Somnambulism.

Somnambulism, also called sleepwalking, classified as a non-rapid eye movement sleep parasomnia, encompasses a range of abnormal paroxysmal behaviors, leading to sleepwalking in dissociated sleep in an altered state of consciousness with impaired judgment and configuring a kind of hierarchical continuum with confusional arousal and night terror. Despite being generally regarded as a benign condition, its potential severity entails social, personal, and even forensic consequences. This comprehensive review provides an overview on the current state of knowledge, elucidating the phenomenon of somnambulism and encompassing its clinical manifestations and diagnostic approaches.

Non-REM Sleep Parasomnias.

OBJECTIVE: Non-rapid eye movement (non-REM) parasomnias are common across the lifespan. This article describes the manifestations, diagnosis, and management of non-REM parasomnias in adults and discusses the social implications of these conditions. LATEST DEVELOPMENTS: Non-REM parasomnias represent a hybrid state of wakefulness and sleep, often triggered by events that increase the frequency of arousals or make it more difficult to fully arouse from sleep. Sleep deprivation, certain medications, and untreated obstructive sleep apnea are known to provoke parasomnias, particularly in those who are genetically predisposed. Non-REM parasomnias include disorders of arousal (ie, sleepwalking, sleep terrors, and confusional arousals), sleep-related eating disorder, and exploding head syndrome. Clinical overlap exists between sleep-related eating disorder and disorders of arousal, suggesting that sleep-related eating disorder may be a fourth disorder of arousal or a manifestation of sleepwalking. Exploding head syndrome is a unique parasomnia of uncertain etiology. ESSENTIAL POINTS: Non-REM parasomnias can range from minor nuisances to severe, life-altering events. While some patients with non-REM parasomnia experience significant consequences during sleep, wakefulness, or both, non-REM parasomnias do not pose a major risk to most patients. For all patients with non-REM parasomnias, safety should be explicitly discussed and addressed. Nonpharmacologic treatment should be prioritized, as increasing total sleep time, avoiding triggering substances, and treating comorbid sleep disorders is often sufficient for the management of non-REM parasomnias. If symptoms persist despite these interventions, treatment with clonazepam or other medications can be considered.

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.

Sleepwalking, sleep terrors, sexsomnia and other disorders of arousal: the old and the new.

Disorders of arousal (DOA) is an umbrella term initially covering classical sleepwalking, sleep terrors, and confusional arousals, and now including a wider spectrum of specialised forms of non rapid eye movement (non REM) parasomnias such as sexsomnia, sleep-related eating disorder, and sleep-related choking syndrome. Growing evidence has shown that DOA are not restricted to children but are also prevalent in adults (2%-4% of the adult population). While DOA run in family, genetics studies remain scarce and inconclusive. In addition to the risk of injury on themselves and others (including sexual assaults in sexsomnia), adults with DOA frequently suffer from excessive daytime sleepiness, pain, and altered quality of life. The widespread view of DOA as automatic and amnesiac behaviours has now been challenged by subjective (dream reports) and objective (dream-enacting behaviours documented on video-polysomnography) observations, suggesting that sleepwalkers are 'dream walking' during their episodes. Behavioural, experiential, cognitive, and brain (scalp electroencephalography [EEG], stereo-EEG, high density-EEG, functional brain imaging) data converge in showing a dissociated pattern during the episodes. This dissociated pattern resembles the new concept of local arousal with a wake-like activation in motor and limbic regions and a preserved (or even increased) sleep intensity over a frontoparietal network. EEG and behavioural criteria supporting the DOA diagnosis with high sensitivity and specificity are now available. However, treatment is still based on controlling priming and precipitating factors, as well as on clinicians' personal experience with sedative drugs. Placebo-controlled trials are needed to improve patients' treatment. DOA deserve more attention from sleep researchers and clinicians.

Dissociation of motor control from motor awareness in awake sleepwalkers: An EEG study in virtual reality.

Recent behavioral evidence from a virtual reality (VR) study indicates that awake sleepwalkers show dissociation of motor control and motor awareness. This dissociation resembles the nocturnal disintegration of motor awareness and movement during episodes of sleepwalking. Here, we set out to examine the neural underpinnings of altered motor awareness in sleepwalkers by measuring EEG modulation during redirected walking in VR. To this end, we measured scalp EEG during ongoing motor behavior to provide information on motor processing and its modulation in VR. Using this approach, we discovered distinct EEG patterns associated to dual tasking and sub-threshold motor control in sleepwalkers compared to control subjects. These observations provide further electrophysiological evidence for the proposed brain-body dissociation in awake sleepwalkers. This study shows proof-of-principle that EEG biomarkers of movement in a VR setting add to the understanding of altered motor awareness in sleepwalkers. In a broader perspective, we confirm the feasibility of using the additional dimensionality in VR providing novel diagnostic biomarkers not accessible to conventional clinical investigations. In future studies, this approach could contribute to the diagnostic work-up of patients with a broad spectrum of neurological diseases.

