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

Temporal dynamics of awakenings from slow-wave sleep in non-rapid eye movement parasomnia

Non-rapid eye movement parasomnia disorders, also called disorders of arousal, are characterized by abnormal nocturnal behaviours, such as confusional arousals or sleep walking. Their pathophysiology is not yet fully understood, and objective diagnostic criteria are lacking. It is known, however, that behavioural episodes occur mostly in the beginning of the night, after an increase in slow-wave activity during slow-wave sleep. A better understanding of the prospect of such episodes may lead to new insights in the underlying mechanisms and eventually facilitate objective diagnosis. We investigated temporal dynamics of transitions from slow-wave sleep of 52 patients and 79 controls. Within the patient group, behavioural and non-behavioural N3 awakenings were distinguished. Patients showed a higher probability to wake up after an N3 bout ended than controls, and this probability increased with N3 bout duration. Bouts longer than 15 min resulted in an awakening in 73% and 34% of the time in patients and controls, respectively. Behavioural episodes reduced over sleep cycles due to a reduction in N3 sleep and a reducing ratio between behavioural and non-behavioural awakenings. In the first two cycles, N3 bouts prior to non-behavioural awakenings were significantly shorter than N3 bouts advancing behavioural awakenings in patients, and N3 awakenings in controls. Our findings provide insights in the timing and prospect of both behavioural and non-behavioural awakenings from N3, which may result in prediction and potentially prevention of behavioural episodes. This work, moreover, leads to a more complete characterization of a prototypical hypnogram of parasomnias, which could facilitate diagnosis.

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.

Challenges in diagnosing NREM parasomnias: Implications for future diagnostic classifications

NREM parasomnias are frequent and potentially disabling sleep disorders characterized by recurrent abnormal behaviors emerging from NREM sleep. Recently, several studies provided more detailed clinical and polysomnographic characterization of NREM parasomnia which may enhance the diagnostic process. Several revisions of the diagnostic criteria have been proposed in the classification of sleep disorders, the latest being ICSD-3-TR in 2023 with no changes on NREM parasomnias since ICSD-3 published in 2014. We performed an extensive literature review to assess the evidence on the procedure of its diagnosis. We dissected the inconsistencies and shortcomings in the ICSD-3-TR to propose a revision of the current diagnostic criteria. We highlighted the limits of several clinical criteria which should rather be supportive features than mandatory criteria. Infrared cameras with video-recordings with are promising tools to precisely characterize home episodes. Sensitive and specific polysomnographic markers of NREM parasomnias have been identified and should be considered in future revisions. We also suggest the use of diagnostic specifiers (clinical subtypes, clinical significance, levels of severity, age effect, levels of certainty) to define homogeneous subgroups of patients for therapeutic intervention and research purposes. In conclusion, we advocate for significant changes in the current diagnostic criteria of NREM parasomnias for future classification.

Fearful arousals in sleep terrors and sleep-related hypermotor epileptic seizures may involve the salience network and the acute stress response of Cannon and Selye

We consider the disorders of arousal and sleep-related hypermotor epilepsy as genetic twin-conditions, one without, one with epilepsy. They share an augmented arousal-activity during NREM sleep with sleep-wake dissociations, culminating in sleep terrors and sleep-related hypermotor seizures with similar symptoms. The known mutations underlying the two spectra are different, but there are multifold population-genetic-, family- and even individual (the two conditions occurring in the same person) overlaps supporting common genetic roots. In the episodes of disorders of arousal, the anterior cingulate, anterior insular and pre-frontal cortices (shown to be involved in fear- and emotion processing) are activated within a sleeping brain. These regions overlap with the seizure-onset zones of successfully operated sleep-related hypermotor seizures, and notably, belong to the salience network being consistent with its hubs. The arousal-relatedness and the similar fearful confusion occurring in sleep terrors and hypermotor seizures, make them alike acute stress-responses emerging from sleep; triggered by false alarms. The activation of the anterior cingulate, prefrontal and insular regions in the episodes of both conditions, can easily mobilize the hypothalamo-pituitary-adrenal axis (preparing fight-flight responses in wakefulness); through its direct pathways to and from the salience network. This hypothesis has never been studied.

