Medicolegal aspects of complex behaviours arising from the sleep period: A review and guide for the practising sleep physician

Understanding Sexual Parasomnias: A Review of the Current Literature on Their Nature, Diagnosis, Impacts, and Management

Sexual behavior during sleep, known as sexual parasomnias, has captured the interest of researchers and clinicians. These parasomnias involve various sexual activities that occur unconsciously during sleep. Although relatively rare, they can profoundly affect well-being and relationships and can carry legal consequences. Understanding their nature, prevalence, and causes is crucial for advancing knowledge in this field. This article revisits the topic of sexsomnia, presenting new data and discussing cases published from 2007 to 2023. By analyzing these cases, we aim to enhance recognition, diagnosis, and management of sexsomnia, reducing stigma and providing better support for affected individuals.

A case-control study of sexualised behaviour in sleep: A strong association with psychiatric comorbidity and relationship difficulties

Sexualised behaviour in sleep (SBS) is a relatively rare parasomnia consisting of instinctive behaviours of a sexual nature occurring during non-rapid-eye movement (NREM) sleep. Little information exists at present regarding the clinical features and onset of this condition as well as its link to psychiatric comorbidity, other sleep disorders and history of adverse early life experience. Aims were to typify the condition further and compare features of SBS patients to those with other NREM parasomnias.

METHODS

Details of 335 consecutive patients presenting to a single tertiary sleep centre with non-rapid eye movement (NREM)-parasomnias over a 15-year period (2005-2020) were examined. Data were collated by reviewing case-notes for anthropometric data, past medical history, clinical findings, and video polysomnography. SBS patients were compared to a cohort of 270 non-SBS, NREM-sleep disorder patients (case-control) to ascertain whether they had any distinguishing features from other parasomnias classified in this group.

RESULTS

Sixty-five patients with SBS were identified: 58 males, 7 females (comprising 19.4% of the cohort overall). Mean age at presentation was 33(±9.5) years. Onset of behaviours was commoner in adulthood in the SBS cohort, whereas non-SBS, NREM-parasomnia onset (n = 270) was commoner in childhood: 61.1% and 52.9% respectively (p = 0.007). An association was identified between the presence of psychiatric diagnoses and onset of SBS (p = 0.028). Significant triggers for SBS behaviours included alcohol consumption (p < 0.001), intimate relationship difficulties (p = 0.009) and sleep deprivation (p = 0.028). Patients with SBS were significantly more likely to report sleepwalking as an additional NREM behaviour (p < 0.001). Males were more likely to present at clinic together with their bedpartner and females presented alone. A history of SBS appeared to be more common in those working in the armed forces or the police compared to those presenting with non-SBS, NREM-parasomnias (p = 0.004).

CONCLUSIONS

SBS is more common in clinical practice than previously described and presents with some distinguishing features within the NREM disorder category. This study is the first to identify that onset in childhood or lack of amnesia does not preclude the condition and that patterns of presentation differ between men and women. Sleepwalkers particularly should be asked about SBS. Comorbid psychiatric conditions, profession and intimate partner difficulties are strong determinants of the presentation.

What respiratory physicians should know about parasomnias

Parasomnias have significant quality-of-life, prognostic and potentially forensic implications for patients and their bed-partners. Identifying key clinical features will accelerate diagnosis and appropriate management for these patients. Parasomnias are undesirable physical events or experiences that arise out of, or during, sleep. They can include movements, behaviours, emotions, perceptions, dreams or autonomic nervous system activity. While more common during childhood, they can persist into, or present de novo, during adulthood. Parasomnias can arise out of non-rapid eye movement (NREM) sleep, as in confusional arousals, sleepwalking, sleep terrors or sleep-related eating disorder, or out of REM sleep, as in REM behaviour disorder, recurrent isolated sleep paralysis or nightmare disorder. Sleep-related hypermotor epilepsy is an important differential diagnosis to consider in patients presenting with a parasomnia. A thorough clinical history, including a collateral history if available, is crucial to identify characteristic clinical features. Video polysomnography is useful to identify macro- and micro-sleep architectural features, characteristic behavioural events, and any concomitant sleep pathologies. Treatment of parasomnias involves a combined approach of pharmacological and non-pharmacological intervention, including safety measures, sleep hygiene and medicines such as clonazepam or melatonin to improve sleep consolidation and reduce behavioural activity. As parasomnias can not only be disruptive for the patient and their bed-partner but have important prognostic or forensic consequences, an understanding of their pathophysiology, clinical features and management is valuable for any respiratory physician who may encounter them.

Educational aims

To understand the common features of NREM and REM parasomnias.To differentiate between the causes of motor behaviours during sleep.To discuss the treatment approach for NREM and REM parasomnias.

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.

Adult NREM Parasomnias: An Update

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

Rapid eye movement sleep behavior disorder and the link to alpha-synucleinopathies

Rapid eye movement (REM) sleep behavior disorder (RBD) involves REM sleep without atonia in conjunction with a recurrent nocturnal dream enactment behavior, with vocalizations such as shouting and screaming, and motor behaviors such as punching and kicking. Secondary RBD is well described in association with neurological disorders including Parkinson's disease (PD), multiple system atrophy (MSA), and other conditions involving brainstem structures such as tumors. However, RBD alone is now considered to be a potential harbinger of later development of neurodegenerative disorders, in particular PD, MSA, dementia with Lewy bodies (DLB), and pure autonomic failure. These conditions are linked by their underpinning pathology of alpha-synuclein protein aggregation. In RBD, it is therefore important to recognize the potential risk for later development of an alpha-synucleinopathy, and to investigate for other potential causes such as medications. Other signs and symptoms have been described in RBD, such as orthostatic hypotension, or depression. While it is important to recognize these features to improve patient management, they may ultimately provide clinical clues that will lead to risk stratification for phenoconversion. A critical need is to improve our ability to counsel patients, particularly with regard to prognosis. The ability to identify who, of those with RBD, is at high risk for later neurodegenerative disorders will be paramount, and would in addition advance our understanding of the prodromal stages of the alpha-synucleinopathies. Moreover, recognition of at-risk individuals for neurodegenerative disorders may ultimately provide a platform for the testing of possible neuroprotective agents for these neurodegenerative disorders.