Self-reported developmental changes in the frequency and characteristics of somnambulistic and sleep terror episodes in chronic sleepwalkers.

BACKGROUND: Far from being benign, somnambulistic episodes can be frequent and/or severe and potentially injurious. Episodes may also be accompanied by sleep mentation with variable degrees of retrograde amnesia. The present study investigated how somnambulistic episodes unfold from childhood through adulthood, a topic that remains understudied. METHODS: Adult sleepwalkers with a diagnosis of primary somnambulism and a childhood onset of the disorder (n = 113) were assessed for changes in frequency of their episodes, recall of episode-related sleep mentation and aggressive episodes during childhood, adolescence and adulthood. In addition, sleepwalkers (n = 52) with childhood-onset of sleep terrors were assessed for developmental changes in sleep terror frequency. RESULTS: Results indicate that the frequency of somnambulistic episodes remains unchanged during childhood and adolescence before increasing during adulthood. An opposite trend was observed for sleep terrors. The frequency of aggressive somnambulistic episodes and of sleep mentation associated with somnambulism increased from childhood to adolescence and into adulthood. By contrast, the recall of sleep mentation associated with sleep terrors did not change over time. Additionally, a higher frequency of aggressive somnambulistic episodes predicted a higher frequency of sleep mentation associated with somnambulism. These patterns were similar across men and women. CONCLUSION: Our study demonstrates that in chronic sleepwalkers, sleep mentation associated with somnambulistic episodes increases with age while episodes worsen in frequency and severity from childhood to adulthood. These findings add to the limited literature in the field and provide valuable insights into how key clinical characteristics of somnambulism evolve across the lifespan.

Disorders of arousal in 4 older men: evidence from clinical practice.

STUDY OBJECTIVES: To describe clinical and video-polysomnographic features of disorders of arousal (DoA) in older adults. METHODS: Four consecutive male patients with nocturnal motor behaviors underwent a clinical interview, neurologic examination, laboratory tests, brain magnetic resonance imaging, and nocturnal in-laboratory or 24- to 48-hour home video polysomnography. The patients repeated an evaluation after 6 months of follow-up, including a 48-hour home video polysomnography in 2 patients. RESULTS: The patients were aged 65-72 years, and 1 patient has Parkinson disease. Sleep-related behavioral episodes had begun from 12-55 years before our observation. Three patients presented with a positive family history for DoA. Sleep motor episodes were described as suddenly raising the head or trunk, sitting in bed, screaming, speaking, gesturing, and sleepwalking (in 1 patient). When questioned, all patients seemed confused, rarely reporting any dream-like content. We recorded 25 DoA episodes of different intensity and complexity arising from nonrapid eye movement sleep. The semiology of the episodes was similar to that described in younger patients, consisting of sleep terrors and confusional arousals. All patients presented with physiological rapid eye movement sleep muscle atonia. Medication therapy reduced the frequency of the episodes in 2/4 patients. CONCLUSIONS: DoA may begin in adulthood and persist or arise in older adults, sometimes causing sleep-related injuries. Motor patterns of DoA in older adults are similar to those of younger patients. A combined clinical examination and video polysomnography recording are crucial in establishing a definitive diagnosis of nocturnal motor behavior in all older adults and especially in those affected by neurodegenerative diseases. CITATION: Loddo G, Fragiacomo F, Mainieri G, et al. Disorders of arousal in 4 older men: evidence from clinical practice. J Clin Sleep Med. 2022;18(1):129-136.

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.

The Arousal Disorders Questionnaire: a new and effective screening tool for confusional arousals, Sleepwalking and Sleep Terrors in epilepsy and sleep disorders units.

BACKGROUND: Arousal Disorders (DoA) include Confusional Arousals, Sleepwalking and Sleep Terrors. DoA diagnosis is mainly clinical but no validated questionnaires exist for DoA screening according to the criteria of the International Classification of Sleep Disorders, Third Edition. Recently our group proposed the Arousal Disorders Questionnaire (ADQ) as a new diagnostic tool for DoA diagnosis. The objective of this study was to evaluate the diagnostic accuracy of the ADQ in a sleep and epilepsy center. METHODS: One interviewer blinded to clinical and video-polysomnographic (VPSG) data administered the ADQ to 150 patients consecutively admitted to our Sleep and Epilepsy Centers for a follow-up visit. The final diagnosis, according to VPSG recordings of at least one major episode, classified patients either with DoA (DoA group) or with other sleep-related motor behaviors confounding for DoA (nDoA group). RESULTS: 47 patients (31%) composed the DoA group; 56 patients with REM sleep behavior disorder, 39 with sleep-hypermotor epilepsy, six with night eating syndrome, and two with drug-induced DoA composed the nDoA group. The ADQ had a sensitivity of 72% (95% CI: 60-82) and a specificity of 96% (95% CI: 89-98) for DoA diagnosis; excluding the items regarding consciousness and episode recall, sensitivity was 83% (95% CI: 71-90) and specificity 93% (95% CI: 86-97). CONCLUSIONS: The ADQ showed good accuracy in screening patients with DoA in a sleep and epilepsy center setting. Diagnostic criteria related to cognition and episode recall reduced ADQ sensitivity, therefore a better definition of these criteria is required, especially in adults.