Sleep and epilepsy: A clinical and pathophysiological overview

The interaction between sleep and epilepsy is complex. A better understanding of the mechanisms linking sleep and epilepsy appears increasingly important as it may improve diagnosis and therapeutic strategies in patients with epilepsy. In this narrative review, we aim to (i) provide an overview of the physiological and pathophysiological processes linking sleep and epilepsy; (ii) present common sleep disorders in patients with epilepsy; (iii) discuss how sleep and sleep disorders should be considered in new therapeutic approaches to epilepsy such as neurostimulation; and (iv) present the overall nocturnal manifestations and differential diagnosis between epileptic seizures and parasomnia.

Nocturnal agitation: From sleep state dissociation to sleep-related dissociative state

Nocturnal agitation refers to a broad spectrum of symptoms from simple movements to aggressive behaviors with partial or complete loss of awareness. An accurate identification of its etiology is critical for appropriate therapeutic intervention. In children and young adults, distinguishing between non-rapid eye movement (NREM) sleep parasomnias and psychogenic non-parasomniac manifestations, a condition known as sleep-related dissociative disorder (SRDD), can be challenging. This review aims to summarize current clinical, neurophysiological, and epidemiological knowledge on NREM parasomnia and SRDD, and to present the pathophysiological hypotheses underlying these nocturnal manifestations. Sleepwalking, sleep terror and confusional arousals are the three main presentations of NREM parasomnias and share common clinical characteristics. Parasomniac episodes generally occur 30minutes to three hours after sleep-onset, they are usually short, lasting no more than few minutes and involve non-stereotyped, clumsy behaviors with frequent amnesia. The prevalence of NREM parasomnia decreases from 15-30% in children to 2-4% in adults. Parasomniac episodes are incomplete awakening from the deepest NREM sleep and are characterized by a dissociated brain activity, with a wake-like activation in motor and limbic structures and a preserved sleep in the fronto-parietal regions. SRDD is a less known condition characterized by dramatic, often very long episodes with frequent aggressive and potentially dangerous behaviors. SRDD episodes frequently occur in quiet wakefulness before falling asleep. These dissociative manifestations are frequently observed in the context of psychological trauma. The pathophysiology of SRDD is poorly understood but could involve transient changes in brain connectivity due to labile sleep-wake boundaries in predisposed individuals. We hypothesize that SRDD and NREM parasomnia are forms of sleep-related dissociative states favored by a sleep-wake state dissociation during sleep-onset and awakening process, respectively.

Home nocturnal infrared video to record non-rapid eye movement sleep parasomnias

To assess the feasibility, the acceptability and the usefulness of home nocturnal infrared video in recording the frequency and the complexity of non-rapid eye movement sleep parasomnias in adults, and in monitoring the treatment response. Twenty adult patients (10 males, median age 27.5 years) with a diagnosis of non-rapid eye movement parasomnia were consecutively enrolled. They had a face-to-face interview, completed self-reported questionnaires to assess clinical characteristics and performed a video-polysomnography in the Sleep Unit. Patients were then monitored at home during at least five consecutive nights using infrared-triggered cameras. They completed a sleep diary and questionnaires to evaluate the number of parasomniac episodes at home and the acceptability of the home nocturnal infrared video recording. Behavioural analyses were performed on home nocturnal infrared video and video-polysomnography recordings. Eight patients treated by clonazepam underwent a second home nocturnal infrared video recording during five consecutive days. All patients had at least one parasomniac episode during the home nocturnal infrared video monitoring, compared with 75% during the video-polysomnography. A minimum of three consecutive nights with home nocturnal infrared video was required to record at least one parasomniac episode. Most patients underestimated the frequency of episodes on the sleep diary compared with home nocturnal infrared video. Episodes recorded at home were often more complex than those recorded during the video-polysomnography. The user-perceived acceptability of the home nocturnal infrared video assessment was excellent. The frequency and the complexity of the parasomniac episodes decreased with clonazepam. Home nocturnal infrared video has good feasibility and acceptability, and may improve the evaluation of the phenotype and severity of the non-rapid eye movement parasomnias and of the treatment response in an ecological setting.

