Pediatric and adolescent sleep disorders are common and often disturbing to either the patient or the family. Sleep disorders can adversely impact physical and mental health. Nonrestorative sleep can hamper a child’s ability to concentrate and control emotions and behavior. Sleep disorders vary among age groups, but most can occur with varying frequency at any age. Several disorders are typically seen only during the first 3 years of life, including colic, excessive nighttime feedings, and sleep-onset association disorder. A number of conditions are common during childhood but begin to improve as the child ages. The non-REM sleep parasomnias—including sleepwalking, confusional arousals, and night terrors—are the most common in this category. Nightmares are also common in childhood but can occur at any age.

The sleep-related breathing disorders include obstructive sleep apnea, central sleep apnea, central alveolar hypoventilation syndrome, and Cheyne-Stokes respirations. These disorders can occur at any age, although the treatment options vary by age (Table 12-1).

The most frequent sleep-related problem for children between ages 6 months and 3 years is difficulty going to sleep or staying asleep throughout the night.1 Multiple factors have been implicated in the occurrence of repetitive night waking and inability to fall asleep: infant temperament, nutrition, physical discomfort, mild allergy, and parental marital conflict.2,3

Sleep-Onset Association Disorder

Clinical Features

Complaints of sleep problems in the infant and young child usually come from the parents, not the child. Nighttime awakenings sometimes become worrisome to parents. However, most often the problems reflect certain established patterns of interaction between the parent and the child at time of sleep transition. Nighttime arousals are very common in all ages; however, older children and adults are usually unaware of these disruptions.

Causes/Pathogenesis

A parent may incorrectly conclude that nocturnal awakenings are abnormal, becoming involved in the sleep transition process. The child may become accustomed to parental intervention and become unable to make the transition back to sleep alone, creating a sleep problem or sleep-onset association disorder. The child becomes reliant on the parent to help complete the sleep transition regardless of the time of night.

Diagnosis and Treatment

Diagnosis is usually made with a careful history. Children with this disorder often rapidly respond to simple gradual behavioral interventions, which helps the child learn a new set of sleep-associated habits.4

Difficulties Learning to Sleep Alone

Clinical Features

Sleeping alone throughout the night without parental intervention is a learned process. All children wake up 5 to 8 times per night, at the end of each sleep cycle, but some children are able to put themselves back to sleep without parental awareness. Most infants are capable of learning this process from about 5 to 7 months of age.1

Diagnosis and Treatment

The key is to gradually withdraw the amount of parental involvement at sleep onset. The same parental behavior response is required for middle-of-the-night awakenings. Consistency is also of critical importance if a treatment plan is going to work, especially in conditioning the child to sleep throughout the night. If fear is affecting the progression of this process, it is important to effectively deal with child and/or parental anxiety. Fear can prevent sleep, and fear of safety for one’s child can alter a planned behavioral intervention. In certain cases, it will be important to have parents problem solve about their child’s fear and how to best accommodate the behavioral treatment plan.

Excessive Nighttime Feedings

Clinical Features

Studies have shown that an increase in nighttime awakenings among infants and toddlers may be related to nighttime feedings. Infants fed large quantities at night (8-32 oz) have been shown to have continued and frequent awakenings, ranging up to eight per night.4-7 Repeated awakenings for ingestion of fluid directly disrupt the functioning of circadian-modulated systems, which may cause further deleterious effects on sleep–wake stabilization.4,8,9

Diagnosis and Treatment

Diagnosis can be made from a characteristic history: multiple nighttime awakenings, return to sleep only with feeding, significant fluid intake during the night, and extremely wet diapers. Treatment consists of a gradual decrease in the frequency of feedings during the night.4 Frequent awakenings, three or more per night in a child over 6 months of age, may cause sleep fragmentation that is harmful to the child. As feedings are decreased and associated habits are eliminated over a couple of weeks, sleep consolidation usually promptly occurs.7