Night Stepping: Fitbit Cracks the Case.

ABSTRACT: The most common sleep disorders that can result in injurious or violent behaviors include REM sleep behavioral disorder, sleepwalking, comorbid parasomnias, sleep-related dissociative disorder, and obstructive sleep apnea. Video polysomnography is usually indicated to evaluate recurring sleep-related injury in adults. Only one-third of patients with complex paroxysmal nocturnal events will have one of their habitual events on a single night of in-laboratory video polysomnography, most often those who have prominent, high-frequency motor features. We report evidence of sleep walking induced by sodium oxybate identified by steps recorded on a consumer wearable device coinciding with clinical history and evidence of injury.

Diagnostic criteria for disorders of arousal: A video-polysomnographic assessment.

OBJECTIVE: To assess video-polysomnographic (vPSG) criteria and their cutoff values for the diagnosis of disorders of arousal (DOAs; sleepwalking, sleep terror). METHODS: One hundred sixty adult patients with DOAs and 50 sex- and age-matched healthy participants underwent a clinical evaluation and vPSG assessment to quantify slow wave sleep (SWS) interruptions (SWS fragmentation index, slow/mixed and fast arousal ratios, and indexes per hour) and the associated behaviors. First, a case-control analysis was performed in 100 patients and the 50 controls to define the optimal cutoff values using receiver operating characteristic curves. Their sensitivity was then assessed in the other 60 patients with DOAs. RESULTS: The SWS fragmentation index and the mixed, slow, and slow/mixed arousal indexes and ratios were higher in patients with DOAs than controls. The highest area under the curve (AUC) values were obtained for the SWS fragmentation and slow/mixed arousal indexes (AUC = 0.88 and 0.90, respectively). The SWS fragmentation index cutoff value of 6.8/h reached a sensitivity of 79% and a specificity of 82%. The slow/mixed arousal index had a sensitivity of 94% for the 2.5/h cutoff, and 100% specificity for 6/h. Both parameters showed good interrater agreement, and their sensitivities were confirmed in the second group of patients. Combining electroencephalographic parameters and video-based behavioral analyses increased the correct classification rate up to 91.3%. INTERPRETATION: Frequent slow/mixed arousals in SWS and complex behaviors during vPSG are strongly associated with DOAs, and could be promising biomarkers for the diagnosis of non-rapid eye movement parasomnias. Ann Neurol 2018;83:341-351.

Specific motor patterns of arousal disorders in adults: a video-polysomnographic analysis of 184 episodes.

OBJECTIVE: To compile an objective accurate description of the motor patterns of adult arousal disorders (ADs). METHODS: We reviewed 59 nocturnal video-polysomnographic (VPSG) recordings of 30 adult patients (>15 years) with a history of sleepwalking (SW). We scrutinized the semeiology of all 184 episodes recorded, classifying them into three groups according to three semeiological motor patterns characterized by increasing intensity and complexity: simple arousal movements (pattern I), characterized by head flexion/extension, head flexion/extension and limb movement or head flexion/extension and partial trunk flexion/extension; rising arousal movements (pattern II), characterized by a complete trunk flexion with patient sitting up in bed; and complex arousal with ambulatory movements (pattern III) characterized by SW. The VPSG recordings were compared to those of 10 healthy controls. RESULTS: AD patients presented with 169 pattern I, 37 pattern II, and nine pattern III episodes. Pattern I developed into pattern II in 17 cases and into pattern II followed by pattern III in five patients. Pattern II developed into pattern III in four patients. Onset was abrupt in 55% of the episodes. Episodes lasted a mean (±standard deviation) of 33 ± 35 s. Movements tended to halt temporarily during 72% of the episodes. We recorded 248 movements during sleep in the healthy controls, none of whom presented with AD patterns. CONCLUSION: We identified three specific motor patterns in AD patients not previously reported and not observed in healthy controls. Identification of these patterns could be important for diagnosis and serve as the basis for a new definition of AD in adults.

Sexsomnia: A Specialized Non-REM Parasomnia?

