Disrupted nighttime sleep in narcolepsy

Characterization and treatment patterns of patients treated with immediate-release sodium oxybate for narcolepsy: A propensity score-matched cohort study

BACKGROUND

Sodium oxybate (SXB) is strongly recommended for narcolepsy treatment. Comorbidities and treatment patterns of patients with narcolepsy treated vs not treated with SXB are unknown.

METHODS

An electronic health record-based search identified first-time Mayo Clinic patients with ≥ 1 narcolepsy-specific International Classification of Diseases 9th/10th Revision code and ≥ 1 diagnostic mention of narcolepsy in clinical notes (1975-2020). Common comorbidities were compared between age/sex matched cohorts with and without SXB treatment using odds ratios. Reasons for SXB therapy not being continued or taken as directed were identified using manual chart review.

RESULTS

Of the 4387 patients with narcolepsy identified, 8 % (n = 351) received SXB treatment and 92 % (n = 4036) did not. The most common comorbidities (>20 % overall population) were insomnia, fatigue, depression, hypertension, hyperlipidemia, obstructive sleep apnea, diabetes mellitus, arrhythmia, and idiopathic hypersomnia. In the cohorts of 351 matched patients, no significant differences between cohorts were observed for any comorbidity at any time point (overall, 5 years before or after diagnosis). Among patients who received SXB, 113 had clinical notes indicating discontinuation of SXB, with a reason documented for 71 (most common: lack of efficacy [n = 11]). Of the 24 recorded reasons for patients missing the second nightly SXB dose, the most frequent was the inability to wake up, with consequences noted the next day of increased symptoms.

CONCLUSIONS

No significant differences in comorbidities were observed between cohorts. Although SXB is a highly effective treatment for narcolepsy, this study highlights challenges patients face while taking twice-nightly SXB, which may result in underuse/misuse and suboptimal treatment.

Use of Portable 24-Hour Polysomnography as Alternative Diagnostic Tool for Narcolepsy Type 1 in Adults and Children

BACKGROUND AND OBJECTIVES

The diagnosis of narcolepsy type 1 (NT1) currently requires the multiple sleep latency test (MSLT), or a nocturnal sleep-onset REM period (SOREMP) combined with typical cataplexy, or alternatively the determination of CSF hypocretin-1 (CSF-hcrt-1) deficiency. We evaluated the 24-hour polysomnography (PSG) recordings in adult and pediatric patients as an alternative diagnostic tool.

METHODS

Patients of any age, referred to the narcolepsy center of a university hospital for suspected central disorder of hypersomnolence (CDH), were consecutively recruited between 2013 and 2022. Participants underwent 2 days (day1-night1-day2-night2) of continuous dynamic PSG followed by MSLT. When consent was given, CSF-hcrt-1 was measured. The accuracy of 24-hour PSG variables from night1 and day2 (index test) was assessed with receiver operating characteristic (ROC) curve analysis in identifying NT1 based on current criteria (applied to night2-PSG, MSLT, and CSF-hcrt1). The markers with area under the curve (AUC) ≥0.75 were then tested in adults and children, separately, and to diagnose NT1 and narcolepsy type 2 (NT2) in different scenarios.

RESULTS

Eight hundred seven patients (30.1% pediatric, 52.4% male) were included, and 709 had CSF-hcrt-1 measured. According to the standard criteria, 322 were diagnosed with NT1 (mean age 26.7 ± 17.1 years, 40.4% pediatric, 54.0% male) and 484 with non-NT1 (mean age 32.7 ± 16.5 years, 23.3% pediatric, 51.3% male), encompassing 31 with NT2, 163 with idiopathic hypersomnia, and 281 with other diagnoses. Detecting SOREMP ≥1 during daytime resulted in AUC = 0.84 (95% CI 0.82-0.87), with 84.4% sensitivity and 84.5% specificity for NT1. Performance was superior to all nighttime-PSG measures (p < 0.001) including nighttime-SOREMP (AUC = 0.77, 95% CI 0.74-0.80; sensitivity = 62.1%, specificity = 91.7%) and did not differ from 24-hour SOREMP ≥1 (AUC = 0.85, 95% CI 0.82-0.87; sensitivity = 89.7%, specificity = 80.2%). The combination of daytime-SOREMP ≥1 with cataplexy showed AUC = 0.89 (95% CI 0.86-0.91) for NT1, superior to the combination of nighttime-SOREMP with cataplexy (AUC = 0.78, 95% CI 0.76-0.81, p < 0.001) and similar to MSLT criteria for narcolepsy (AUC = 0.90, 95% CI 0.88-0.92, p = 0.36). Performances were similar in adults and children. Daytime-SOREMP ≥1 identified NT1 and NT2 combined within all CDH with a sensitivity of 80.8% and specificity of 88.0%.

CONCLUSIONS

The detection of daytime-SOREMP during dynamic 24-hour PSG is more accurate than nighttime-SOREMP for diagnosing narcolepsy and, combined with cataplexy, is comparable with MSLT criteria for the identification of NT1. These results offer the prospect of 24-hour PSG diagnostics for NT1 in the home setting.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that daytime SOREMP during a 24-hour PSG accurately distinguishes NT1 in patients with a clinical history of possible cataplexy from those who do not have NT1.

The Lehigh Valley Health Network Narcolepsy Cohort: clinical and polysomnographic analysis of 304 cases

STUDY OBJECTIVE

We aimed to characterize clinical features, comorbidities, and polysomnographic characteristics of a large cohort of patients with narcolepsy.

METHODS

We undertook a retrospective chart and polysomnographic review of all patients with a diagnosis of narcolepsy type 1 (NT1) or narcolepsy type 2 (NT2) seen within the Lehigh Valley Health Network between 2000 and 2022.

RESULTS

We found 304 cases with a diagnosis of narcolepsy (52 NT1, 252 NT2), based on International Classification of Sleep Disorders, third edition criteria. Compared to NT2, patients with NT1 had younger diagnosis age (24.5 vs 27.4 years, P = .03), shorter diagnostic gap (3.0 vs 4.6 years, P = .002), more frequent sleep paralysis (55.8% vs 19.4%, P < .0001) and hypnagogic hallucinations (46.2% vs 25.4%, P = .003), and higher Epworth Sleepiness Scale scores (17.8 vs 16.7, P = .02). The most common comorbid sleep disorders were breathing disorders (17.4%) and insomnia (15.5%). Migraine was the most common neurological disorder. Depression was more common in NT2 than NT1 (12 [23.1%] vs 94 [37.3%], P = .05). On the Multiple Sleep Latency Test, patients with NT1 had more sleep onset rapid eye movement periods than patients with NT2 (≥ 3 sleep onset rapid eye movement periods in 59.2% vs 26.9%, P < .0001). Only in NT2, hypnagogic hallucinations and higher Epworth Sleepiness Scale scores were associated with higher numbers of sleep onset rapid eye movement periods (P = .0277 and P = .0179, respectively).

