The multiple sleep latency test

Correlation analysis between HLA-DQA1*0102/DQB1*0602 genotypes and narcolepsy patients in China

Background and objective

At present, the etiology of narcolepsy is not fully understood, and it is generally believed to be an autoimmune reaction caused by interactions between environmental and genetic factors. Human leukocyte antigen (HLA) class II genes are strongly associated with this gene, especially HLA-DQB1*0602/DQA1*0102. In this study, we mainly analyzed the correlation between different genotypes of HLA-DQB1*0602/DQA1*0102 and clinical manifestations in Chinese patients with narcolepsy.

Experimental method

Narcolepsy patients who were treated at the Department of Neurology, The First Affiliated Hospital of Shandong First Medical University from January 2021 to September 2023 were selected. General information, sleep monitoring data, cerebrospinal fluid (CSF) orexin levels, and human leukocyte antigen gene typing data were collected. The statistical analysis was performed using SPSS 26.0, and the graphs were drawn using GraphPad Prism 9.5.

Main results

A total of 78 patients were included in this study. The DQA1 and DQB1 gene loci were detected in 54 patients, and only the DQB1 gene locus was detected in 24 narcoleptic patients. The most common allele at the HLA-DQB1 locus was *0602 (89.7%), and the most common genotype at this locus was *0602*0301 (19.2%), followed by *0602*0602 (17.9%). The most common phenotype of the HLA-DQA1 locus is *0102 (92.6%), and the most common genotype of this locus is *0102*0102 (27.8%), followed by *0102*0505 (14.8%). There were significant differences (p < 0.05) between HLA-DQB1*0602-positive and HLA-DQB1*0602-negative patients in terms of orexin-A levels, presence or absence of cataplexy, UNS, PSG sleep latency, REM sleep latency, N1 sleep percentage, oxygen depletion index, and average REM latency on the MSLT. The HLA-DQA1*0102-positive and HLA-DQA1*0102-negative patients showed significant differences (p < 0.05) in disease course, presence or absence of sudden onset, PSG REM sleep latency, N1 sleep percentage, and average REM latency on the MSLT. There were significant differences in the average REM latency of the MSLT between HLA-DQB1*0602/DQA1*0102 homozygous and heterozygous patients p < 0.05, and no differences were found in the baseline data, orexin-A levels, scale scores, or other sleep parameters.

Conclusion

Different genotypes of HLA-DQA1*0102/DQB1*0602 are associated with symptoms of cataplexy in Chinese narcoleptic patients. Homozygous individuals have a shorter mean REM latency in the MSLT, greater genetic susceptibility, and relatively more severe sleepiness.

Poor Sleep Quality in Jamaican Adults With Sickle Cell Disease: Prevalence, Risk Factors, and Association With Quality of Life

Poor sleep and chronic illnesses have a bidirectional relationship where presence of one can worsen the other. Sickle cell disease (SCD) is associated with significant morbidity and early mortality. In this study, we examine sleep quality, its predictors, and its association with quality of life in Jamaican adults with SCD. This cross-sectional study evaluated 177 well adult SCD patients for sleep quality using The Pittsburgh Sleep Quality Index (PSQI) and quality of life using the Adult Sickle Cell Quality of Life Measurement Information System (ASCQ-Me). Multiple linear regression models examined the predictors of poor sleep quality. The mean global PSQI score was 6.9 (SD 4.2) with 56.5% having poor sleep quality. Women had significantly worse scores for sleep efficiency (p 0.005), sleep latency (p 0.03) and higher use of sleeping medications (p 0.02). Those overweight/obese had significantly worse subjective sleep quality (p 0.001) and sleep efficiency (p 0.05). In multivariate regression analysis, overweight individuals had poorer sleep quality (OR: 2.9; 95% C.I.: 1.07, 7.88) than those with normal weight whereas those unemployed and looking for a job had lower prevalence of poor sleep quality (OR 0.2; 95% C.I.: 0.05, 0.77) compared to employed individuals. Participants with good sleep quality had significantly better functioning in all 5 domains of the ASCQ-Me. In conclusion, persons with SCD who are overweight or obese are at increased risk of poor sleep which can negatively affect quality of life. Patient populations and healthcare providers will need to manage the emerging burden of overweight/obesity.