Introduction: To describe patients with sexsomnia and to contrast their clinical and sleep measures with those of healthy controls and sleepwalkers. Aims and Methods: Subjects referred for sexsomnia and for sleepwalking/night terror were interviewed, completed the Paris Arousal Disorder Severity Scale (PADSS), and were monitored 1-2 nights with video-polysomnography. Results: Seventeen patients (70.6% male, aged 17-76 years) had sexsomnia, with amnestic fondling of the bed partner (n = 11), complete sexual intercourse (n = 8), masturbation (n = 8), and spontaneous orgasm (n = 1). The sexual behaviors were more direct during sleep than during wakefulness (n = 12), leading to 6 sexual assaults, including intra-conjugal rape (n = 3), assault of a family member (n = 2), rape of a friend (n = 1), and forensic consequences (n = 2). In 47% of sexsomnia patients, there was a history or current occurrences of sleepwalking/night terrors. Patients with sexsomnia had more N3 awakenings than healthy matched controls and the same amount as regular sleepwalkers. Half of them presented evidence of cortico-cortical dissociation, including concomitant slow (mostly frontal) and rapid (mostly temporal and occipital) electroencephalography (EEG) rhythms, with concomitant N3 penile erection in 1 case. Of 89 sleepwalkers, 10% had previous episodes of amnestic sexual behaviors, with a higher PADSS-A score and a trend of a higher total PADSS score than the 80 sleepwalkers without sexsomnia. Conclusion: In this single-center series, we confirmed the male predominance of sexsomnias and its potential for severe clinical and forensic consequences. The results suggest a continuum of regular sleepwalking, sleepwalking with occasional sexsomnia, and quasi-exclusive sexsomnia.

[REM-sleep behavior disorder and sleepwalking in a patient with Parkinson's disease and essential tremor]. / Rasstroistvo povedeniia v faze bystrogo sna i snokhozhdenie u patsienta s nachal'noi bolezn'iu Parkinsona i éssentsial'nym tremorom.

REM-sleep behavior disorder (RBD), a form of parasomnia, is characterized by motor and/or speech activity during sleep corresponding to the dream content. RBD is currently considered as a marker of onset of neurodegenerative diseases (sinucleinopathies) and as a most specific early symptom of Parkinson's disease (PD). The authors describe a clinical case of a patient with the combination of essential tremor, initial signs of PD and RBD. A polysomnographic study has confirmed clinical signs of RBD and determined the disturbances of sleep architecture: the increase in falling asleep, number of awakenings, wakefulness during sleep, the absence of deep slow-wave sleep. The particular features of the patient were essential tremor and sleep walking.

Scalp and Source Power Topography in Sleepwalking and Sleep Terrors: A High-Density EEG Study.

STUDY OBJECTIVES: To examine scalp and source power topography in sleep arousals disorders (SADs) using high-density EEG (hdEEG). METHODS: Fifteen adult subjects with sleep arousal disorders (SADs) and 15 age- and gender-matched good sleeping healthy controls were recorded in a sleep laboratory setting using a 256 channel EEG system. RESULTS: Scalp EEG analysis of all night NREM sleep revealed a localized decrease in slow wave activity (SWA) power (1-4 Hz) over centro-parietal regions relative to the rest of the brain in SADs compared to good sleeping healthy controls. Source modelling analysis of 5-minute segments taken from N3 during the first half of the night revealed that the local decrease in SWA power was prominent at the level of the cingulate, motor, and sensori-motor associative cortices. Similar patterns were also evident during REM sleep and wake. These differences in local sleep were present in the absence of any detectable clinical or electrophysiological sign of arousal. CONCLUSIONS: Overall, results suggest the presence of local sleep differences in the brain of SADs patients during nights without clinical episodes. The persistence of similar topographical changes in local EEG power during REM sleep and wakefulness points to trait-like functional changes that cross the boundaries of NREM sleep. The regions identified by source imaging are consistent with the current neurophysiological understanding of SADs as a disorder caused by local arousals in motor and cingulate cortices. Persistent localized changes in neuronal excitability may predispose affected subjects to clinical episodes.

Sleepwalking episodes are preceded by arousal-related activation in the cingulate motor area: EEG current density imaging.

OBJECTIVE: To investigate local arousal fluctuations in adults who received ICSD-2 diagnosis of somnambulism. METHODS: EEG neuroimaging (eLORETA) was utilized to compare current density distribution for 4s epochs immediately preceding sleepwalking episode (from -4.0 s to 0 s) to the distribution during earlier 4s epochs (from -8.0 s to -4.0 s) in 20 EEG segments from 15 patients. RESULTS: Comparisons between eLORETA images revealed significant (t>4.52; p<0.05) brain activations before onset of sleepwalking, with greater current density within beta 3 frequency range (24-30 Hz) in Brodmann areas 33 and 24. CONCLUSIONS: Sleepwalking motor events are associated with arousal-related activation of cingulate motor area. SIGNIFICANCE: These results support the notion of blurred boundaries between wakefulness and NREM sleep in sleepwalking.