CONCLUSION

This is one of the largest monocentric studies to date of patients with narcolepsy and confirms the frequent comorbidities of narcolepsy. Specific clinical characteristics and comorbidities may help differentiate NT1 from NT2.

CITATION

Jiang RY, Rochart R, Chu I, Duka S, Vendrame M. The Lehigh Valley Health Network Narcolepsy Cohort: clinical and polysomnographic analysis of 304 cases. J Clin Sleep Med. 2025;21(3):479-491.

Sodium Oxybate: Practical Considerations and Patient Perspectives

Narcolepsy is a rare, chronic sleep disorder with significant impacts on the quality of life of people affected by the disorder. People with narcolepsy (PWN) are a diverse patient population with evolving symptoms, comorbidities, and perspectives. As PWN have varying needs, clinicians should consider a more personalized approach to therapy, including active participation of PWN in their care and shared decision-making between patient and clinician to achieve optimal outcomes. In this review, we discuss the various characteristics and challenges of PWN, present illustrative clinical case scenarios of PWN, provide clinicians with a proposed framework to best address therapy for PWN, and demystify concerns with sodium oxybate.

MRI-based surrogates of brain clearance in narcolepsy type 1

Brain clearance involves the drainage of waste molecules from the brain, a process that is suggested to be amplified during sleep. Recently proposed MRI-based methods attempt to approximate human brain clearance with surrogate measures. The current study aimed to explore whether two brain clearance surrogates are altered in narcolepsy. We processed diffusion-weighted and functional resting-state images to extract two surrogates: Diffusion Tensor Imaging Along the Perivascular Space (DTI-ALPS index), and dBOLD-CSF coupling. Both measures were analysed in 12 drug-free, awake people with narcolepsy type 1 and 11 age- and sex-matched controls, as well as in relation to clinical features. We also assessed the correlation between the DTI-ALPS index and dBOLD-CSF coupling. The DTI-ALPS index and dBOLD-CSF coupling amplitude did not show significant differences between narcolepsy and controls, nor significant relations with the severity of excessive daytime sleepiness. We found a significant correlation between dBOLD-CSF coupling and sleep efficiency, as well as a significant correlation between the DTI-ALPS index and dBOLD-CSF coupling. The hypothesis of altered brain clearance in narcolepsy type 1 is not supported by evidence from the current study. The two surrogates correlated with each other, suggesting that both offer different perspectives from the same underlying physiology. Yet, the suitability of the surrogates as brain clearance markers remains debatable. Whereas DTI is not exclusively sensitive to perivascular fluid, dBOLD-CSF coupling is reflecting large-scale CSF motion. Future work should explore other surrogate markers, preferably during sleep, to better understand the possible role of altered brain clearance in narcolepsy type 1 symptomatology.

Impaired sleep-dependent memory consolidation in pediatric narcolepsy type 1

STUDY OBJECTIVES

Disrupted nighttime sleep is common in pediatric narcolepsy type 1, yet its cognitive impact is unknown. As N2 sleep spindles are necessary for sleep-dependent memory consolidation, we hypothesized that narcolepsy type 1 impairs memory consolidation via N2 sleep fragmentation and N2 sleep spindle alterations.

METHODS

We trained 28 pediatric narcolepsy type 1 participants and 27 healthy controls (HCs) on a spatial declarative memory task before a nocturnal in-lab polysomnogram and then gave them a cued recall test upon awakening in the morning. We extracted wake and sleep stage bout numbers and N2 spindle characteristics from the polysomnogram and conducted mixed model analysis of sleep-dependent memory consolidation to identify group differences.

RESULTS

Narcolepsy type 1 participants had shorter N2 bout durations and associated shorter N2 spindles versus HC, but other N2 spindle features were similar. Narcolepsy type 1 participants had worse memory performance postsleep than HCs after adjusting for age and gender (mean memory consolidation HC: -3.1% ± 18.7, NT1: -15.6 ± 24.8, main effect group × time of testing F = 5.3, p = .03). We did not find significant relationships between sleep-dependent memory consolidation and N2 spindle characteristics. Notably, increased N1% was associated with worse sleep-dependent memory consolidation with results driven by the narcolepsy type 1 group.

CONCLUSIONS

Sleep-dependent memory consolidation is mildly impaired in youth with narcolepsy type 1 and findings may be attributed to increases in N1 sleep. Further studies are needed to determine if these findings are generalizable and reversible with sleep-based therapies.

Characterizing disrupted nighttime sleep and associated functional outcomes in youth with narcolepsy type 1

STUDY OBJECTIVES

Disrupted nighttime sleep and sleep instability are common in children and adolescents with narcolepsy type 1, but optimal objective sleep measures have not been determined. We compared self-reported and objective sleep measures between young people with narcolepsy type 1 and healthy controls and test the hypotheses that the wake/non-rapid eye movement sleep stage 1 (N1) index is the best objective measure of perceived nocturnal wakings vs other disrupted nighttime sleep measures reported in the literature and is associated with daytime functional problems.

METHODS

n = 26 healthy controls and n = 27 narcolepsy type 1 participants ages 8-21 years completed a 15-item habitual sleep quality survey and an in-lab polysomnogram. We compared group survey responses and performed stepwise regression of sleep quality and instability measures with a survey question ("During the night, I wake more than once"). Last, we used logistic regression to identify associations between the wake/N1 index with daytime functional concerns across groups.

RESULTS

Compared to healthy controls, narcolepsy type 1 participants reported more frequent restless sleep, nighttime moaning/groaning/talking, tossing and turning, and nocturnal wakings (all P values < .01), but no greater difficulties in falling asleep or returning back to sleep. Across groups, self-reported waking from sleep was associated with increased wake/N1 index and selective serotonin reuptake inhibitor/selective norepinephrine re-uptake inhibitor use. The wake/N1 index was associated with daytime fatigue but no other behavioral or cognitive concerns.