Diagnosis and Management of NREM Sleep Parasomnias in Children and Adults

Non-rapid eye movement (NREM) sleep parasomnias are recurrent abnormal behaviors emerging as incomplete arousals out of NREM sleep. Mounting evidence on NREM sleep parasomnias calls for an update of clinical and therapeutical strategies. In the current review, we summarize the state of the art and provide the necessary background to stimulate a critical revision of diagnostic criteria of disorders of arousal (DoA), the most common NREM sleep parasomnia. In particular, we highlight the poor sensitivity of the diagnostic items related to amnesia and absence of conscious experiences during DoA episodes, encourage the role of video-polysomnography and home-video recordings in the diagnostic and treatment work-up, and suggest three levels of diagnostic certainty based on clinical and objective findings. Furthermore, we highlight current gaps of knowledge that prevent the definition of standard guidelines and future research avenues.

Violent and Complex Behaviors and Non-Restorative Sleep Are the Main Features of Disorders of Arousal in Adulthood: Real Picture or a More Severe Phenotype?

Disorders of arousal (DoA) are NREM parasomnias characterized by motor and emotional behaviors emerging from incomplete arousals from deep sleep. DoA are largely present in pediatric populations, a period during which they are labeled as self-limited manifestations. However, an extensive literature has shown that DoA can persist in adulthood, with different characteristics from childhood DoA. Adult DoA patients usually report excessive daily sleepiness, sleep-related violence during DoA episodes or potentially harmful behaviors, which are rare in childhood. The semeiological features of DoA episodes in adulthood may complicate differential diagnoses with other motor manifestations during sleep, in particular sleep-related hypermotor epilepsy. However, it cannot be excluded that adults with DoA attending sleep centers constitute a more severe phenotype, thus not being representative of adult DoA in the general population. Video-polysomnographic studies of DoA document a spectrum of motor patterns of different complexities, the simplest of which may often go unnoticed. Despite the different complexities of the episodes, neurophysiologic studies showed the co-existence of deep sleep and wakefulness during DoA episodes or even before their onset. These aspects make DoA an ideal model to investigate the mechanisms regulating local sleep, sleep arousal and cognitive functions including spatial and temporal orientation, attention or memory.

Neuropsychological and Behavioral Profile in Sleep-Related Hypermotor Epilepsy (SHE) and Disorders of Arousal (DOA): A Multimodal Analysis

STUDY OBJECTIVES

Disorder of arousal (DOA) and sleep-related hypermotor epilepsy (SHE) are complex, often bizarre, involuntary sleep behaviors, whose differential diagnosis may be challenging because they share some clinical features, such as sleep fragmentation. Mounting evidence highlights the critical role of sleep in cognitive functions. Controversial findings are raised about the cognitive profile in SHE; however, no studies have investigated the cognitive profile in DOA. This study aimed to assess whether sleep instability affects cognitive functions in patients with SHE or DOA.

METHODS

This study analyzed 11 patients with DOA, 11 patients with SHE, and 22 healthy controls (HC). They underwent full-night video polysomnography (vPSG) and comprehensive neuropsychological and behavioral evaluation. Differences in the variables of interest among the SHE group, DOA group, and their respective control groups were evaluated. The auto-contractive map (auto-CM) system was used to evaluate the strength of association across the collected data.

RESULTS

The SHE group had reduced sleep efficiency and increased wake after sleep onset (WASO); both the SHE and DOA groups showed increased % of N2 and REM sleep compared to the HC group. Neuropsychological and behavioral evaluations showed a different cognitive profile in the SHE group with respect to the HC group. The auto-CM showed that Pittsburgh Sleep Quality Index (PSQI), Beck depression inventory (BDI), MWCST_PE, Epworth sleepiness scale (ESS), WASO, N1, and % REM were strictly correlated with SHE, whereas the SE and arousal index (AI) were strictly related to DOA.

CONCLUSIONS

Patients with SHE and DOA present different cognitive and psychiatric profiles, with subtle and selective cognitive impairments only in those with SHE, supporting the discriminative power of cognitive and psychiatric assessment in these two conditions.

