.

Focal seizures can have motor and/or sensory components, depending on which areas of what is termed eloquent cortex become involved in the seizure. However, the seizure may originate in a portion of the cortex that does not produce obvious physical symptoms (termed the silent or noneloquent cortex ), and physical signs of the seizure only develop if the seizure discharge spreads to involve eloquent cortex. Seizures with clear electrical abnormalities but minimal or absent physical symptoms are commonly referred to as electrographic seizures or subclinical seizures . Subclinical electrographic seizures, particularly during sleep, can be associated with deterioration in development, behavior, attention, and learning.

Focal motor seizures produce rhythmic jerking (clonic) movements of the limb or limbs contralateral to the primary motor cortex involved. Other focal motor seizures include involuntary turning of the head and eyes in 1 direction (version), vocalization, and speech arrest. There may be tonic stiffening and extension of the arm ipsilateral to the seizure onset.

Involvement of the sensory cortex produces simple somatosensory experiences such as paresthesia or numbness, often with a dysesthetic quality, and visual, auditory, olfactory, or gustatory phenomena. Some of these sensory phenomena can be quite complex, including structured visual hallucinations, sensations of depersonalization, and affective symptoms such as anxiety or fear. Epileptic phenomena are a rare cause for such phenomena, and a broad differential diagnosis should be considered for paroxysmal spells where the primary symptoms are sensory or affective.

As the seizure continues to spread, both cerebral hemispheres may become engaged, and there is generalized clonic jerking of the body that closely resembles a GTC seizure. These secondarily generalized seizures may be mistaken for a generalized seizure if the onset is not witnessed. Occasionally after a seizure, there is persistent focal weakness or hemiparesis known as Todd palsy , which is strongly suggestive of a contralateral focal onset to the seizure.

Generalized Seizures

Generalized seizures are defined as seizures in which the first clinical changes indicate initial involvement of both hemispheres. Motor involvement, if present, is bilateral, as are the initial EEG changes. Consciousness is impaired in most generalized seizures, but not in all; for instance, brief myoclonic seizures and some atonic seizures may not be associated with any impairment of consciousness.

Absence (petit mal) seizures begin with sudden interruption of activity and staring; they are usually brief and end abruptly without postictal confusion. Simple absence seizures consist of only motionlessness and a blank stare lasting for several seconds, with immediate postictal reanimation. Lip-smacking, fumbling, or searching hand movements, or convulsive swallowing can appear during longer seizures, or preictal activities may be continued in a slow, automatic manner. Paroxysmal alterations in autonomic function may also accompany absence seizures, including pupillary dilation, pallor, flushing, sweating, salivation, piloerection, or a combination of these. Absence seizures that are more typically accompanied by eyelid fluttering, facial twitching, or myoclonic jerks of the trunk or extremities are referred to as complicated absence seizures. Atypical absence seizures are described as absence seizures with a less abrupt beginning and end, with more pronounced changes in muscle tone, and of longer duration. Distinctions should be made between the clinical features of absence seizures, focal dyscognitive seizures, and episodic daydreaming ( Table 30.5 ). Staring spells that are prolonged beyond 15-20 seconds are less likely to represent absence seizures due to incorrect duration. Staring spells in infants and toddlers are also unlikely to represent absence seizures due to incorrect age of onset. Early-onset generalized epilepsy is associated with rare genetic syndromes. Children with prolonged staring spells, particularly starting at a young age, are at higher risk of partial-onset seizures or behavioral spells.

Tonic-clonic seizures are perhaps the most dramatic of the epileptic seizures. The tonic phase begins with sudden sustained contraction of facial, axial, and limb muscle groups, and there may be an initial involuntary stridorous cry or a moan secondary to contraction of the diaphragm and chest muscles against a partially closed glottis (the ictal cry ). The tonic contraction is maintained for seconds to 10s of seconds, during which time the child falls if standing, is apneic and may become cyanotic, may bite the sides of their tongue, and may pass urine. The clonic phase of the seizure begins when the tonic contraction is repeatedly interrupted by momentary relaxation of the muscular contraction. This gives the appearance of generalized jerking as the contraction resumes after each relaxation. At the end of the clonic phase, the body relaxes and the patient is unconscious with deep respiration. If roused, the patient is confused, may complain of muscle soreness, and usually wishes to sleep.