CONCLUSIONS

Disrupted nighttime sleep is a multifactorial complaint that differs from insomnia. We believe the wake/N1 index is a useful sleep instability measure that should be helpful in research and as a treatment target in clinical practice, especially for fatigue concerns.

CITATION

Heckler G, Worhach J, Wang G, et al. Characterizing disrupted nighttime sleep and associated functional outcomes in youth with narcolepsy type 1. J Clin Sleep Med. 2025;21(2):355-363.

Identifying time-resolved features of nocturnal sleep characteristics of narcolepsy using machine learning

The differential diagnosis of narcolepsy type 1, a rare, chronic, central disorder of hypersomnolence, is challenging due to overlapping symptoms with other hypersomnolence disorders. While recent years have seen significant growth in our understanding of nocturnal polysomnography narcolepsy type 1 features, there remains a need for improving methods to differentiate narcolepsy type 1 nighttime sleep features from those of individuals without narcolepsy type 1. We aimed to develop a machine learning framework for identifying sleep features to discriminate narcolepsy type 1 from clinical controls, narcolepsy type 2 and idiopathic hypersomnia. The population included polysomnography data from 350 drug-free individuals (114 narcolepsy type 1, 90 narcolepsy type 2, 105 idiopathic hypersomnia, and 41 clinical controls) collected at the National Reference Centers for Narcolepsy in Montpelier, France. Several sets of nocturnal sleep features were explored, as well as the value of time-resolving sleep architecture by analysing sleep per quarter-night. Several patterns of nighttime sleep evolution emerged that differed between narcolepsy type 1, clinical controls, narcolepsy type 2 and idiopathic hypersomnia, with increased nighttime instability observed in patients with narcolepsy type 1. Using machine learning models, we identified rapid eye movement sleep onset as the best single polysomnography feature to distinguish narcolepsy type 1 from controls, narcolepsy type 2 and idiopathic hypersomnia. By combining multiple feature sets capturing different aspects of sleep across quarter-night periods, we were able to further improve between-group discrimination and could identify the most discriminative sleep features. Our results highlight salient polysomnography features and the relevance of assessing their time-dependent changes during sleep that could aid diagnosis and measure the impact of novel therapeutics in future clinical trials.

Connecting clinicians and patients: The language of narcolepsy

Narcolepsy is a rare lifelong sleep disorder characterized by excessive daytime sleepiness with variable expression of cataplexy, sleep paralysis, sleep-related hallucinations and disrupted nocturnal sleep. Affected individuals also experience additional impairing symptoms, including (but not limited to) difficulties with attention, memory and concentration, brain fog, mood instability and fatigue, with a substantial impact on everyday life. Diagnostic delays of up to 10 years are common, primarily due to the substantial heterogeneity in clinical presentation of narcolepsy symptoms and presence of significant comorbidities. The disconnect in language used by clinicians and patients could be a factor contributing to diagnostic delays, but it has not been much studied. We followed a two-part approach to investigate the impact of this possible mismatch in language use. Firstly, a comprehensive literature search was conducted to identify publications reporting discrepancies in language relating to narcolepsy symptoms used by clinicians and patients. As a gap in the literature was anticipated, we supplemented the search results with practical strategies based on our clinical experience to facilitate dialog between clinicians and people living with narcolepsy, as well as proposing future research ideas. The findings of the narrative review, complemented by expert clinical opinion, are intended to help clinicians recognize narcolepsy symptoms and to refer patients with suspected narcolepsy, when appropriate. Although it is unknown to what extent a disconnect in language may contribute to diagnostic delays, we hope that better recognition of the varied clinical presentations of narcolepsy will lead to timelier diagnosis and help improve patient outcomes.

Efficacy of once-nightly sodium oxybate (FT218) on daytime symptoms in individuals with narcolepsy with or without concomitant alerting agent use: A post hoc analysis from the phase 3 REST-ON trial

OBJECTIVE/BACKGROUND

Extended-release, once-nightly sodium oxybate (ON-SXB) significantly improved narcolepsy symptoms in participants in the phase 3, randomized, double-blind, placebo-controlled REST-ON trial. This post hoc analysis of REST-ON data evaluated ON-SXB efficacy in participants with or without concomitant alerting agent use.

PATIENTS/METHODS

Participants with narcolepsy aged >16 years were randomized 1:1 to ON-SXB (week 1: 4.5 g, weeks 2-3: 6 g, weeks 4-8: 7.5 g, weeks 9-13: 9 g) or placebo. Primary endpoints in this post hoc analysis included change from baseline in mean sleep latency on the Maintenance of Wakefulness Test (MWT), Clinical Global Impression-Improvement (CGI-I) rating, and number of weekly cataplexy episodes. The secondary endpoints were change from baseline in the Epworth Sleepiness Scale (ESS) score and in objective and subjective disrupted nighttime sleep parameters. Post hoc analyses assessed participants with and without alerting agent use across 6-, 7.5-, and 9-g doses.

RESULTS

In the modified intent-to-treat population, 119 (63 %) were (ON-SXB, n = 66; placebo, n = 53) and 71 (37 %) were not (ON-SXB, n = 31; placebo, n = 40) taking alerting agents. Regardless of alerting agent use, treatment with ON-SXB resulted in significant improvements vs placebo (all doses, P < 0.05) for MWT, CGI-I, and number of weekly cataplexy episodes. Significant improvements in ESS (all doses, P < 0.05) with ON-SXB vs placebo were observed in the alerting agent use cohort. Directional improvements in ESS were reported with all doses in the no alerting agent use group.

CONCLUSIONS

Regardless of concomitant alerting agent use, ON-SXB improved daytime and nighttime narcolepsy symptoms vs placebo.

Understanding the Patient Experience with Twice-Nightly Sodium Oxybate Therapy for Narcolepsy: A Social Listening Experiment

BACKGROUND/OBJECTIVES

Narcolepsy is a chronic neurologic disorder associated with substantial challenges that affect the social, emotional, and financial quality-of-life domains. A social listening analysis and structured survey were conducted to better understand the candid perspective of people with narcolepsy (PWN) and their experience with twice-nightly sodium oxybate (SXB).

METHODS

To characterize conversations and experiences in narcolepsy communities where SXB was mentioned, a social media analysis was conducted from August 2011 to October 2022. A structured survey was administered to PWN taking oxybate therapy from October 2022 to November 2022.