Objective evaluation of excessive daytime sleepiness

Excessive daytime sleepiness (EDS) is multifactorial. It combines, among other things, an excessive propensity to fall asleep ("physiological sleepiness") and a continuous non-imperative sleepiness (or drowsiness/hypo-arousal) leading to difficulties remaining awake and maintaining sustained attention and vigilance over the long term ("manifest sleepiness"). There is no stand-alone biological measure of EDS. EDS measures can either capture the severity of physiological sleepiness, which corresponds to the propensity to fall asleep, or the severity of manifest sleepiness, which corresponds to behavioral consequences of sleepiness and reduced vigilance. Neuropsychological tests (The psychomotor vigilance task (PVT), Oxford Sleep Resistance Test (OSLeR), Sustained Attention to Response Task (SART)) explore manifest sleepiness through several sustained attention tests but the lack of normative values and standardized protocols make the results difficult to interpret and use in clinical practice. Neurophysiological tests explore the two main aspects of EDS, i.e. the propensity to fall asleep (Multiple sleep latency test, MSLT) and the capacity to remain awake (Maintenance of wakefulness test, MWT). The MSLT and the MWT are widely used in clinical practice. The MSLT is recognized as the "gold standard" test for measuring the severity of the propensity to fall asleep and it is a diagnostic criterion for narcolepsy. The MWT measures the ability to stay awake. The MWT is not a diagnostic test as it is recommended only to evaluate the evolution of EDS and efficacy of EDS treatment. Even if some efforts to standardize the protocols for administration of these tests have been ongoing, MSLT and MWT have numerous limitations: age effect, floor or ceiling effects, binding protocol, no normal or cutoff value (or determined in small samples), and no or low test-retest values in some pathologies. Moreover, the recommended electrophysiological set-up and the determination of sleep onset using the 30‑sec epochs scoring rule show some limitations. New, more precise neurophysiological techniques should aim to detect very brief periods of physiological sleepiness and, in the future, the brain local phenomenon of sleepiness likely to underpin drowsiness, which could be called "physiological drowsiness".

A narrative review on insomnia and hypersomnolence within Major Depressive Disorder and bipolar disorder: A proposal for a novel psychometric protocol

Sleep disorders have become increasingly prevalent, with many adults worldwide reporting sleep dissatisfaction. Major Depressive Disorder (MDD) and Bipolar Disorder (BD) are common conditions associated with disrupted sleep patterns such as insomnia and hypersomnolence. These sleep disorders significantly affect the progression, severity, treatment, and outcome of unipolar and bipolar depression. While there is evidence of a connection between sleep disorders and depression, it remains unclear if sleep features differ between MDD and BD. In light of this, this narrative review aims to: (1) summarize findings on common sleep disorders like insomnia and hypersomnolence, strongly linked to MDD and BD; (2) propose a novel psychometric approach to assess sleep in individuals with depressive disorders. Despite insomnia seems to be more influent in unipolar depression, while hypersomnolence in bipolar one, there is no common agreement. So, it is essential adopting a comprehensive psychometric protocol for try to fill this gap. Understanding the relationship between sleep and MDD and BD disorders are crucial for effective management and better quality of life for those affected.

Sleep deprivation detected by voice analysis

Sleep deprivation has an ever-increasing impact on individuals and societies. Yet, to date, there is no quick and objective test for sleep deprivation. Here, we used automated acoustic analyses of the voice to detect sleep deprivation. Building on current machine-learning approaches, we focused on interpretability by introducing two novel ideas: the use of a fully generic auditory representation as input feature space, combined with an interpretation technique based on reverse correlation. The auditory representation consisted of a spectro-temporal modulation analysis derived from neurophysiology. The interpretation method aimed to reveal the regions of the auditory representation that supported the classifiers' decisions. Results showed that generic auditory features could be used to detect sleep deprivation successfully, with an accuracy comparable to state-of-the-art speech features. Furthermore, the interpretation revealed two distinct effects of sleep deprivation on the voice: changes in slow temporal modulations related to prosody and changes in spectral features related to voice quality. Importantly, the relative balance of the two effects varied widely across individuals, even though the amount of sleep deprivation was controlled, thus confirming the need to characterize sleep deprivation at the individual level. Moreover, while the prosody factor correlated with subjective sleepiness reports, the voice quality factor did not, consistent with the presence of both explicit and implicit consequences of sleep deprivation. Overall, the findings show that individual effects of sleep deprivation may be observed in vocal biomarkers. Future investigations correlating such markers with objective physiological measures of sleep deprivation could enable "sleep stethoscopes" for the cost-effective diagnosis of the individual effects of sleep deprivation.

