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STUDY OBJECTIVES: To update the literature on the diagnostic category of sleep-related dissociative disorders (SRDDs), involving psychogenic dissociation, since the time of their inclusion in the parasomnias section of the International Classification of Sleep Disorders, second edition, in 2005; to summarize the most salient clinical and video-polysomnographic (vPSG) findings and typical clinical profile from all reported cases; and to provide the rationale for the re-inclusion of the group of SRDDs in future editions of the International Classification of Sleep Disorders. METHODS: A systematic computerized literature search was conducted searching for SRDDs, nocturnal dissociative disorders, and nocturnal dissociation. RESULTS: Nine additional cases were identified, with sufficient clinical history and vPSG findings to justify the diagnosis of SRDDs, supplementing the 11 cases cited in the International Classification of Sleep Disorders, second edition, for a total of 20 cases. Twenty-six other cases with vPSG testing were found, with 18 cases reported in abstracts and 8 cases reported in a publication with compelling histories of SRDDs and 2 consecutive vPSG studies, but without the vPSG findings explicitly reported for any case. In more than half of all reported cases, there was objective diagnostic confirmation for SRDDs consisting of the hallmark finding of abnormal nocturnal behaviors arising from sustained electroencephalography wakefulness, or during wake–sleep transitions, without epileptiform activity. These nocturnal behaviors often replicated daytime psychogenic dissociative behaviors. A history of trauma (physical, sexual, emotional) was an almost universal finding, along with major psychopathology. All patients, except for one, had prominent histories of daytime dissociative disorders. Many of the patients were referred on account of a presumed parasomnia. CONCLUSIONS: Cases of SRDDs continue to be reported, often as a “parasomnia mimic,” with psychogenic dissociation being clearly distinguished from physiologic sleep–wake dissociation as found in primary sleep disorders such as narcolepsy, rapid eye movement sleep behavior disorder, etc. Eleven reasons are provided for why the category of SRDDs should be re-included in future editions of the International Classification of Sleep Disorders, and in the parasomnias section. CITATION: Schenck CH, Cramer Bornemann M, Kaplish N, Eiser AS. Sleep-related (psychogenic) dissociative disorders as parasomnias associated with a psychiatric disorder: update on reported cases. J Clin Sleep Med. 2021;17(4):803–810.

Parasomnias, or undesirable events accompanying sleep, encompass a broad spectrum of behaviors and experiences. Classification of parasomnias has undergone a significant transformation in the International Classification of Sleep Disorders Third Edition. Underlying this new classification is the understanding that Wake, NREM sleep, and REM sleep are not mutually exclusive states. Recent advances in neuroscience support the State Dissociation paradigm which would allow for an unstable admixture of components of these states to coexist. Parasomnias are the clinical manifestation of this state instability. This article briefly reviews the characteristics, demographics, and pathophysiology of the core parasomnias and associated disorders, with emphasis on disorders of arousal and diagnosis and prognostic significance of REM sleep behavior disorder.

This review of sleep-related violence reports the nature of the underlying sleep-suspected conditions enountered and helps establish the spectrum of sleep-related behaviors resulting in forensic consequences. This information may begin to bridge the gap between the differing medical and legal concepts of automatisms (complex motor behaviors occurring in the absence of conscious awareness and therefore without culpability). Sleep medicine professionals are increasingly asked by legal professionals whether a sleep-related condition could have played a role in a forensic-related event. Inasmuch as sleep medicine is a relatively young field, there is scant information to address these questions. The three most prevalent criminal allegations of the 351 consecutive possible sleep forensic-related referrals to a single sleep medicine center over the past 11 years were sexual assault, homicide/manslaughter or attempted murder, and driving under the influence. The overwhelming possible sleep disorder implicated was sexsomnia, accounting for 41%, or 145 out of 351 cases. Of the 351 referrals, 111 were accepted following thorough case review. In general, cases not accepted were declined on the basis of little or no merit or contamination by alcohol intoxication. Of those cases accepted, the proposed initial claim that a sleep phenomenon was operant was supported in approximately 50%, which were mostly non-rapid eye movement disorders of arousal. No cases were felt to be due to rapid eye movement sleep behavior disorder.

