Clinical evaluation of parasomnias

Introduction There are 15 different parasomnias discussed in the International Classification of Sleep Disorders, 2nd edition (ICSD-2). They are undesirable physical or experiential events that accompany sleep. These disorders consist of abnormal sleep-related movements, behaviors, emotions, perceptions, dreaming, and autonomic nervous system functioning. They are disorders of arousal, and sleep stage transition. Many of the parasomnias are manifestations of central nervous system activation and autonomic nervous system changes with skeletal muscle activity. There are also other sleep-related movement disorders that are not parasomnias but need to be considered in the differential diagnosis. These sleep-related movement disorders are listed as a separate category from parasomnias in the ICSD-2, and include, among others, restless legs syndrome (RLS), periodic limb movement disorder (PLMD), sleep-related leg cramps, sleep-related bruxism, and sleep-related rhythmic movement disorder. In addition, parasomnias can often occur in conjunction with other sleep disorders, such as obstructive sleep apnea syndrome or narcolepsy, and it is not uncommon for several parasomnias to occur in the same patient (Table 4.1). Parasomnias can contribute to impaired academic or occupational performance, disturbances of mood and social adjustment. Marriages and relationships may be adversely affected by the disordered sleep of a spouse or bed partner. Often, parasomnias may be markers of other disorders; for instance, somnambulism can be provoked by obstructive sleep apnea. Accordingly, complaints of abnormal movements or behaviors need to be taken seriously and an evaluation of these problems requires a systematic approach.