Frequencies and Associations of Narcolepsy-Related Symptoms: A Cross-Sectional Study

Depressive symptoms in patients with hypersomnia measured with Beck Depression Inventory

BACKGROUND

Patients with central hypersomnia (HCO) often show symptoms of depression. Despite of many studies conducted in this field, the link between these two disorders remains unclear. In order to contribute data to this research, we examined the question of which depressive symptoms characterize these patients. Furthermore, we investigated the differences between HCO who were more or less depressed regarding insomnia, sleep quality and daytime tiredness.

METHODS AND MATERIAL

The retrospective analysis assesses the presence and kind of depressive symptoms as measured by the Beck Depression Inventory (BDI) in 168 HCO including narcolepsy type I (NAR1), narcolepsy type II (NAR2) and idiopathic hypersomnia (HYP). Sleep parameters from one night of polysomnography, scores of questionnaires for insomnia and for daytime sleepiness, and data from sustained attention tests were compared between HCO with and without depression, as determined by BDI scores (cut off >12).

RESULTS

According to BDI scores 52% exhibited no depression. The BDI items pertaining to tiredness and work inhibition exhibited elevated scores, whereas those pertaining to suicidality showed low scores. No difference was found between depressed and non-depressed HCO with regard to daytime vigilance performance or daytime sleepiness. However, depression was associated with older age, higher insomnia scores, and a shorter sleep time on polysomnography.

CONCLUSION

A potential interpretation of our findings is that depressive symptoms in HCO may be a consequence of restricted life quality due to hypersomnia. Thus, therapeutical effort should focus more intensely on coping strategies.

Insomnia-related rodent models in drug discovery

Despite the widespread prevalence and important medical impact of insomnia, effective agents with few side effects are lacking in clinics. This is most likely due to relatively poor understanding of the etiology and pathophysiology of insomnia, and the lack of appropriate animal models for screening new compounds. As the main homeostatic, circadian, and neurochemical modulations of sleep remain essentially similar between humans and rodents, rodent models are often used to elucidate the mechanisms of insomnia and to develop novel therapeutic targets. In this article, we focus on several rodent models of insomnia induced by stress, diseases, drugs, disruption of the circadian clock, and other means such as genetic manipulation of specific neuronal activity, respectively, which could be used to screen for novel hypnotics. Moreover, important advantages and constraints of some animal models are discussed. Finally, this review highlights that the rodent models of insomnia may play a crucial role in novel drug development to optimize the management of insomnia.

Diagnostic challenges and burden of idiopathic hypersomnia: a systematic literature review

Idiopathic hypersomnia (IH) is a rare neurological sleep disorder, characterized by excessive daytime sleepiness despite normal sleep duration, that can significantly impact patient's lives. The burden of IH goes beyond excessive daytime sleepiness, pervading all aspects of everyday life. Characteristic and burdensome symptoms of IH include sleep inertia/drunkenness, long sleep duration, and daytime cognitive dysfunction. This systematic review assessed current knowledge regarding IH diagnostic challenges and burden of illness. Literature searches for original epidemiological, clinical, humanistic, or economic research relevant to IH published between 2012 and 2022 in MEDLINE, Embase, Cochrane, gray literature (diagnostic criteria and treatment guidelines), conferences (2019-2022), and clinical trial databases yielded 97 articles. Findings indicate that IH remains a poorly defined diagnosis of exclusion that is difficult to distinguish from narcolepsy type 2 because of symptom overlap and inadequacies of objective testing. Consequently, individuals with IH endure diagnostic delays of up to 9 years. The economic burden of IH has not been characterized to any appreciable extent. Pharmacological treatment options can improve symptoms and functional status, but rarely restores normal levels of functioning. These findings highlight the need to reclassify central disorders of hypersomnolence. Further collaboration is now required between research groups to identify and validate objective markers to help redefine diagnostic criteria for IH. This would move IH into a position that could benefit from future targeted therapeutic interventions. The study was funded by Takeda Development Center Americas, Inc.

