Violent somnambulism: A parasomnia of young men with stereotyped dream-like experiences

Shared EEG correlates between non-REM parasomnia experiences and dreams

Sleepwalking and related parasomnias result from incomplete awakenings out of non-rapid eye movement sleep. Behavioral episodes can occur without consciousness or recollection, or in relation to dream-like experiences. To understand what accounts for these differences in consciousness and recall, here we recorded parasomnia episodes with high-density electroencephalography (EEG) and interviewed participants immediately afterward about their experiences. Compared to reports of no experience (19%), reports of conscious experience (56%) were preceded by high-amplitude EEG slow waves in anterior cortical regions and activation of posterior cortical regions, similar to previously described EEG correlates of dreaming. Recall of the content of the experience (56%), compared to no recall (25%), was associated with higher EEG activation in the right medial temporal region before movement onset. Our work suggests that the EEG correlates of parasomnia experiences are similar to those reported for dreams and may thus reflect core physiological processes involved in sleep consciousness.

The parasomnia defense in sleep-related homicide: A systematic review and a critical analysis of the medical literature

This review critically analyzes the forensic application of the Parasomnia Defense in homicidal incidents, drawing from medical literature on disorders of arousal (DOA) and rapid-eye-movement sleep behavior disorder (RBD). A systematic search of PubMed, Scopus, Embase, and Cochrane databases was conducted until October 16, 2022. We screened English-language articles in peer-reviewed journals discussing murders committed during sleep with a Parasomnia Defense. We followed PRISMA guidelines, extracting event details, diagnosis methods, factors influencing the acts, perpetrator behavior, timing, motives, concealment, mental experiences, victim demographics, and court verdicts. Three sleep experts evaluated each case. We selected ten homicides, four attempted homicides, and one homicide/attempted homicide that met inclusion/exclusion criteria. Most cases were suspected DOA as unanimously confirmed by experts. RBD cases were absent. Among aggressors, a minority reported dream-like experiences. Victims were primarily female family members killed in or near the bed by hands and/or with sharp objects. Objective sleep data and important crime scene details were often missing. Verdicts were ununiform. Homicides during DOA episodes, though rare, are documented, validating the Parasomnia Defense's use in forensics. RBD-related fatal aggression seems very uncommon. However, cases often lack diagnostic clarity. We propose updated guidelines to enhance future reporting and understanding of such incidents.

Non-REM parasomnias: a scoping review of dreams and dreamlike mentation

AIM

To establish patterns or themes of dreams and dreamlike mentation content reported in all forms of non-rapid eye movement (NREM) parasomnias and to identify gaps in the current understanding of this topic.

METHODS

A scoping review of available evidence on dreams and dreamlike mentation in NREM parasomnias was conducted in accordance with the PRISMA-ScR guidelines. We searched peer-reviewed literature using Google Scholar, PubMed, Ovid (Embase), Ovid Medline®, Global Health, and APA Psych Info. The Mixed Method Appraisal Tool (MMAT) was used to appraise the quality of selected articles.

RESULTS

The final analysis included 16 studies. All of the studies were from high-income countries. The studies reported on dreams and dreamlike mentation in NREM parasomnias, but there was scarcity of literature for sexsomnia, sleep-related eating disorder, and confusional arousal. All of the studies had the highest quality as shown by the MMAT (76%-100%). Emotions such as apprehension and misfortune were associated with sleepwalking and sleep terrors.

CONCLUSION

Sleep studies involving collection of dream content immediately following NREM parasomnia could significantly minimize reporting bias and improve dream data quality.

Nocturnal visual hallucinations in patients with disorders of arousal: a novel behavioral and EEG pattern

AIM

To investigate clinical and video-polysomnography (VPSG) findings of hallucinatory experiences in patients suffering from disorders of arousal (DOA) in the absence of other pathologies.

METHODS

The authors retrospectively reviewed the records of 370 adults with DOA. Thirty (8.1%) patients concomitantly reported complex nocturnal visual hallucinations. VPSG recordings were scrutinized, and motor behavioral and electroencephalogram (EEG) patterns were classified according to previous descriptions of DOA.

