Non-rapid Eye Movement Parasomnias Research Articles

Parasomnias: Common and Rare Types, Diagnosis, Prevention, and Management of NREM Parasomnias

Parasomnias are described as undesirable motor activity displayed during sleep. Parasomnias are generally characterized by abrupt talking, screaming, walking, confusional arousals, bruxism (ie, teeth grinding), or other complex activity arising from non-rapid eye movement (NREM) stages, rapid eye movement (REM) stages, or transitions between sleep stages and sleep-wake states. Parasomnias are associated with a poor recall of events by the patient, making information from a bed partner valuable. The use of attended polysomnography (PSG) with continuous audio and video recording and the inclusion of extended electro-encephalographic (EEG) montage is required to diagnose REM parasomnias. PSG is not required for the diagnosis of NREM parasomnias, as these are diagnosed by clinical history. Nonpharmacologic interventions that are effective for NREM parasomnias include relaxation, hypnosis, anticipatory awakenings, and ensuring environmental safety to reduce the risk of injury to the patient, bed partners, and family members. Pharmaceuticals shown to have significant effectiveness in NREM parasomnias include melatonin, benzodiazepines, tricyclic antidepressants, and medications that reduce arousals. [ Psychiatr Ann . 2021;51(12):550–555.]

A series of 8 cases of sleep-related psychogenic dissociative disorders and proposed updated diagnostic criteria.

To identify the most relevant clinical and video-polysomnographic characteristics of patients with sleep-related dissociative disorders (SRDDs) and to propose a framework for new diagnostic criteria. We searched potential SRDD cases from the scientific literature and from a database of patients referred for clinical and video-polysomnographic assessment in a single sleep disorders center for disruptive nocturnal behaviors (n = 731). The most relevant clinical and neurophysiological characteristics of the cases were extracted and a descriptive analysis was performed. Twenty-six SRDD cases (8 new and 18 previously published cases) were reviewed. Almost all cases of SRDDs occurred in a context of past traumatic events or abuse and were associated with at least 1 comorbid psychiatric disorder. We highlighted 4 relevant clinical characteristics of SRDD useful for the differential diagnosis with parasomnias: episodes of long duration of more than 1 hour (90.9%), self-inflicted injuries (83.3%), occurrence while awake close to bedtime (35.7%), and the presence of daytime dissociative symptoms (72.7%). The video-polysomnography documented typical episodes of SRDD with prolonged wakefulness before, during, and after the event in 11/26 cases. New diagnostic criteria for SRDD were proposed, with 3 levels of certainty for the diagnosis based on clinical, video-polysomnographic, and homemade video findings. More than 30 years after its formal identification, SRDD is not currently recognized as an official diagnostic entity. We better delineate the clinical and neurophysiological features of SRDD and propose a framework for its reinstatement in the next revisions of the sleep and psychiatric disorders classifications. Lopez R, Lefevre L, Barateau L, Micoulaud-Franchi J-A, Dauvilliers Y, Schenck CH. A series of 8 cases of sleep-related psychogenic dissociative disorders and proposed updated diagnostic criteria. J Clin Sleep Med. 2022;18(2):563-573.

A Novel Group Cognitive Behavioral Therapy Approach to Adult Non-rapid Eye Movement Parasomnias.

Background: Following the success of Cognitive Behavioral Therapy (CBT) for insomnia, there has been a growing recognition that similar treatment approaches might be equally beneficial for other major sleep disorders, including non-rapid eye movement (NREM) parasomnias. We have developed a novel, group-based, CBT-program for NREM parasomnias (CBT-NREMP), with the primary aim of reducing NREM parasomnia severity with relatively few treatment sessions.Methods: We investigated the effectiveness of CBT-NREMP in 46 retrospectively-identified patients, who completed five outpatient therapy sessions. The outcomes pre- and post- CBT-NREMP treatment on clinical measures of insomnia (Insomnia Severity Index), NREM parasomnias (Paris Arousal Disorders Severity Scale) and anxiety and depression (Hospital Anxiety and Depression Scale), were retrospectively collected and analyzed. In order to investigate the temporal stability of CBT-NREMP, we also assessed a subgroup of 8 patients during the 3 to 6 months follow-up period.Results: CBT-NREMP led to a reduction in clinical measures of NREM parasomnia, insomnia, and anxiety and depression severities [pre- vs. post-CBT-NREMP scores: P (Insomnia Severity Index) = 0.000054; P (Paris Arousal Disorders Severity Scale) = 0.00032; P (Hospital Anxiety and Depression Scale) = 0.037]. Improvements in clinical measures of NREM parasomnia and insomnia severities were similarly recorded for a subgroup of eight patients at follow-up, demonstrating that patients continued to improve post CBT-NREMP.Conclusion: Our findings suggest that group CBT-NREMP intervention is a safe, effective and promising treatment for NREM parasomnia, especially when precipitating and perpetuating factors are behaviorally and psychologically driven. Future randomized controlled trials are now required to robustly confirm these findings.