The effects of social jetlag and sleep variability on sleepiness in a population-based study: The mediating role of sleep debt

Sleepiness is a multicausal condition, and previous research has highlighted associations between this symptom and the circadian timing system, specifically concerning social jetlag and sleep variability. Recent inquiries have shown that the effects of social jetlag on sleepiness can be confounded with the consequences of sleep debt. In light of the current evidence, we aimed to assess the effects of social jetlag and sleep variability on sleepiness and the potential mediating role of sleep debt. We used data from the EPISONO study, a cross-sectional population-based study with a sample size of 1042 participants, representative of the city of Sao Paulo, Brazil. Participants completed the UNIFESP Sleep Questionnaire (self-reported bedtime and get-up time) and the Epworth Sleepiness Scale (subjective daytime sleepiness). Subsequently, sleep-corrected mid-sleep time (chronotype), total sleep time, social jetlag (absolute difference between the mid-sleep time on workdays and mid-sleep time on free days), sleep variability (standard deviation of mid-sleep time), and sleep debt (difference between total sleep time on workdays and free days) were calculated. Generalised linear models were used to test whether social jetlag and sleep variability affected sleepiness. Mediation models were used to determine if any observed significant effects were mediated by sleep debt. The prevalence of social jetlag was 23% for >1 h and 12% for >2 h. The mean sleep variability was 41 ± 30 min. Social jetlag had a significant effect on the Epworth Sleepiness Scale scores. This association was no longer statistically significant after controlling for age, sex, body mass index, work schedule, and chronotype. A significant indirect effect of social jetlag on sleep debt and subsequently on the Epworth Sleepiness Scale scores was found. No effect of sleep variability on sleepiness could be identified. In conclusion, the association between social jetlag and sleepiness was mediated by sleep debt but was not independent of demographic, work, and chronotype variables. This study provides new evidence on the importance of circadian misalignment and sleep debt for sleep health on a population level.

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.

Narcolepsy and Idiopathic Hypersomnia

Narcolepsy types 1 and 2 and idiopathic hypersomnia are primary Central Nervous System (CNS) disorders of hypersomnolence characterized by profound daytime sleepiness and/or excessive sleep need. Onset of symptoms begins typically in childhood or adolescence, and children can have unique presentations compared with adults. Narcolepsy type 1 is likely caused by immune-mediated loss of orexin (hypocretin) neurons in the hypothalamus; however, the causes of narcolepsy type 2 and idiopathic hypersomnia are unknown. Existing treatments improve daytime sleepiness and cataplexy but there is no cure for these disorders.

Anxiety and depression in patients with narcolepsy

We analysed the co-existence of psychopathology in patients with narcolepsy at our centre. We performed an observational retrospective descriptive analysis of patients with a diagnosis of narcolepsy, with and without psychopathology, who attended our sleep disorders unit from October 2012 to October 2021. A total of 51patients with narcolepsy (mean [SD] age 41.10 [14.71] years; 23 [45.1%] males and 28 [54.90%] females) were included. In all, 27 patients (52.94%) and 24 patients (47.06%) had narcolepsy with and without cataplexy, respectively. Of the total, 18 (33.33%) had a mood disorder: 18 with anxiety disorder (33.33%). Of these patients 14 (27.45%) had major depression, two (4%) had attempted suicide, one (2%) had manic outbreak, and one (2%) had substance abuse. Of the 18 patients with anxiety and depression, 10 (55.55%) and eight (44.44%) had narcolepsy with and without cataplexy, respectively. In the comparative analysis, a statistically significant relationship was found between younger age and the presence of anxiety. The prevalence of anxiety and depression in patients with narcolepsy was triple that of the general population, especially in younger patients. Psychopathology precedes the diagnosis of narcolepsy in most patients, not being reactive to diagnosis. This high prevalence suggests a possible biological relationship between both disorders, which should be assessed with larger studies.

Examining the impact of excessive daytime sleepiness on utility scores in patients with obstructive sleep apnoea and/or narcolepsy in five European countries

BACKGROUND

Excessive daytime sleepiness (EDS) is a cardinal symptom of narcolepsy and affects many patients with obstructive sleep apnoea (OSA). EDS is associated with reduced quality of life, increased accident risk, and poor workplace performance. Given the impact of EDS, the ability to predict health-related utility from sleepiness is valuable for examining the cost effectiveness of novel treatments. The aim of this study was to examine the association between EDS and EQ-5D in patients with OSA and/or narcolepsy by modelling EQ-5D utility scores from Epworth Sleepiness Scale (ESS) scores.