Emergence of different dimensions of sleepiness in a general population sample: An EPISONO study

INTRODUCTION

Recent evidence supports the idea that sleepiness has several dimensions, comprising psychophysiological phenomena, such as sleep propensity and sleepiness perception. The Epworth Sleepiness Scale (ESS) is among one of the most used sleepiness assessment tools, but recent data suggest that it might not detect problematic impairments in sleep health. More research is warranted investigating sleepiness dimensions with large sample sizes, using both objective and subjective methods of analyzing sleep.

METHODS

We used data from the Epidemiological Sleep Study (EPISONO), a major study carried out in Brazil using a representative sample of 1042 participants of the general population of Sao Paulo city, who completed questionnaires and underwent type I polysomnography. Sleepiness was measured by the ESS (sleep propensity) and the UNIFESP Sleep Questionnaire, which asked about the frequency of feeling sleepy during the day (sleepiness perception). The participants were distributed into 4 groups in respect of excessive daytime sleepiness (EDS) according to the following criteria: 1) having an ESS score >10 (ESS group). 2) feeling sleepy ≥3 times per week (Frequent EDS group). 3) the combined criteria (Combined EDS group). 4) having no evidence of EDS (no EDS group). The UNIFESP Sleep Questionnaire was used to obtain self-reported sleep duration, sleep debt, and sleep duration variability. Participants also completed the Pittsburgh Sleep Quality Index, the Insomnia Severity Index, and a pre-polysomnography sleep questionnaire.

RESULTS

After removing participants with missing data, there were 620 participants with no EDS, 255 individuals in the ESS group, 68 in the Frequent EDS group, and 73 in the Combined EDS group. Compared to the no EDS group, the ESS and Combined EDS groups had significantly increased sleep efficiency, diminished sleep latency, wake after sleep onset, and self-reported weekly sleep duration. The Frequent and Combined EDS groups had significantly higher scores in the Insomnia Severity Index and Pittsburgh Sleep Quality Index. All EDS groups had an increased likelihood of nonrestorative sleep. EDS frequency and the ESS scores were significantly correlated.

CONCLUSIONS

Participants with a high sleep propensity had a profile suggesting prior sleep deprivation, while high sleepiness perception was associated with impaired sleep quality. These findings indicated that, in the general population, these instruments evaluated separate sleepiness dimensions with different associations, highlighting that screening using a combination of instruments might be more effective in detecting impairments in sleep health.

Myopia and sleep in children-a systematic review

Worldwide, approximately one in three people are myopic or short-sighted. Myopia in children is of particular concern as younger onset age implies a higher risk of progression, and consequently greater risk of developing vision-threatening complications. The importance of sleep in children's health has long been acknowledged, but evidence for its role in childhood myopia is fairly new and mixed results were presented across studies. To facilitate better understanding of this relationship, a broad literature search, up to and including October 31, 2022, was performed using three databases (PubMed, Embase, and Scopus). Seventeen studies were included in the review, covering four main aspects of sleep, namely duration, quality, timing, and efficiency, and their associations with myopia in children. The present literature review discussed these studies, revealed potential limitations in their methodologies, and identified gaps that need to be addressed in the future. The review also acknowledges that current evidence is insufficient, and the role of sleep in childhood myopia is far from being fully understood. Future studies that primarily, objectively, and accurately assess sleep and myopia, taking other characteristics of sleep beyond duration into consideration, with a more diverse sample in terms of age, ethnicity, and cultural/environmental background, and control for confounders such as light exposure and education load are much needed. Although more research is required, myopia management should be a holistic approach and the inclusion of sleep hygiene in myopia education targeting children and parents ought to be encouraged.

Larger hypothalamic volume in narcolepsy type 1

STUDY OBJECTIVES

Narcolepsy type 1 (NT1) is a neurological sleep disorder. Postmortem studies have shown 75%-90% loss of the 50 000-70 000 hypocretin-producing neurons and 64%-94% increase in the 64 000-120 000 histaminergic neurons and conflicting indications of gliosis in the hypothalamus of NT1 patients. The aim of this study was to compare MRI-based volumes of the hypothalamus in patients with NT1 and controls in vivo.