Gastroesophageal reflux-related Non-Rapid Eye Movement parasomnia mimicking sleep-related hypermotor epilepsy

• Asymptomatic gastroesophageal reflux disease can cause laryngospasm is sleep. • Laryngospasm related arousals can lead to NREM parasomnias in someone with disturbed N3 sleep. • Sleep related laryngospasm should be on the differential for both NREM parasomnias and SHE.

EEG Patterns Prior to Motor Activations of Parasomnias: A Systematic Review.

IntroductionNon-rapid eye movement (NREM) parasomnias are defined as abnormal nocturnal behaviors that typically arise from the NREM sleep stage 3 during the first sleep cycle. The polysomnographic studies showed an increase in sleep fragmentation and an atypical slow wave activity (SWA) in participants with NREM parasomnias compared to healthy controls. To date, the pathophysiology of NREM parasomnias is still poorly understood. The recent investigation of the EEG patterns immediately before parasomnia events could shed light on the motor activations’ processes. This systematic review aims to summarize empirical evidence about these studies and provide an overview of the methodological issues.MethodsA systematic literature search was carried out in PubMed, Web of Science, and Scopus, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The documents obtained were evaluated using the Newcastle–Ottawa Scale (NOS).ResultsNine studies were included in the qualitative synthesis. The major evidence revealed an increased slow frequency EEG activity immediately before the motor activations in frontal and central areas and increased beta activity in the anterior cingulate cortices.DiscussionThe investigation of EEG patterns before parasomniac episodes could provide new insight into the study of NREM parasomnia pathophysiology. The high- and low-frequency EEG increase before the episodes could represent a predictive electrophysiological pattern of the motor activations’ onset. Overall, identifying specific sleep markers before parasomnias might also help differentiate between NREM parasomnias and other motor sleep disorders. Different methodological protocols should be integrated for overcoming the lack of consistent empirical findings. Thus, future studies should focus on the topographical examination of canonical EEG frequency bands to better understand spatial and time dynamics before the episodes and identify the networks underlying the onset of activations.

Sexsomnia in Active Duty Military: A Series of Four Cases.

Sexsomnia is a type of non-rapid eye movement (NREM) parasomnia in which sexual behaviors arise during sleep; these behaviors are varied and can include masturbation, orgasms with or without self-stimulation, sexual vocalizations and talking, and sexual fondling and/or intercourse with the bed partner. The military creates a challenging environment, with sleep deprivation, shift work, and increased psychosocial stress that may predispose service members to an increased risk for all NREM parasomnias, including sexsomnia. Given that sexsomnia is sometimes invoked in sexual assault military lawsuits, it may behoove the military community to understand how this condition usually manifests so that its medicolegal implications can be addressed more clearly. Here, we present the largest case series of sexsomnia to date in active duty military service members, which adds to the limited literature on such cases in the military and to the broader but still growing literature on this rare disorder. We compare and contrast these cases with the available literature to highlight their similarities and differences in addition to commenting on the relevance of these cases in forensic investigations. As none of these cases were involved in legal issues, they could provide useful information about this rare condition in individuals who are less likely to be affected by the biases that are inherent to litigation.

Sleep-related hypermotor epilepsy and non-rapid eye movement parasomnias: Differences in the periodic and aperiodic component of the electroencephalographic power spectra.