RESULTS

From the social media analysis, the largest topic was related to "cataplexy", with 537 posts/comments. The most frequent term was "xyrem", with 22,200 mentions. Of the 87 survey respondents, 85 respondents had narcolepsy, 75.3% (64/85) reported missing their second dose of immediate-release SXB or mixed-salt oxybates, and 58.8% (50/85) of respondents reported that they took their second dose of oxybate > 4 h after the first dose. Respondents reported poor sleep quality as the greatest effect or issue experienced after missing their second oxybate dose. When respondents were asked whether they had ever been injured after waking to take their second oxybate dose, 31.8% (27/85) of respondents reported an injury.

CONCLUSIONS

PWN taking twice-nightly oxybates often report inconsistent adherence to the prescribed dosing, which results in negative consequences in their lives. This research provided an anonymized forum for PWN to voice challenges with middle-of-the-night awakenings that they may be reluctant to explain to their clinician.

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.

Sleep architecture in idiopathic hypersomnia: the influence of age, sex, and body mass index

This study aimed to progress the understanding of idiopathic hypersomnia (IH) by assessing the moderating influence of individual characteristics, such as age, sex, and body mass index (BMI) on sleep architecture. In this retrospective study, 76 IH participants (38.1 ± 11.3 years; 40 women) underwent a clinical interview, an in-laboratory polysomnography with a maximal 9-h time in bed and a multiple sleep latency test (MSLT). They were compared to 106 healthy controls (38.1 ± 14.1 years; 60 women). Multiple regressions were used to assess moderating influence of age, sex, and BMI on sleep variables. We used correlations to assess whether sleep variables were associated with Epworth Sleepiness Scale scores and mean sleep onset latency on the MSLT in IH participants. Compared to controls, IH participants had shorter sleep latency (p = 0.002), longer total sleep time (p < 0.001), more time spent in N2 sleep (p = 0.008), and showed trends for a higher sleep efficiency (p = 0.023) and more time spent in rapid eye movement (REM) sleep (p = 0.022). No significant moderating influence of age, sex, or BMI was found. More severe self-reported sleepiness in IH patients was correlated with shorter REM sleep latency and less N1 sleep in terms of proportion and duration (ps < 0.01). This study shows that, when compared to healthy controls, patients with IH had no anomalies in their sleep architecture that can explain their excessive daytime sleepiness. Moreover, there is no moderating influence of age, sex, and BMI, suggesting that the absence of major group differences is relatively robust.

Executive function performance in children and adolescent patients with narcolepsy type 1

OBJECTIVE

The executive function profile in patients with narcolepsy type 1 (NT1) has been mentioned; however, limited research exists on children and adolescent patients with NT1.This study aims to assess executive function in children and adolescent patients with NT1 in China, examine potential influencing factors and evaluate the short-term treatment effect on executive function.

METHODS

53 NT1 patients (36 males, age 12.2 ± 3.4 years) and 37 healthy controls (23 males, age 12.2 ± 2.5 years) underwent self-reported measures assessing subjective sleepiness, depression, anxiety and sleep quality. A comprehensive neuropsychological test was administered to assess executive function domains, including processing speed, inhibitory control, cognitive flexibility and working memory. These assessments were repeated in NT1 patients after three-day regular drug treatment.

RESULTS

NT1 patients exhibited higher levels of excessive daytime sleepiness, depression, anxiety, and poor sleep quality compared to healthy controls. Patients showed impaired processing speed, inhibitory control and cognitive flexibility (p < 0.05), whereas working memory was unaffected (p > 0.05). Regression analysis revealed that parameters from sleep monitoring, such as sleep efficiency and sleep latency, were correlated with executive function performance after controlling for age, gender, and education years. The short-term treatment led to improvements in inhibitory control, cognitive flexibility, and working memory.

CONCLUSION

The findings showed that executive function was impaired among children and adolescent patients with NT1, which was associated with objective sleep parameters. Furthermore, this study emphasizes the necessity of neuropsychological assessments and early interventions among children and adolescent NT1 patients.

Clinical and video-polysomnographic characterization of restless sleep disorder in adult patients

Adults with restless sleep disorder (RSD) have never been studied clinically and polysomnographically. This study aimed to describe the clinical manifestation, duration, and distribution of sleep-related movements in adult patients with restless sleep disorder. Patients who had performed VPSG from Jan 2021 to Jan 2022 and met the diagnosis criteria of RSD were enrolled in the study. Patients' bed partners were also interviewed or telephoned in identifying this disorder. Scoring of movements during sleep was according to the diagnosis criteria of RSD and scoring of large muscle group movements during sleep proposed by the International RLS Study Group in 2020 and 2021, respectively. The clinical manifestation, the distribution of sleep stage as well as the types and duration of the movements were carefully recorded and analyzed. We included ten patients in the study with a mean age of 27.6 years (range 22-38). There was a male prevalence in adults with RSD. The study highlighted the findings from video-polysomnography, which indicated frequent sleep-related movements occurring throughout the Night. These movements were most prominent during N1 and N2 sleep stage, followed by REM sleep, while fewer movements were observed during N3 sleep. Adults with RSD experienced significant daytime functioning impairments, including non-refreshing sleep, daytime fatigue/sleepiness, and mood disturbance. Two of the patients in the study were diagnosed with anxiety and depression, further underscoring the impact of RSD on mental health. Adult patients also suffer from severe RSD, and the RSD that originates in childhood tends to persist into adulthood. In these cases, longer duration of the disease and poor sleep quality may be associated with an increased risk of developing psychiatric comorbidities. Our cases represent an objectively documented type of RSD in younger adult patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41105-024-00524-1.

Effects of modafinil on nocturnal sleep patterns in patients with narcolepsy: A cohort study

BACKGROUND

Patients with narcolepsy often experience disturbed nighttime sleep. Modafinil is commonly prescribed for hypersomnolence, but its impacts on nocturnal sleep remain unclear. This study uses actigraphy to examine the effect of modafinil on both hypersomnolence and nocturnal sleep patterns in patients with narcolepsy.