METHODS

We used a segmentation tool based on deep learning included in Freesurfer and computed the volume of the whole hypothalamus, left/right part of the hypothalamus, and 10 hypothalamic subregions. We included 54 patients with post-H1N1 NT1 (39 females, mean age 21.8 ± 11.0 years) and 114 controls (77 females, mean age 23.2 ± 9.0 years). Group differences were tested with general linear models using permutation testing in Permutation Analysis of Linear Models and evaluated after 10 000 permutations, yielding two-tailed P-values. Furthermore, a stepwise Bonferroni correction was performed after dividing hypothalamus into smaller regions.

RESULTS

The analysis revealed larger volume for patients compared to controls for the whole hypothalamus (Cohen's d = 0.71, p = 0.0028) and for the left (d = 0.70, p = 0.0037) and right part of the hypothalamus (d = 0.65, p = 0.0075) and left (d = 0.72, p = 0.0036) and right tubular-inferior (d = 0.71, p = 0.0037) hypothalamic subregions.

CONCLUSIONS

In conclusion, patients with post-H1N1 NT1 showed significantly larger hypothalamic volume than controls, in particular in the tubular-inferior subregions which could reflect several processes as previous studies have indicated neuroinflammation, gliosis, and changes in the numbers of different cell types.

Validating Force Sensitive Resistor Strip Sensors for Cardiorespiratory Measurement during Sleep: A Preliminary Study

Sleep disorders can impact daily life, affecting physical, emotional, and cognitive well-being. Due to the time-consuming, highly obtrusive, and expensive nature of using the standard approaches such as polysomnography, it is of great interest to develop a noninvasive and unobtrusive in-home sleep monitoring system that can reliably and accurately measure cardiorespiratory parameters while causing minimal discomfort to the user's sleep. We developed a low-cost Out of Center Sleep Testing (OCST) system with low complexity to measure cardiorespiratory parameters. We tested and validated two force-sensitive resistor strip sensors under the bed mattress covering the thoracic and abdominal regions. Twenty subjects were recruited, including 12 males and 8 females. The ballistocardiogram signal was processed using the 4th smooth level of the discrete wavelet transform and the 2nd order of the Butterworth bandpass filter to measure the heart rate and respiration rate, respectively. We reached a total error (concerning the reference sensors) of 3.24 beats per minute and 2.32 rates for heart rate and respiration rate, respectively. For males and females, heart rate errors were 3.47 and 2.68, and respiration rate errors were 2.32 and 2.33, respectively. We developed and verified the reliability and applicability of the system. It showed a minor dependency on sleeping positions, one of the major cumbersome sleep measurements. We identified the sensor under the thoracic region as the optimal configuration for cardiorespiratory measurement. Although testing the system with healthy subjects and regular patterns of cardiorespiratory parameters showed promising results, further investigation is required with the bandwidth frequency and validation of the system with larger groups of subjects, including patients.

How hypocretin agonists may improve the quality of wake in narcolepsy

Excessive daytime sleepiness (EDS) is a complex symptom characterized by a strong urge to sleep during daytime accompanied by problems such as attention deficits, anxiety, and lower cognitive performance. The efficacy of treatments for EDS is determined by their ability to decrease sleepiness, and less attention has been given to the effects these compounds have on the quality of the wake itself. Hypocretin (HCRT; orexin) signalling is implicated in narcolepsy, and hypocretin receptor 2 (HCRTR2) agonists are in clinical trials for treating EDS in narcolepsy. Here, we review preclinical research to determine how HCRTR2 agonists may affect attention and anxiety compared with other EDS treatment strategies. We conclude that such compounds may improve not only the quantity but also the quality of wake, and we hope that they will create opportunities for more nuanced treatment strategies in narcolepsy.

Clinical considerations for the diagnosis of idiopathic hypersomnia

Idiopathic hypersomnia is a sleep disorder of neurologic origin characterized by excessive daytime sleepiness, with sleep inertia, long, unrefreshing naps, and prolonged nighttime sleep being key symptoms in many patients. Idiopathic hypersomnia is described in the International Classification of Sleep Disorders, 3rd Edition as a central disorder of hypersomnolence with distinct clinical features and diagnostic criteria; however, confirming the diagnosis of idiopathic hypersomnia is often challenging. Diagnosis of idiopathic hypersomnia is based on objective sleep testing and the presence of associated clinical features but may be difficult for clinicians to recognize and correctly diagnose because of its low prevalence, clinical heterogeneity, and symptoms, which are similar to those of other sleep disorders. The testing required for diagnosis of idiopathic hypersomnia also presents logistical barriers, and reliability of objective sleep measures is suboptimal. The pathophysiology of idiopathic hypersomnia remains unknown. In this review, clinical considerations related to the pathogenesis, diagnosis, and management of idiopathic hypersomnia will be discussed, including perspectives from the European Union and United States.

