Classification of Sleep Disorders

To determine clinicians' patterns of use of the International Classification of Sleep Disorders (ICSD) and their ratings of its utility and organization. A telephone survey was conducted in one clinician practicing at each of 206 sleep centers accredited by the American Academy of Sleep Medicine (AASM). Descriptive analyses were performed, and ratings for various sleep classifications were compared with ANOVA and post- hoc tests. Clinicians at 230/251 (92%) of contacted centers agreed to participate, and data from 206/251 (82%) were actually collected. The ICSD was used by 91.7% of clinicians for clinical decision making but by lower percentages for billing or medical record keeping. Features of the ICSD pertaining to clinical descriptions and differential diagnosis were rated as most useful. The Association of Sleep Disorders Centers (ASDC) classification was rated more highly than ICSD in organization and ease of use. The ICSD and ASDC systems were rated more highly than other sleep disorders classifications in terms of organization, "fit" to patients, and ease of use. The ICSD is used widely by clinicians, primarily for diagnostic purposes, and is preferred over more general sleep disorders classification systems. However, more favorable ratings for the ASDC compared to ICSD indicate the value clinicians place on easy-to-use, symptom-oriented classifications.

Evolution of the Classification of Sleep Disorders

The classification of sleep disorders has been of particular interest to clinicians ever since they were initially recognized. The International Classification of Sleep Disorders, 2nd edn (ICSD-2) classification lists 85 sleep disorders, each presented in detail and with a descriptive diagnostic text that includes specific diagnostic criteria. The ICSD-2 has eight major categories: (1) the insomnias; (2) the sleep-related breathing disorders; (3) the hypersomnias not due to a sleep-related breathing disorder; (4) the circadian rhythm sleep disorders; (5) the parasomnias; (6) the sleep-related movement disorders; (7) other sleep disorders; and (8) isolated symptoms, apparently normal variants, and unresolved issues (Table 1.1).

The recognition and growth of sleep medicine as a clinical specialty is manifested by the inclusion of sleep disorders in disease classification systems from the 1970s. The task of developing a classification system for sleep disorders has been undertaken by three organizations, namely, the World Health Organization (WHO), the American Psychiatric Association (APA) and associations and societies involved in sleep medicine as a clinical discipline, most recently the American Academy of Sleep Medicine (AASM). Three different classification systems have evolved: first, with sleep disorders being added to a general coding system, the International Classification of Diseases (ICD)(World Health Organization 1977, 1994, 2011); second, designed for use by mental health professionals, the Diagnostic and Statistical Manual of Mental Disorders (DSM)(American Psychiatric Association 1994, 2013); and third, developed by and for specialists in sleep medicine, the International Classification of Sleep Disorders (ICSD)(Association of Sleep Disorders Centers 1979, 1990, 1997; American Academy of Sleep Medicine 2005, 2014). A summary of the development of these three nosologies from the 1970s to the present is summarized in Table 2.1. In examining their development, it is important to recognize how the classification systems should, and do, evolve in response to other classification systems, as well as advances in scientific knowledge and clinical experience.

ABSTRACTTaking into consideration that shift work has a wide-ranging impact on circadian and sleep functioning, it seems likely that shift work increases the risk of a general sleep disturbance, spread out over a multitude of comorbid sleep disorders. The aim of the present study is to analyze and present the sleep disorder data of 250 shift workers and 971 permanent day workers, taken from a nationally representative sample. Additional data concerning duration, timing, and quality of sleep, daytime functioning and social/family variables were added to the analyses. The results showed that the shift workers experienced significantly more difficulties with the variability of their sleep times, reported more napping and considered themselves more as poor sleepers than the day workers. Most importantly, shift work, in comparison with day work, appeared associated with a significantly higher prevalence of the clinical, International Classification of Sleep Disorders’ defined symptoms of nearly all main sleep disorders (including shift work disorder). For shift workers, the prevalence of a general sleep disturbance was 39.0% (95%CI 33.2 – 45.2), significantly higher than for day workers (24.6%, 95%CI 22.0 – 27.4). Moreover, shift workers were characterized by high levels of sleep disorder comorbidity. In addition, exclusively for shift workers, the prevalence of disordered sleep systematically decreased across decades of life and was considerably higher for single versus partnered shift workers. This study adds to the insight into the interacting factors that determine shift work coping and may play a role in occupational health interventions aimed at reducing sleep problems and thus improving the resilience and tolerance of the shift worker.