METHODS

Prior to treatment, 87 patients with narcolepsy wore an actigraphy for 7-14 days to assess their nighttime sleep. After evaluation, they received a daily dose of 200-400 mg of modafinil in the morning and wore an actigraphy again six months after initiating treatment. Questionnaires, including the Epworth-Sleepiness-Scale (ESS), the Visual-Analogue-for-Hypersomnolence (VAS), and the Short-Form-36-Health-Survey (SF-36), were used to evaluate hypersomnolence and quality of life both before and after treatment. Paired t-tests and independent samples t-tests were used for pre- and post-treatment comparisons and subgroup analysis. We used the Pearson's correlation test to measure the correlations between the sleep parameters of the actigraphy and data of the questionnaires.

RESULTS

Improvements in hypersomnolence were noted following modafinil treatment, and we observed no significant deterioration in nocturnal sleep parameters by the actigraphy. The total number of awakenings by actigraphy significantly decreased (p = 0.005), especially in females (p = 0.008), while sleep onset latency significantly increased in children/adolescents (p = 0.014). Correlations were found between the sleep parameters of the actigraphy and ESS, VAS, and SF-36 scores.

CONCLUSION

Modafinil treatment may not worsen nighttime sleep in patients with narcolepsy. However, it should be administered with care in children and adolescents.

Recommended protocols for the Multiple Sleep Latency Test and Maintenance of Wakefulness Test in children: guidance from the American Academy of Sleep Medicine

The American Academy of Sleep Medicine commissioned a task force of clinical experts in pediatric sleep medicine to review published literature on performing the Multiple Sleep Latency Test (MSLT) and Maintenance of Wakefulness Test for diagnosis and management of central disorders of hypersomnolence among children and adolescents. This paper follows a format similar to that of the paper "Recommended protocols for the Multiple Sleep Latency Test and Maintenance of Wakefulness Test in adults: guidance from the American Academy of Sleep Medicine" that was published in 2021. Since there is insufficient evidence to specify a recommended protocol for the Maintenance of Wakefulness Test in children and adolescents, this paper focuses only on the MSLT protocol. This protocol paper provides guidance to health care providers who order, sleep specialists who interpret, and technical staff who administer the MSLT to pediatric patients. Similar to the adult protocol paper, this document provides guidance based on pediatric expert consensus and evidence-based data when available. Topics include patient preparation, evaluation of medication and substance use, sleep needs before testing, scheduling considerations, optimal test conditions for youth, and documentation. Specific changes recommended for pediatric MSLT protocols include (1) provision of a minimum of 7 hours of sleep (with a minimum 8-hour recording time) on polysomnography the night before the MSLT, ideally meeting age-based needs; (2) use of clinical judgment to guide the need for sleep-disordered breathing treatments before polysomnography-MSLT testing; and (3) shared patient-health care provider decision-making regarding modifications in the protocol for children and adolescents with neurodevelopmental/neurological disorders, young age, and/or delayed sleep phase.

CITATION

Maski KP, Amos LB, Carter JC, Koch EE, Kazmi U, Rosen CL. Recommended protocols for the Multiple Sleep Latency Test and Maintenance of Wakefulness Test in children: guidance from the American Academy of Sleep Medicine. J Clin Sleep Med. 2024;20(4):631-641.

Effectiveness of an intervention program on physical activity in children with narcolepsy type 1

OBJECTIVES

Physical activity (PA) is recommended as part of the management of narcolepsy type 1 (NT1). This study aimed at 1) characterizing PA in children and adolescents treated for NT1 using objective and subjective measurements, 2) evaluating how PA is associated with NT1 symptoms and comorbidities, and 3) evaluating the effects of an Adapted Physical Activity (APA) program on PA and clinical characteristics.

PATIENTS/METHODS

Patients with NT1 from the National Reference Center of Narcolepsy (Lyon, France) were consecutively included in an APA intervention protocol. Narcolepsy symptoms and comorbidities were collected using standardized questionnaires and sustained attention was evaluated using the Bron-Lyon Attention Stability Test before and after the four-week APA intervention. PA was measured objectively using actigraphy throughout the study.

RESULTS

Twenty-seven NT1 patients were included (median age 14.7 years [8.3-18.4], cataplexy 88.9%, obesity 37.0%). At baseline, 52.4% of the patients had satisfactory PA levels according to international recommendations. Patients with leisure-time PA (LTPA) showed higher quality of life than patients without. 45% of the patients increased PA during the intervention compared to baseline. These responsive patients had more depressive feelings and tended to have lower objective PA than non-responsive patients at baseline. No significant correlation was found between PA levels before and during the intervention and other clinical data.

CONCLUSIONS

Most children with NT1 showed satisfying PA levels despite their daytime sleepiness. LTPA engagement was associated with higher quality of life. An APA intervention could be effective in children with narcolepsy, especially for those with depressive feelings.

Exploring exercise, physical wellbeing and the role of physiotherapy: perspectives from people with narcolepsy

Narcolepsy is associated with reduced quality of life and physical performance. The study aimed to explore the attitudes of people with Type 1 narcolepsy towards exercise and physical activity, their physical wellbeing, and the potential role of physiotherapy. Semi-structured interviews were conducted with 22 people with narcolepsy attending a dedicated outpatient narcolepsy clinic located in Dublin, Ireland. Transcripts were iteratively coded; a thematic analysis was undertaken, and key themes were identified. Four themes were identified: 'Barriers and Facilitators to Exercising', 'Social Concerns', 'Health Concerns' and 'Suggestions for the Role of Physiotherapy'. Future research should explore the potential role of exercise to help manage narcolepsy-related symptoms in this population.

Effects of oxybate dose and regimen on disrupted nighttime sleep and sleep architecture

Many components of sleep are disrupted in patients with narcolepsy, including sleep quality, sleep architecture, and sleep stability (ie, frequent awakenings/arousals and frequent shifts from deeper to lighter stages of sleep). Sodium oxybate, dosed twice nightly, has historically been used to improve sleep, and subsequent daytime symptoms, in patients with narcolepsy. Recently, new formulations have been developed to address the high sodium content and twice-nightly dosing regimen of sodium oxybate: low-sodium oxybate and once-nightly sodium oxybate. To date, no head-to-head trials have been conducted to compare the effects of each oxybate product. This review aims to give an overview of the existing scientific literature regarding the impact of oxybate dose and regimen on sleep architecture and disrupted nighttime sleep in patients with narcolepsy. Evidence from 5 key clinical trials, as well as supporting evidence from additional studies, suggests that sodium oxybate, dosed once- and twice-nightly, is effective in improving sleep, measures of sleep architecture, and disrupted nighttime sleep in patients with narcolepsy. Direct comparison of available efficacy and safety data between oxybate products is complicated by differences in trial designs, outcomes assessed, and statistical analyses; future head-to-head trials are needed to better understand the advantage and disadvantages of each agent.