Understanding and approaching excessive daytime sleepiness

Excessive daytime sleepiness (EDS) is a public health issue. However, it remains largely undervalued, scarcely diagnosed, and poorly supported. Variations in the definition of EDS and limitations in clinical assessment lead to difficulties in its epidemiological study, but the relevance of this symptom from a socioeconomic perspective is inarguable. EDS might be a consequence of several behavioural issues leading to insufficient or disrupted sleep, as well as a consequence of sleep disorders including sleep apnoea syndrome, circadian disorders, central hypersomnolence disorders (narcolepsy and idiopathic hypersomnia), other medical or psychiatric conditions, or medications. Furthermore, EDS can have implications for health as it is thought to act as a risk factor for other conditions, such as cardiovascular and neurodegenerative disorders. Because of the heterogeneous causes of EDS and the complexity of its pathophysiology, management will largely depend on the cause, with the final aim of making treatment specific to the individual using precision medicine and personalised medicine.

Secondary Narcolepsy as Worsening Sign in a Pediatric Case of Optic Pathway Glioma

Narcolepsy, a neurologic disorder that leads to excessive daytime sleepiness, may represent a rare consequence of neoplastic lesions involving the sellar/parasellar and hypothalamic regions, the anatomical areas responsible for wakefulness. Optic pathway gliomas represent the most common neoplasm of these regions and present an excellent overall survival, while long-term neurologic impairments, such as visual loss, endocrinopathies, or sleep disorders, are the principal causes of morbidity. In this case report, we describe a non-NF1 patient suffering from a very extensive optical pathway glioma, who several years after the diagnosis in a radiological condition of stable disease, presented with severe narcolepsy, a rare complication, that led to the death of the patient.

Revisiting the Concept of Vigilance

Vigilance deficits can be observed after a period of prolonged, continuous wakefulness. In this context there has been extensive research targeting the impact of sleep deficits on different aspects of vigilance, but the underlying concept of vigilance was hardly ever addressed and discussed. One reason for this shortcoming is the unclear and ambiguous definition of the term vigilance, which is commonly used interchangeably with sustained attention and even wakefulness. This confusion is the result of a wide range of misleading definitions, starting in the 1940s, as psychologists redefined the concept of vigilance suggested by British Neurologist, Henry Head, in 1923. Nevertheless, the concept of vigilance is still useful and innovative, especially in treating sleep problems in children and young adults. This paper reviews the current usage of the term vigilance in sleep-wake-research and describes not only the benefits, but even more clearly, its limitations. By re-focusing on the definitions given by Henry Head, the concept of vigilance is an innovative way to gather new insights into the interplay between sleep- and daytime behaviors. In addition, future research on vigilance should consider three perspectives: 1st vigilance perceived as a process to allocate resources, 2nd vigilance associated with compensatory behaviors and 3rd the role of vigilance in human environmental interactions. This approach, understood as a conceptual framework, provides new perspectives by targeting sleep-wake behaviors as a 'real life' outcome measure, reflecting both physical and cognitive performance as well as sleep quality and quantity.

Excessive Daytime Sleepiness in Parkinson's Disease

Excessive daytime sleepiness (EDS) is one of the most common sleep disorders in Parkinson's disease (PD). It has attracted much attention due to high morbidity, poor quality of life, increased risk for accidents, obscure mechanisms, comorbidity with PD and limited therapeutic approaches. In this review, we summarize the current literature on epidemiology of EDS in PD to address the discrepancy between subjective and objective measures and clarify the reason for the inconsistent prevalence in previous studies. Besides, we focus on the effects of commonly used antiparkinsonian drugs on EDS and related pharmacological mechanisms to provide evidence for rational clinical medication in sleepy PD patients. More importantly, degeneration of wake-promoting nuclei owing to primary neurodegenerative process of PD is the underlying pathogenesis of EDS. Accordingly, altered wake-promoting nerve nuclei and neurotransmitter systems in PD patients are highlighted to providing clues for identifying EDS-causing targets in the sleep and wake cycles. Future mechanistic studies toward this direction will hopefully advance the development of novel and specific interventions for EDS in PD patients.

