Rudolph's Pediatrics, 22nd Ed.

CHAPTER 567. Other Paroxysmal Disorders

Sanjeev V. Kothare

Many childhood disorders have paroxysmal features. It is therefore not uncommon that these episodes are interpreted as seizures. In this section, common disorders that may mimic epilepsy are emphasized.

BREATH-HOLDING SPELLS

Breath-holding spells (BHS) occur most often between the ages of 6 months and 6 years, with a prevalence rate of 4% to 27%1. There may be a familial predisposition to BHS in 20% to 35% of cases.2 The predisposing setting is frustration, anger, fear, or reaction to pain, which leads to crying or a tantrum. The child then holds his or her breath in expiration, often resulting in pallor, cyanosis, or a mixture of both.3 When the spell resolves without loss of consciousness, it is called simple. The child may appear dazed and ultimately lose consciousness and may even have a few convulsive movements or tonic stiffening. Convulsive activity has been seen in up to 55% of children with BHS. The entire episode lasts less than a few minutes, and the child is not impaired for a prolonged period after the attack. The etiology is unclear but data suggest excessive centrally mediated sympathetic reflex activity in cyanotic breath-holders, and excessive centrally mediated parasympathetic reflex activity in pallid breath-holders. EEGs during the event fail to show any electrographic seizures; diffuse background slowing of the EEG in the theta-delta range accompanied with slowing of the heart rate is often seen. Conditions besides seizures that can mimic BHS include central apnea due to an Arnold-Chiari malformation, gastroesophageal reflux (GER), prolonged QT syndrome with syncope, brain stem lesions, rage, panic attacks, and Munchausen-en-proxy. Treatment is directed at reassuring the parents of the benign nature of BHS and its ultimate natural remission. Oral iron therapy at 5 to 6 mg/kg/day of elemental iron has been found to be beneficial in some cases.4 Educating the parent about intervention during the event including placing in the lateral position to prevent aspiration and applying a gentle thrust on the back to reinitiate respiration is important. Issues regarding the disruptive effects on the parents and extended family and difficulty in obtaining child care and baby-sitting need to be addressed. Seventeen percent go on to develop syncope by teenage years.

SANDIFER SYNDROME

The syndrome is characterized by gastroesophageal reflux disease (GERD) presenting with spastic torticollis and paroxysmal dystonic head and neck movements, head/eyes version, irritability, crying, vomiting, and abdominal pain, with or without hiatus hernia.7 The diagnosis is confirmed with a 24-hour pH probe study, ideally combined with multiple impedance monitoring to correlate reflux events with occurrence of symptoms. The symptoms of Sandifer syndrome respond very well to medical management with use of proton pump inhibitors.

PARASOMNIAS

Parasomnias are defined as undesirable events or experience that occur predominantly during sleep. They are subclassified into disorders of arousal from Non-REM sleep, or those associated with REM sleep. They include disorders such as confusional arousal, sleep terrors, sleepwalking and nightmares. The diagnosis and approach to these disorders is further described in Chapter 509.

Less common disorders in childhood include: 1) REM sleep behavior disorders that are characterized by enacting unpleasant and combative dreams with complex movement that can be violent but can be seen in children with the use of selective serotonin reuptake inhibitors, or accompanying narcolepsy and Tourette syndrome; Recurrent isolated sleep paralysis characterized by a generalized inability to speak, or to move the trunk, head and limbs that occurs during the transitional period between sleep and wakefullness; 3) Sleep-related hallucinations characterized by vivid dreams, or perceptions not based in reality, that occur at sleep onset (hypnagogic hallucinations) or on awakening (hypnopompic hallucinations) that occur in otherwise healthy individuals but are frequently seen as part of the symptoms of narcolepsy; 4) Enuresis (discussed in Chapter 468); 5) Exploding head syndrome that is characterized by a terrifying perception of a loud noise, accompanied by myoclonic jerks or the perception of a flash of light while falling asleep, with no associated pain or headache (these episodes are anxiety promoting but require no treatment; 6) Sleep-related eating disorder that consists of episodes of sleep-walking with out-of-control eating binges, usually 2 to 3 hours after sleep-onset. These are seen most often in teenagers and adults and are associated with the use of hypnotics like zolpidem; 7) Catathrenia characterized by nocturnal groaning for clusters of 2 minutes to an hour during sleep, usually accompanied with changes in heart rate; 8) Sleep starts, also called hypnic jerks of the whole body during sleep-wake transition. Variation of this disorder include episodes of tinnitus or visual sensations which may occur without the motor jerks. 9) Sleep-sex disorders occurring during sleep without conscious awareness; 10) Sleeptalking; 11) Hypnic headaches that occur 4 to 6 hours after sleep onset and last 30 to 60 minutes; and 12) Head banging, also called jactatio capitis nocturna, which consists of rhythmic movements of head and body at sleep onset in infants and toddlers.

PAROXYSMAL DYSTONIA/TORTICOLLIS

Benign paroxysmal torticollis (BPT) of infancy is a self-limiting condition that appears in early infancy and disappears spontaneously by school age. There are recurrent episodes of torticollis, usually alternating from side to side. Episodes usually continue for several hours to a few days.18 The etiology remains unknown.  Usually no specific treatment is necessary. Details of various possible mechanisms to explain its pathogenesis have been summarized online.

CONVERSION DISORDER

Conversion reaction is defined by as a physical (sensory, motor, or autonomic) symptom that occurs after stress or conflict, is not intentionally produced, and is without evident somatic cause, resulting in significant impairment.20Primary gain is achieved via the symptom that symbolizes the unconscious conflict, and secondary gain by the gratification the patient receives from the sympathy and attention from the family and friends. The overall prevalence of this condition is about 1% to 3% in childhood and adolescence. It is commonly seen in children ages 10 to 15 years, being twice as common in girls than boys.

The symptoms can be varied, but in general, younger children present with unresponsiveness, whereas older children present with agitated behaviors. Psychogenic seizures, a form of a conversion reaction, are commonly mis-diagnosed as seizures. It is preferable to consider these events as nonepileptic seizures (NES) rather than pseudoseizures or psychogenic seizures. In children, such events account for 12% to 43% of admissions to the epilepsy monitoring units to rule out true seizures.21 Unresponsiveness without motor manifestations is the most common feature of psychogenic seizures, seen more often in younger children, while motor manifestations are more common in teenage girls. These include irregular movements that switch from one extremity to another with preserved consciousness, side-to-side head movements, pelvic thrusting, violent asynchronous features without self-injury or urinary incontinence, suggestibility, happening in the presence of company, and during wakefulness, forced eye closure, and prolonged duration of the event in spite of intervention.

Besides seizures, other physiological and organic conditions such as behavioral phenomenon including staring spells, stereotypy, gastroesophageal reflux, shuddering attacks, tics, other paroxysmal movement disorders, Munchausen-en-proxy, and factitious disorders need also to be ruled out.23

Intervention strategies may need involvement of multiple specialists including a psychologist, psychiatrist, social worker, neurologist, and the primary care physician.24 Follow-up at 3 months has shown that 75% to 90% of patients recovered completely; less than 10% showed no improvement. Poor outcome has been correlated with longer duration of the condition before diagnosis, history of sexual abuse, and the premorbid personality of the patient.25

Definition of conversion reaction, its prevalence, further evaluation of patients, and details of treatment have been described online.