Parasomnias are complex behaviors occurring out of or during sleep. Parasomnias are increasingly presented as proof of an automatism in criminal cases involving violence. The sleep forensics expert must have an up-to-date understanding of current sleep science and research, diagnostic and clinical techniques, and the legal requirements of expert testimony and scientific evidence. Sleepwalking and related disorders typically follow sudden, partial awakenings from deep sleep. Higher-level cognition is severely limited or absent, and complex behaviors often consist of “automatic” behaviors not initiated or guided by memory or planning. Sleepwalking and related disorders are noted to occur during deep sleep and often require a genetic predisposition or priming factors. Prior cases of sleepwalking violence find that the victim of sleepwalking violence—most often a family member—seeks out the sleepwalker. The history of sleepwalking includes reports of episodes and sometimes criminal court cases of murder, assault, and rape.

Parasomnias are complex behaviors or experiences occurring out of or during sleep. Attempts at presenting parasomnias under the guise of the “Sleepwalking Defense” are increasing as potential explanations to account for violent behaviors in a broad range of criminal allegations ranging from assault and battery, to rape, and homicide. The sleep forensics expert must have a current understanding of neuroscience and somnology, sleep medicine with its clinical and diagnostic techniques, and the legal requirements of expert testimony pertaining to the presentation of scientific evidence. Historically, sleepwalking was understood upon a multitude of superstitious as well as religious-based constructs. It took until 1986 with the discovery of REM Sleep Behavior Disorder (RBD), a disorder in which individuals exhibit violent dream enactment behavior in REM sleep, which further strengthened the foundation that sleepwalking is predominantly due to aberrant neurophysiologic signaling in the brain though many discredited and pseudoscientific concepts continue to remain popular today. The development of a reasonable differential diagnosis for violent nocturnal behaviors, including NREM-related parasomnias (or Disorders of Arousal) and RBD, is not difficult as many present with characteristic clinical features. Sleepwalking and related disorders typically follow sudden partial awakenings from slow wave or deep sleep. Executive level functions and cognition are offline or severely limited and complex behaviors appear “automatic” in nature. Once abruptly aroused out of slow wave sleep, the sleepwalker may find themselves in an unstable state that has not yet been fully declared with a deactivated prefrontal cortex and midbrain structures that remain activated. It is upon this platform that overt behaviors may arise from sleep without awareness with more complex behaviors often taking on the appearance of reflexive primal expressions which may be violent, gustatory, or copulatory in nature. In any given episode of sleepwalking, violence may be possible though cases involving forensics implications are rare. In the vast majority of sleep-related violence with forensics implications, the victim was in relatively close proximity to the sleepwalker and may have inadvertently been the trigger for the event. Sleepwalking in adults occurs intermittently, and nocturnal wandering may not necessarily be sleepwalking. The sleep forensics expert understands that the strength of the argument in a court of law which associates any given Parasomnia with a criminal allegation ultimately rests upon effectively excluding other potential causes and cross contaminating influences (i.e., pharmaceutical effects) while providing a temporal association between a clinical condition and the degree of consciousness, or lack thereof, with the event in question. Thus, the role of the sleep forensics expert is much more than providing a clinical diagnosis and instead should, without bias, effectively facilitate the process in the courtroom to arrive at an educated decision.

Individuals with restless legs syndrome (RLS) (Willis-Ekbom disease [WED]) usually have periodic leg movements (PLMs). The suggested immobilization test (SIT) measures sensory and motor features of WED during wakefulness. Surface electromyogram (EMG) recordings of the anterior tibialis (AT) are used as the standard for counting PLMs. However, due to several limitations, leg activity meters such as the PAM-RL were advanced as a potential substitute. In our study, we assessed the validity of the measurements of PLM during wakefulness (PLMW) in the SIT for PAM-RL using both default and custom detection threshold parameters compared to AT EMG.Data were obtained from 39 participants who were diagnosed with primary WED and who were on stable medication as part of another study using the SIT to repeatedly evaluate WED symptoms over 6-12 months. EMG recordings and PAM-RL, when available, were used to detect PLMW for each SIT. Complete PAM-RL and polysomnography (PSG) EMG data were available for 253 SITs from that study. The default PAM-RL (dPAM-RL) detected leg movements based on manufacturer's noise (resting) and signal (movement) amplitude criteria developed to accurately detect PLM during sleep (PLMS). The custom PAM-RL (cPAM-RL) similarly detected leg movements except the noise and movement detection parameters were adjusted to match the PAM-RL data for each SIT.The distributions of the differences between either dPAM-RL or cPAM-RL and EMG PLMW were strongly leptokurtic (Kurtosis2) with many small differences and a few unusually large differences. These distributions are better described by median and quartile ranges than mean and standard deviation. Despite an adequate correlation (r=0.66) between the dPAM-RL and EMG recordings, the dPAM-RL on average significantly underscored the number of PLMW (median: quartiles=-13: -51.2, 0.0) and on Bland-Altman plots had a significant magnitude bias with greater underscoring for larger average PLMW/h. There also was an adequate correlation (r=0.70) between cPAM-RL and EMG but with minimal underscoring of PLMW (median quartiles=0.0; -20, 10) and no significant magnitude bias. Two scorers independently scoring 13% of the SITs showed an adequate interscorer reliability of 0.96-0.98.Our study confirms our expectation that measuring PLMW in a SIT using dPAM-RL is not valid and that adjustments to the detection threshold criteria are required. The PAM-RL, using parameters customized for each SIT provided a valid and reliable measure of PLMW with minimal magnitude bias compared to the AT EMG recordings.