Myoclonic seizures are sudden, brief, shocklike contractions of muscles. They may involve the whole body or a portion of the axial musculature such as the face and trunk, or they may be limited to the limbs. They can be isolated or repetitive, irregular or rhythmic. Myoclonic seizures arise from the cortex and are associated with a distinct EEG pattern. Some forms of myoclonus are of brainstem or spinal origin; those occurring without other seizure types are not regarded as epileptic myoclonus but thought of as movement disorders .

Generalized tonic seizures begin in the same way as tonic-clonic seizures; a massive generalized contraction produces any combination of facial grimacing, neck and trunk flexion or extension, abduction or elevation of the arms, and flexion of the hips. Subtle tonic seizures may produce only facial grimacing and slight neck and trunk flexion. Tonic seizures may be accompanied by pronounced autonomic activity with diaphoresis, flushing, pallor, and tachycardia, even when the muscular contraction is slight.

Atonic seizures are characterized by a sudden decrease or loss of postural muscle tone. The extent of muscle involvement may vary; an atonic seizure may be limited to a sudden head drop with slack jaw or may result in a fall because of loss of axial and limb muscle tone. The falls are referred to as drop attacks , and because they are unexpected and sudden in onset, they often result in injury.

Electroencephalographic Studies

The incidence of EEG epileptiform activity in normal children without a history of seizures is very low (<2%); such findings are associated with a strong family history of genetic epilepsy. The incidence of recurrent epileptic seizures in patients with focal EEG spikes is 83%. In a child with suspected seizures, the finding of focal or generalized epileptiform activity on the EEG supports a diagnosis of epilepsy, whereas multiple negative EEG studies capturing both wakefulness and sleep argue against such a diagnosis, and should prompt the physician to consider alternative diagnoses and to attempt to record the episodes.

There are 2 basic types of EEGs: conventional and amplitude-integrated . A conventional EEG utilizes 19 or more electrodes distributed symmetrically over both hemispheres and along the midline. A routine outpatient EEG is run for at least 20 minutes, and more often 40-60 minutes. A prolonged EEG, or long-term monitoring, is run for over 24 hours, and can even be performed for over a week at a time. This type of prolonged study can be performed on an ambulatory basis at home, or as an inpatient in an epilepsy monitoring unit. Amplitude-integrated EEG, by contrast, utilizes only 2 or 4 EEG electrodes, and is primarily used in neonatal intensive care units.

An EEG should always attempt to capture sleep, and most will include hyperventilation and photic stimulation, all of which potentially activate epileptiform discharges, increasing the diagnostic yield. Hyperventilation produces absence seizures in about 80% of children with childhood absence epilepsy. Intermittent photic stimulation produces generalized epileptic discharges in several of the generalized epileptic syndromes, but photosensitivity is overall rare in epilepsy. Recording during wakefulness and sleep performed after sleep deprivation may have the highest yield. Overnight recording in the hospital provides for prolonged sampling of the interictal EEG in wakefulness and spontaneous sleep. For any patient with refractory seizures or an uncertain diagnosis, the use of video and EEG monitoring is usually helpful in clarifying the diagnosis. Defining the exact seizure type may lead to modification of drug treatment or consideration of epilepsy surgery, or a nonepileptic paroxysmal disorder may be discovered.

A single normal EEG does not definitively exclude a seizure disorder, particularly in people with infrequent seizures or seizures in specific contexts, such as illness or sleep.

Neuroimaging Studies

Magnetic resonance imaging (MRI) is superior to computed tomography for the evaluation of epilepsy. Any patient with a history or examination suspicious for focal-onset epilepsy should have MRI of the brain, unless the syndrome is clearly that of benign focal epilepsy of childhood with centrotemporal spikes. MRI may also reveal an abnormality in patients with symptomatic generalized epilepsy. Functional neuroimaging is important in the assessment of candidates for surgical resection in patients with intractable seizures. When available, a 3.0 Tesla MRI of the brain with specific protocols dedicated to epilepsy evaluation (e.g., proper alignment of the imaging axis with the hippocampi) is preferred.

