NREM parasomnias

Considerable progress has been made in the systematic study of nonrapid eye movement (NREM) sleep parasomnias. This chapter focuses on the clinical features, prevalence, pathophysiology, associated sleep parameters, and clinical variants of the prototypic NREM sleep parasomnias, namely confusional arousals, sleepwalking, and sleep terrors. Whereas the occurrence of NREM parasomnias in children is frequently viewed as relatively benign, these disorders often pose greater problems, including sleep-related injuries, in affected adults. Most episodes arise from sudden but incomplete arousal from slow-wave sleep and sometimes from stage 2 sleep. Factors that deepen or fragment sleep can facilitate or precipitate NREM parasomnias in predisposed individuals. NREM parasomnias can be associated with various primary sleep disorders or with medical conditions. Diagnosis of NREM parasomnias can often be made based on a detailed history, although some patients may require more extensive evaluations, including polysomnographic study with an expanded EEG montage. Sleep deprivation and the presentation of auditory stimuli during slow-wave sleep are two techniques that can increase the occurrence of behavioral manifestations under laboratory conditions. A variety of nonpharmacological treatments have been recommended for long-term management of NREM parasomnias, whereas pharmacological agents should be considered only if the behaviors are hazardous or extremely disruptive.