Limit Setting

Inability to set limits at bedtime can also lead to sleep deterioration. Typical bedtime struggles may consist of requests for water, stories, use of the bathroom, and adjustment of lights.4,7 A diagnosis of this sort can be made from the history. Through history-taking it may become clear that the parents are unable to enforce nighttime rules with enough consistency to keep the child in bed and quiet so that he or she falls asleep. Parents may have to learn to be firm in their limit setting, enforcing a regular bedtime ritual with an end-point. The child should also be kept in his or her bedroom with the use of a gate of some sort or closure of the door if necessary. Positive behavior modification, such as a sticker, star chart, or other prizes for staying in bed, may elicit a positive response.4

Fear

Fear and nightmares are also commonly seen in early childhood, as part of normal development. A truly anxious child at night should be handled in the same manner whether the child’s fears were initially expressed during waking or sleep. Mild fears often respond to supportive firmness and a stable social setting. Positive reinforcement, with rewards for staying in bed, may help motivate the child. Treatment may also consist of sleep schedule correction, progressive relaxation,10 and progressive desensitization.11

Colic

Clinical Features

Colic is the most common medical condition that affects the sleep of young infants. It causes inconsolable fussiness and crying, typically in the late afternoon and evening. Although symptoms usually remit by 3 to 4 months of age, continuing sleep disturbances are common, secondary to altered sleep schedules and habitual patterns of parental responsiveness.7

Diagnosis and Treatment

Colic is diagnosed when there are unexplained spells of crying in healthy infants. Treatment mainly focuses around education and management strategies for helping parents cope with the stresses of caring for the infant.12

In the course of clinical practice many unusual nocturnal phenomena may be described by patients or parents. The correct diagnosis can usually be ascertained from the clinical history alone, but in some cases polysomnography may be necessary. Additional EEG leads should be used if a seizure disorder is suspected. Additional EMG leads can be useful in patients with movement disorders.

Nocturnal movement disorders are extremely common in the pediatric population. In some cases, these events are so common that they may be considered a normal component of childhood and are usually “outgrown.”

Restless Legs Syndrome

Clinical Features

Restless legs syndrome (RLS) is a disorder composed of four principal diagnostic criteria:

1. 
   

   Intense, irresistible desire to move limbs, usually with uncomfortable feeling in the limbs

   
   
2. 
   

   Symptoms worsen with decreased activity

   
   
3. 
   

   Symptoms improve with activity

   
   
4. 
   

   Symptoms are typically worse at night13

Patients, especially young children may have difficulty describing the symptoms. Children may get into trouble at school or at home because they have difficulty sitting still. RLS is underdiagnosed or misdiagnosed because of these factors.

RLS may cause significant sleep disturbance, especially with sleep onset. Patients may describe the subjective symptoms of RLS in a number of ways including creepy, crawly, tingly, like worms or bugs crawling under the skin, painful, burning, aching, and electrical. They may have difficulty describing the symptoms. In children, these symptoms can easily be mistaken for “growing pains.”

Restless legs syndrome may coexist with periodic limb movements disorder (PLMD, described below) but are not always seen together. A comparison of the two syndromes appears in Table 12-2.

Epidemiology

RLS has an age-adjusted prevalence of up to 10% of adults. It is less common in children and increases with increasing age. The symptom severity also typically worsens with increasing age. Primary RLS is a genetic disorder with an autosomal dominant pattern. Secondary RLS associated with a precipitating factor, is less common. Renal failure, iron deficiency, and diabetes may contribute to the restlessness. In children, growing pains may mimic or cause restless legs.

Evaluation

The laboratory evaluation of RLS includes serum ferritin, screening for uremia, and screening for diabetes. Low normal ferritin levels (20-60) may be associated with RLS and frequently respond to treatment with iron.14 Polysomnography is not indicated in the evaluation of RLS, unless there is suspicion of a concomitant sleep disorder.