Quality of life in adolescents with narcolepsy type 1- a transversal study in a tertiary hospital

PURPOSE

- Narcolepsy type 1 (NT1) is a rare chronic sleep disorder, usually arising by adolescence that negatively impacts quality of life. It is characterized by excessive daytime sleepiness (EDS), cataplexy, hypnagogic/hypnopompic hallucinations, sleep paralysis and sleep fragmentation. The goals of this work were to characterize NT1 adolescents regarding sleep characteristics, health-related quality of life (HRQoL) and future life perspectives and later to compare this group with a control group of healthy adolescents (HA).

METHODS

- Transversal descriptive/analytical study including NT1 patients followed in a sleep center of a tertiary hospital and 23 HA. Data were collected through an online survey, fulfilled by the participants, including four sections: demographics; questionnaire evaluating sleep and EDS; questionnaire evaluating HRQoL; inquiry regarding future perspectives. An extra section for the NT1 group only, comprising questions about the characterization of narcolepsy, was included.

RESULTS

22 NT1 adolescents were included, with a median age of 15.0 years-old. Beyond EDS, all had presented cataplexy - 19 still reported it. Twenty patients took psychostimulants regularly for EDS, while 13 patients took venlafaxine or fluoxetine for cataplexy. Nineteen adolescents took regular naps and 19 maintained psychological appointments. Self-reported sleep quality was similar between groups (p = 0.112). EDS was identified in seven NT1 patients and none in the control group. HRQOL was significantly lower in NT1 patients only for the physical well-being domain (p = 0.001). Regarding future perspectives, results were similar, except for a lower probability of getting a driver's license in NT1 patients, despite no statistical significance (p = 0.104).

DISCUSSION

Daytime sleepiness is difficult to control in NT1, despite specialized treatment. HRQoL was similar between groups in all domains except for the physical well-being. Despite good adherence to pharmacological and non-pharmacological treatments (namely psychological therapy) that account for these good results, the physical well-being domain is difficult to manage.

Implications of Oxybate Dosing Regimen for Sleep, Sleep Architecture, and Disrupted Nighttime Sleep in Patients with Narcolepsy: A Commentary

Narcolepsy is associated with disrupted nighttime sleep (DNS). Sodium oxybate (SXB; Xyrem®), administered twice nightly, is indicated for the treatment of cataplexy and excessive daytime sleepiness in patients 7 years or older with narcolepsy. Recently, low-sodium oxybate (LXB, Xywav®; for people 7 years of age and older), which contains 92% less sodium than SXB and is dosed twice nightly, and sodium oxybate for extended release (SXB-ER; Lumryz™; for adults), which contains equal sodium to SXB and is dosed once nightly, have also been approved to treat cataplexy or excessive daytime sleepiness in narcolepsy. This paper reviews the evidence regarding the overall impact of oxybate administration, and impact of different oxybate dosing regimens (once nightly, SXB-ER; twice nightly, SXB), on DNS in narcolepsy utilizing polysomnographic data from five clinical trials (three assessing SXB in adults [referred to here as SXB trials 1, 2, and 3], one assessing SXB in children [referred to as the pediatric SXB trial], and one assessing SXB-ER in adults [REST-ON]). Both once-nightly and twice-nightly oxybate regimens similarly improved symptoms of DNS. Regardless of dosing regimen, people with narcolepsy treated with oxybate experience roughly 42-53 arousals and 9-38 awakenings each night, with one of these awakenings on twice-nightly oxybate being due to the second dosing requirement in studies of SXB. Additionally, for SXB, but not SXB-ER, polysomnographic data has been analyzed by half of the night, demonstrating a greater positive impact on sleep architecture in the second half of the night, which might be related to its nonlinear pharmacokinetic profile. We conclude that while once-nightly and twice-nightly oxybate dosing regimens differ in their pharmacokinetic profiles, both improve DNS in patients with narcolepsy to a similar degree.

Eurycoma longifolia (Tongkat Ali) enhances wakefulness during active periods but facilitates sleep during resting periods in C57BL/6 mice

The effects of the Eurycoma longifolia (also known as Tongkat Ali [TA]) on sleep and wakefulness was evaluated in C57BL/6 mice. While TA has been used as an aphrodisiac in males, it exhibits various pharmacological effects. The most notable effect observed with TA was wake-enhancement during the second half of the active period, accompanied by significant elevations in core body temperature (CBT). In contrast, sleep was enhanced during the resting period (i.e., increase in rapid eye movement [REM] sleep and delta electroencephalography [EEG] power in non-REM sleep) with significant declines in CBT. The transition of TA's effects between resting and active periods was rapid. The results of the experiments in constant darkness indicate that TA prolongs the circadian tau and that this transition is governed by circadian clock mechanisms rather than light exposure. TA did not demonstrate efficacy in aiding sleep in an acute stress-induced insomnia model; thus, TA may be more suitable as a wake-enhancing agent for daytime sleepiness, as sleep propensity tends to accumulate towards the end of active period. Since TA amplifies the rest-activity pattern, prolongs circadian tau and increases REM sleep, thereby reversing some common symptoms seen in elderly subjects, it may also hold promise as a rejuvenating medicine.

Efficacy of once-nightly sodium oxybate (FT218) in narcolepsy type 1 and type 2: post hoc analysis from the Phase 3 REST-ON Trial

STUDY OBJECTIVES

Post hoc analyses from the phase 3 REST-ON trial evaluated efficacy of extended-release once-nightly sodium oxybate (ON-SXB; FT218) vs placebo for daytime sleepiness and disrupted nighttime sleep in narcolepsy type 1 (NT1) and 2 (NT2).

METHODS

Participants were stratified by narcolepsy type and randomized 1:1 to ON-SXB (4.5 g, week 1; 6 g, weeks 2-3; 7.5 g, weeks 4-8; and 9 g, weeks 9-13) or placebo. Assessments included mean sleep latency on Maintenance of Wakefulness Test (MWT) and Clinical Global Impression-Improvement (CGI-I) rating (coprimary endpoints) and sleep stage shifts, nocturnal arousals, and patient-reported sleep quality, refreshing nature of sleep, and Epworth Sleepiness Scale (ESS) score (secondary endpoints) separately in NT1 and NT2 subgroups.