SummaryOver the last two decades, our understanding of clinical and pathophysiological aspects of sleep‐related epileptic and non‐epileptic paroxysmal behaviours has improved considerably, although it is far from complete. Indeed, even if many core characteristics of sleep‐related hypermotor epilepsy and non‐rapid eye movement parasomnias have been clarified, some crucial points remain controversial, and the overlap of the behavioural patterns between these disorders represents a diagnostic challenge. In this work, we focused on segments of multichannel sleep electroencephalogram free from clinical episodes, from two groups of subjects affected by sleep‐related hypermotor epilepsy (N = 15) and non‐rapid eye movement parasomnias (N = 16), respectively. We examined sleep stages N2 and N3 of the first part of the night (cycles 1 and 2), and assessed the existence of differences in the periodic and aperiodic components of the electroencephalogram power spectra between the two groups, using the Fitting Oscillations & One Over f (FOOOF) toolbox. A significant difference in the gamma frequency band was found, with an increased relative power in sleep‐related hypermotor epilepsy subjects, during both N2 (p < .001) and N3 (p < .001), and a significant higher slope of the aperiodic component in non‐rapid eye movement parasomnias, compared with sleep‐related hypermotor epilepsy, during N3 (p = .012). We suggest that the relative power of the gamma band and the slope extracted from the aperiodic component of the electroencephalogram signal may be helpful to characterize differences between subjects affected by non‐rapid eye movement parasomnias and those affected by sleep‐related hypermotor epilepsy.

NonREM Disorders of Arousal and Related Parasomnias: an Updated Review.

Parasomnias are abnormal behaviors and/or experiences emanating from or associated with sleep typically manifesting as motor movements of varying semiology. We discuss mainly nonrapid eye movement sleep and related parasomnias in this article. Sleepwalking (SW), sleep terrors (ST), confusional arousals, and related disorders result from an incomplete dissociation of wakefulness from nonrapid eye movement (NREM) sleep. Conditions that provoke repeated cortical arousals, and/or promote sleep inertia, lead to NREM parasomnias by impairing normal arousal mechanisms. Changes in the cyclic alternating pattern, a biomarker of arousal instability in NREM sleep, are noted in sleepwalking disorders. Sleep-related eating disorder (SRED) is characterized by a disruption of the nocturnal fast with episodes of feeding after arousal from sleep. SRED is often associated with the use of sedative-hypnotic medications, in particular the widely prescribed benzodiazepine receptor agonists. Compelling evidence suggests that nocturnal eating may in some cases be another nonmotor manifestation of Restless Legs Syndrome (RLS). Initial management should focus upon decreasing the potential for sleep-related injury followed by treating comorbid sleep disorders and eliminating incriminating drugs. Sexsomnia is a subtype of disorders of arousal, where sexual behavior emerges from partial arousal from nonREM sleep. Overlap parasomnia disorders consist of abnormal sleep-related behavior both in nonREM and REM sleep. Status dissociatus is referred to as a breakdown of the sleep architecture where an admixture of various sleep state markers is seen without any specific demarcation. Benzodiazepine therapy can be effective in controlling SW, ST, and sexsomnia, but not SRED. Paroxetine has been reported to provide benefit in some cases of ST. Topiramate, pramipexole, and sertraline can be effective in SRED. Pharmacotherapy for other parasomnias continues to be less certain, necessitating further investigation. NREM parasomnias may resolve spontaneously but require a review of priming and predisposing factors.

Utility of the Frontal Lobe Epilepsy Parasomnia Scale in Evaluation of Children With Nocturnal Events.

BACKGROUND: Sleep-related hypermotor epilepsy (SHE) and nocturnal non-rapid eye movement parasomnias are difficult to differentiate. Neurologists and sleep medicine clinicians largely rely on clinical history when evaluating nocturnal spells. When the diagnosis is in question, referral for video electroencephalogram monitoring is the standard. However, there are no guidelines as to when this evaluation is needed. The Frontal Lobe Epilepsy Parasomnia (FLEP) scale was developed to assist clinicians in differentiating the two among adults. The aim of this study was to provide a preliminary evaluation of the FLEP for use with children. METHODS: This was a retrospective pilot instrument validation study with a convenience sample of 17 children seen in neurology or sleep medicine clinics. To determine concurrent validity, FLEP scores were compared with clinical diagnoses by neurology providers confirmed by electroencephalography. RESULTS: With a cutoff score of 2, the modified FLEP distinguished between children with and without SHE. The FLEP tool had a specificity of 0.58, implying that 7 of the 12 children without SHE would have been accurately recommended to follow up for parasomnia management rather than more urgent evaluation of potential frontal lobe epilepsy. CONCLUSIONS: With some minor adaptations for children, the FLEP satisfactorily distinguished between SHE and non-SHE patients.

