Nonepileptic paroxysmal disorders in children

INTRODUCTION — 

Epilepsy is a condition characterized by recurrent seizures. The term seizure refers to a transient occurrence of signs and/or symptoms due to abnormally excessive neuronal activity of the brain. Nonepileptic paroxysmal events are defined as sudden, episodic, involuntary changes in behavior, sensation, or consciousness that resemble epileptic seizures but are not accompanied by abnormal ictal discharges in the brain [1]. Some episodes may be due to physiologic changes (eg, producing presyncope and syncope) while others may be psychiatric in nature, with conversion disorders producing functional seizures, also known as psychogenic nonepileptic seizures (PNES).

Nonepileptic paroxysmal events are common in children and can lead to multiple trials of anticonvulsant medications before the correct diagnosis is recognized. Many pediatric epilepsy centers find that up to 20 percent of referrals do not have epileptic seizures [2-6]. Some of these children are referred for evaluation of spells that are later determined to be temper tantrums, oppositional defiant behavior, and attention deficit hyperactivity disorder (ADHD). Others have nonepileptic paroxysmal disorders that may look like seizures and may even have loss of consciousness and unusual motor phenomena (table 1). Clinical features and home video recordings (eg, from a smartphone) can help distinguish these nonepileptic paroxysmal events from epileptic seizures. In difficult cases, electroencephalography (EEG), particularly video-EEG monitoring, is useful.

The common nonepileptic disorders that can mimic seizures in children will be reviewed here. Nonepileptic paroxysmal events more common in infancy and in adolescents are presented separately. (See "Nonepileptic paroxysmal disorders in neonates and infants" and "Nonepileptic paroxysmal disorders in adolescents and adults".)

A more detailed review of the clinical and historical phenomena that help distinguish true seizures from nonepileptic events is discussed separately. (See "Seizures and epilepsy in children: Classification, etiology, and clinical features" and "Seizures and epilepsy in children: Clinical and laboratory diagnosis".)

MIGRAINE

Migraine syndromes — Recurrent headaches with a family history of migraine rarely present a diagnostic dilemma. However, acute neurologic events due to migraine or related conditions can be misdiagnosed as seizures, particularly those with uncommon manifestations such as loss or alteration of consciousness, visual hallucinations, confusion, total blindness, hemiparesis, or brainstem signs.

Migraine with aura — Migraine with aura is a recurrent headache disorder characterized by attacks of transient neurologic symptoms usually followed by headaches. Auras are progressive neurologic deficits or disturbances. They often last for several minutes but may be longer. They typically precede but also may follow the onset of a headache. Symptoms of a migraine aura may be visual, sensory, speech and/or language, motor, brainstem, or retinal. (See "Pathophysiology, clinical features, and diagnosis of migraine in children", section on 'Migraine aura'.)

Visual disturbances are the most common type of aura with migraine. Bilateral visual symptoms are less typical in children and adolescents than adults. Focal numbness and tingling are the second-most common type of aura and usually involve the lips, lower face, and fingers of one hand. Less frequently, migraine aura causes speech, language, motor, brainstem, or retinal deficits. Some patients have several types of aura symptoms that vary with attacks.

Some focal epileptic visual cortex phenomena may be difficult to distinguish from the nonepileptic visual auras due to migraine [7].

Migraine with brainstem aura — Migraine with brainstem aura, formerly known as basilar-type migraine, is a rare form of migraine characterized by aura symptoms of brainstem dysfunction, but motor weakness is not present. The auras consist of two or more brainstem symptoms such as vertigo, dysarthria, tinnitus, diplopia, bilateral paresthesias, decreased level of consciousness, or hypacusis. Onset is usually between ages 7 and 20 years and is more common in females. (See "Migraine with brainstem aura".)

Hemiplegic migraine — The main feature that distinguishes hemiplegic migraine is the presence of motor weakness as a manifestation of aura in at least some attacks. In addition to weakness, the aura in hemiplegic migraine also includes visual, sensory, and/or language disturbance. Severe episodes may also include fever, lethargy, coma, and seizures. (See "Hemiplegic migraine".)