Obstructive sleep apnea is a prevalent disease which if left untreated can negatively impact many physiologic systems, most notably the cardiovascular system, resulting in chronic dysfunction, and even has the potential to present as sudden unexpected death. This review details prevalence of the disease, the physiologic mechanisms which account for its sequelae, clinical diagnosis in the living, treatment options, and morbidity and mortality. Additionally, specific discussion focuses on death investigation where obstructive sleep apnea may have contributed to the death of an individual and implications for death certification.

This issue of Sleep Medicine Clinics explores the fascinating phenomenon of complex behaviors arising from the sleep period, occasionally with dramatic and unfortunate forensic implications. The concept of state dissociation provides a framework for understanding these behaviors and has important implications for consciousness in general. Acknowledgment of the fact that wakefulness/sleep and consciousness/unconsciousness are not mutually exclusive states but rather are characterized by fluid and often fluctuating boundaries will help to explain many curious clinical phenomena and will effect a change in the legal concepts of intent, responsibility, and culpability. There is now overwhelming evidence that the primary states of being (wakefulness [W], non–rapid

OBJECTIVE To assess maintenance of efficacy and tolerability of gabapentin enacarbil in patients with moderate to severe primary restless legs syndrome (RLS). PATIENTS AND METHODS This study (conducted April 18, 2006, to November 14, 2007) comprised a 24-week, single-blind (SB) treatment phase (gabapentin enacarbil, 1200 mg) followed by a 12-week randomized, double-blind (DB) phase. Responders from the SB phase (patients with improvements on the International Restless Legs Scale [IRLS] and investigator-rated Clinical Global Impression–Improvement scale at week 24 and stable while taking a gabapentin enacarbil dose of 1200 mg for at least 1 month before randomization) were randomized to gabapentin enacarbil, 1200 mg, or placebo once daily at 5 pm with food. The primary end point was the proportion of patients experiencing relapse (worse scores on the IRLS and investigator-rated Clinical Global Impression of Change scale on 2 consecutive visits at least 1 week apart or withdrawal because of lack of efficacy) during the DB phase. RESULTS A total of 221 of 327 patients completed the SB phase, 194 (96 in the gabapentin enacarbil group and 98 in the placebo group) were randomized to DB treatment, and 168 (84 in the gabapentin enacarbil group and 84 in the placebo group) completed the DB phase. A significantly smaller proportion of patients treated with gabapentin enacarbil (9/96 [9%]) experienced relapse compared with the placebo-treated patients (22/97 [23%]) (odds ratio, 0.353; 95% confidence interval, 0.2-0.8; P =.02). Somnolence and dizziness were the most common adverse events. One death occurred (unintentional choking during the SB phase) and was judged as being unrelated to the study drug. No clinically relevant changes were observed in laboratory values, in vital signs, or on electrocardiograms. CONCLUSION Gabapentin enacarbil, 1200 mg, maintained improvements in RLS symptoms compared with placebo and showed long-term tolerability in adults with moderate to severe primary RLS for up to 9 months of treatment.