NREM Sleep Parasomnias Commencing in Childhood: Trauma and Atopy as Perpetuating Factors

Objective/Background: Phenotyping of non-rapid-eye-movement (NREM) parasomnias is currently poorly undertaken. This study aimed to determine whether there are differences phenotypically among childhood-, adolescent-, and adult-onset NREM parasomnias continuing into and presenting in adulthood. Patients/Methods: A retrospective, cohort study of patients presenting with NREM parasomnia between 2008 and 2019 (n = 307) was conducted. Disorders included sleepwalking (n = 231), night terrors (n = 150), sexualised behaviour in sleep (n = 50), and sleep-related eating disorder (n = 28). Results: Compared to the adult-onset NREM behaviours group, the childhood- and adolescent-onset groups were more likely to have a family history of NREM behaviours (p < 0.001), experience a greater spectrum of NREM disorders (p = 0.001), and report a history of sleep-talking significantly more frequently (p = 0.014). Atopy was most prevalent in the childhood-onset group (p = 0.001). Those with childhood-onset NREM parasomnias were significantly more likely to arouse from N3 sleep on video polysomnography (p = 0.0003). Psychiatric disorders were more likely to be comorbid in the adult-onset group (p = 0.012). A history of trauma coinciding with onset of NREM behaviours was significantly more common in the childhood- and adolescent-onset groups (p < 0.001). Conclusions: Significant differences exist across childhood-, adolescent-, and adult-onset NREM parasomnia presenting in adulthood. This study suggests that adult-onset slow-wave sleep disorders may be confounded by psychiatric disorders resulting in nocturnal sleep disruption and that unresolved traumatic life experiences perpetuate NREM disorders arising in childhood and comprise one of the strongest external risk factors for triggering and perpetuating these disorders in adolescence.

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.

Sleep and epilepsy: A snapshot of knowledge and future research lines

Sleep and epilepsy have a reciprocal relationship, and have been recognized as bedfellows since antiquity. However, research on this topic has made a big step forward only in recent years. In this narrative review we summarize the most stimulating discoveries and insights reached by the "European school." In particular, different aspects concerning the sleep-epilepsy interactions are analysed: (a) the effects of sleep on epilepsy; (b) the effects of epilepsy on sleep structure; (c) the relationship between epilepsy, sleep and epileptogenesis; (d) the impact of epileptic activity during sleep on cognition; (e) the relationship between epilepsy and the circadian rhythm; (f) the history and features of sleep hypermotor epilepsy and its differential diagnosis; (g) the relationship between epilepsy and sleep disorders.

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.

EEG Activation Does Not Differ in Simple and Complex Episodes of Disorders of Arousal: A Spectral Analysis Study

PURPOSE

Disorders of arousal (DoA) are characterized by incomplete awakening from NREM sleep, with the admixture of both deep sleep and wake EEG activity. Previous observations suggested that changes in EEG activity could be detected in the seconds preceding DoA episodes. The aims of this work were to characterize the topography of EEG spectral changes prior to DoA episodes and to investigate whether or not behavioral complexity could be predicted by changes in EEG immediately preceding behavioral onsets.

PATIENTS AND METHODS

We collected 103 consecutive video-polysomnographic recordings of 53 DoA adult patients and classified all episodes as simple, rising and complex arousal movements. For each episode, a 5-second window preceding its motor onset ("pre-event") and a 60-second window from 2 to 3 minutes before the episodes ("baseline") were compared. Subsequently, a between-group comparison was performed for the pre-event of simpler versus the more complex episodes.

RESULTS

Spectral analysis over 325 DoA episodes showed an absolute significant increase prior to DoA episodes in all frequency bands excluding sigma, which displayed the opposite effect. In normalized maps, the increase was relatively higher over the central/anterior areas for both slow and fast frequency bands. No significant differences emerged from the comparison between simpler and more complex episodes.

CONCLUSION

Taken together, these results show that deep sleep and wake-like EEG rhythms coexist over overlapping areas before DoA episodes, suggesting an alteration of local sleep mechanisms. Episodes of different complexity are preceded by a similar EEG activation, implying that they possibly share a similar pathophysiology.

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.

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

Over 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.