RESULTS

The modified intent-to-treat population comprised 190 participants (NT1, n = 145; NT2, n = 45). Significant improvements were demonstrated with ON-SXB vs placebo in sleep latency for NT1 (all doses, p < .001) and NT2 (6 and 9 g, p < .05) subgroups. Greater proportions of participants in both subgroups had CGI-I ratings of much/very much improved with ON-SXB vs placebo. Sleep stage shifts and sleep quality significantly improved in both subgroups (all doses vs placebo, p < .001). Significant improvements with all ON-SXB doses vs placebo in refreshing nature of sleep (p < .001), nocturnal arousals (p < .05), and ESS scores (p ≤ .001) were reported for NT1 with directional improvements for NT2.

CONCLUSIONS

Clinically meaningful improvements of a single ON-SXB bedtime dose were shown for daytime sleepiness and DNS in NT1 and NT2, with less power for the limited NT2 subgroup.

Retrospective cohort study of hypersomnias of central origin from two Australian tertiary sleep disorders services

BACKGROUND

Hypersomnias of central origin (HOCO) are diverse in origin and symptomatology and remain poorly described in an Australian population. We hypothesised that the rate of human leukocyte antigen (HLA) DQB1*0602 positivity in the Australian cohort would be comparable to international registries.

AIMS

The current study aims to evaluate epidemiological and clinical characteristics of Australian patients with HOCO, including prevalence of HLA DQB1*0602 positivity, the most specific HLA marker associated with narcolepsy.

METHODS

This is a retrospective study. Patients ≥ 16 years of age presenting with symptoms of hypersomnolence who attended one of two Australian sleep centres (New South Wales and Queensland) in the preceding 24 months and had undergone both HLA serology and multiple sleep latency tests (MSLTs) were included. Main outcome measures included demographics, HLA DQB1*0602 positivity, MSLT, and clinical parameters (presence of auxiliary narcolepsy symptoms, laboratory tests, relevant prescribed medications).

RESULTS

Eighty-eight patients were included. HLA DQB1*0602 positivity was highest in those with type 1 narcolepsy (NT1) (95.7%) and lowest in those without a classifiable disorder (9.1%). Mean sleep latency was lowest and number of sleep-onset rapid eye movement periods (SOREMPs) highest in the NT1 group. Comorbid disorders, particularly depression and overweight/obesity, were prevalent in all cohorts. Across all diagnostic groups, dexamphetamine was the most commonly prescribed agent for excessive daytime sleepiness.

CONCLUSIONS

Patients with HOCO assessed in two specialised Australian clinics demonstrate comparable clinical characteristics to other published cohorts internationally; however, available pharmacological agents in Australia do not reflect international standards of care.

Narcolepsies, update in 2023

Narcolepsy type 1 (NT1) and type 2 (NT2), also known as narcolepsy with and without cataplexy, are sleep disorders that benefited from major scientific advances over the last two decades. NT1 is caused by the loss of hypothalamic neurons producing orexin/hypocretin, a neurotransmitter regulating sleep and wake, which can be measured in the cerebrospinal fluid (CSF). A low CSF level of hypocretin-1/orexin-A is a highly specific and sensitive biomarker, sufficient to diagnose NT1. Orexin-deficiency is responsible for the main NT1 symptoms: sleepiness, cataplexy, disrupted nocturnal sleep, sleep-related hallucinations, and sleep paralysis. In the absence of a lumbar puncture, the diagnosis is based on neurophysiological tests (nocturnal and diurnal) and the presence of the pathognomonic symptom cataplexy. In the revised version of the International Classification of sleep Disorders, 3rd edition (ICSD-3-TR), a sleep onset rapid eye movement sleep (REM) period (SOREMP) (i.e. rapid occurrence of REM sleep) during the previous polysomnography may replace the diurnal multiple sleep latency test, when clear-cut cataplexy is present. A nocturnal SOREMP is very specific but not sensitive enough, and the diagnosis of cataplexy is usually based on clinical interview. It is thus of crucial importance to define typical versus atypical cataplectic attacks, and a list of clinical features and related degrees of certainty is proposed in this paper (expert opinion). The time frame of at least three months of evolution of sleepiness to diagnose NT1 was removed in the ICSD-3-TR, when clear-cut cataplexy or orexin-deficiency are established. However, it was kept for NT2 diagnosis, a less well-characterized disorder with unknown clinical course and absence of biolo biomarkers; sleep deprivation, shift working and substances intake being major differential diagnoses. Treatment of narcolepsy is nowadays only symptomatic, but the upcoming arrival of non-peptide orexin receptor-2 agonists should be a revolution in the management of these rare sleep diseases.

Central Disorders of Hypersomnolence

OBJECTIVE

The goals of this article are to describe the clinical approach to and management of patients with central disorders of hypersomnolence, and to understand and differentiate available diagnostic tools.

LATEST DEVELOPMENTS

Updated clinical practice guidelines for the treatment of central disorders of hypersomnolence and narcolepsy specifically highlight new treatment options. Approval for a lower-sodium oxybate formulation that contains 92% less sodium than the standard sodium oxybate for the treatment of narcolepsy and idiopathic hypersomnia adds to the number of medications available for these disorders, allowing for a more tailored management of symptoms.

ESSENTIAL POINTS

Central disorders of hypersomnolence are characterized by excessive daytime sleepiness that impacts daily functions. These disorders can be differentiated by obtaining a detailed clinical sleep history and by a thoughtful interpretation of sleep diagnostic testing. Tailoring treatment approaches to meet the needs of individuals and accounting for medical and psychiatric comorbidities may improve quality of life.

Metabolic disturbances in children with narcolepsy: a retrospective study

STUDY OBJECTIVES

To determine the prevalence of metabolic syndrome (MS) in children with narcolepsy and to evaluate their clinical and sleep characteristics according to the different components of MS.

METHODS

This retrospective study consisted of 58 de novo children with narcolepsy (median age: 12.7 years, 48.3% of boys). The recently published MS criteria in a French population of children were used. Clinical and sleep characteristics were compared between groups with different components of MS.

RESULTS

MS was present in 17.2% of children with narcolepsy, among whom 79.3% presented with high homeostasis model assessment for insulin resistance (HOMA-IR), 25.9% with high body mass index, 24.1% with low high-density lipoprotein cholesterol (HDL-C), and 12.1% with high triglycerides. Patients with at least two MS components had more night eating behaviors and tended to have lower percentage of slow-wave sleep and more fragmented sleep. On multiple sleep latency test, they had shorter mean sleep latencies to rapid eye movement (REM), non-REM sleep and tended to have more sleep onset REM periods (SOREMPs) than those with less than two MS components.