Summary An increasing number of criminal cases have claimed the defendant to be in a state of sleepwalking or related disorders induced by high quantities of alcohol. Sleepwalkers who commit violent acts, sexual assaults and other criminal acts are thought to be in a state of automatism, lacking conscious awareness and criminal intent. They may be acquitted in criminal trials. On the other hand, criminal acts performed as the result of voluntary alcohol intoxication alone cannot be used as a complete defense. The alcohol-induced sleepwalking criminal defense is most often based on past clinical or legal reports that ingestion of alcohol directly ‘triggers’ sleepwalking or increased the risk of sleepwalking by increasing the quantity of slow wave sleep (SWS). A review of the sleep medicine literature found no sleep laboratory studies of the effects of alcohol on the sleep of clinically diagnosed sleepwalkers. However, 19 sleep laboratory studies of the effects of alcohol on the sleep of healthy non-drinkers or social drinkers were identified with none reporting a change in SWS as a percentage of total sleep time. However, in six of 19 studies, a modest but statistically significant increase in SWS was found in the first 2–4 h. Among studies of sleep in alcohol abusers and abstinent abusers, the quantity and percentage of SWS was most often reduced and sometimes absent. Claims that direct alcohol provocation tests can assist in the forensic assessment of these cases found no support of any kind in the medical literature with not a single report of testing in normative or patient groups and no reports of validation testing of any sort. There is no direct experimental evidence that alcohol predisposes or triggers sleepwalking or related disorders. A legal defense of sleepwalking resulting from voluntarily ingested alcohol should be consistent with the current state of art sleep science and meet generally accepted requirements for the diagnosis of sleepwalking and other parasomnias.

Dose-related effects of atrial overdrive pacing (AOP) on sleep-related breathing disorder (SRBD) were studied. Fourteen patients with pacemakers with moderate to severe SRBD (mean screening apnea-hypopnea index [AHI] 35.2 +/- 21.9 events/hour) were randomized to 3 levels of pacing (50, 10, and 20 beats/min greater than the mean nocturnal heart rate) and studied by polysomnography, observing for changes in AHI. At the 2 AOP levels, no significant change was observed in the primary end point of reduction in AHI. Additionally, there was no observed impact on secondary end points of the study. Cyclic variation of heart rate was progressively abolished with higher levels of AOP without affecting AHI. Large variations were observed between the screening and control studies in SRBD indexes in a number of patients. In conclusion, AOP demonstrated no benefit to predominantly obstructive SRBD disorder of at least moderate severity.

Parasomnias are undesirable behavioral or experiential phenomena arising from the sleep period. Once felt to be a unitary phenomenon, it is now clear that a wide variety of sleep disorders are capable of resulting in complex behaviors arising during sleep. The most common are disorders of arousal and rapid eye movement sleep disorder. Less common conditions include nocturnal seizures and psychogenic dissociative states. Malingering and Munchausen syndrome by proxy, while they are not actually parasomnias, may masquerade as parasomnias. Careful clinical and sleep laboratory evaluation can usually provide an accurate diagnosis with effective therapeutic implications. Due to the potential forensic implications, sleep medicine specialists may be asked to participate in legal proceedings resulting from sleep-related violence. An awareness of the spectrum of such behaviors, and their clinical and legal evaluation, is becoming more important in the practice of sleep medicine.

N A RECENT publication, Ebrahim and colleagues state in their abstract that they have provided an assessment of “all known scientific studies of the effects of alcohol on the nocturnal sleep of healthy volunteers” (Ebrahim et al., 2013, p. 539). Our review of this article found it to be seriously flawed by research design and statistical problems. Ebrahim and colleagues (2013) selected 20 published articles concerned with the effects of alcohol on sleep in humans. Numerous articles were excluded from consideration. Within these articles are 38 groups of subjects based on other criteria such as sex or dose of alcohol administered. Although all sleep stages were addressed, Ebrahim and colleagues (2013) focus on the effects of alcohol on slow-wave sleep (SWS); variously known as or abbreviated as SWS, deep sleep, Stages 3 + 4. Current nomenclature combines stages 3 and 4 sleep and renames them “N3”(Iber et al., 2007). As noted in their conclusion, One area of debate and sometimes controversy has been the issue of the impact of alcohol on SWS. For the first time, all the available data are presented here and based on the findings from all available studies, and in the majority, alcohol clearly increases SWS in the first part of sleep at all doses, across gender and ages. Data for the impact of alcohol on total night SWS display a dose dependent effect with low doses showing no clear trend, moderate doses show a trend toward an increase in SWS and with high doses there is a significant and clear effect of increasing total SWS. This effect is consistent across gender and age groups. (Ebrahim et al., 2013, pp. 547–548)

Restless legs syndrome (RLS) is thought to be due to abnormalities of iron metabolism in the central nervous system; however, occasional cases are associated with lesions of the spinal cord, spinal rootlets, and peripheral nervous system. This is a case report of RLS exacerbated by shingles with a review of the literature of extra-cerebral lesions or disorders causing or contributing to RLS.