Evaluation of the First Seizure

There is no clinical sign or diagnostic investigation that determines with certainty whether a child presenting with a first seizure has epilepsy or has had an isolated seizure. The assessment of patients with a first seizure must include a search for etiologic agents and features that may indicate the risk of recurrence. Factors to be considered include the circumstances of the seizure, the health of the child in the time before the seizure, the recent sleep patterns, the possibility of abuse or trauma, and the chance of ingestion of prescription or street drugs or syndromes such as the neurocutaneous disorders ( Table 30.6 ).

The recurrence risk after a first unprovoked seizure, usually defined as a seizure or flurry of seizures within 24 hours in patients older than 1 month, is ~40-50%.

The most important predictor of recurrence appears to be the existence of an underlying neurologic disorder. The existence of intellectual disabilty or cerebral palsy is a common antecedent to epilepsy, as is a history of significant head injury. An EEG with generalized or focal epileptiform discharges or with focal or generalized slowing is also predictive of recurrence. Focal seizures are more likely to be associated with recurrence, although patients with such seizures are also more likely to have an existing neurologic deficit or an abnormal EEG. The duration of the first seizure or a presentation in status epilepticus is not associated with a higher incidence of recurrence. A family history of epilepsy is not a predictor of recurrence. Earlier age at onset, particularly before the age of 12 months, has been associated with a higher risk of recurrent seizures.

Most authorities believe that the majority of patients with a first seizure should not be treated unless the risk of recurrence is judged to be significantly higher than average. An abnormal neurologic examination, an abnormal MRI of the brain, and abnormal EEG all increase the risk of recurrence; the greater the number of risk factors, the more likely an AED may be initiated after a first known seizure, although some neurologists will still elect to wait for a second confirmed seizure. In adults or adolescents, the issues of driving and employment may influence the decision to treat a first seizure, but in otherwise healthy and developmentally normal children, there is almost no indication for chronic AED treatment in response to a single seizure. Activities such as bathing, driving, and swimming must be carefully supervised.

The decision to begin AED therapy is usually made after a patient has had 2 or more seizures in a short interval of time (6-12 months). Treatment with AEDs lowers the recurrence rate by about 50%.

Neonatal Period

The paroxysmal disorders seen in the neonatal period (birth to 8 weeks) are presented in Table 30.9 .

Acute Symptomatic Seizures and Occasional Seizures

Most neonatal seizures are acute symptomatic seizures, and the number of children who continue to have seizures after the neonatal period is relatively small. Neonatal seizures have been classified according to the clinical features as subtle, tonic, clonic, and myoclonic. However, not all of these clinical seizure types have consistent ictal EEG patterns. The classification of neonatal seizures reflects the variable, poorly organized, and often subtle clinical expression of epileptic seizures at this age. Typical GTC or absence seizures are not seen at this age, perhaps because of the limited capacity of the neonatal brain for interhemispheric synchrony. Patterns include the following:

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  Clinical seizures consistently associated with an EEG seizure pattern:

  
  
  
  
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    Clonic seizures with focal or multifocal jerking of the face or extremities fit this category, as do focal tonic seizures with focal tonic posturing of a limb or asymmetric posturing of the axial musculature. Clinical seizures with consistent focal jerking or posturing of 1 limb are most consistently correctly identified at the bedside, and are most commonly associated with a focal structural defect, such as a focal perinatal stroke.

  
  
  
  
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  Clinical seizures sometimes associated with an EEG seizure pattern:

  
  
  
  
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    Myoclonic seizures consist of single or multiple flexor jerks of the upper or lower limbs. An ictal EEG pattern is not always seen in this group. Fragmentary (multifocal) myoclonus is not always associated with an ictal EEG.

  
  
  
  
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  Clinical seizures not consistently associated with an EEG seizure pattern:

  
  
  
  
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    These include motor automatisms characterized by a diversity of signs, including any of the following: wide-eyed staring, rapid blinking, eyelid fluttering, drooling, sucking, repetitive limb movements such as rowing or swimming with the arms or pedaling with the legs, apnea, hyperpnea, tonic eye deviation, and vasomotor skin color changes. This group of subtle seizures is generally associated with EEG background abnormalities such as suppression; the seizure itself may not have a consistent EEG correlate. This is reflective of diffuse cerebral dysfunction, such as seen in hypoxic-ischemic encephalopathy or metabolic disorders.

