Parasomnias

Priya Prashad, MD

Introduction

•Parasomnias are undesirable physical events or experiences that occur during entry into sleep, within sleep, or during arousal from sleep.

•Many parasomnias emerge and peak during the childhood years, the most common being the arousal parasomnias: confusional arousals, sleep terrors, nightmares, and somnambulism or sleepwalking.

Etiology

•Parasomnia may occur during non–rapid eye movement (REM) sleep, during REM sleep, or during transitions to and from sleep.

Epidemiology

—Confusional arousals occur in 17.3% of children aged 3–13 years.

—Sleepwalking has an 18.3% lifetime prevalence.

—Sleep terrors are experienced by 1%–6.5% of children and 2.2% of adults.

Pathophysiology

•Arousal parasomnias have similar predisposing characteristics and triggers that are suggestive of a common pathophysiology.

•Parasomnias tend to run in families, so there may be a genetic factor.

•Parasomnias may be triggered by increased arousal from sleep, including obstructive sleep apnea (OSA), restless legs syndrome, periodic limb movement of sleep, or gastroesophageal reflux.

•Other triggers include sleep deprivation, illness, sleeping in a new or unfamiliar environment, and fever.

•These disorders are most common in childhood, particularly the pre-school age, and usually resolve by adolescence.

Clinical features

Non-REM Sleep Disorders of Arousal

•Result from incomplete arousal from non-REM (NREM) sleep

•Occur at the transition from deep NREM (stage N3) sleep into the lighter stages of NREM sleep (N1 or N2) or from stage N3 into the awake state

Confusional Arousals

•Confusional arousals occur mainly in infants and toddlers.

•They begin with whimpering or moaning, then evolve to calling out or crying.

•The child cries out words like “no” or “go away,” appears distressed, and remains inconsolable.

•The child appears confused (with eyes open or closed), very agitated, or even combative.

•Episodes may last 5–15 minutes before the child calms and returns to sleep.

Sleep Terrors

•These are more intense than confusional arousals.

•They begin with a loud scream and an intense look of fear, mydriasis, sweating, and tachycardia; episodes can last several minutes.

•The child is unaware of caregiver presence and will be confused and disoriented if awakened.

•Attempts to console the child may prolong or intensify the episode.

•Thrashing or other bodily movement is common.

•The child tends not to remember the episode in the morning.

Somnambulism

•