Changed Cerebral White Matter Structural Network Topological Characters and Its Correlation with Cognitive Behavioral Abnormalities in Narcolepsy Type 1

OBJECTIVE

In the current study we investigated topological abnormalities of the cerebral white matter networks in narcolepsy type 1 (NT1) patients and its relationship with their cognitive abnormalities using diffusion tensor imaging (DTI) technology.

METHODS

DTI and the Beijing version of the Montreal Cognitive Assessment (MoCA-BJ) were applied to 30 NT1 patients and 30 age-matched healthy controls. DTI studies were also carried using the 3T MRI system. Next, DTI data was used to establish a cerebral white matter network for all subjects and graph theory was applied to analyze the topological characteristics of the white matter structural network. Topographical parameters (such as local efficiency (Eloc), global efficiency (Eglob) and small-world (σ)) between NT1 patients and controls were then compared. The correlation between MoCA-BJ scores and topological parameters was also analyzed.

RESULTS

MoCA-BJ scores in NT1 patients were lower than those in the healthy controls. Compared with healthy controls, the global efficiency of the white matter network and attributes of the small world network were significantly reduced in NT1 patients. Finally, the global efficiency of the white matter structural network was related to the MoCA-BJ score of NT1 patients.

CONCLUSION

The abnormal topological characteristics of the white matter structural network in NT1 patients may be associated with their cognitive impairment.

High prevalence of pathological alertness and wakefulness on maintenance of wakefulness test in adults with focal-onset epilepsy

BACKGROUND

Excessive daytime sleepiness (EDS) is a common complaint in adults with epilepsy (AWE), but objective evaluation is lacking. We used the maintenance of wakefulness test (MWT) to objectively measure the ability of adults with focal-onset epilepsy to maintain wakefulness in soporific conditions.

METHODS

Adults with epilepsy participating in a study investigating the effects of lacosamide on sleep and wakefulness underwent baseline ambulatory polysomnography (PSG)/EEG followed by MWT. Mean sleep latency (MSL) and mean percent sleep time (MST, mean percentage of non-wake EEG scored in 3-sec bins from lights out to sleep onset averaged over the 4 MWT trials) were quantified. Subjective sleepiness was assessed by the Epworth Sleepiness Scale (ESS). Spearman correlation and linear regression assessed relationships between MWT parameters, ESS and relevant sleep and epilepsy-related variables.

RESULTS

Maintenance of wakefulness test MSL in 51 AWE (mean age 43.5 ± 13 years, 69% female, mean BMI 24.6 ± 11.2 kg/m²) was 21.7 ± 11.9 min; 45.1% had an abnormally short MSL <19.4 min and 15.7% <8 min. MST was 9.3% [3.3, 19.1]. Mean ESS score was 8.8 ± 5.7; 39% had elevated ESS (>10). No correlation between subjective ESS and objective MSL (p = 0.67) or MST (p = 0.61) was found. MSL was significantly shorter in subjects with focal to bilateral tonic-clonic seizures (FBTCS; 7.9 min [13.6, 22.3]) compared to those without (27.4 min [21.2, 33.6], p = 0.013). Younger subjects had shorter MSL; MSL increased 3.2 min for every 10-year increase in age.

CONCLUSION

We found a high prevalence of objective sleepiness/difficulty maintaining wakefulness on the MWT and subjective sleepiness using the ESS in AWE without a correlation between the two. More severe objective sleepiness was found in subjects with a history of FBTCS and younger age. Further research is needed to determine mechanistic underpinnings and optimal measurements of pathological sleepiness in people with epilepsy given the burden of it on quality of life.