    
    
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    Generalized tonic seizures and focal and multifocal myoclonus are also often not associated with neonatal ictal EEG patterns, and when seen in stuporous or comatose children, the jerks may not be epileptic. However, if the EEG is completely normal, it is unlikely that the behaviors of concern represent subtle seizures.

  
  

Some simple clinical observations should guide the assessment of neonates with episodic abnormal behaviors. Epileptic behaviors are typically repetitive and stereotyped, but are not provoked by stimulation of the child or increased with increasing intensity of a stimulus. Nonepileptic movements may disappear with repositioning of a limb or the child. Gentle restraint of a limb should be able to suppress or abort nonepileptic motor activity, whereas epileptic movements are still palpable. The association of abnormal eye movements with unusual behavior or limb movements suggests a seizure rather than nonepileptic behavior.

Diagnostic investigations.

EEG monitoring is useful in the evaluation of suspicious fluctuations in vital signs in neonates who are paralyzed and intubated or comatose, or in neonates with subtle but repetitive episodes of unusual behavior.

Many neonatal intensive care units have the capability to perform amplitude-integrated EEG (aEEG), which is a reduced electrode monitoring method that uses time-compressed baseline trends of 2 or 4 channels of EEG to allow the bedside practitioner to look for changes suspicious for seizure. However, both the sensitivity and specificity of aEEG are lower than that of full-montage conventional EEG; less than 50% if only a single channel of aEEG is available, but up to 76% and 78%, respectively, when 2 channels of raw EEG are available for comparison and direct review by expert aEEG interpreters. Conventional EEG is recommended over aEEG when both are available; however, the use of aEEG is associated with lower total seizure duration in neonates compared to no monitoring.

Proper treatment must include a thorough search for the cause of the seizures, because many conditions necessitate specific treatment. The possible etiologic factors are numerous and diverse ( Tables 30.10 and 30.11 ). The most common cause is hypoxic-ischemic encephalopathy (60-65%); it is important to make a positive diagnosis of this historically and to exclude conditions such as local anesthetic toxicity, pyridoxine-dependent seizures, prenatal injury, and metabolic encephalopathies that may masquerade as perinatal asphyxia.

TABLE 30.10

Causes of Neonatal Seizures

Ages 1-4 Days

Hypoxic-ischemic encephalopathy Drug withdrawal, maternal drug use of narcotics or barbiturates Drug toxicity: lidocaine, penicillin Intraventricular hemorrhage Acute metabolic disorders Hypocalcemia Perinatal asphyxia, small for gestational age Sepsis Maternal diabetes, hyperthyroidism, or hypoparathyroidism Hypoglycemia Perinatal insults, prematurity, small for gestational age Maternal diabetes Hyperinsulinemic hypoglycemia Sepsis Hypomagnesemia Hyponatremia or hypernatremia Iatrogenic or inappropriate antidiuretic hormone secretion Inborn errors of metabolism Galactosemia Hyperglycinemia Urea cycle disorders Pyridoxine deficiency (must be considered at any age)

Ages 4-14 Days

Infection Meningitis (bacterial), encephalitis (enteroviral, herpes simplex) Metabolic disorders Hypocalcemia Diet, milk formula Hypoglycemia, persistent Inherited disorders of metabolism: galactosemia, fructosemia, leucine sensitivity Hyperinsulinemic hypoglycemia Anterior pituitary hypoplasia, pancreatic islet cell tumor Beckwith syndrome Drug withdrawal, maternal drug use of narcotics or barbiturates Benign neonatal convulsions, familial and nonfamilial Kernicterus, hyperbilirubinemia

Ages 2-8 Weeks

Infection Herpes simplex or enteroviral encephalitis, bacterial meningitis Head injury Subdural hematoma, child abuse Inherited disorders of metabolism Aminoacidurias, urea cycle defects, organic acidurias Neonatal adrenoleukodystrophy Malformations of cortical development Lissencephaly Focal cortical dysplasia Tuberous sclerosis Sturge-Weber syndrome

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