A lack of specific motor patterns between rhythmic/non-rhythmic masticatory muscle activity and bodily movements in sleep bruxism

Purpose The aims of the present study were to investigate the temporal relationships between jaw and bodily movements and clarify motor processes in the genesis of rhythmic masticatory muscle activity (RMMA) in sleep bruxism (SB).Methods Video-polysomnography recordings were obtained from ten subjects with SB (mean age: 23.4 ± 1.6 years) and ten matched normal controls (CTL) (mean age: 24.4 ± 3.2 years). RMMA and nonspecific masseter activity (NSMA) were scored in association with bodily movements in the leg, arm, head, and trunk using electromyography and video recordings. The relationship between oromotor episodes and bodily movements was assessed in terms of sleep stage distributions and temporal relationships. Cardiac changes preceding oromotor episodes in stage N2 were assessed.Results Approximately 80% of RMMA and NSMA were associated with movements in one or more body sites. RMMA and NSMA were more frequently associated with movements of the leg (70-75%) and arm (40-55%) than movements of the head (17-22%) and trunk (5-25%). The relationship between oromotor episodes and bodily movements did not significantly differ among sleep stages. Oromotor episodes and bodily movements did not show a consistent temporal pattern in the SB and CTL groups. Regardless of the temporal relationship between oromotor episodes and bodily movements, the mean heart rate significantly increased by 5 beats before the onset of oromotor episodes.Conclusions No specific temporal motor patterns were found between RMMA and bodily movements. RMMA and NSMA represent a repertoire of arousal-related autonomic motor responses during sleep.

Sleep-Related Hypermotor Epilepsy vs Disorders of Arousal in Adults: A Step-Wise Approach to Diagnosis

Disorders of arousal (DoA) and sleep-related hypermotor epilepsy (SHE) are sleep-related events characterized by complex, often bizarre, and violent behaviors. DoA are involuntary motor manifestations of various complexities occurring during incomplete awakening from non-rapid eye movement sleep. SHE is a focal epilepsy characterized by stereotyped hyperkinetic or/and asymmetric tonic/dystonic seizures usually arising from non-rapid eye movement sleep. Even if many aspects regarding DoA and SHE have been clarified, the differential diagnosis remains challenging, because DoA and SHE share some semiologic features and genetic background. The clinical history, collected from the patient and his/her witness, represents the first and common milestone in the diagnosis. Validated questionnaires constitute suitable screening tools that could guide further analysis. The worldwide availability of homemade video recordings has increased the possibility of adding more objective information to the clinical history alone. The confirmed diagnosis relies on video-polysomnographic recording although it requires time, economic resources, and specific skills for the analysis. In this review we propose a simple diagnostic algorithm for the differential diagnosis between DoA and SHE in adults, based on the most updated knowledge, from the simpler tool to the most specific and tailored one.

Disorders of Arousal: A Chronobiological Perspective

Non-rapid eye movement (NREM) sleep parasomnias are characterized by motor and emotional behaviors emerging from incomplete arousals from NREM sleep and they are currently referred to as disorders of arousal (DoA). Three main clinical entities are recognized, namely confusional arousal, sleep terror and sleepwalking. DoA are largely present in pediatric populations, an age in which they are considered as transitory, unhabitual physiological events. The literature background in the last twenty years has extensively shown that DoA can persist in adulthood in predisposed individuals or even appear de novo in some cases. Even though some episodes may arise from stage 2 of sleep, most DoA occur during slow wave sleep (SWS), and particularly during the first two sleep cycles. The reasons for this timing are linked to the intrinsic structure of SWS and with the possible influence on this sleep phase of predisposing, priming and precipitating factors for DoA episodes. The objective of this paper is to review the intrinsic sleep-related features and chronobiological aspects affecting SWS, responsible for the occurrence of the majority of DoA episodes during the first part of the night.