Increased behavioral inhibition trait and negative stress coping in non-rapid eye movement parasomnias.

Reduced gray matter volume in the posterior cingulate cortex (PCC) has recently been found in patients with non-rapid eye movement (NREM) parasomnia, providing a neuroanatomical substrate for the arousal state dissociation. It remains unclear whether PCC changes in NREM parasomnias might also play a role in cognitive or affective dysfunction in these patients. The aim of this exploratory study was to investigate neurobehavioral correlates of PCC abnormalities in patients with NREM parasomnia. The Reinforcement Sensitivity Theory of Personality Questionnaire and the Stress Coping Questionnaire were used to assess personality and stress coping in 15 patients with NREM parasomnia and 15 age- and sex-matched healthy controls. Patients' left PCC gray matter volume was quantified with voxel-based morphometry on 3 Tesla T1-weighted magnetic resonance imaging data. In the Reinforcement Sensitivity Theory of Personality Questionnaire, increased trait reactivity of the behavioral inhibition system and goal-drive persistence contributed most to the discrimination of patients and controls. In the Stress Coping Questionnaire, patients showed an increased negative coping trait (ie, anxious rumination) related to an increase in adjusted left PCC volume. The results suggest subclinical behavioral abnormalities in patients with NREM parasomnias. Such traits might trigger maladaptive emotion regulation processes related to a relative PCC volume increase. The findings encourage further longitudinal studies on this topic, which can provide insights into the causal relations underlying the PCC volume-behavior correlation. Such future studies will have a more direct implication for the clinical management of patients with NREM parasomnias.

Seizures with paroxysmal arousals in sleep-related hypermotor epilepsy (SHE): Dissecting epilepsy from NREM parasomnias.

Sleep-related hypermotor epilepsy (SHE) is a focal epilepsy characterized by seizures occurring mostly during sleep, ranging from brief seizures with paroxysmal arousals (SPAs) to hyperkinetic seizures and ambulatory behaviors. SPAs are brief and stereotypic seizures representing the beginning of a major seizure. Distinguishing SPAs from disorders of arousal (DOAs) and their briefest episodes called simple arousal movements (SAMs) is difficult. We performed a characterization of SPAs and SAMs to identify video-polysomnographic (VPSG) features that can contribute to the diagnosis of SHE or DOA. Fifteen SHE, 30 DOA adult patients, and 15 healthy subjects underwent full-night VPSG. Two neurologist experts in sleep disorders and epilepsy classified all the sleep-related movements and episodes recorded. For each SPAs and SAMs, sleep stage at onset, duration, limb involvement, progression, and semiology have been identified. A total of 121 SPAs were recorded, emerging mostly during stage 1-2 non-rapid eye movement (NREM) sleep (median duration: 5seconds). At the beginning, the SPAs motor pattern was hyperkinetic in 78 cases (64%), involving more than three non-contiguous or all body parts. The standard was a constant progression of movements during SPAs without any motor arrests. In DOA patients a total of 140 SAMs were recorded (median duration: 12seconds) mostly emerging during stage 3 NREM sleep. In SAMs, we did not observe any tonic/dystonic or hypermotor patterns or stereotypy; motor arrest was present over the course of about half of the episodes. In comparison with both DOA and healthy subjects, SHE patients showed a higher number of sleep-related movements per night and a reduction of sleep efficiency. SPAs and SAMs present different semiological and clinical features. Their recognition could be useful to drive the diagnosis when major episodes are not recorded during VPSG in patients with a clear clinical history of SHE or DOA.

The potential role of micro-RNA-211 in the pathogenesis of sleep-related hypermotor epilepsy