Relationship of migraine and seizures — True epileptic seizures are rarely triggered by a migraine aura, and it is unusual for a headache to precede an epileptic seizure. More commonly, a migraine-like headache follows a seizure. This latter association is particularly common with generalized tonic-clonic seizures and after partial seizures arising in the occipital regions.

Seizure triggered by migraine should be suspected if the child has a history or new diagnosis of migraine with aura and if the seizure occurred during or within one hour of an attack of migraine with aura [8].

Migraine may be associated with epilepsy in children. A population-based case-control study found an association between incident epilepsy and migraine with aura (odds ratio [OR] 8.1, 95% CI 2.7-24.3) but not migraine without aura [9].

Distinguishing migraine from seizure — Although there is overlap between migraine and seizure, certain clinical features can help differentiate the two [7,10,11]:

●Migraine aura tends to evolve gradually over minutes, whereas epileptic seizure aura tends to occur over seconds.

●With migraine, aura symptoms spread slowly over several minutes to an hour; with seizure, the symptoms spread quickly and rarely last more than a few minutes.

●With migraine, consciousness is usually preserved, although mild confusion may occur; with focal aware seizures, consciousness and memory of the event are also preserved, but with focal unaware seizures (previously referred to as complex partial seizures), loss of consciousness or impaired awareness is common.

●Motor activity during an episode is rare for migraine and strongly suggests seizure.

●Prolonged confusion or lethargy after an attack favors seizure but can occur in some forms of migraine, especially migraine with brainstem aura.

SYNDROMES POSSIBLY RELATED TO MIGRAINE

Benign paroxysmal vertigo — Benign paroxysmal vertigo (BPV) is a disorder of early childhood manifested by recurrent episodes of brief disequilibrium. It is classified as an episodic syndrome that may be associated with migraine [8]. During the attacks, the child appears frightened and off balance, often reaching out to steady himself. The events may be associated with nystagmus, diaphoresis, nausea, and vomiting. Older children will grab nearby persons or furniture for support to prevent falling and may complain of vertigo or dizziness.

Episodes usually last less than a minute and are not associated with an altered consciousness. They usually occur in clusters, often daily for several days in a row, then remit for several weeks, followed by further episodes.

The disorder is typically benign and may resolve without treatment, but some children have attacks that may persist into adolescence [12,13]. Many patients will subsequently develop typical migraine [14,15]. A family history of migraine is also often noted [9]. The pathophysiology of BPV of childhood is unknown.

There are no laboratory tests that have been useful in establishing the diagnosis of BPV.

BPV remains a diagnosis of exclusion. The main role of the clinician is to differentiate these episodes from seizures, particularly in young children who cannot describe the attacks and whose level of consciousness can be difficult to determine. (See "Causes of dizziness and vertigo in children and adolescents", section on 'Benign paroxysmal vertigo of childhood'.)

Benign paroxysmal torticollis — Benign paroxysmal torticollis is considered a migraine equivalent disorder, characterized by periods of an abnormal, sustained posture of the head and neck in which the head tilts to one side, with the face rotated toward the opposite side. Episodes typically last hours, sometimes days, and may alternate sides. Onset is in infancy but may persist into early childhood, resolving by the age of five years in most cases. (See "Acquired torticollis in children", section on 'Benign paroxysmal torticollis'.)

Alice in Wonderland syndrome — This syndrome is characterized by episodes of visual hallucinations, bizarre perceptual distortions, or impairments of time sense that may accompany or precede a headache. Symptoms typically last for several days. Alice in Wonderland syndrome can affect patients of any age, although it is more common in childhood and adolescence. The cause of is uncertain; migrainous ischemia and cortical irritability is a proposed etiology. (See "Types of migraine and related syndromes in children", section on 'Alice in Wonderland syndrome'.)