Systematic Review of Sleep Characteristics in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

(1) Background—Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a multifaceted illness characterized by profound and persistent fatigue unrelieved by rest along with a range of other debilitating symptoms. Experiences of unrefreshing and disturbed sleep are frequently described by ME/CFS patients. This is the first systematic review assessing sleep characteristics in ME/CFS. The aim of this review is to determine whether there are clinical characteristics of sleep in ME/CFS patients compared to healthy controls using objective measures such as polysomnography and multiple sleep latency testing. (2) Methods—the following databases—Pubmed, Embase, Medline (EBSCO host) and Web of Science, were systematically searched for journal articles published between January 1994 to 19 February 2021. Articles that referred to polysomnography or multiple sleep latency testing and ME/CFS patients were selected, and further refined through use of specific inclusion and exclusion criteria. Quality and bias were measured using the Joanna Briggs Institute checklist. (3) Results—twenty observational studies were included in this review. The studies investigated objective measures of sleep quality in ME/CFS. Subjective measures including perceived sleep quality and other quality of life factors were also described. (4) Conclusions—Many of the parameters measured including slow- wave sleep, apnea- hypopnea index, spectral activity and multiple sleep latency testing were inconsistent across the studies. The available research on sleep quality in ME/CFS was also limited by recruitment decisions, confounding factors, small sample sizes and non-replicated findings. Future well-designed studies are required to understand sleep quality in ME/CFS patients.

Clinical characteristics of sleep apnea in middle-old and oldest-old inpatients: symptoms and comorbidities

BACKGROUND

Obstructive sleep apnea (OSA) is prevalent in older adults but still underdiagnosed for many reasons, such as underreported symptoms, non-specific ones because of the comorbidities and polypharmacy, or the social belief of sleep problems as normal with aging.

OBJECTIVES

To identify salient symptoms and comorbidities associated with OSA, diagnosed by nocturnal respiratory polygraphy in geriatric inpatients.

METHOD

We conducted a retrospective, cross-sectional study in a sample of 102 geriatric inpatients from a French Geriatric University Hospital. We reviewed medical records to collect demographic, medical information including comorbidities, the geriatric cumulative illness rating scale (CIRS-G), subjective sleep-related symptoms and data of overnight level three portable sleep polygraphy recording.

RESULTS

Among classic OSA symptoms, only excessive daytime sleepiness (p = 0.02) and nocturnal choking (p = 0.03) were more prevalent in older inpatients with OSA (n = 64) than in those without (n = 38). The prevalence of comorbidities and mean CIRS-G scores were not different between groups except for the lower prevalence of chronic obstructive pulmonary disease and the higher level of creatinine clearance in OSA patients. Multivariate analysis showed OSA was associated with excessive daytime sleepiness (OR = 2.83, p = 0.02) in symptoms-related model and with composite CIRS-G score (OR 1.26, p = 0.04) in comorbidities-related model.

CONCLUSIONS

Only excessive daytime sleepiness and comorbidity severity (composite CIRS-G score) were associated with the objective diagnosis of OSA, while other usual clinical OSA symptoms and comorbidities in geriatric inpatients were not. These findings emphasize the importance of excessive daytime sleepiness symptom, when reported in comorbid older patients, strongly suggesting OSA and requiring adequate nocturnal exploration.

The Dual Orexin Receptor Antagonist DORA-22 Improves Mild Stress-induced Sleep Disruption During the Natural Sleep Phase of Nocturnal Rats

Dual orexinergic antagonists (DORAs) have been recently developed as a pharmacotherapy alternative to established hypnotics. Hypnotics are largely evaluated in preclinical rodent models in the dark/active period yet should be ideally evaluated in the light/inactive period, analogous to when sleep disruption occurs in humans. We describe here the hypnotic efficacy of DORA-22 in rodent models of sleep disturbance produced by cage changes in the light/inactive period. Rats were administered DORA-22 or the GABA receptor-targeting hypnotic eszopiclone early in the light period, then exposed to six hourly clean cage changes with measurements of NREM sleep onset latency. Both compounds initially promoted sleep (hours 1 and 2), with DORA-22 exhibiting a more rapid hypnotic onset; and exhibited extended efficacy, evident six hours after administration in a sleep latencies test. A common complaint concerning hypnotic use is lingering hypersomnolence, and this is a concern in pharmacotherapy of the elderly. A second study was designed to determine a minimal dose of DORA-22 which would initially promote sleep but exhibit minimal extended hypnotic effect.Animals were administered DORA-22, then exposed for six hours to a single cage previously dirtied by a conspecific, followed by return to home cage. EEG measures indicated that all DORA-22 doses largely promoted sleep in the first hour. The lowest dose (1 mg/kg) did not decrease sleep onset latency at the six-hour timepoint, suggesting no residual hypersomnolence. We described here DORA-22 hypnotic efficacy during the normal sleep period of nocturnal rats, and demonstrate that well-chosen (low) hypnotic doses of DORA-22 may be hypnotically effective yet have minimal lingering effects.