Sleep-related hypermotor epilepsy (SHE) is a rare epileptic syndrome characterized by epileptic seizures which occur during the non-rapid eye movement (NREM) stage of sleep. It manifests with hypermotor semiology resembling violent limb movements and an asymmetric tonic-dystonic posture. The genes which are responsible for the autosomal dominant form of SHE (ADSHE) and whose function is to code the sub-unit of the neuronal acetylcholine receptor are well known. Considering that ADSHE is a prototype of SHE, it is thought that the dysfunction of the cortico-subcortical cholinergic network, which regulates the cycle of sleep, has a key role in the epileptogenesis of this syndrome. Namely, studies to date, have shown that the hypercholinergic activity is sufficient for the development of epileptic seizures, even though the exact mechanism remains to be elucidated. NREM parasomnias are sleep disorders that are the most difficult to differentiate from SHE due to a similar clinical presentation. Considering the clinical similarities, NREM occurrence and probable genetic connection, it is considered that fundamentally, both of these conditions share a common pathophysiological mechanism i.e. cholinergic dysfunction. The main difference between SHE and NREM parasomnias are the genuine epileptic seizures that are responsible for the semiology in SHE. These genuine seizures are not present in NREM parasomnias. Why this is so, remains to be elucidated. Considering that animal studies have shown that dynamic changes and the decreased levels of microRNA-211 contribute to epileptic seizures and to changes in cholinergic pathways, our hypothesis is that epileptic seizures and the development of epileptogenesis in SHE are a consequence of cholinergic dysfunction and decreased levels of microRNA-211 as opposed to NREM parasomnias where there is a stable level of microRNA-211, preventing epileptogenesis despite the cholinergic system dysfunction.

1225 Sexsomnia: A Case of Sleep Masturbation And Sleeping In An Open Work Environment

Abstract Introduction Sleep sex or sexsomnia is classified in the International Classification of Sleep Disorders as a non-rapid eye movement (NREM) parasomnia. The overall prevalence is unknown but several conditions such as obstructive sleep apnea (OSA), shift work, and/or insufficient sleep have been reported as factors affecting the frequency of NREM parasomnias. Parasomnias, with sexsomnias in particular, can cause significant emotional distress to patients and their families. We present a case of co-morbid sexsomnia and OSA in a patient serving in the military that had the complicating factor of sleeping in open quarters. Report of Case A 40-year-old male in active duty military without significant past medical history or medication use presented to clinic with a two year history of disruptive sleep masturbation reported by wife. Patient’s wife reported no instances of attempted sexual intercourse. The patient had no recollection of the episodes. The frequency and nature of the episodes were causing personal and marital distress. Patient was also concerned about work responsibilities, since he was periodically required to sleep in open environments. After initial clinic evaluation, patient underwent a video polysomnography (vPSG) with an extended EEG montage. No parasomnia activity was captured on vPSG but patient was diagnosed with moderate OSA. He was started on continuous positive airway pressure (CPAP) therapy, resulting in decreased number of episodes with relapses corresponding to nights without CPAP usage. Conclusion Sexsomnia cases require careful history taking and evaluation. The nature of the episodes and the sleep environment of the patient must be examined for any medico-legal ramification as there are court precedents of sexual assault charges made in sexsomnia-related cases. The military environment is unique with group-sleeping conditions, often in austere environments. If sexsomnia were to be misinterpreted as indecent exposure, under the military code of conduct, this could have significant career implications.

Diagnosis and management of nonrapid eye movement-parasomnias.

Nonrapid eye movement (NREM) parasomnias are common sleep disorders that potentially have significant personal, social and forensic implications. They represent a unique opportunity in nature to explore the coexistence of sleep and wake-state in the human brain. Neuroimaging and electroencephalography have advanced our understanding of NREM-parasomnia pathophysiology, and the interplay between wakefulness and sleep. These disorders are increasingly viewed as resulting from an evolutionary process with a basis in uni-hemispheric brain activity in sleep seen in some animals, maintaining consciousness and ability to act against life-threatening situations. Although current classification of NREM parasomnia phenotypes distinguishes between disorders of arousal and other types of behaviours, evidence increasingly points to there being a significant overlap between the various phenotypes. Treatment practice appears more standardized nowadays based on larger case series, but randomized control trials are still needed. NREM-parasomnia is a very common disorder of uncertain pathogenesis but of known pathophysiology, the diagnosis of which remains primarily clinical.

Chapter 26 - Clinical neurophysiology of NREM parasomnias

The nonrapid eye movement (NREM) parasomnias range from age-related developmental phenomena in children to aggressive and injurious motor behaviors in all age groups. These parasomnias are commonly referred to as disorders of arousal and are an important cause of sleep-related injury. Genetic predisposition plays a role in the disorders of arousal, most evident in sleepwalking. Important concepts guiding our current understanding of the pathophysiology of the NREM parasomnias include sleep state instability (a propensity for arousal during NREM sleep), sleep inertia (incomplete awakening from NREM sleep), state dissociation (an ability to simultaneously straddle both NREM sleep and wakefulness), and activation of central pattern generators (permitting expression of subcortically determined motor behaviors without conscious higher cortical input). Management is multifaceted with an emphasis on education and nonpharmacologic measures. The purpose of this chapter is to review wake and NREM neurobiology and update our current understanding of NREM parasomnia pathophysiology, epidemiology, genetics, clinical features, precipitating factors, neurophysiologic evaluation, diagnosis, and clinical management.