The Consensus Development Conference on sleep disorders convened by the National Institute of Mental Health in 1979 [14] subdivided insomnia into transient, short term, and long term or chronic conditions. The first type lasts one to several days, the second, from one to 4 weeks and chronic insomnia for more than 4 weeks. The first and second types will be dealt with in this chapter, i.e. insomnia which is systematically linked to a clearly determined, perfectly identifiable cause, occurring in persons with a history of normal sleep. The International Classification of Sleep Disorders (ICSD) [9] comprises four sections, dyssomnias, parasomnias, sleep disorders associated with medical or psychiatric disorders and “proposed” sleep disorders. The section on dyssomnias itself comprises three subgroups: intrinsic sleep disorders, extrinsic sleep disorders and circadian rhythm sleep disorders. Most transient and short term insomnias are classed in the subgroup of extrinsic disorders, i.e. those whose causes are external to the organism Four of the main ones will be dealt with here: insomnia due to inadequate sleep hygiene, environment-related insomnia, altitude insomnia and adjustment or short term insomnia, to which will be added insomnia due to transient physical stress, pain, coughing, pruritis, not explicitly mentioned in the ICSD, as well as rebound insomnia following the discontinuation of certain hypnotics.

Impacts of shift work on sleep and circadian rhythms

The main aim of this thesis was to examine sleep in adolescents and young adults during the first 10 years after diagnosis and treatment for childhood cancer: what has been the impact of being critically ill, undergoing extensive treatment and the type of cancer on sleep and how do we measure, identify and intervene in sleep problems and disorders in this patient group. In chapter 2, we evaluated the psychometric properties of the Dutch versions of the Pediatric PROMIS item banks for sleep disturbance (SD), sleep-related impairment (SRI) and fatigue in Dutch children and adolescents from the general population, since they have not been validated yet in this translation. The SD item bank did not meet all assumptions for item response theory (IRT) modeling (not unidimensional). The SRI and fatigue item banks met the assumptions and measured reliably, in which computerized adaptive testing (CAT) outperformed the full and short forms. Overall, this study shows that the Dutch pediatric PROMIS item banks for SRI and Fatigue are efficient and reliable in measuring sleep-related impairment and fatigue in Dutch children and adolescents, but further research is needed for the SD item bank. In chapter 3, we systematically reviewed the literature on risk factors associated with steroid-induced adverse psychological reactions (APRs) and sleep problems in children diagnosed with Acute Lymphoblastic Leukemia (ALL). The findings reveal that there were few high-quality prospective studies and sample sizes were small, necessitating caution in interpreting the results. We therefore formulated recommendations regarding risk factors associated with steroid-induced APRs and sleep problems and in addition recommend to invest in more high-quality studies to draw more substantiated conclusions. We recommend using standardized prospective registration of steroid-induced APRs and sleep problems, alongside the identification of risk factors in forthcoming studies involving children with ALL. In chapter 4, we assessed the prevalence of six sleep disorders based on the International Classification of Sleep Disorders, second edition (ICSD-2) in 576 adolescent and young adult childhood cancer patients in follow-up after treatment (aged 12-26; at least six months post-treatment). We found insomnia (9.6%) to be most prevalent disorder followed by circadian rhythm sleep disorder (CRSD; 8.1%), restless legs syndrome (7.6%), parasomnia (3.5%), hypersomnia (3.5%), and sleep-related breathing disorders (1.8%). A considerable proportion of participants expressed a need for sleep treatment (ranging from 42% to 72% depending on the sleep disorder), but only a small percentage received such treatment (0% to 5.6%). These findings emphasize the treatment access gap for sleep treatment among childhood cancer patients during their follow-up care. In chapter 5, we assessed the prevalence of insomnia-only, daytime fatigue-only, the coexistence of insomnia and daytime fatigue symptoms, and associated risk factors among 565 childhood cancer patients (aged 12-26; at least six months post-treatment). In total, 61.8% of the patients reported no insomnia or daytime fatigue symptoms, while 38.2% experienced symptoms. Among those with symptoms, 48.1% reported both insomnia and daytime fatigue, 34.7% had insomnia only, and 17.1% experienced daytime fatigue only. Our results indicate that approximately 40% of patients suffer from either insomnia or fatigue, with half of them experiencing both simultaneously. In chapter 6, we describe the study protocol of our randomized-controlled trial evaluating the effectiveness of online cognitive behavioral therapy for insomnia (online CBT-i) i-Sleep youth on insomnia symptoms in adolescents and young adults who finished childhood cancer treatment. We hypothesize that the intervention will improve sleep efficiency (actigraphy) and insomnia severity (self-report) on the short-term compared to the control group, which is maintained on the long-term up to a year after the intervention. We also aim to study the acceptability of the online intervention in the adolescent target group.