Alternating hemiplegia of childhood — Alternating hemiplegia of childhood is a rare neurodevelopmental disorder characterized by recurrent hemiplegic attacks of either side. The episodes are variable in length, lasting from minutes to days [16,17]. Onset is typically in the first months of life [18]. Initial clinical features may resemble migraine with motor aura. However, the disorder is typically associated with additional clinical features such as progressive encephalopathy, developmental delay, seizures, oculomotor palsy, and autonomic dysfunction. (See "Types of migraine and related syndromes in children", section on 'Alternating hemiplegia of childhood'.)

NONEPILEPTIC STARING SPELLS — 

Staring spells or pseudoabsences occur in children with intellectual disability, attention deficit hyperactivity disorder (ADHD), autism, and in some otherwise healthy children [3,19]. In one series, these nonepileptic staring spells made up one-third of nonepileptic events in children referred for video-EEG monitoring [5].

Staring spells have been associated with a number of other nonepileptic events, including daydreaming, intense focus, hyperactivity, self-gratification, psychogenic nonepileptic seizures (PNES), inattentiveness secondary to sleep apnea, and stereotypies [19,20].

●Clinical features – Nonepileptic staring spells usually occur when the child is either bored or inactive, such as when watching television or sitting in a classroom [5,19]. The staring episodes are associated with inattention lasting seconds to minutes. They can be interrupted by tactile or vocal stimulation (but usually not hand-waving). They rarely occur during physical activity and are never associated with automatisms, myoclonus, or the other motor signs that typify true absence seizures.

●Evaluation – Nonepileptic staring spells (pseudoabsences) must be distinguished from seizures in childhood absence epilepsy (CAE) and focal seizures with impaired awareness.

The evaluation includes diagnostic hyperventilation, which can provoke absence seizures in most untreated patients with CAE, and sleep-deprived video-EEG that includes both intermittent photic stimulation and hyperventilation. Brain imaging is not necessary for the diagnosis of nonepileptic staring spells or CAE but should be obtained if focal seizures are suspected or confirmed. (See "Childhood absence epilepsy", section on 'Evaluation'.)

Hyperventilation is an effective trigger of typical absence seizures and can be a useful tool in the primary care office setting. However, both true and pseudoabsence seizures may be precipitated by hyperventilation. The child is asked to deeply overbreathe for at least three minutes. Younger children can be asked to blow out imaginary candles or blow objects out of the examiner's hand. (See "Childhood absence epilepsy", section on 'Hyperventilation'.)

A small percentage of children may have benign nonepileptic staring spells during hyperventilation that result from altered consciousness caused by the alkalosis and decreased cerebral blood flow [21]. A concurrent EEG will show generalized high-voltage slow activity, the expected EEG changes in the hyperventilating healthy child, but no epileptiform activity. An inexperienced electroencephalographer may confuse this striking slow activity, called a "build-up," with the paroxysmal activity of an absence seizure.

●Diagnosis – The diagnosis of nonepileptic staring spells is made by exclusion of seizures, particularly CAE. The clinical features of distractibility, maintained responsiveness to tactile stimulation, maintenance of posture, absence of automatisms or myoclonus, and normal EEG pattern support nonepileptic staring spells [22]. The diagnosis of CAE is reviewed in detail separately. (See "Childhood absence epilepsy", section on 'Diagnosis'.)

●Management – There is no specific treatment; reassurance is advised.

PSYCHOGENIC NONEPILEPTIC SEIZURES — 

Psychogenic nonepileptic seizures (PNES), also called functional seizures, are reviewed here briefly and discussed in detail separately. (See "Functional seizures: Etiology, clinical features, and diagnosis".)

PNES are dramatic behavioral events in a conscious individual that are often misdiagnosed as epileptic seizures (and may lead to treatment with antiseizure medications) or misdiagnosed as syncope. PNES most commonly present in the third decade of life; however, all age groups can be affected. In children, the events typically occur in teenage patients with affective and anxiety disorders and are less common in younger children. Comorbid epilepsy is common, particularly in children. A family history of seizures or a friend or acquaintance with seizures is a risk factor. (See "Functional seizures: Etiology, clinical features, and diagnosis", section on 'Epidemiology and population characteristics'.)