RESULTS

Thirty DOA patients reported seeing images of objects, people, and animals; either distorted, static, or mobile. The images disappeared with increased illumination in 80% of patients, and 23.3% reported preceding dream imagery. In addition to the classical DOA patterns on VPSG, a distinct pattern of behavioral and EEG manifestation associated with complex hallucinatory episodes was identified in 16 (53.3%) DOA patients. This consisted of low-voltage mixed-frequency EEG activity before eye opening that persisted while patients were observed staring or visually tracking before the onset of motor behavior.

CONCLUSION

A novel, distinct behavioral and EEG pattern in patients with DOA and history of reported complex nocturnal visual hallucinations was identified. This may represent a unique phenotype of dissociation between sleep states that merits further investigation.

Medicolegal aspects of non-rapid eye movement parasomnias

INTRODUCTION

In a subset of adults with non-rapid eye movement (NREM) parasomnias, clinical variants might be violent in nature and can potentially result in unintentional but considerable harm. As such, there is substantial interest on the forensic ramifications of these sleep behaviours.

METHODS

This review examined the diagnostic criteria for parasomnias established in the context of international classification systems; medicolegal case reports; legal frameworks; and court cases in and outside of Singapore, to provide an overview of the implications of NREM parasomnias.

RESULTS

Violent or injurious behaviours that occurred in the context of somnambulism, otherwise known as sleepwalking, have challenged traditional legal theories of criminal culpability. Yet little has changed in the application of sleep science to criminal responsibility. In Singapore, the defence of somnambulism has hitherto not been directly raised. Nonetheless, sleep medicine practitioners may increasingly be requested to render their opinions on legal issues pertaining to violent or injurious behaviours allegedly arising during sleep. Although the understanding of NREM parasomnias has improved, there is still a dearth of evidence to support both medical and legal decisions in this area.

CONCLUSION

NREM parasomnias come with disquieting legal and forensic implications for adjudicating criminal responsibility. There is a need to critically examine legal perspectives on behaviours occurring during sleep. More reliable empirical studies investigating the pathophysiology of NREM parasomnias can offer clearer diagnostic guidelines and address complex behaviours of NREM that often come with medicolegal implications.

Parasomnias in patients with addictions-a systematic review

Parasomnias are involuntary behaviors or subjective experiences during sleep. Our objective was to review existing information on the presence of parasomnias in patients with addictions or during treatment for addictions. Information about parasomnias related to rapid-eye-movement (REM) and non-REM sleep in patients with addictions, while using substances or in abstinence, was reviewed. A systematic search of published articles reporting parasomnias as a consequence of drug use or abuse was conducted in the PubMed and SciELO databases. The search for the studies was performed in three phases: (1) by title, (2) by abstract, and (3) by complete text. The search was performed independently by two researchers, who then compared their results from each screening phase. Seventeen articles were found. The consumption of alcohol was reported in association with arousal disorders, such as sexsomnia and sleep-related eating disorder; and REM sleep behavior disorder was reported during alcohol withdrawal. Cocaine abuse was associated with REM sleep behavior disorder with drug consumption dream content. Overall, we found that several types of parasomnias were very frequent in patients with addictions. To avoid accidents in bedroom, legal problems, and improve evolution and prognosis; must be mandatory to include security measures related to sleep period; avoid pharmacological therapy described as potential trigger factor; improve sleep hygiene; and give pharmacological and behavioral treatments for patients with these comorbid sleep disorders.

Mental Activity During Episodes of Sleepwalking, Night Terrors or Confusional Arousals: Differences Between Children and Adults

OBJECTIVE/BACKGROUND

Night terrors, sleepwalking and confusional arousals are behavioral manifestations of incomplete awakenings from sleep. According to international diagnostic criteria, these behaviors occur in the absence of any mental experience, or in the presence of very limited cognition or dream imagery (eg, a single visual scene). The aim of this study was to systematically and retrospectively investigate the mental content associated with sleep terrors and/or sleepwalking in both children and adults.