Sexual behaviors in sleep have gained wide recognition and can take on many expressions. These behaviors have been given many popular terms including “sexsomnia” and “sleep sex” but the most common primary pathway through the platform of sleep is as a disorder of arousal from NREM sleep. The public’s fascination with “sexsomnia” may equate this condition with unrestrained libidinous sexual intercourse between strangers but the most common expression of this condition may be an inappropriate and unwanted emerging intimacy between individuals who by tacit agreement have chosen to sleep in close proximity. Major influences for which there is clinical-based evidence that may promote sleep-related abnormal sexual behaviors include sleep deprivation and obstructive sleep apnea (OSA). Alcohol has long been erroneously cited in the past as a priming influence for disorders of arousal from NREM sleep, including sleep-related abnormal sexual behaviors. The sleep forensics experience in the United States has revealed an alarming increase in the number of cases of sexual assaults purported to be attributed to “sexsomnia”. If such legal cases are indeed a bellwether, a proposal could be made for more rigorous controlled epidemiologic studies into this condition to better define its prevalence and characteristics as part of public policy to ensure personal and public safety—especially in those who cosleep with children. Despite its increasing recognition, there also remains significant skepticism, if not disdain, related to “sexsomnia” as witnessed by published reports served by the National District Attorneys Association’s National Center for Prosecution of Child Abuse. To counteract media driven bias and the general skepticism emanating from an adversarial-driven court system, this chapter presents a progressive medicolegal case-based approach in analyzing potential sleep-related abnormal sexual behaviors to equip the sleep medicine professional with a combination of cognitive neuroscience constructs and salient clinical features to navigate the topology of sexual behavior in sleep in order to provide the most appropriate patient-centered care with the potential to be a resource to the legal community when indicated.

Argument that physicians called upon for expert testimony in court have an ethical duty to educate the jury by offering opinions based upon published, clinically based evidence and peer-reviewed medical literature. Virtual Mentor is a monthly bioethics journal published by the American Medical Association.

Sir, The recent Letter to the Editor by Drs Ebrahim and Fenwick (2012) challenges one sentence in a 2010 article published in Brain (Siclari et al. , 2010) stating that, because of the lack of reliable evidence, alcohol-induced sleepwalking should not be allowed as a defence to criminal acts. This, in turn, refers to an article published 22 years ago (Mahowald et al. , 1990). Drs Ebrahim and Fenwick express concern that defendants who have allegedly committed criminal acts while severely intoxicated with alcohol are potentially being denied a valid defence. In our opinion, claims of alcohol-induced sleepwalking violence or sleep sex …

Objectives/Hypothesis: Previous feasibility studies have shown that electrical stimulation of the hypoglossal nerve can improve obstructive sleep apnea (OSA). The current study examined the safety and preliminary effectiveness of a second generation device, the Upper Airway Stimulation (UAS) system, and identified baseline predictors for therapy success. Study Design: Two consecutive open prospective studies. Methods: UAS systems were implanted in patients with moderate to severe OSA who failed or were intolerant of continuous positive airway pressure (CPAP). The study was conducted in 2 parts. In part 1, patients were enrolled with broad selection criteria. Apnea hypopnea index (AHI) was collected using laboratory-based polysomnography at preimplant and postimplant visits. Epworth Sleepiness Scale (ESS) and Functional Outcomes of Sleep Questionnaire (FOSQ) were also collected. In part 2, patients were enrolled using selection criteria derived from the experience in part 1. Results: In part 1, 20 of 22 enrolled patients (two exited the study) were examined for factors predictive of therapy response. Responders had both a body mass index ≤32 and AHI ≤50 (P < .05) and did not have complete concentric palatal collapse. Part 2 patients (n = 8) were selected using responder criteria and showed an improvement on AHI from baseline, from 38.9 ± 9.8 to 10.0 ± 11.0 (P < .01) at 6 months postimplant. Both ESS and FOSQ improved significantly in part 1 and 2 subjects. Conclusions: The current study has demonstrated that therapy with upper airway stimulation is safe and efficacious in a select group of patients with moderate to severe OSA who cannot or will not use CPAP as primary treatment.