PNES can take a variety of forms, but two broad forms, convulsive PNES and swoon PNES, are the most common. The tables summarize the main features distinguishing convulsive PNES from tonic-clonic seizures (table 2) and swoon PNES from syncope (table 3). (See "Functional seizures: Etiology, clinical features, and diagnosis", section on 'Clinical manifestations'.)

Factors that should arouse suspicion for PNES are listed in the table (table 4). PNES are best distinguished from true seizures by capture of an event on video-EEG monitoring. (See "Functional seizures: Etiology, clinical features, and diagnosis", section on 'Video-EEG monitoring'.)

SYNCOPE — 

Syncope is an abrupt loss of consciousness due to an interruption of energy sources to the brain, usually because of a sudden reduction of cerebral perfusion.

Vasovagal — In children, most cases of syncope are vasovagal (neurocardiogenic) in origin. They are distinguished from seizures by the situation in which they occur (emotional stress, prolonged upright posture, pain) accompanying pallor, prodromal lightheadedness and visual changes, and lack of postictal state. (See "Causes of syncope in children and adolescents", section on 'Vasovagal syncope'.)

Cardiac — Rare, but potentially life-threatening cardiac conditions (eg, long QT syndrome) can also present with syncope in children [23]. These events often present without provocation or prodrome and may mimic a seizure, although pallor is common and postictal confusion is rare. These patients usually have an abnormal cardiac examination (table 5) and/or electrocardiogram (ECG). (See "Causes of syncope in children and adolescents", section on 'Life-threatening conditions'.)

Breath-holding spells — These often persist into childhood but usually present during infancy. (See "Breath-holding spells".)

Syncope in children is discussed separately. (See "Causes of syncope in children and adolescents" and "Emergency evaluation of syncope in children and adolescents".)

MOVEMENT DISORDERS — 

Hyperkinetic movement disorders or dyskinesias include chorea, dystonia, athetosis, tics, tremors, and ballism. These are described separately. (See "Hyperkinetic movement disorders in children".)

Syndromes

Tics and stereotypies

●Tics – These are relatively brief, sudden, rapid, and intermittent movements (motor tics) or sounds (vocal tics). They may be repetitive and stereotypic. Tics are usually abrupt in onset and brief (clonic tics) but may be slow and sustained (dystonic tics). Tics are associated with a premonitory feeling that is relieved by performing the tics. In contrast to other hyperkinetic dyskinesias or epileptic seizures, children with tics are distractible, and the tics may be temporarily suppressed [5]. Tics can occur in Tourette syndrome but may also be an isolated phenomenon or accompany other disorders, as outlined in the table (table 6). (See "Hyperkinetic movement disorders in children", section on 'Tic disorders' and "Tourette syndrome: Pathogenesis, clinical features, and diagnosis".)

Tics differ from epilepsy by the variability of the movement, the urge to perform tics, and the ability to temporarily suppress a tic. The myoclonic jerks of juvenile myoclonic epilepsy can be mistaken for tics but differ in that myoclonic seizures are most frequent in the morning and can be triggered by sleep deprivation, fatigue, and alcohol [24,25]. (See "Juvenile myoclonic epilepsy", section on 'Clinical features'.)

●Stereotypies – Also called mannerisms, stereotypies are repetitive, purposeless actions such as arm/hand flapping, head banging, head rolling, and body rocking. Onset usually occurs before three years of age. Like tics, stereotypies also may be consciously suppressed and decreased by distraction. Unlike tics, stereotypies are not preceded by a progressive urge or relief following the activities. Often, they manifest as self-stimulating behaviors in response to tension and anxiety and may comfort the patient.

Stereotypies may occur alone or may be secondary to trauma, drugs (eg, chronic amphetamine abuse), or toxic-metabolic insult. These movements can be seen in typical children but are more common in children with schizophrenia, intellectual disability, and autism and are characteristic of Rett syndrome. (See "Hyperkinetic movement disorders in children" and "Rett syndrome: Genetics, clinical features, and diagnosis".)

