Associations of sleep disorders with serum neurofilament light chain levels in Parkinson's disease.

BACKGROUND: Sleep disorders are a prevalent non-motor symptom of Parkinson's disease (PD), although reliable biological markers are presently lacking. OBJECTIVES: To explore the associations between sleep disorders and serum neurofilament light chain (NfL) levels in individuals with prodromal and early PD. METHODS: The study contained 1113 participants, including 585 early PD individuals, 353 prodromal PD individuals, and 175 healthy controls (HCs). The correlations between sleep disorders (including rapid eye movement sleep behavior disorder (RBD) and excessive daytime sleepiness (EDS)) and serum NfL levels were researched using multiple linear regression models and linear mixed-effects models. We further investigated the correlations between the rates of changes in daytime sleepiness and serum NfL levels using multiple linear regression models. RESULTS: In baseline analysis, early and prodromal PD individuals who manifested specific behaviors of RBD showed significantly higher levels of serum NfL. Specifically, early PD individuals who experienced nocturnal dream behaviors (ß = 0.033; P = 0.042) and movements of arms or legs during sleep (ß = 0.027; P = 0.049) showed significantly higher serum NfL levels. For prodromal PD individuals, serum NfL levels were significantly higher in individuals suffering from disturbed sleep (ß = 0.038; P = 0.026). Our longitudinal findings support these baseline associations. Serum NfL levels showed an upward trend in early PD individuals who had a higher total RBDSQ score (ß = 0.002; P = 0.011) or who were considered as probable RBD (ß = 0.012; P = 0.009) or who exhibited behaviors on several sub-items of the RBDSQ. In addition, early PD individuals who had a high total ESS score (ß = 0.001; P = 0.012) or who were regarded to have EDS (ß = 0.013; P = 0.007) or who exhibited daytime sleepiness in several conditions had a trend toward higher serum NfL levels. CONCLUSION: Sleep disorders correlate with higher serum NfL, suggesting a link to PD neuronal damage. Early identification of sleep disorders and NfL monitoring are pivotal in detecting at-risk PD patients promptly, allowing for timely intervention. Regular monitoring of NfL levels holds promise for tracking both sleep disorders and disease progression, potentially emerging as a biomarker for evaluating treatment outcomes.

Sleep disturbance in clinical and preclinical scrapie-infected sheep measured by polysomnography.

Neurodegenerative diseases are characterised by neuronal loss and abnormal deposition of pathological proteins in the nervous system. Among the most common neurodegenerative diseases are Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease and transmissible spongiform encephalopathies (TSEs). Sleep and circadian rhythm disturbances are one of the most common symptoms in patients with neurodegenerative diseases. Currently, one of the main objectives in the study of TSEs is to try to establish an early diagnosis, as clinical signs do not appear until the damage to the central nervous system is very advanced, which prevents any therapeutic approach. In this paper, we provide the first description of sleep disturbance caused by classical scrapie in clinical and preclinical sheep using polysomnography compared to healthy controls. Fifteen sheep classified into three groups, clinical, preclinical and negative control, were analysed. The results show a decrease in total sleep time as the disease progresses, with significant changes between control, clinical and pre-clinical animals. The results also show an increase in sleep fragmentation in clinical animals compared to preclinical and control animals. In addition, sheep with clinical scrapie show a total loss of Rapid Eye Movement sleep (REM) and alterations in Non Rapid Eyes Movement sleep (NREM) compared to control sheep, demonstrating more shallow sleep. Although further research is needed, these results suggest that prion diseases also produce sleep disturbances in animals and that polysomnography could be a diagnostic tool of interest in clinical and preclinical cases of prion diseases.

Single-channel EOG sleep staging on a heterogeneous cohort of subjects with sleep disorders.

Objective.Sleep staging based on full polysomnography is the gold standard in the diagnosis of many sleep disorders. It is however costly, complex, and obtrusive due to the use of multiple electrodes. Automatic sleep staging based on single-channel electro-oculography (EOG) is a promising alternative, requiring fewer electrodes which could be self-applied below the hairline. EOG sleep staging algorithms are however yet to be validated in clinical populations with sleep disorders.Approach.We utilized the SOMNIA dataset, comprising 774 recordings from subjects with various sleep disorders, including insomnia, sleep-disordered breathing, hypersomnolence, circadian rhythm disorders, parasomnias, and movement disorders. The recordings were divided into train (574), validation (100), and test (100) groups. We trained a neural network that integrated transformers within a U-Net backbone. This design facilitated learning of arbitrary-distance temporal relationships within and between the EOG and hypnogram.Main results.For 5-class sleep staging, we achieved median accuracies of 85.0% and 85.2% and Cohen's kappas of 0.781 and 0.796 for left and right EOG, respectively. The performance using the right EOG was significantly better than using the left EOG, possibly because in the recommended AASM setup, this electrode is located closer to the scalp. The proposed model is robust to the presence of a variety of sleep disorders, displaying no significant difference in performance for subjects with a certain sleep disorder compared to those without.Significance.The results show that accurate sleep staging using single-channel EOG can be done reliably for subjects with a variety of sleep disorders.