METHODS

Data were obtained from the Europe 2016/2017 National Health and Wellness Survey, an online, general population survey, designed to represent the age and gender composition of each country's adult population. Analyses included 2,348 patients self-reporting symptomatic and diagnosed OSA (n = 2,277), narcolepsy (n = 48), or both (n = 23). Multivariable models were used to examine ESS as a predictor of EQ-5D utility while adjusting for covariates of interest. Results were validated following the National Institute for Health and Care Excellence Decision Support Unit guidelines for predictive modelling.

RESULTS

Utility decreased as EDS severity increased (no EDS: 0.711 ± 0.251, mild: 0.685 ± 0.261, moderate: 0.643 ± 0.268, severe: 0.559 ± 0.323). Whereas participants with only OSA or only narcolepsy did not differ in utility, those with both conditions had lower scores (0.685 ± 0.266 and 0.627 ± 0.325 vs. 0.439 ± 0.340, respectively). Piecewise linear regression identified a single breakpoint at ESS score of 11.29. In the final model, for each point increase in ESS score, the corresponding decrease in EQ-5D utility was larger among patients with ESS scores ≥ 12 compared to patients with ESS scores ≤ 11 (model slopes: -0.0131 vs. -0.0026, respectively). Findings from the validation sample confirmed these results.

CONCLUSIONS

This study demonstrates the impact of sleepiness on quality of life (QoL) and its negative impact irrespective of sleep condition (OSA or narcolepsy). The breakpoint identified is relatively consistent with the established ESS cutoff score ≥ 11, which demarcates pathological sleepiness. Furthermore, as EDS severity worsens (increases) on the ESS, the impact on QoL is greater.

Pharmacologic Therapy for Narcolepsy

Narcolepsy is a lifelong disorder that adversely affects daytime function and quality of life. Major symptoms include excessive daytime sleepiness with irrepressible sleep attacks and cataplexy. Recent developments in the understanding of the pathobiology of narcolepsy, as well as the neuronal systems involved in the regulation of wakefulness have led to development of new pharmacologic approaches to therapy. In this paper, we review available pharmacologic treatments for narcolepsy as well as agents currently under investigation.

Objective REM sleep characteristics of recurrent isolated sleep paralysis: a case-control study

STUDY OBJECTIVES

Recurrent isolated sleep paralysis (RISP) is a rapid eye movement (REM) parasomnia characterized by a dissociative state with characteristics of REM sleep and wakefulness. Pathophysiology has not yet been clarified and very little research has been performed using objective polysomnographic measures with inconsistent results. The main aim of our study was to find whether higher REM sleep fragmentation is consistent with the theory of state dissociation or whether signs of dissociation can be detected by spectral analysis.

METHODS

Nineteen participants in the RISP group and 19 age- and gender-matched participants in the control group underwent two consecutive full-night video-polysomnography recordings with 19-channel electroencephalography. Apart from sleep macrostructure, other REM sleep characteristics such as REM arousal index, percentage of wakefulness and stage shifts within REM sleep period were analyzed, as well as power spectral analysis during REM sleep.

RESULTS

No difference was found in the macrostructural parameters of REM sleep (percentage of REM sleep and REM latency). Similarly, no significant difference was detected in REM sleep fragmentation (assessed by REM sleep arousal index, percentage of wakefulness and stage shifts within REM sleep). Power spectral analysis showed higher bifrontal beta activity in the RISP group during REM sleep.

CONCLUSIONS

The results showed an underlying persistent trait of higher cortical activity that may predispose patients with SP to be more likely to experience recurrent episodes, without any apparent macrostructural features including higher REM sleep fragmentation.

Quality of life and procrastination in post-H1N1 narcolepsy, sporadic narcolepsy and idiopathic hypersomnia, a Swedish cross-sectional study

OBJECTIVE/BACKGROUND

A cross-sectional study of health-related quality of life (HRQoL), procrastination and the relation to sleepiness, depression and fatigue in post-H1N1 narcolepsy type 1 (NT1), sporadic NT1 and idiopathic hypersomnia (IH).

PATIENTS/METHODS

Participants with NT1 and IH were enrolled from the Department of Neurology, Sahlgrenska University Hospital in Gothenburg (Sweden). All participants completed questionnaires about medication, employment, studies, transfer income, sleepiness, HRQoL, depression, fatigue and three questionnaires for procrastination.