In most cases, stereotypies differ from epileptic automatisms by the preserved awareness during and after the movements, as well as the absence of other features suggesting seizures [11].

Paroxysmal dyskinesias — These paroxysmal movement disorders are classified according to the setting in which they occur and can include a variety of movements including dystonia, ballism, and chorea. These disorders can present in childhood, adolescence, or early adulthood. These are briefly described below and are discussed separately. (See "Etiology, clinical features, and diagnostic evaluation of dystonia", section on 'Paroxysmal dyskinesia with dystonia'.)

●Paroxysmal kinesigenic dyskinesia (PKD) – This disorder consists of brief (less than one minute) attacks of choreoathetosis, dystonia, or both that are precipitated by sudden normal movement (eg, standing up). Movements may be unilateral or bilateral. Consciousness is retained. Many individuals have a brief, nonspecific warning or aura prior to an attack. The interictal examination is normal. PKD may be hereditary (due to pathogenic variants in the PRRT2 gene), sporadic/idiopathic, or secondary (due to multiple sclerosis, stroke, traumatic brain injury) and is more common in boys than girls.

●Paroxysmal nonkinesigenic dyskinesia (PNKD) – PNKD is characterized by attacks of spontaneous, severe dystonia that may be precipitated by alcohol, caffeine, and stress. The duration of these episodes may be two minutes or several hours, occasionally a day or two. Causes include pathogenic variants in the PNKD gene.

●Paroxysmal exercise-induced dyskinesia (PED) – This disorder consists of brief episodes of dystonia that occur after several minutes of exercise. Typically, the part of the body that has been doing the most exercise becomes dystonic. The abnormal movement resolves gradually with cessation of the exercise. PED may be a sporadic or hereditary condition, associated with pathogenic variants in the SLC2A1 gene, which cause glucose transporter 1 (GLUT1) deficiency syndrome.

●Nocturnal paroxysmal dystonia – Also known as paroxysmal hypnogenic dyskinesia, this disorder consists of dystonic or dyskinetic episodes during or immediately after arousal from non-rapid eye movement (REM) sleep or, more rarely, during wakefulness. These episodes may be epileptic in origin due to autosomal dominant sleep-related hypermotor epilepsy, also known as nocturnal frontal lobe epilepsy. (See "Sleep-related epilepsy syndromes", section on 'Sleep-related hypermotor epilepsy (SHE)'.)

Hyperekplexia — Hyperekplexia is a rare genetic disorder with onset in the neonatal period with tonic spasms, nocturnal myoclonus, and an exaggerated startle reflex. The spasms lessen in severity and usually disappear as the child grows older, but an excessive startle response may persist throughout life, elicited even by minor visual, auditory, or tactile stimuli. (See "Nonepileptic paroxysmal disorders in neonates and infants", section on 'Hyperekplexia'.)

Sandifer syndrome — Sandifer syndrome is characterized by gastroesophageal reflux with torsion spasms of the neck and abnormal posturing. Onset ranges from infancy through childhood. (See "Acquired torticollis in children", section on 'Sandifer syndrome'.)

Distinguishing movement disorders from seizures — Movement disorders are rarely confused with seizures when the motor activity is classic in appearance and is sustained rather than episodic. Also, impaired consciousness does not occur with movement disorders and, when present, strongly suggests seizures. However, the diagnosis can be confusing when movement disorders present with episodic symptoms and when focal epileptic seizures are characterized by isolated dystonic posturing.

Patients with dystonia and other movement disorders may obtain symptomatic relief from sensory tricks, such as lightly touching their face in cervical dystonia. This phenomenon is known as geste antagoniste and may be a useful feature distinguishing these from epilepsy.

In children with cognitive impairment, differentiating nonepileptic movements from seizures can be especially challenging. Seizures and nonepileptic motor events often coexist in these patients. In these and other situations, video-EEG monitoring can be extremely helpful [6].

SLEEP DISORDERS — 

Episodes arising out of sleep disturbances are a common cause of nonepileptic events in children referred for video-EEG monitoring [5].