Cardiopulmonary Coupling Spectrogram as an Ambulatory Method for Assessing Sleep Disorders in Patients With Autoimmune Encephalitis.

BACKGROUND AND OBJECTIVES: Sleep disorders are a common and important clinical feature in patients with autoimmune encephalitis (AE); however, they are poorly understood. We aimed to evaluate whether cardiopulmonary coupling (CPC), an electrocardiogram-based portable sleep monitoring technology, can be used to assess sleep disorders in patients with AE. METHODS: Patients fulfilling the diagnostic criteria of AE were age- and sex-matched with recruited healthy control subjects. All patients and subjects received CPC testing between August 2020 and December 2022. Demographic data, clinical information, and Pittsburgh Sleep Quality Index (PSQI) scores were collected from the medical records. Data analysis was performed using R language programming software. RESULTS: There were 60 patients with AE (age 26.0 [19.8-37.5] years, male 55%) and 66 healthy control subjects (age 30.0 [25.8-32.0] years, male 53%) included in this study. Compared with healthy subjects, patients with AE had higher PSQI scores (7.00 [6.00-8.00] vs 3.00 [2.00-4.00], p < 0.001), lower sleep efficiency (SE 80% [71%-87%] vs 92% [84%-95%], p < 0.001), lower percentage of high-frequency coupling (25% [14%-43%] vs 45% [38%-53%], p < 0.001), higher percentage of REM sleep (19% ± 9% vs 15% ± 7%, p < 0.001), higher percentage of wakefulness (W% 16% [11%-25%] vs 8% [5%-16%], p = 0.074), higher low-frequency to high-frequency ratio (LF/HF 1.29 [0.82-2.40] vs 0.91 [0.67-1.29], p = 0.001), and a higher CPC-derived respiratory disturbance index (9.78 [0.50-22.2] vs 2.95 [0.40-6.53], p < 0.001). Follow-up evaluation of 14 patients showed a decrease in the PSQI score (8.00 [6.00-9.00] vs 6.00 [5.00-7.00], p = 0.008), an increased SE (79% [69%-86%] vs 89% [76%-91%], p = 0.030), and a decreased W% (20% [11%-30%] vs 11% [8%-24], p = 0.035). Multiple linear regression indicated that SE (-7.49 [-9.77 to -5.21], p < 0.001) and LF/HF ratio (0.37 [0.13-0.6], p = 0.004) were independent factors affecting PSQI scores in patients with AE. DISCUSSION: Sleep disorders with autonomic dysfunction are common in patients with AE. Improvements in the PSQI score and SE precede the restoration of sleep microstructural disruption in the remission stage. CPC parameters may be useful in predicting sleep disorders in patients with AE.

Assessment of Sleep Disorders in Patients with CVID.

Inborn errors of immunity have been associated with reduced health-related quality of life and increased fatigue. Sleep disorders, which have been shown to contribute to fatigue and other health concerns, are prevalent in the general population, but there are limited studies evaluating these conditions in patients with common variable immunodeficiency (CVID). Our aim was to evaluate the prevalence of fatigue, sleep disturbances, and sleep-disordered breathing in adults with CVID. Patients completed 4 validated, self-administered questionnaires and a 1-night disposable home sleep apnea test. Our results demonstrated increased median Patient-Reported Outcomes Measurement Information System fatigue scores of 58.7 in patients with CVID in addition to clinically significant fatigue as measured by Fatigue Severity Scale score (median, 5.2) and overall poor sleep quality based on global Pittsburgh Sleep Quality Index score (median, 9.0). For CVID patients who completed the home sleep apnea test, 76.9% met criteria for sleep-disordered breathing with an Apnea-Hypopnea Index score of 5 or greater. The results of our study indicate that patients with CVID may have increased rates of undiagnosed sleep disorders that may contribute to increased fatigue and reduced health-related quality of life.