Parasomnias are defined as unpleasant or undesirable behavioral or experiential phenomena that occur predominately or exclusively during the sleep period. Most parasomnias represent the simultaneous admixture of wakefulness and sleep. This chapter focuses on the clinical features, pathophysiology, diagnosis, and treatment of the two most common parasomnias: (1) disorders of arousal (confusional arousals, sleepwalking, and sleep terrors), which represent admixtures of wakefulness and nonrapid eye movement sleep; and (2) rapid eye movement (REM)-sleep behavior disorder (RBD), which is a manifestation of admixed wakefulness and REM sleep. Disorders of arousal are very common, perhaps part of the normal human condition, and are not the manifestation of underlying psychiatric disease. RBD is often the harbinger of degenerative neurological conditions, particularly the synucleinopathies (Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy); it is a frequent accompaniment of narcolepsy with cataplexy, and may be induced by numerous medications, particularly the selective serotonin reuptake inhibitors and the serotonin–norepinephrine reuptake inhibitors. Parasomnia behaviors underscore the fact that consciousness, being ever so evanescent, exists on a broad spectrum and is not an easily delineated dichotomous state. Such a dynamic understanding of consciousness has significant scientific, legal, and social implications raising interesting and difficult questions regarding awareness, responsibility, culpability, and even what it means to be human. Emphasis is placed upon the importance of the emerging field of Sleep Forensics in the evaluation of violent, injurious, or alleged criminal behaviors resulting from these parasomnias.

Sleep is clearly not only a whole-brain or global phenomenon, but can also be a local phenomenon. This accounts for the fact that the primary states of being (wakefulness, NREM sleep, and REM sleep) are not necessarily mutually exclusive, and components of these states may appear in various combinations, with fascinating clinical consequences. Examples include: sleep inertia, narcolepsy, sleep paralysis, lucid dreaming, REM sleep behavior disorder, sleepwalking, sleep terrors, out-of-body experiences, and reports of alien abduction. The incomplete declaration of state likewise has implications for consciousness - which also has fluid boundaries. Fluctuations in the degree of consciousness are likely explained by abnormalities of a “spatial and temporal binding rhythm” which normally results in a unified conscious experience. Dysfunctional binding may play a role in anesthetic states, autism, schizophrenia, and neurodegenerative disorders. Further study of the broad spectrum of dissociated states of sleep and wakefulness that are closely linked with states of consciousness and unconsciousness by basic neuroscientists, clinicians, and members of the legal profession will provide scientific, clinical and therapeutic insights, with forensic implications.

Although generally considered as mutually exclusive, violence and sleep can coexist. Violence related to the sleep period is probably more frequent than generally assumed and can be observed in various conditions including parasomnias (such as arousal disorders and rapid eye movement sleep behaviour disorder), epilepsy (in particular nocturnal frontal lobe epilepsy) and psychiatric diseases (including delirium and dissociative states). Important advances in the fields of genetics, neuroimaging and behavioural neurology have expanded the understanding of the mechanisms underlying violence and its particular relation to sleep. The present review outlines the different sleep disorders associated with violence and aims at providing information on diagnosis, therapy and forensic issues. It also discusses current pathophysiological models, establishing a link between sleep-related violence and violence observed in other settings.

Rapid eye movement (REM) sleep behavior disorder (RBD) is characterized by loss of the muscle atonia of REM sleep, with release of complex and violent behaviors that are often attempted dream-enactments. This study reviewed the literature on RBD with regard to potentially lethal behavior. A total of 39-41 clinical cases of RBD associated with potentially lethal behaviors to self and/or others were found, involving a child and adults of all age groups, that manifested as choking/headlock (n = 22-24), defenestration/near-defenestration (n = 7), and diving from bed (n = 10). A total of 80.8% (n = 21) were males; 19.2% (n = 5) were females; mean age was 65.6 +/- (SD) 13.8 years (range: 27-81 years, and a child). (Gender/age data were not listed in the remaining cases.) An etiologic association of RBD with a neurologic disorder (or with pharmacotherapy of psychiatric disorders, n = 4) was present in 21-23 patients. Thus, RBD carries well-documented, potential forensic consequences during RBD episodes that could possibly have been misinterpreted as suicidal or homicidal behavior.

