Background: Sleep terrors and sleepwalking are described as arousals from slow wave sleep with no or poor mental recollection.
Objective: To characterize the mental content retrospectively associated with sleep terrors or sleepwalking.
Setting: University Hospital
Design: Controlled prospective cohort
Participants: Forty-three patients referred for severe sleepwalking/sleep terrors (age: 26 ± 7 y, 46% men, 5 with sleep terrors only, 8 with sleepwalking only, and 30 with both), matched with 25 healthy control subjects.
Intervention: Thirty-eight of the 43 patients (88%) underwent an interview about the frequency, time, behaviors, and mental content associated with the episodes of sleepwalking and sleep terrors, whenever they occurred over a lifetime. The mental contents were classified for complexity (Orlinski score), and for characters, emotions, fortune/misfortune, and social interactions (Hall and Van de Castle categories). Patients and control subjects underwent an overnight video-polysomnogram.
Results: Seventy-one percent of the patients reported at least 1 dreamlike mentation associated with the sleepwalking/sleep terrors episode. The dreamlike mentation action corresponded with the observed behavior. A total of 106 dreamlike mentations were collected (mean: 3 ± 3.4 dreamlike mentations/patient, range 0-17). Most (95%) dreamlike mentations consisted of a single visual scene. These dreamlike mentations were frequently unpleasant, with aggression in 24% (the dreamer being always the victim), misfortune in 54%, and apprehension in 84%. The patients with dream mentations reported more severe daytime sleepiness.
Conclusion: Short, unpleasant dreamlike mentations may occur during sleepwalking/sleep terrors episodes, suggesting that a complex mental activity takes place during slow wave sleep. Sleepwalking may thus represent acting out of the corresponding dreamlike mentation.
Keywords: Sleepwalking, sleep terror, dream