The prevalence and risk factors of shift work disorder among nurses: A systematic review and meta-analysis.

Search filters for systematic reviews and meta-analyses in sleep medicine.

Normal circadian rhythms are synchronized to a regular 24 h environmental light-dark cycle, and the suprachiasmatic nucleus and the hormone melatonin have important roles in this process. Desynchronization of circadian rhythms, as occurs in chronobiological disorders, can produce severe disturbances in sleep patterns. According to the International Classification of Sleep Disorders, circadian rhythm sleep disorders (CRSDs) include delayed sleep phase syndrome, advanced sleep phase syndrome, non-24 h sleep-wake disorder, jet lag and shift-work sleep disorder. Disturbances in the circadian phase position of plasma melatonin levels have been documented in all of these disorders. There is compelling evidence to implicate endogenous melatonin as an important mediator in CRSD pathophysiology, although further research involving large numbers of patients will be required to clarify whether the disruption of melatonin secretion is a causal factor in CRSDs. In this Review, we focus on the use of exogenous melatonin and light therapy to treat the disturbed sleep-wake rhythms seen in CRSDs.

Teleworking during a pandemic: perspective of an idiopathic hypersomnia patient.

The topic 'Emerging Talents in Sleep Disorders' is dedicated to highlighting students and early career researchers within the field of sleep disorders. They are bringing exciting new ideas to the field. However, many of these ideas are not communicated to a broader audience. We recognize that this is because many students and early career researchers may lack a platform to share their ideas. This topic gives an opportunity to succeed with their manuscripts.Chen Tien-Yu et al., reported the prevalence and effects of sleep-disordered breathing on middle-aged patients with sedative-free generalized anxiety disorder ( https://doi.org/10.3389/fpsyt.2022.1067437 ). Generalized anxiety disorder (GAD) and sleepdisordered breathing (SDB) share similar symptoms, such as poor sleep quality, irritability, and poor concentration during daily activities. This study investigates the proportion of undiagnosed SDB and its impacts on anxiety severity and autonomic function in newly diagnosed, sedativefree GAD patients. They found that an average age 55 years and mean BMI 23 kg/m2 patients with GAD and matched controls had an undiagnosed SDB prevalence of approximately 50%. Also noticed that SDB correlated with worsening anxiety severity and reduced cardiac autonomic function. Importantly, age and BMI were major risk factors for predicting undiagnosed SDB. Nakajima S et al described the transdiagnostic association between subjective insomnia and depressive symptoms in major psychiatric disorders (https://doi.org/10.3389/fpsyt.2023.1114945). Comorbid depressive symptoms are associated with clinically important issues such as reduced quality of life, a poor prognosis, and increased suicide risk. This study investigated whether the association between insomnia and depressive symptoms is also found in other psychiatric disorders. In schizophrenia, a relation between depressive symptoms and insomnia was also found by objective sleep assessment methods using sleep EEG. Their results suggest that the association between subjective insomnia and depressive symptoms is a transdiagnostic feature in major psychiatric disorders.Ding Q et al examined validation of a portable monitor compared with polysomnography for screening of obstructive sleep apnea in polio survivors (https://doi.org/10.3389/fneur.2023.1137535). Sleep-disordered breathing (SDB) is highly prevalent in polio survivors. Obstructive sleep apnea (OSA) is the most frequent type. Full polysomnography (PSG) is recommended for OSA diagnosis in patients with comorbidities by current practice guidelines, but it is not always accessible. They studied whether type 3 portable monitor (PM) or type 4 PM might be a viable