RESULTS

Post-H1N1, sporadic NT1 and IH all scored higher than healthy controls on Epworth Sleepiness Scale (ESS), Patient Health Questionnaire (PHQ-9) and Fatigue Severity Scale (FSS), whereas EQ-5D-5L index and VAS was lower than for healthy individuals, but with no difference between groups. Post-H1N1 NT1 had a larger proportion of participants prescribed with sodium oxybate (44% vs. 9%, p = 0.003) and dexamphetamine (62% vs. 17%, p = 0.03) compared to sporadic NT1. The latter also in significantly higher doses than in sporadic NT1 (46 ± 12 vs. 25 ± 10 and 47.5 ± 21 mg, p < 0.0001). Post-H1N1 NT1 also had significantly higher scores on Pure Procrastination Scale (PPS), Irrational Procrastination Scale (IPS) and Susceptibility to Temptation Scale (STS), indicating a higher degree of procrastination. Multivariate analysis showed that depression, and to some extent fatigue, were predictors in NT1 for both HRQoL and procrastination.

CONCLUSIONS

The results show that health-related quality of life is impaired and tendency to procrastinate is higher in patients suffering from NT1 and both attributes can in part be explained by depressive symptoms. These findings highlight the impact of symptoms other than sleep and wakefulness regulation in patients with NT1.

Giving a voice to cataplectic experience: recollections from patients with narcolepsy type 1

STUDY OBJECTIVES

The objective of this study was to assess the narratives from the recalled accounts of cataplexy attacks of patients with narcolepsy type 1 (NT1).

METHODS

Twenty-two drug-naive adult patients meeting the International Classification of Sleep Disorders criteria for the diagnosis of NT1 referring to the Narcolepsy Center of the University of Bologna in the year 2017 underwent a semistructured interview focusing on their personal experiences during the cataplectic attacks. Verbatim transcripts were analyzed by thematic analysis of elementary contexts using T-LAB software.

RESULTS

The thematic analysis performed on the entire body text showed 3 clusters that explained 36.2%, 34.1%, and 29.7% of the variance, respectively: a cluster related to situations that trigger attacks of cataplexy, a cluster to bodily sensations, and another control strategies during episodes. The thematic content highlighted a tendency to disregard emotional experiences, thus affecting the ability to name, recognize, and regulate critical emotions.

CONCLUSIONS

The study showed that patients with NT1 spoke of their cataplectic attacks in terms of self-reported bodily experiences, trigger situations, and their management. Therefore, patients may have developed strategies of symptom management focused on emotion avoidance and/or inhibition.

Intraperitoneal injection of ginkgolide B, a major active compound of Ginkgo biloba, dose-dependently increases the amount of wake and decreases non-rapid eye movement sleep in C57BL/6 mice

The terpene lactones of Ginkgo biloba extract, namely ginkgolides (A, B, and C) and bilobalide, possess antioxidant, anti-inflammatory, and neuroprotective effects. They are widely prescribed for the treatment of cerebral dysfunctions and neurological impairments. In addition, they demonstrate antagonistic action at the gamma-aminobutyric acid type A and glycine receptors, which are members of the ligand-gated ion channel superfamily. In the present study, the effects of ginkgolides (A, B, and C) and bilobalide on sleep in C57BL/6 mice were investigated. Ginkgolide B was found to dose-dependently increase the amount of wake and decrease that of non-rapid eye movement sleep without changes in the electroencephalography power density of each sleep/wake stage, core body temperature and locomotor activity for the first 6 h after intraperitoneal injection. Of note, the amount of wake after injection of 5 mg/kg of ginkgolide B showed a significant increase (14.9 %) compared with that of vehicle (P = 0.005). In contrast, there were no significant differences in the amount of sleep, core body temperature, and locomotor activity in the mice injected with ginkgolide A and C. Bilobalide briefly induced a decrease in locomotor activity but did not exert significant effects on the amounts of sleep and wake. The modes of action of the wake-enhancing effects of ginkgolide B are unknown. However, it may act through the antagonism of gamma-aminobutyric acid type A and glycine receptors because it is established that these inhibitory amino acids mediate sleep and sleep-related physiology. It is of interest to further evaluate the stimulant and awaking actions of ginkgolide B on the central nervous system in clinical and basic research studies.