Treatment

Dopamine agonist therapy is the mainstay of RLS treatment in adults. No agents have been FDA approved for treatment of RLS in children. Use of simple nonpharmacological therapies may be of some benefit, including teaching the child to visualize an activity or simply allowing the child to move the legs. Teachers should be informed of the condition and the fact that it is not a form of attention-deficit disorder should be reinforced. Symptoms may be caused by an underlying iron or vitamin deficiency, and supplementing with iron, vitamin B12, or folate (as indicated) may be sufficient to relieve symptoms in these specific cases. A potential treatment algorithm is outlined in Figure 12-1.

Periodic Limb Movement Disorder

Clinical Features

Periodic limb movement disorder (PLMD) is “characterized by periodic episodes of repetitive and highly stereotyped limb movements that occur during sleep.”15 While these movements usually occur in the legs, they can also occur in the arms. There is usually extension of the toe and flexion of the ankle, knee, and hip. Most patients are not aware of the movements. The sleep disruption associated with the movements can lead to insomnia or daytime somnolence. There is a repetitive increase in EMG activity (most often measured over the anterior tibialis muscle) lasting 0.5 to 5 seconds. The movement can be synchronous or asynchronous with the other leg or only involve one extremity. Both legs (and even the arms) should be monitored if PLMD is suspected. The movements are between 5 and 90 seconds apart. Most of the time, the movements occur every 20 to 40 seconds. Four or more consecutive movements are needed to count them as periodic limb movements (PLMs). The PLM index is the total number of PLMs divided by the total hours of sleep. A PLM index over 5 is considered abnormal. Often, PLMs are associated with arousals. A PLM-arousal index may also be noted on the sleep study interpretation. While many assume that the higher the PLM-arousal index, the more likely one is to suffer from daytime sleepiness, this has not been proven.16

Individuals with RLS, narcolepsy, and obstructive sleep apnea often have PLMs on a polysomnogram. While all patients with PLMD and most patients with RLS have periodic limb movements on a sleep study, only the RLS patients have the daytime annoying sensations in their limbs that improve with movement. Use of caffeine, neuroleptics, alcohol, monoamine oxidase inhibitors, or tricyclic antidepressants can cause periodic limb movements. Withdrawal of benzodiazepines, barbiturates, and certain hypnotics can cause or aggravate PLMS. PLMs are reportedly rare in children but increase in prevalence with age. PLMs may be seen in patients who are asymptomatic from them. Inadequate sleep habits, psychophysiologic insomnia, and other causes of daytime tiredness need to be considered and treated before placing a patient on medication for PLMs.

There are a few conditions that mimic PLMs. Sleep starts or hypnic jerks are frequently mentioned by patients. These occur in drowsiness, may be associated with a feeling of falling, and do not recur repetitively throughout sleep. Seizures can cause nighttime kicking movements but may also cause nocturnal enuresis, morning musculoskeletal soreness, or bleeding from oral laceration. An expanded additional 16-lead EEG on the polysomnogram is invaluable in identifying these individuals. Many people with sleep apnea have PLMs that disappear with initiation of effective treatment of the obstructive sleep apnea including surgery or continuous positive airway pressure (CPAP).

Rhythmic Movement Disorder

Clinical Features

Rhythmic movement disorder (RMD) “comprises a group of stereotyped, repetitive movements involving large muscles, usually of the head and neck; the movements typically occur immediately prior to sleep onset and are sustained into light sleep” (ICSD (15)). This can manifest as repetitive head banging, leg banging or body rolling. The movements typically start during drowsiness. Movements typically occur at a frequency of 0.5 to 2 times per second. While very common in normal infants, it is sometimes associated with a static encephalopathy, autism, or psychopathology in older children and adults. It is thought to have a self-soothing effect for some individuals. It appears to be more common in males. The noise from the movements can be disturbing to family members. While injuries, even serious injury such as subdural hematoma, are is possible, they are not common. It is very important to have the technologist accurately document what was seen at the time this occurs in the sleep laboratory. Continuous video monitoring usually easily confirms the diagnosis.