alternative to PSG for the diagnosis of OSA in post-polio subjects. The insightful study showed Type 3 PM and Type 4 PM could be alternative ways to screen OSA for polio survivors, especially for moderate to severe OSA. Sun J et al reviewed Global research on cancer and sleep: a bibliometric and visual analysis of the last two decades (https://doi.org/10.3389/fneur.2023.1139746). This systemic review analyzed the research status, hotspots, and frontiers of global research on cancer and sleep through bibliometrics and provided references and guidance for future research. Cancer and sleep disruption and the influencing factors of sleep quality is an emerging topic. This study systematically analyzed the hotspots and frontiers in the field of cancer and sleep research. The authors named multiple foal topics for further research studies such as, intervention measures for the cancer symptom cluster, the bioavailability of exogenous melatonin, the relationship between OSA and cancer, the mechanism of tumor-induced sleep disruption, the dose-response relationship between sleep duration and cancer risk.Sleep problems are a growing public health concern worldwide. The 2023 Sleep in America poll conducted by the National Sleep Foundation showed that almost 65% of adults who are dissatisfied with their sleep have mild or severe depressive symptoms (1). The International Classification of Sleep Disorders by American Academy of Sleep Medicine lists 60 specific sleep disorders, the most common of which are insomnia, sleep apnea, restless legs syndrome, and narcolepsy (2).The close association between altered sleep pattern and diseases makes sleep a valuable diagnostic biomarker for non-invasive early diagnosis of some diseases. As sleep disorders increase with age and age is considered one of the major predictors of morbidity and mortality. Despite the diverse nature of sleep disorders, they have far-reaching, detrimental effects on population health and increase both morbidity and mortality of various chronic diseases (3). The chronic effects of sleep disorders deserve more attention from doctors, researchers, and society. As well as a better understanding of the mechanisms of sleep, new approaches to diagnose and treat sleep disorders are urgently needed. The editorial team thanks reviewers for their constructive criticism.

Impact of Neurological Diseases

Excessively sleepy teenagers and young adults without sleep-disordered breathing are diagnosed with either narcolepsy type 1 or narcolepsy type 2, or hypersomnia, based on the presence/absence of cataplexy and the results of a multiple sleep latency test. However, there is controversy surrounding this nomenclature. We will try to find the differences between different diagnoses of hypersomnia from the results of the long-term follow-up evaluation of a sleep study. We diagnosed teenagers who had developed excessive daytime sleepiness based on the criteria of the International Classification of Sleep Disorders, 3rd edition. Each individual received the same clinical neurophysiologic testing every year for 5years after the initial diagnosis of narcolepsy type 1 (n=111) or type 2 (n=46). The follow-up evaluation demonstrated that narcolepsy type 1 (narcolepsy-cataplexy) is a well-defined clinical entity, with very reproducible clinical neurophysiologic findings over time, whereas patients with narcolepsy type 2 presented clear clinical and test variability. By the fifth year of the follow-up evaluation, 17.6% of subjects did not meet the diagnostic criteria of narcolepsy type 2, and 23.9% didn't show any two sleep-onset rapid eye movement periods in multiple sleep latency during the 5-year follow-up. Therefore narcolepsy type 1 (narcolepsy-cataplexy) is a well-defined syndrome, with the presentation clearly related to the known consequences of destruction of hypocretin/orexin neurons. Narcolepsy type 2 covers patients with clinical and test variability over time, thus bringing into question the usage of the term "narcolepsy" to label these patients.