Sleep-Related Hypermotor Epilepsy: Etiology, Electro-Clinical Features, and Therapeutic Strategies

Sleep-related hypermotor epilepsy (SHE) is a group of clinical syndromes with heterogeneous etiologies. SHE is difficult to diagnose and treat in the early stages due to its diverse clinical manifestations and difficulties in differentiating from non-epileptic events, which seriously affect patients' quality of life and social behavior. The overall prognosis for SHE is unsatisfactory, but different etiologies affect patients' prognoses. Surgical treatment is an effective method for carefully selected patients with refractory SHE; nevertheless, preoperative assessment remains challenging because of the low sensitivity of noninvasive scalp electroencephalogram and imaging to detect abnormalities. However, through a careful analysis of semiology, the clinician can deduce the potential epileptogenic zone. This paper summarizes the research status of the background, etiology, electro-clinical features, diagnostic criteria, prognosis, and treatment of SHE to provide a more in-depth understanding of its pathophysiological mechanism, improve the accuracy in the diagnosis of this group of syndromes, and further explore more targeted therapy plans.

Commonalities and Differences in NREM Parasomnias and Sleep-Related Epilepsy: Is There a Continuum Between the Two Conditions?

Introduction: Differential diagnosis between disorders of arousal (DoA) and sleep-related hypermotor epilepsy (SHE) often represents a clinical challenge. The two conditions may be indistinguishable from a semiological point of view and the scalp video-polysomnography is often uninformative. Both disorders are associated with variable hypermotor manifestations ranging from major events to fragments of a hierarchical continuum of increasing intensity, complexity, and duration. Given their semiological overlap we decided to explore the sleep texture of DoA and SHE seeking for similarities and differences.

Methods: We analyzed sleep macrostructure and CAP (cyclic alternating pattern) parameters in a cohort of 35 adult DoA patients, 40 SHE patients and 24 healthy sleepers, all recorded and scored in the same sleep laboratory. Nocturnal behavioral manifestations included minor motor events, paroxysmal arousals and major attacks in SHE, and simple, rising, or complex arousal movements in DoA.

Results: Compared to healthy controls, DoA and SHE showed similar amounts of sleep efficiency, light sleep, deep sleep, REM sleep, CAP subtypes. Both groups also showed slow wave sleep fragmentation and an increased representation of stage N3 in the second part of the night. The only discriminating elements between the two conditions regarded sleep length (more reduced in DoA) and sleep instability (more elevated in SHE). In DoA recordings, all motor episodes arose from NREM sleep: 37% during light NREM stages and 63% during stage N3 (simple arousal movements: 94%). In SHE recordings, 57% of major attacks occurred during stage N3.

Conclusions: So far, emphasis has been placed on the differentiation of sleep-related epilepsy and NREM arousal disorders. However, the impressive analogies between DoA and SHE suggest the existence of an underestimated continuum across the conditions, linked by increased levels of sleep instability, higher amounts of slow wave sleep and NREM/REM sleep imbalance. Sleep texture is extremely similar in the two conditions, although CAP metrics disclose quantitative differences. In particular, SHE patients show a higher arousal instability compared to DoA subjects. Given their clinical and epidemiological overlap, a common genetic background is also hypothesized. In such a perspective, we suggest that the consolidated dichotomy DoA vs. SHE should be reappraised.

Video-Polysomnographic Assessment for the Diagnosis of Disorders of Arousal in Children

OBJECTIVES

To highlight the slow-wave sleep (SWS) fragmentation and validate the video-polysomnographic (vPSG) criteria and cutoffs for the diagnosis of disorders of arousal (DOA) in children, as already reported in adults.

METHODS

One hundred children (66 boys, 11.0 ± 3.3 years) with frequent episodes of DOA and 50 nonparasomniac children (32 boys, 10.9 ± 3.9 years) underwent vPSG recording to quantify SWS characteristics (number of N3 sleep interruptions, fragmentation index, slow/mixed and fast arousal ratios, and indexes per hour) and associated behaviors. We compared SWS characteristics in the 2 groups and defined the optimal cutoff values for the diagnosis of DOA using receiver operating characteristic curves.

RESULTS

Patients with DOA had higher amounts of N3 and REM sleep, number of N3 interruptions, SWS fragmentation, and slow/mixed arousal indexes than controls. The highest area under the curve (AUC) values were obtained for SWS fragmentation and slow/mixed arousal indexes with satisfactory classification performances (AUC 0.80, 95% confidence interval [CI] 0.73-0.87; AUC 0.82, 95% CI 0.75-0.89). SWS fragmentation index cutoff value of 4.1/h reached a sensitivity of 65.0% and a specificity of 84.0%. Slow/mixed arousal index cutoff of 3.8/h reached a sensitivity of 69.0% and a specificity of 82.0%. At least one parasomniac episode was recorded in 63.0% of patients and none of the controls. Combining behavioral component by vPSG increased sensitivity of both biomarkers to 83% and 89%, respectively.