Age of Alzheimer's disease diagnosis in people with Down syndrome and associated factors: Results from the Horizon 21 European Down syndrome consortium.

INTRODUCTION: People with Down syndrome (DS) have high risk of developing Alzheimer's disease (AD). This study examined mean ages of AD diagnosis and associations with co-occurring conditions among adults with DS from five European countries. METHODS: Data from 1335 people with DS from the Horizon 21 European DS Consortium were used for the analysis. RESULTS: Mean ages of AD diagnosis ranged between 51.4 (SD 7.0) years (United Kingdom) and 55.6 (SD 6.8) years (France). Sleep-related and mental health problems were associated with earlier age of AD diagnosis. The higher number of co-occurring conditions the more likely the person with DS is diagnosed with AD at an earlier age. DISCUSSION: Mean age of AD diagnosis in DS was relatively consistent across countries. However, co-occurring conditions varied and impacted on age of diagnosis, suggesting that improvements can be made in diagnosing and managing these conditions to delay onset of AD in DS. HIGHLIGHTS: Mean age of AD diagnosis was relatively consistent between countries Sleep problems and mental health problems were associated with earlier age of AD diagnosis APOE ε4 carriers were diagnosed with AD at an earlier age compared to non-carriers Number of co-occurring conditions was associated with earlier age of AD diagnosis No differences between level of intellectual disability and mean age of AD diagnosis.

Association between sleep problems and functional disability in community-dwelling older adults.

BACKGROUND: Sleep problems are frequently observed in older adults. They can lead to changes in the individual's physical, occupational, cognitive, and social functioning, compromising the performance of activities of daily living and contributing to the occurrence of functional disability. This study evaluated the association between sleep problems and functional disability in community-dwelling older adults. METHODS: This was a cross-sectional study with data from 10,507 Brazilian community-dwelling older adults participating in the 2013 National Health Survey. The exposure variable was self-reported sleep problems in the last two weeks. The outcome measure was functional disability assessed from self-reported questionnaires, categorized into basic activities of daily living (BADL) and instrumental activities of daily living (IADL), and defined as not being able to perform or having little or a lot of difficulty in at least one of the activities investigated in the domain of interest. RESULTS: Older adults who reported sleep problems had 1.53 (95%CI: 1.34; 1.75) and 1.42 (95%CI: 1.26; 1.59) greater odds of having a disability in BADL and IADL when compared to individuals who reported having no sleep problems. CONCLUSIONS: Older adults with sleep problems were more likely to have a functional disability, both in BADL and IADL. Thus, it is important to implement strategies to screen for sleep problems in older adults in primary health care as a preventive strategy for functional disability.

Assessment of sleep disturbance in patients with Wilson's disease.

BACKGROUND: Wilson's disease (WD) is frequently manifested with anxiety, depression and sleep disturbance; this investigation aimed to elucidate these manifestations and identify the influencing factors of sleep disturbance. METHODS: Sleep disturbance, anxiety and depression were compared in 42 WD and 40 age- and gender-matched healthy individuals. 27 individuals indicated a neurological form of the disease (NV), and 15 had a non-neurological variant (NNV). RESULTS: This investigation revealed that the Parkinson's disease sleep scale (PDSS) score of WD individuals was lower, whereas their Epworth Sleepiness Scale (ESS), Pittsburgh sleep quality index (PSQI), Hamilton Anxiety Scale (HAMA), and Hamilton Depression Scale (HAMD) scores were higher than the healthy individuals (p < 0.05). Furthermore, the WD subjects had markedly increased prevalence of poor sleep quality, anxiety, and depression than healthy individuals (p < 0.05). Subgroup analysis showed that NV subjects had significantly higher scores on the UWDRS, PSQI, HAMA, and HAMD scales than those in the NV group, as well as higher rates of EDS, anxiety, and depression (p < 0.05). In patients with sleep disturbance, we identified UWDRS, neurological variant, and depression as associated factors. The linear regression model demonstrated depression as the dominant risk factor. CONCLUSIONS: Depression is highly correlated with and is a determinant of sleep disturbance in WD patients.

Temporal network of experience sampling methodology identifies sleep disturbance as a central symptom in generalized anxiety disorder.