Legal Aspects of Sleep Medicine in the 21st Century

Multiple manifestations of sleep disorders may interact with the law, making it important to increase awareness of such interactions among clinicians. Patients with excessive sleepiness may have civil (and in some states criminal) liability if they fall asleep while driving and cause a motor vehicle accident. Employers may be held vicariously liable because of the actions of sleepy employees. Hence, awareness of causes of excessive sleepiness, such as sleep deprivation and OSA, is increasing among trucking, railroad, and other safety-sensitive occupations. Interestingly, litigation related to perioperative complications because of OSA is more frequent than nonoperative issues such as a failure to diagnose OSA. Parasomnia-associated sleep-related violence represents a challenge to clinicians because they may be asked to consider parasomnia as a possible contributing, mitigating, or exculpatory factor in criminal proceedings. Clinicians should also familiarize themselves with the legal and regulatory aspects of running an independent sleep laboratory. Sleep telemedicine practice using 21st century technology has opened novel and unique challenges to existing laws. In this review, we cover the most common interactions between sleep disorders and the law, including the challenges of excessive sleepiness and driving, other legal issues involving patients with OSA, and the liabilities associated with parasomnia disorder. We will also cover some practical legal aspects involving independent sleep laboratories and the field of sleep telemedicine.

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.

Legal and Regulatory Aspects of Sleep Disorders

Sleep disorders may interact with the law, making awareness important. Insufficient sleep and obstructive sleep apnea (OSA) are prevalent and associated with excessive sleepiness. Patients with excessive sleepiness may have civil or criminal liability if they fall asleep and cause a motor vehicle accident. Awareness of screening and treatment of OSA is increasing in certain industries. Parasomnia associated sleep-related violence represents a challenge to clinicians, who may be called on to consider parasomnia as a contributing, mitigating, or exculpatory factor in criminal proceedings. Improving access to sleep medicine care is an important aspect in reducing the consequences of sleep disorders.

Sleep in a legal context: The role of the expert witness

Sleep experts are called to assist the jury in deciding the mental state of the accused at the time of their alleged criminal behaviour. This task is difficult as the literature on many sleep disorders, particularly sleepwalking and other parasomnias, is still largely a matter of case reports and case series. The probative value of much of the evidence given is not known. Sleep behaviour in the courts present a number of difficulties which illustrate the dilemmas that face an expert witness faced with ambiguous data and uncertain principles with which to interpret them. Additionally there are substantial policy issues involved which are not always adequately addressed in expert evidence. We outline the role of expert witnesses in such cases.

Review: psychiatric and medical consequences of disordered sleep

OBJECTIVES

The aim of this article is to draw attention to the clinical importance of disordered sleep in psychiatry and to demonstrate the growing awareness of medical illness as a complication of disordered sleep. As background to these main objectives, some general points are made to illustrate present-day approaches to the common and often serious problem of sleep disturbance.

METHODS

The review is based on a literature search from which key publications were selected to illustrate, in turn, main connections between disordered sleep and psychiatric and medical conditions.

RESULTS

Many such connections are described. Throughout psychiatry, regarding patients whatever their age, these connections have implications for clinical assessment and management. Emphasis is placed on the risk of misdiagnosis of sleep disorders as psychiatric or medical conditions. Examples of this are provided. The growing evidence that disordered sleep can predispose to medical illness is discussed.

CONCLUSION

As the subject of sleep and its disorders is particular relevant in psychiatry, a working knowledge of modern sleep medicine is important in all branches of psychiatric and other medical practice as well as in clinical research.

Sleep-related violence and sexual behavior in sleep: a systematic review of medical-legal case reports

OBJECTIVE

To review systematically medical-legal cases of sleep-related violence (SRV) and sexual behavior in sleep (SBS).

SEARCH METHODS

We searched Pubmed and PsychINFO (from 1980 to 2012) with pre-specified terms. We also searched reference lists of relevant articles.

SELECTION CRITERIA

Case reports in which a sleep disorder was purported as the defense during a criminal trial and in which information about the forensic evaluation of the defendant was provided.

DATA EXTRACTION AND ANALYSIS

Information about legal issues, defendant and victim characteristics, circumstantial factors, and forensic evaluation was extracted from each case. A qualitative-comparative assessment of cases was performed.

RESULTS

Eighteen cases (9 SRV and 9 SBS) were included. The charge was murder or attempted murder in all SRV cases, while in SBS cases the charge ranged from sexual touching to rape. The defense was based on sleepwalking in 11 of 18 cases. The trial outcome was in favor of the defendant in 14 of 18 cases. Defendants were relatively young males in all cases. Victims were usually adult relatives of the defendants in SRV cases and unrelated young girls or adolescents in SBS cases. In most cases the criminal events occurred 1-2 hours after the defendant's sleep onset, and both proximity and other potential triggering factors were reported. The forensic evaluations widely differed from case to case.

CONCLUSION

SRV and SBS medical-legal cases did not show apparent differences, except for the severity of the charges and the victim characteristics. An international multidisciplinary consensus for the forensic evaluation of SRV and SBS should be developed as an urgent priority.