CONCLUSIONS

We confirmed that SWS fragmentation and slow/mixed arousal indexes are 2 relevant biomarkers for the diagnosis of DOA in children, with different cutoffs obtained than those validated in adults.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that SWS fragmentation and slow/mixed arousal indexes on vPSG accurately identify children with DOA.

Eyes wide open minds shut best identify disorders of arousal in adult sleepwalkers

Grigg-Damberger M, Foldvary-Schaefer N. Eyes wide open minds shut best identify disorders of arousal in adult sleepwalkers. J Clin Sleep Med. 2020;16(1):7–8.

Simple behavioral criteria for the diagnosis of disorders of arousal

STUDY OBJECTIVES

This case-control study aimed to identify and validate behavioral markers supporting the diagnosis of disorders of arousal (DOA) with video polysomnography.

METHODS

All behaviors associated with 1,335 episodes of N3 interruptions were compared in 52 adult patients with DOA versus 52 participants without DOA (healthy control patients and patients with insomnia, hypersomnia, or sleep apnea syndrome).

RESULTS

Patients with DOA had more frequent (5.1 ± 2.4 versus 3.4 ± 1.9 interruptions/N3 time) and longer (35.8 ± 33 versus 23.1 ± 21.4 sec) arousals and awakenings from N3 than control patients. In the DOA group, the onset of behaviors was more abrupt, and behaviors including eye opening (69% versus 16%), head raising (41% versus 9%), visually exploring the environment (27% versus 1%), expression of fear/surprise (21% versus zero), speaking (18% versus 0.3%), trunk raising (13% versus 0.3%), and interacting with the environment (13% versus 0.5%), were (unlike quiet, comfort behaviors) more frequent than in control patients. A cutoff of two or more N3 interruptions containing eye opening yielded a sensitivity of 94.2% and a specificity of 76.9% for a DOA diagnosis. This accuracy was confirmed in a second set of data (second night of monitoring). Behaviors including an expression of fear/surprise (67.3%), sitting (32.7%), screaming, and standing up were specific to patients with DOA.

CONCLUSIONS

A simple, behavioral video marker of behavioral reactions during N3 interruption (ie, opening the eyes at least two times in the same night) was sensitive, specific, and reproducible for discriminating patients with DOA from sleep laboratory control patients.

CLINICAL TRIAL REGISTRATION

This study is a surrogate study of NCT02648568 and NCT03074578 on ClinicalTrials.gov.

Polysomnographic features differentiating disorder of arousals from sleep-related hypermotor epilepsy

Objective

The differential diagnosis between sleep-related hypermotor epilepsy (SHE) and disorders of arousal (DOA) may be challenging. We analyzed the stage and the relative time of occurrence of parasomnic and epileptic events to test their potential diagnostic accuracy as criteria to discriminate SHE from DOA.

Methods

Video-polysomnography recordings of 89 patients with a definite diagnosis of DOA (59) or SHE (30) were reviewed to define major or minor events and to analyze their stage and relative time of occurrence. The “event distribution index” was defined on the basis of the occurrence of events during the first versus the second part of sleep period time. A group analysis was performed between DOA and SHE patients to identify candidate predictors and to quantify their discriminative performance.

Results

The total number of motor events (i.e. major and minor) was significantly lower in DOA (3.2 ± 2.4) than in SHE patients (6.9 ± 8.3; p = 0.03). Episodes occurred mostly during N3 and N2 in DOA and SHE patients, respectively. The occurrence of at least one major event outside N3 was highly suggestive for SHE (p = 2*e-13; accuracy = 0.898, sensitivity = 0.793, specificity = 0.949). The occurrence of at least one minor event during N3 was highly suggestive for DOA (p = 4*e-5; accuracy = 0.73, sensitivity = 0.733, specificity = 0.723). The “event distribution index” was statistically higher in DOA for total (p = 0.012) and major events (p = 0.0026).