BACKGROUND: A temporal network of generalized anxiety disorder (GAD) symptoms could provide valuable understanding of the occurrence and maintenance of GAD. We aim to obtain an exploratory conceptualization of temporal GAD network and identify the central symptom. METHODS: A sample of participants (n = 115) with elevated GAD-7 scores (Generalized Anxiety Disorder 7-Item Questionnaire [GAD-7] ≥ 10) participated in an online daily diary study in which they reported their GAD symptoms based on DSM-5 diagnostic criteria (eight symptoms in total) for 50 consecutive days. We used a multilevel VAR model to obtain the temporal network. RESULTS: In temporal network, a lot of lagged relationships exist among GAD symptoms and these lagged relationships are all positive. All symptoms have autocorrelations and there are also some interesting feedback loops in temporal network. Sleep disturbance has the highest Out-strength centrality. CONCLUSIONS: This study indicates how GAD symptoms interact with each other and strengthen themselves over time, and particularly highlights the relationships between sleep disturbance and other GAD symptoms. Sleep disturbance may play an important role in the dynamic development and maintenance process of GAD. The present study may develop the knowledge of the theoretical model, diagnosis, prevention and intervention of GAD from a temporal symptoms network perspective.

Factors associated with sleep disturbances in children and adolescents with Angelman Syndrome.

BACKGROUND: Angelman Syndrome (AS) is a rare genetic disorder characterised by hyperactivity, overexcitability, developmental delays, and lack of speech. METHODS: This study used secondary data analysis to investigate sleep disturbances in children and adolescents (n = 212) who are enrolled in the Global Angelman Syndrome Registry. Participants were divided into two groups based on the presence or absence of sleep disturbance. The cut-off score of 40 on the Sleep Disturbance Scale for Children was used to indicate the presence or absence of sleep disturbances. Sleep disturbances and their association with co-occurring conditions were examined regarding challenging behaviour, language and communication, infancy history, gastrointestinal symptoms, and epilepsy. Multiple regression was then conducted to investigate possible predictors for sleep disturbances. RESULTS: Children and adolescents with AS, with and without sleep disturbances, differed considerably regarding anxiety. Sleep disturbances were significantly associated with an ability to use spoken words and computerised communication devices, and anxiety was a predictor of sleep disturbances. CONCLUSION: Future research is necessary to replicate this novel research, and to advance the clinical treatment of sleep disturbances in children and adolescents with AS.

Persian version of brief infant sleep questionnaire (BISQ): a psychometric evaluation.

BACKGROUND: The high prevalence of sleep problems and their negative consequences on children and parents highlight the need to design early screening instruments to evaluate sleep problems in early childhood. We aimed to determine the validity and reliability of the Brief Infant Sleep Questionnaire (BISQ) among the Iranian population. METHODS AND MATERIALS: This study included 646 one-year-old infants by random sampling from the PERSIAN birth cohort study. Following the forward-backward translation of the BISQ, its psychometric properties, including construct validity in terms of concurrent and convergent validities as well as reliability, were evaluated. RESULTS: The CVIs and CVR ranged between 0.8 and 1.00 for all items. Therefore, we keep all the items of the original version of the BISQ in the Persian BISQ. Concurrent validity was assessed by comparing items of the Persian BISQ among different maternal views regarding their infant's sleep. All BISQ items were significantly different among the two levels of maternal view about the infant's sleep problem except daytime sleep duration. The convergent validity of the BISQ was evaluated by calculating the correlation between BISQ items and the ISQ (infant sleep questionnaire) total score as a similar tool. ISQ score was adequately correlated with nocturnal sleep latency and the number of waking at night (rs ranged from 0.59 to 0.72). In addition, the associations of mothers' and infants' demographic variables and nutritional and gestational variables with BISQ items were presented to confirm construct validity. Strong correlations were found between the repeated sleep measures for sleep arrangement, sleep position, and sleep situation (kappa ranged from 0.65 to 0.84), nocturnal sleep duration, daytime sleep duration number of wakings at night, night waking duration, nocturnal sleep latency and sleep-onset time (ICC ranged 0.91 to 0.99). CONCLUSION: The Persian version of the BISQ is a reliable and valid measure for assessing sleep problems in infants. It would be helpful to be utilized for the early diagnosis of infants' sleep problems.

Psychological symptoms and quality of life in patients with inflammatory bowel disease in China: A multicenter study.