Adult NREM Parasomnias: An Update.

Our understanding of non-rapid eye movement (NREM) parasomnias has improved considerably over the last two decades, with research that characterises and explores the causes of these disorders. However, our understanding is far from complete. The aim of this paper is to provide an updated review focusing on adult NREM parasomnias and highlighting new areas in NREM parasomnia research from the recent literature. We outline the prevalence, clinical characteristics, role of onset, pathophysiology, role of predisposing, priming and precipitating factors, diagnostic criteria, treatment options and medico-legal implications of adult NREM parasomnias.

Video polysomnographic findings in non-rapid eye movement parasomnia.

Although video polysomnography (vPSG) is not routinely recommended for the evaluation of typical cases of non‐rapid eye movement (NREM) parasomnias, it can aid diagnosis of unusual cases, other sleep disorders and complicated cases with REM behaviour disorder (RBD), and in differentiating parasomnias from epilepsy. In this study, we aimed to assess vPSG findings in consecutive patients with a clinical diagnosis of NREM‐parasomnia covering the whole phenotypic spectrum. Five hundred and twelve patients with a final diagnosis of NREM parasomnia who had undergone vPSG were retrospectively identified. vPSGs were analysed for features of NREM parasomnia and for the presence of other sleep disorders. Two hundred and six (40.0%) patients were clinically diagnosed with sleepwalking, 72 (14.1%) with sleep terrors, 39 (7.6%) with confusional arousals, 15 (2.9%) with sexsomnia, seven (1.4%) with sleep‐related eating disorder, 122 (23.8%) with mixed phenotype, and 51 (10.0%) with parasomnia overlap disorder (POD). The vPSG supported the diagnosis of NREM parasomnia in 64.4% of the patients and of POD in 98%. In 28.9% of the patients, obstructive sleep apnea (OSA) or/and periodic limb movements during sleep (PLMS) were identified, most commonly in older, male, sleepy and obese patients. vPSG has a high diagnostic yield in patients with NREM parasomnia and should be routinely performed when there is diagnostic doubt, or in patients where there is a suspicion of OSA and PLMS.

The Co-Occurrence of Sexsomnia, Sleep Bruxism and Other Sleep Disorders.

Background: Sleep sex also known as sexsomnia or somnambulistic sexual behavior is proposed to be classified as NREM (non-rapid eye movement) parasomnia (as a clinical subtype of disorders of arousal from NREM sleep—primarily confusional arousals or less commonly sleepwalking), but it has also been described in relation to REM (rapid eye movement) parasomnias. Methods: The authors searched the PubMed database to identify relevant publications and present the co-occurrence of sexsomnia and other sleep disorders as a non-systematic review with case series. Results: In the available literature the comorbidity of sexsomnia and other sleep disorders were reported mainly in case reports and less in case series. Sexsomnia was reported both with one and with multiple sleep-related disorders, with NREM parasomnias and obstructive sleep apnea (OSA) being the most commonly reported. Furthermore, the authors enrich the article with new findings concerning two novel cases of sleep bruxism triggering recurrent sexsomnia episodes. Conclusions: Sexsomnia has still not been reported in the literature as often as other parasomnias. The coexistence of sexsomnia and other sleep-related disorders should be more thoroughly examined. This could help both in sexsomnia as well as other sleep-related disorders management.

It's Not a Nightmare: Understanding Sleep Terrors.

Sleep terrors, one of the non-rapid eye movement parasomnias, are interesting nighttime phenomena that can be distressing for parents. For most children, this behavior is temporary and does not cause significant problems. However, some psychiatric conditions may have a higher prevalence of parasomnias, including sleep terrors. Although sleep terrors may be a benign and common event in children, a basic mental health examination should include a sleep-related screening to possibly identify underlying issues. Nurses must be knowledgeable about sleep terrors and able to provide education and support when parents share their concerns. [Journal of Psychosocial Nursing and Mental Health Services, 56(8), 11-14.].

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.