Compromised Dynamic Cerebral Autoregulation in Patients With Central Disorders of Hypersomnolence

Objective: We aimed to investigate the dynamic cerebral autoregulation (dCA) in patients with central disorders of hypersomnolence during wakefulness.

Methods: Thirty-six patients with central disorders of hypersomnolence were divided into three groups according to polysomnography and multiple sleep latency test results: the idiopathic hypersomnia group (IH), narcolepsy type 1 without rapid-eye-movement sleep behavior disorder group (NT1-RBD), and narcolepsy type 1 with rapid-eye-movement sleep behavior disorder group (NT1 + RBD), with 12 patients in each group. Twelve sex- and age-matched healthy controls were recruited. We assessed the Epworth sleepiness scale (ESS) and dCA of all subjects. dCA was assessed by analyzing the phase difference (PD) using transfer function analysis. The ESS and dCA were analyzed before and after standardized treatment in 24 patients with narcolepsy type 1.

Results: The overall PD of the IH, NT1-RBD, and NT1 + RBD groups were lower than that of the control group (P < 0.001). There were no significant differences between the overall PD of the NT1-RBD and NT1 + RBD group (P > 0.05). The ESS scores decreased and the overall PD increased after treatment in 24 patients with narcolepsy type 1 (P < 0.001). Multivariable analysis showed that mean sleep latency in multiple sleep latency test was independently associated with impaired overall PD (P < 0.05).

Conclusions: The dCA is impaired in patients with central disorders of hypersomnolence. The impairment of dCA occurs irrespective of NT1-RBD/+RBD. The ESS score and dCA improved in patients with narcolepsy type 1 after medication treatment. The mean sleep latency in multiple sleep latency test was independently associated with impaired dCA.

Clinical Trial Registration:www.ClinicalTrials.gov, identifier: NCT02752139.

Subjective and objective hypersomnia highly prevalent in adults with epilepsy

INTRODUCTION

Sleepiness is among the most common complaints of people with epilepsy, but objective documentation is lacking. We systematically investigated subjective and objective sleepiness in an observational cross-sectional cohort of adults with epilepsy (AWE).

METHODS

This is a prospective study of AWE consecutively recruited without foreknowledge of sleep/wake complaints. Polysomnography (PSG) with 18-channel electroencephalography (EEG) followed by multiple sleep latency testing (MSLT) was performed. Patients completed the Epworth Sleepiness Scale (ESS), a single-item question assessing excessive daytime sleepiness (EDS), and a 7-day sleep and seizure diary. Multivariable linear models were used to assess the association between MSLT mean sleep latency (MSL) and interests with adjustment of covariates of interest. Receiver operating characteristics (ROC) analysis was performed to evaluate the discrimination capability of ESS on MSL < 8 min and <5 min and investigate the optimal cutpoints.

RESULTS

Among 127 AWE (mean age: 38.7 ± 13.7 years), abnormal MSL (<8 min) was observed in 49.6% and MSL <5 min in 31.5%. While 78% reported feeling sleepy during the day on a single-item question, only 24% had elevated scores on the ESS (>10/24). The ESS score was associated with MSL even after adjusting for seizure frequency, antiseizure medication (ASM) standardized dose and number, age, gender, depression and insomnia symptom severity, and apnea-hypopnea index (HPI) and total sleep time on PSG (coefficients [95% confidence interval (CI)]: -0.26 [-0.48, -0.05], p = 0.018). The area under the curve (AUC) of the ESS ROC predicting MSL < 8 min and MSL < 5 min were similar: 0.62 (95%CI: 0.52-0.72) and 0.62 (95%CI: 0.51-0.74).

CONCLUSIONS

This is the largest prospective cross-sectional observational study to date using MSLT in AWE. We found subjective and objective daytime sleepiness highly prevalent in AWE and not explained by seizure frequency, ASM burden, symptoms of insomnia/depression, or PSG findings although those with MSL < 5 min were more likely to have obstructive sleep apnea (OSA). Pathologic sleepiness with MSL < 8 min was present in half of AWE. Nearly one-third of AWE unselected for sleep/wake complaints had MSL < 5 min, a range typical of narcolepsy.