AIMS: To investigate the current situation of mental psychology and quality of life (QoL) in patients with inflammatory bowel disease (IBD) in China, and analyze the influencing factors. METHODS: A unified questionnaire was developed to collect clinical data on IBD patients from 42 hospitals in 22 provinces from September 2021 to May 2022. Multivariate Logistic regression analysis was conducted, and independent influencing factors were screened out to construct nomogram. The consistency index (C-index), receiver operating characteristic (ROC) curve, area under the ROC curve (AUC), calibration curve, and decision curve analysis (DCA) were used to evaluate the discrimination, accuracy, and clinical utility of the nomogram model. RESULTS: A total of 2478 IBD patients were surveyed, including 1371 patients with ulcerative colitis (UC) and 1107 patients with Crohn's disease (CD). Among them, 25.5%, 29.7%, 60.2%, and 37.7% of IBD patients had anxiety, depression, sleep disturbance and poor QoL, respectively. The proportion of anxiety, depression, and poor QoL in UC patients was significantly higher than that in CD patients (all p < 0.05), but there was no difference in sleep disturbance between them (p = 0.737). Female, higher disease activity and the first visit were independent risk factors for anxiety, depression and sleep disturbance in IBD patients (all p < 0.05). The first visit, higher disease activity, abdominal pain and diarrhea symptoms, anxiety, depression and sleep disturbance were independent risk factors for the poor QoL of patients (all p < 0.05). The AUC value of the nomogram prediction model for predicting poor QoL was 0.773 (95% CI: 0.754-0.792). The calibration diagram of the model showed that the calibration curve fit well with the ideal curve, and DCA showed that the nomogram model could bring clinical benefits. CONCLUSION: IBD patients have higher anxiety, depression, and sleep disturbance, which affect their QoL. The nomogram prediction model we constructed has high accuracy and performance when predicting QoL.

The assessment of fatigue and sleep quality among children and adolescents with familial Mediterranean fever: A case-control and correlation study.

To evaluate the sleep quality and fatigue levels in children with familial Mediterranean fever (FMF) in comparison to healthy children. The Pediatric Quality of Life Multidimensional Fatigue Scale (PedsQL-MFS) and the Pittsburgh Sleep Quality Index (PSQI) were the instruments utilized to assess fatigue and sleep quality in children with FMF and controls, respectively. Spearman's rank coefficient was decisive in determining the association between patient-reported outcome measures and disease-related features. Two hundred twenty-five (59.3% female) patients and 182 (51.6% female) healthy counterparts were enrolled in the study. In PSQI, where high scores indicate sleep disturbance, the median score was significantly higher in the patient group (5; 3-6) than the control group (3; 2-4) (p < 0.001). PEDsQL-MFS demonstrated significantly lower fatigue levels in the control group than patients (p = 0.01). The level of fatigue in the patient group was found to increase in correlation with sleep problems (r: - 0.750, p < 0.001). Additionally, a high correlation was present between the PSQI/PedsQL-MFS scores and the number of attacks in the last year (r: - 0.645, p < 0.001/r: 0.721, p < 0.001, respectively). There was no difference in terms of fatigue and sleep disorders between mutations (homozygous, heterozygous, or compound heterozygous) in the MEFV gene (p > 0.05).    Conclusion: High disease activity has a significant negative impact on the sleep quality and fatigue levels of patients with FMF. This study emphasizes the importance of assessing fatigue and sleep quality with objective outcome tools periodically in FMF patients throughout the disease course. What is Known: • Fatigue is a common matter that often accompanies rheumatic diseases and causes disability. • Chronic rheumatic diseases often experience poor sleep quality. What is New: • In high correlation with the disease severity of familial Mediterranean fever, sleep quality decreases and fatigue level increases significantly. • In familial Mediterranean fever patients, a negative correlation is present between age and the general fatigue and sleep/rest related fatigue scores (low scores indicating greater fatigue) and sleep quality is poorer in the adolescent age group.

Sleep quality and psychological disorders in breast cancer female patients receiving radiotherapy at a tertiary oncology center in West Saudi Arabia.