Sleep-related rhythmic movement disorder — Rhythmic movements such as nocturnal head banging, body rocking, and head rolling typically occur in children younger than one year of age as they try to fall asleep but can first appear at any age [26-28]. They also can be present in deep sleep and in wakefulness. They are somewhat more common in children with learning disabilities but occur in children with normal development as well. They can remit within a few years of onset or persist into adulthood. The characteristic nature of the movements is not typical for epilepsy, and patients can often be directed to stop the movements, which is not true for an epileptic seizure. (See "Sleep-related movement disorders in childhood", section on 'Rhythmic movement disorder'.)

Sleepwalking, night terrors, and confusional arousals — These non-rapid eye movement (REM) sleep arousal disorders are common, occurring in 15 to 20 percent of preadolescent children [28]. The diagnosis and treatment of these disorders are discussed separately. (See "Parasomnias of childhood, including sleepwalking", section on 'Disorders of arousal from non-rapid eye movement sleep'.)

●Sleepwalking – Also called somnambulism, sleepwalking occurs in up to 15 percent of children between the ages of 5 and 12 years, with a peak prevalence between four and six years [29]. While eyes are often open, patients demonstrate a low level of awareness with a blank facial expression and reduced responsiveness to stimulation. Movements are usually slow, clumsy, and purposeless, but more complex and directed activity, as well as agitated behaviors, are also described. (See "Parasomnias of childhood, including sleepwalking", section on 'Sleepwalking'.)

Postictal wandering after a night-time seizure may be difficult to differentiate from sleepwalking. Such patients are usually confused and disoriented, not just less responsive (as with sleepwalking). Signs indicating a prior seizure might include incontinence or a bitten tongue.

●Sleep terrors – These are characterized by a sudden, often dramatic arousal with facial expression, vocalization, and other behaviors that express agitation and fear [30]. Tachycardia, diaphoresis, mydriasis, and other autonomic features are prominent. Patients are difficult to arouse and will fall back to sleep spontaneously after a few to several minutes. Sleep terrors can first manifest at an early age, around 18 months, have a peak prevalence at ages five to seven years, and typically resolve prior to adolescence. Triggers include acute stress and sleep deprivation, as well as certain medications including stimulants, neuroleptics, sedatives, and antihistamines. (See "Parasomnias of childhood, including sleepwalking", section on 'Sleep terrors'.)

●Confusional arousals – These are characterized by sudden arousal with disorientation, confusion, agitation, and some semipurposeful motor activity. Vocalization with coherent speech is common, but autonomic activation typical of a night terror is not. Episodes last a few to several minutes. (See "Parasomnias of childhood, including sleepwalking", section on 'Confusional arousals'.)

These disorders (sleepwalking, sleep terrors, and confusional arousals) overlap and have a typical duration of a few to 30 minutes. Episodes arise out of sleep stages 3 and 4, typically within the first half of sleep but after the first 30 to 90 minutes. In an intermediate stage between waking and sleep, patients may not respond normally to questions or other stimuli. Amnesia is common, but some children report brief dream-like images. It is common for an individual and a family to manifest more than one of these disturbances.

●Distinguishing parasomnias from nocturnal seizures – These disorders of arousal can usually be distinguished from nocturnal seizures, which are usually briefer (a few minutes or less), stereotyped, and more frequent, often occurring in clusters [28,30]. By contrast, it is rare for these sleep disturbances to recur in the same night, and their average frequency is one to three times a month. Case reports of night terrors that were determined to be epileptic in origin were atypical for sleep terrors because of their short duration, frequency, and occurrence in the second rather than first half of sleep [31,32]. Recording episodes on video-EEG and polysomnography is necessary when the diagnosis is unclear.