Relationship between T-cell receptor α gene polymorphisms and symptomatic differences in patients with narcolepsy type 1

Supplemental Digital Content is available in the text

Background:

Recent genome-wide association studies have identified an important role of T-cell receptor α (TRA) gene in the development of narcolepsy type 1. However, the role of TRA haplotype polymorphisms in the symptomatic diversity of narcolepsy remains unclear. This study aimed to investigate whether TRA polymorphisms can influence the symptomatic diversity of narcolepsy.

Methods:

Totally, 903 patients with narcolepsy type 1 were included in the study. Patients were divided into different groups according to their symptoms. First, 13 genotyped single nucleotide polymorphisms in the TRA were assessed for their association with symptoms of narcolepsy. We used the Chi-square test to determine differences in genotype frequencies in patients with narcolepsy. Further, we identified the haplotypes and variations of the TRA and tested their association with the symptoms of narcolepsy using a logistic regression model.

Results:

According to the results of the logistic regression, TRA haplotypes TG and CT were significantly associated with auditory hallucination, with odds ratios of 1.235 (95% confidence interval [CI], 1.012–1.507) and 1.236 (95% CI, 1.012–1.511), respectively (P < 0.05).

Conclusions:

The patterns of haplotype in TRA (haplotypes TG and CT) are associated with hypnagogic auditory hallucination in patients with narcolepsy type 1. However, further studies are needed to confirm our results and explore the underlying mechanisms.

Health-Related Quality of Life in Patients With Narcolepsy: A Review of the Literature

Narcolepsy is a chronic disorder characterized by symptoms of excessive daytime sleepiness, irresistible sleep attacks that may be accompanied by cataplexy brought on by emotions, sleep paralysis, and hypnagogic hallucinations. This is a review of 32 empirical articles on health-related quality of life (HRQoL) published in peer-reviewed journals over the past 37 years. Deleterious implications on education, recreation, driving, sexual life, and personality are associated with the disease with a consequent negative psychosocial impact. Sleepiness has an important influence on HRQoL, more than the other symptoms of this disorder that have disrupting roles, too. Therefore, patients with narcolepsy need assistance not only for medication prescription but also in terms of psychological and social support. It is also of importance to assess patients with narcolepsy carefully in terms of depressive symptoms because they may have a major impact on HRQoL with important clinical implications.

Pediatric Sleep Disorders

PURPOSE OF REVIEW

This article provides an overview of the clinical features, diagnosis, and treatment of insomnia, restless legs syndrome, periodic limb movements of sleep, parasomnias, narcolepsy, and sleep-related breathing disorders among children and adolescents.

RECENT FINDINGS

Pediatric presentations of sleep disorders differ from adult presentations, making diagnosis challenging. Specific clinical syndromes, such as cataplexy in children with narcolepsy type 1, can have an altogether different presentation compared to adult-onset symptoms, contributing to diagnostic delays and potential misdiagnoses. More broadly, research shows strong associations between sleep and daytime cognition, mood, and behavior among children with and without neurologic conditions and thus suggests a need to identify and treat sleep problems to optimize daytime functioning.

SUMMARY

Addressing sleep problems in children with neurologic conditions and neurodevelopmental disorders improves quality of life for patients and their families and, in many cases, reduces neurologic disease burden.

Insomnia, parasomnias, and narcolepsy in children: clinical features, diagnosis, and management

Sleep problems are frequently encountered as presenting complaints in child neurology clinical practice. They can affect the functioning and quality of life of children, particularly those with primary neurological and neurodevelopmental disorders, since coexisting sleep problems can add substantially to neurocognitive and behavioural comorbidities. Additionally, symptoms of some sleep disorders such as parasomnias and narcolepsy can be confused with those of other neurological disorders (eg, epilepsy), posing diagnostic challenges for paediatric neurologists. The understanding of the neurophysiology of sleep disorders such as insomnia, parasomnias, and narcolepsy is still evolving. There is a complex relation between the sleeping brain and its waking function. The interplay among genetic factors, alterations in neurotransmitters, electrophysiological changes, and environmental factors potentially contribute to the genesis of these sleep disorders.