PATIENTS AND METHODS

Forty-five consecutive patients referred for a diagnosis of disorders of arousal (DOA) of all subtypes (sleepwalking/sleep terrors/confusional arousals) (25 adults: 30 ± 6 y, 15 females; 20 children: 10 ± 3 y, 6 females) underwent a detailed semi-structured interview about the mental content associated with their nocturnal episodes. The interview was comprehensive of specific questions about their subjective recall rate, several content details (characters, emotions, actions and setting/context), and hallucinatory or dissociative experiences during clinical episodes. Patients' reports were classified for complexity (Orlinsky scale) and content (Hall and Van de Castle categories).

RESULTS

More than two-third of the children (n = 14) could not recall any mental activity associated with their episodes, whereas more than two-third (n = 16) of the adults recalled at least one mental experience. Half of the adult patients (n = 8) estimated that a specific mental content was subjectively present around 50% or more of the times. Seven adults and one child described clear and vivid hallucinatory experiences of "dreamed" objects or characters projected onto their real home environment, in the absence of any reality testing. Five adults and two children described one or more dissociative experiences. The content of the collected reports was dominated by dynamic actions acted out from a self-perspective, often with apprehension and in response to misfortune and danger, in a home-setting environment.

CONCLUSION

These results suggest that current diagnostic criteria are tailored around the typical presentation of DOA in children, and do not always fit to adult patients with DOA. Furthermore, they support the concept that consciousness may reemerge in DOA patients during clinical episodes, in a peculiar dissociated, psychotic-like form.

NREM sleep parasomnias as disorders of sleep-state dissociation

Non-rapid eye movement (NREM) sleep parasomnias (or NREM parasomnias) are fascinating disorders with mysterious neurobiological substrates. These conditions are common and often severe, with social, personal and forensic implications. The NREM parasomnias include sleepwalking, sleep terrors and confusional arousals - collectively termed disorders of arousal (DOAs) - as well as less well-known entities such as sleep-related sexual behaviours and eating disorders. Affected patients can exhibit waking behaviours arising abruptly out of NREM sleep. Although the individual remains largely unresponsive to the external environment, their EEG shows both typical sleep-like and wake-like features, and they occasionally report dreaming afterwards. Therefore, these disorders offer a unique natural model to explore the abnormal coexistence of local sleep and wake brain activity and the dissociation between behaviour and various aspects of consciousness. In this article, we critically review major findings and updates on DOAs, focusing on neurophysiological studies, and offer an overview of new clinical frontiers and promising future research areas. We advocate a joint effort to inform clinicians and the general public about the management and follow-up of these conditions. We also strongly encourage collaborative multicentre studies to add more objective polysomnographic criteria to the current official diagnostic definitions and to develop clinical practice guidelines, multidisciplinary research approaches and evidence-based medical care.

Progress in elucidating the pathophysiological basis of nonrapid eye movement parasomnias: not yet informing therapeutic strategies

Nonrapid eye movement (NREM) or arousal parasomnias are prevalent conditions in children and young adults, apparently provoked by any medical, physical, mental, or pharmacologic/toxic agent disturbing normal biorhythm and causing sleep fragmentation or abundant amount of slow wave sleep. The nadir and the ascending slope of the first sleep cycle of night sleep are the typical periods when NREM parasomnias, especially sleepwalking may occur on sleep-microstructural level; microarousals are the typical moments allowing NREM parasomnias. While sleep-disturbing factors have a clear precipitating effect, a genetic predisposition appears necessary in most cases. A candidate gene for sleepwalking has been identified on chromosome 20q12-q13.12 in one sleepwalking family. NREM parasomnias have a genetic and clinical link with nocturnal-frontal lobe epilepsies; possibly through an abnormality of the acetylcholine-related sleep-control system. The association of NREM parasomnias with the human leukocyte antigen system might be the sign of an autoimmune background to be further clarified. In the treatment of arousal parasomnias, the main tools are adequate sleep hygiene and the management of underlying conditions. Their pharmacotherapy has remained unresolved; the best options are clonazepam and some of the antidepressants, while a psychotherapy approach is also justified.