Sleep starts — Sleep starts, also called hypnic jerks or hypnic myoclonus, refers to a sudden jerking movement upon falling asleep, often accompanied by a subjective sensation of falling [4,5]. These can occur at almost any age and are usually easily recognized. Rarely, hypnic myoclonus can become unusually violent, very frequent, or repetitive and confused for myoclonic seizures or even tonic-clonic seizures. The myoclonic jerks are restricted to sleep, usually in the transition between sleep and wakefulness, and are not associated with other clinical phenomena. (See "Nocturnal muscle cramps".)

OTHERS — 

This topic reviews those imitators of epilepsy that are most common in children. Disorders more typical of infancy or adolescence can occasionally present in this age group as well (table 1). (See "Nonepileptic paroxysmal disorders in neonates and infants" and "Nonepileptic paroxysmal disorders in adolescents and adults".)

INFORMATION FOR PATIENTS — 

UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5^th to 6^th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10^th to 12^th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)

●Basics topic (see "Patient education: Sleepwalking in children (The Basics)")

SUMMARY

●Definition – Nonepileptic paroxysmal events are defined as sudden, episodic, involuntary changes in behavior, sensation, or consciousness that resemble epileptic seizures but are not accompanied by abnormal ictal discharges in the brain. The differential diagnosis of epileptic seizures in children includes a variety of benign, physiologic phenomena as well as pathologic conditions (table 1). Clinical features and home video recordings can help distinguish nonepileptic paroxysmal events from epileptic seizures. In difficult cases, EEG, particularly video-EEG monitoring, is useful. (See 'Introduction' above and "Seizures and epilepsy in children: Clinical and laboratory diagnosis".)

●Migraine and related disorders – Acute neurologic events due to migraine or related conditions can be misdiagnosed as seizures, particularly those with uncommon manifestations such as loss or alteration of consciousness, visual hallucinations, confusion, total blindness, hemiparesis, or brainstem signs.

Slower evolution of symptoms (minutes versus seconds), preservation of consciousness, and absence of postictal phase help distinguish migraine from seizure. (See 'Migraine' above and 'Syndromes possibly related to migraine' above.)

●Nonepileptic staring spells – Staring spells or pseudoabsences occur in children with intellectual disability, attention deficit hyperactivity disorder (ADHD), autism, and in some otherwise healthy children. (See 'Nonepileptic staring spells' above.)

●Psychogenic nonepileptic seizures (PNES) – PNES, also called functional seizures, are dramatic behavioral events in a conscious individual that are often misdiagnosed as epileptic seizures or syncope. All age groups can be affected. PNES can take a variety of forms, but two (convulsive PNES and swoon PNES) are the most common.

The tables summarize the main features distinguishing convulsive PNES from tonic-clonic seizures (table 2) and swoon PNES from syncope (table 3). Factors that should arouse suspicion for PNES are listed in the table (table 4). PNES are best distinguished from true seizures by capture of an event on video-EEG monitoring. (See "Functional seizures: Etiology, clinical features, and diagnosis", section on 'Video-EEG monitoring'.)

●Syncope – Syncope is an abrupt loss of consciousness due to an interruption of energy sources to the brain. Most cases in children are due to a vasovagal mechanism, but cardiac conditions and breath-holding spells are additional considerations. The presence of pallor and absence of postictal phase are useful distinguishing features. (See "Causes of syncope in children and adolescents" and "Breath-holding spells" and "Emergency evaluation of syncope in children and adolescents".)

●Movement disorders – Several common (eg, tics, stereotypies) and rare (eg, paroxysmal dyskinesias) movement disorders may present in children.

Movement disorders are rarely confused with seizures when the motor activity is classic in appearance and is sustained rather than episodic. However, movement disorders presenting with episodic symptoms may be mistaken for focal epileptic seizures that are characterized by myoclonic jerks or isolated dystonic posturing. (See 'Movement disorders' above.)

●Sleep disorders – Episodes arising from sleep disturbances are a common cause of nonepileptic events in children. These include rhythmic movements during sleep, sleepwalking, night terrors, and confusional arousals. Disorders of arousal can usually be distinguished from nocturnal seizures, which are usually briefer (a few minutes or less), stereotyped, and more frequent, often occurring in clusters. (See 'Sleep disorders' above.)