PURPOSE: Breast cancer is the most prevalent type of cancer among women worldwide. Many recently diagnosed and treated breast cancer patients complain about sleep disorders, depression, anxiety, stress, and fatigue. This study aimed to evaluate sleep quality among breast cancer patients and to assess its association with psychological disorders, and socio-demographic and clinical characteristics of patients. METHODS: This cross-sectional study was conducted among women who received radiotherapy for breast cancer (stage 1-3) at King Abdul-Aziz Medical City-Jeddah from January to August 2021. Each participant completed a personal information form, the Pittsburgh Sleep Quality Index (PSQI), the Depression, Anxiety, and Stress Scale-21 (DASS-21), and the International Physical Activity Questionnaire (IPAQ). Clinical data were collected from the medical records to evaluate certain risk factors. Descriptive statistics were used for participant characteristics, and analyses of variance were used to assess associations between the qualitative variables. RESULTS: Fifty-six women with a mean age of 50.1 years and an average of 10 months after cancer diagnosis were included. Poor sleep quality was present in 58% of respondents. Symptomatic depression, anxiety, and stress were found in 34%, 32%, and 30% of women, respectively. Poor sleep quality was associated with depression (p = 0.031), anxiety (p = 0.03), and stress (p = 0.024) and was independently associated with hot flashes. In multivariate analysis, patients with depression or with cancer for more than 6 months were less likely to have good sleep after controlling other variables (21.74 and 14.71 times, respectively). CONCLUSION: Poor sleep quality was present in 58% of women with breast cancer receiving radiotherapy and was significantly associated with depression, anxiety, stress, and hot flashes. Depression level and cancer duration were significant predictors of sleep quality. Early identification and proper management of psychological and sleep disorders are necessary to improve the quality of life and survival of breast cancer patients.

Macro and micro-sleep dysfunctions as translational biomarkers for Parkinson's disease.

Sleep disturbances are highly prevalent among patients with Parkinson's disease (PD) and often appear from the early-phase disease or prodromal stages. In this chapter, we will discuss the current evidence addressing the links between sleep dysfunctions in PD, focusing most closely on those data from animal and mathematical/computational models, as well as in human-based studies that explore the electrophysiological and molecular mechanisms by which PD and sleep may be intertwined, whether as predictors or consequences of the disease. It is possible to clearly state that leucine-rich repeat kinase 2 gene (LRRK2) is significantly related to alterations in sleep architecture, particularly affecting rapid eye movement (REM) sleep and non-REM sleep, thus impacting sleep quality. Also, decreases in gamma power, observed after dopaminergic lesions, correlates negatively with the degree of injury, which brings other levels of understanding the impacts of the disease. Besides, abnormal synchronized oscillations among basal ganglia nuclei can be detrimental for information processing considering both motor and sleep-related processes. Altogether, despite clear advances in the field, it is still difficult to definitely establish a comprehensive understanding of causality among all the sleep dysfunctions with the disease itself. Although, certainly, the search for biomarkers is helping in shortening this road towards a better and faster diagnosis, as well as looking for more efficient treatments.

Setting the clinical context to non-motor symptoms reflected by Park-pain, Park-sleep, and Park-autonomic subtypes of Parkinson's disease.

Non-motor symptoms (NMS) of Parkinson's disease (PD) are well described in both clinical practice and the literature, enabling their management and enhancing our understanding of PD. NMS can dominate the clinical pictures and NMS subtypes have recently been proposed, initially based on clinical observations, and later confirmed in data driven analyses of large datasets and in biomarker-based studies. In this chapter, we provide an update on what is known about three common subtypes of NMS in PD. The pain (Park-pain), sleep dysfunction (Park-sleep), and autonomic dysfunction (Park-autonomic), providing an overview of their individual classification, clinical manifestation, pathophysiology, diagnosis, and potential treatments.

Sleep-Related Dissociative Disorders.

In sleep-related dissociative disorders, phenomena of the psychiatrically defined dissociative disorders emerge during the sleep period. They occur during sustained wakefulness, either in the transition to sleep or following an awakening from sleep. Behaviors during episodes vary widely, and can result in injury to self or others. Daytime dissociative episodes and a background of trauma are almost always present; there is typically major co-existing psychopathology. Diagnosis is based on both clinical history and polysomnography; differential diagnosis primarily involves other parasomnias and nocturnal seizures. Information available about treatment is limited; in a few reported cases, psychological interventions have proven effective.

Sleep-Related Hallucinations.

The diagnostic category of sleep-related hallucinations (SRH) replaces the previous category of Terrifying Hypnagogic Hallucinations in the 2001 edition of International Classification of Sleep Disorders-R. Hypnagogic and hypnopompic hallucinations (HHH) that occur in the absence of other symptoms or disorder and, within the limits of normal sleep, are most likely non-pathological. By contrast, complex nocturnal visual hallucinations (CNVH) may reflect a dimension of psychopathology reflecting different combinations of etiologic influences. The identification and conceptualization of CNVH is relatively new, and more research is needed to clarify whether CNVH share common mechanisms with HHH.