Violent behaviors during sleep may result in events which have forensic science implications. The apparent suicide (for example, leap to death from a second-storey window), assault or murder (for example, molestation, strangulation, stabbing, shooting) may be the unintentional, non-culpable but catastrophic result of disorders of arousal, sleep-related seizures, REM sleep behavior disorder (RBD), or psychogenic dissociative states. Violent sleep-related behaviors have been reviewed in the context of automatic behavior in general, with many well-documented cases resulting from a wide variety of disorders. Conditions associated with sleep-period-related violence fall into two major categories: neurologic and psychiatric. Psychogenic dissociative disorders may arise exclusively or predominantly from the sleep period. Recent interest in the forensic aspects of parasomnias provides sleep medicine professionals with an opportunity to educate and assist the legal profession in cases of sleep-related violence. One infrequently used tactic to improve scientific testimony is to use a court-appointed impartial expert.

REM sleep behavior disorder (RBD) is a fascinating experiment in nature predicted by animal studies in 1964. A defining feature of REM sleep is active paralysis of all somatic musculature (sparing the diaphragm to permit respiration). RBD is characterized by the absence of REM atonia, permitting the appearance of dream-enacting behaviors. These oneiric behaviors may be violent or injurious. RBD typically affects men over the age of 50 years. Longitudinal follow-up has shown that the majority of individuals with RBD will eventually develop additional signs and symptoms of a number of neurodegenerative disorders, most notably one of the synucleinopathies (Parkinson's disease, dementia with Lewy body disease, multiple system atrophy, or pure autonomic failure), often after a prolonged interval lasting more than 10 years. RBD is also a common manifestation of narcolepsy. RBD may be induced by medications, especially the tricyclic antidepressants and serotonin-specific reuptake inhibitors. In most cases, clonazepam is a highly effective treatment.

Parasomnias are undesirable behavioral or experiential phenomena arising from the sleep period. Once felt to be a unitary phenomenon, it is now clear that a wide variety of sleep disorders are capable of resulting in complex behaviors arising during sleep. The most common are disorders of arousal and rapid eye movement sleep disorder. Less common conditions include nocturnal seizures and psychogenic dissociative states. Malingering and Munchausen syndrome by proxy, while they are not actually parasomnias, may masquerade as parasomnias. Careful clinical and sleep laboratory evaluation can usually provide an accurate diagnosis with effective therapeutic implications. Due to the potential forensic implications, sleep medicine specialists may be asked to participate in legal proceedings resulting from sleep-related violence. An awareness of the spectrum of such behaviors, and their clinical and legal evaluation, is becoming more important in the practice of sleep medicine.

This article reviews nine case studies of patients presenting with sleep complaints.

Most violent behaviors arise from wakefulness. It is important to realize that violent behaviors that may have forensic science implications can arise from the sleep period. By virtue of the fact that these behaviors arise from sleep, they are executed without conscious awareness, and, therefore, without culpability. The most common underlying conditions arising from sleep are disorders of arousal (sleepwalking and sleep terrors), the rapid eye movement sleep behavior disorder, and nocturnal seizures. In addition, there are a number of psychiatric conditions (dissociative disorders, malingering, and Munchausen syndrome by proxy) that actually arise from periods of wakefulness occurring during the sleep period. The clinical and medico-legal evaluation of such cases is outlined, and should be performed by a multidisciplinary team of experienced sleep medicine practitioners.

New treatments hold great promise for neurodegenerative disorders such as the synucleinopathies, including pharmacologic, mechanical (deep brain and cortical stimulation, growth factor infusion), and cell-based and gene therapies.1,2 A number of nonmotor signs and symptoms may be present long before the appearance of typical clinical features (table). This prodromal phase has been referred to as the presymptomatic, subclinical, preclinical, or premotor period, which may range from 4 to 6 years, and is thought to be related to nondopaminergic lower brainstem structures or autonomic plexuses. However, the article by Claassen et al.3 in this issue of Neurology ® extends that interval to half a century for REM sleep behavior disorder (RBD) as a harbinger for synucleinopathies (Parkinson disease [PD], multiple system atrophy, pure autonomic failure, and dementia with Lewy bodies). View this table: Table Early nonmotor harbingers of synucleinopathies Human RBD was at one time an isolated observation—simply the consequence of REM sleep without atonia (RWA). Follow-up of middle-aged and older patients with “idiopathic” RBD revealed, however, a surprise: some patients with RBD, after nearly 2 decades, developed PD, with increasing percentages of patients with RBD manifesting some …