Conclusion

The stage and the relative time of occurrence of minor and major motor manifestations represent useful criteria to discriminate DOA from SHE episodes.

Disorders of Arousal in adults: new diagnostic tools for clinical practice

Disorders of Arousal  (DOA) are mental and motor behaviors arising from NREM sleep. They comprise a spectrum of manifestations of increasing intensity from confusional arousals to sleep terrors to sleepwalking.

Although DOA in childhood are usually harmless, in adulthood they are often associated with injurious or violent behaviors to the patient or others. Driving motor vehicles, suspected suicide, and even homicide or attempted homicide have been described during sleepwalking in adults. Furthermore, adult DOA need to be differentiated from other sleep disorders such as Sleep-related Hypermotor Epilepsy or REM Sleep Behavior Disorder.

Although many aspects of DOA have been clarified in the last two decades there is still a lack of objective and quantitative diagnostic criteria for DOA.

Recent advances in EEG analysis and in the semiological characterization of DOA motor patterns have provided a better definition of DOA diagnosis.

Our article focuses on the DOA diagnostic process describing accurately the newest DOA clinical, EEG and video-polysomnographic tools in order to aid clinicians in DOA assessment.

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.

Diagnosis and management of nonrapid eye movement-parasomnias

PURPOSE OF REVIEW

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.

RECENT FINDINGS

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.

SUMMARY

NREM-parasomnia is a very common disorder of uncertain pathogenesis but of known pathophysiology, the diagnosis of which remains primarily clinical.

Non-REM Parasomnia: The Promise of Precision Medicine

Our understanding of non-REM parasomnias is just beginning to unfold the potential biomarkers and underlying pathophysiologic processes that lead to these events. Biomarkers need further investigation and will help us to understand better ways to develop risk models and possible mechanisms. Similarly, as we develop more accurate pathophysiologic-based diagnostic testing for non-REM parasomnias, we will begin the evolution toward a physiologic-based classification scheme that aids the application of precision medicine. This article explores currently known characteristics and exploratory features that may aid in this transition to better understanding our individual patients with non-REM parasomnias and tailoring their treatments.

Clinical Features and Pathophysiology of Disorders of Arousal in Adults: A Window Into the Sleeping Brain

Introduction: Disorders of Arousal (DoA) are NREM parasomnias that have been typically regarded as self-limited childhood manifestations. It is now clear that DoA can persist in adults, often presenting with distinctive characteristics. So far, few studies have described the clinical course and characteristics of DoA in adulthood, therefore a large part of their semiology is ignored. The aim of this study is to describe the clinical manifestations of DoA in an adult population and to provide a pathophysiological interpretation of their features. Methods: We screened our database for all 1,600 adult (≥15 years) patients with sleep-related motor behaviors between 1995 and 2016. We identified 45 patients with typical DoA episodes, of whom a complete history, neurological examination and diagnostic video-polysomnography (VPSG) were available. All patients provided a detailed description of their episodes (with particular regards to semiology, frequency, and association with stressful life events) in different life periods. VPSG recordings were reviewed and DoA episodes were identified and assigned to three different categories according to their complexity. Results: Our population was composed of 45 adult patients ranging between 15 and 76 years. Sleepwalking was reported by 86% of patients, possibly associated with complex interactions with the environment and violent behaviors in 53% of cases; distressing mental contents were reported by 64%. Recall of the episodes was reported in 77% of patients. Non-restorative sleep was reported in 46% of patients. Stress was a potential episode trigger in 80% of patients. VPSG recordings documented 334 DoA episodes. According to our classification of motor patterns, 282 episodes (84%) were Simple Arousal Movements (SAMs), 34 (10%) Rapid Arousal Movements (RAMs) and 18 (5%) Complex Arousal Movements (CAMs). Discussion: Our study confirms that DoA in adulthood present with distinctive characteristics, such as non-restorative sleep, violence and complex, or bizarre behaviors. Alternative classifications of DoA based on motor patterns could be useful to characterize DoA episodes in adults, as different motor patterns often coexist in the same individual and minor episodes are more common but generally underreported by patients. Prospective studies are needed for a definitive characterization of DoA in adulthood throughout the life course.