CONCLUSIONS

Insulin resistance was found to be the core metabolic disturbance in obese as well as in nonobese children with narcolepsy. Children with narcolepsy with at least two MS components presented a more severe daytime sleepiness and a higher prevalence of night-eating behaviors than those with less than two MS components. Such children might benefit from early evaluation and management in order to prevent future complications.

Pharmacological options for narcolepsy: are they the way forward?

INTRODUCTION

Narcolepsy is an under-recognized, rare neurologic disorder of hypersomnolence that is associated with increased mortality and medical and psychiatric co-morbidities. Narcolepsy exerts a substantial economic burden on patients and society. There is currently no cure, and life-long symptomatic therapy is needed. Available drugs do not modify the disease course.

AREAS COVERED

This manuscript provides an overview of narcolepsy symptoms, diagnosis, pathophysiology, current pharmacotherapies, and emerging treatments. Gaps and unresolved issues in diagnosis and management of narcolepsy are discussed to answer whether pharmacological options are the way forward.

EXPERT OPINION

Diagnostic criteria for narcolepsy (ICSD-3) need revision and greater clarity. Improved recognition of cataplexy and other symptoms through educational outreach, new biomarkers, improved test scoring through artificial intelligence algorithms, and use of machine learning may facilitate earlier diagnosis and treatment. Pharmacological options need improved symptomatic therapy in addition to targeted therapies that address the loss of hypocretin signaling. Optimal narcolepsy care also needs a better understanding of the pathophysiology, recognition of the different phenotypes in narcolepsy, identification of at-risk individuals and early recognition of symptoms, better diagnostic tools, and a database for research and disease monitoring of treatment, side-effects, and comorbidities.

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.

Building a deeper understanding of social relationship health in adolescents with narcolepsy disorder

STUDY OBJECTIVES

Common symptoms for patients with narcolepsy can have a significant impact on social health. As one peak for symptom onset is adolescence, these symptoms impact social relationships during a critical developmental period. Much of the existing literature in this domain has relied on broad questionnaires, with less insight into the nuances of patients' potential social struggles.

METHODS

Adolescents (aged 12-17 years) with narcolepsy and their parents individually completed a semistructured interview (n = 14 dyads). Interview transcripts were analyzed using a multistage thematic analysis.

RESULTS

An overarching theme was the difficulty adolescents experienced trying to balance narcolepsy symptom management with engaging in social activities in a meaningful way. Narcolepsy affected social relationships in 3 primary domains: mood, physical activities, and driving. Adolescents reported that they were frustrated with feeling as though narcolepsy sometimes defined their social lives. Adolescents and parents expressed a desire for medical providers to better understand their evolving priorities, to validate their social limitations, and to provide more information around the social implications of narcolepsy and its treatment.

CONCLUSIONS

Narcolepsy has a significant impact on social relationships in adolescents, one that is not adequately managed in current clinical care models. A routine, structured assessment of social health is a vital first step for providers treating adolescents with narcolepsy. Medical centers and patient organizations can play an important role in facilitating social opportunities for this underserved population.

CITATION

Zhou ES, Revette A, Heckler GK, Worhach J, Maski K, Owens JA. Building a deeper understanding of social relationship health in adolescents with narcolepsy disorder. J Clin Sleep Med. 2023;19(3):491-498.

The Impact of Symptom Severity on Health-Related Quality of Life in People with Narcolepsy Type 1

OBJECTIVE

To assess the impact of symptom severity on health-related quality of life (HRQoL) in people with narcolepsy type 1 (NT1).

METHODS

A total of 174 people with NT1 were enrolled. They completed the Narcolepsy Severity Scale (NSS) and EQ-5D-3L consisting of five dimensions (EQ-5D utility values) and a visual analog scale (EQ-5D VAS). The relationship between severity of symptoms and HRQoL dimensions was evaluated by Pearson correlation analyses. Logistic regression was used to identify significant predictors of HRQoL. Nomogram was established based on results of independent predictors of factors on logistic regression analyses.

RESULTS

The mean score for NSS, EQ-5D utility values, and EQ-5D VAS were 29.8 (10.08), 0.78 (0.09), and 64.30 (19.84) in people with NT1, respectively. NSS score showed a significant correlation with self-care (r = 0.157, p < .05), usual activities (r = 0.236, p < .01), pain/discomfort (r = 0.174, p < .05), anxiety/depression (r = 0.2, p < .01), and EQ-5D utility values (r = -.261, p < .01). EDS (excessive daytime sleep), cataplexy, hallucinations, paralysis, and disrupted nocturnal sleep (DNS) were significantly associated to EQ-5D VAS (r ranged from -0.154 to -0.354, p < .05). EDS (OR = -0.297) and DNS (OR = -0.16) were predictors of HRQoL. NSS score (OR = -0.360) and treatment (OR = 0.215) were predictors of the metrics of HRQoL. The C-indices of the nomogram were 0.726.

CONCLUSION

The severity of symptoms could disrupt self-care and usual activities, and increase pain/discomfort and anxiety/depression. HRQoL might be improved by alleviating symptom severity.

Orexin, Sleep, Sympathetic Neural Activity, and Cardiovascular Function

Inadequate sleep duration and quality are associated with reduced cardiovascular health and increased mortality. Experimental evidence points to the sympathetic nervous system as a key mediator in the observed relationship between poor sleep and cardiovascular dysfunction. However, brain mechanisms underpinning the impaired sympathetic function associated with poor sleep remain unclear. Recent evidence suggests the central orexin system, particularly orexins A and B and their receptors, have a key regulatory role for sleep in animal and human models. While orexin system activity has been observed to significantly impact sympathetic regulation in animals, the extension of these findings to humans has been difficult due to an inability to directly assess orexin system activity in humans. However, direct measures of sympathetic activity in populations with narcolepsy and chronic insomnia, 2 sleep disorders associated with deficient and excessive orexin neural activity, have allowed indirect assessment of the relationships between orexin, sleep, and sympathetic regulation. Further, the recent pharmaceutical development of dual orexin receptor antagonists for use in clinical insomnia populations offers an unprecedented opportunity to examine the mechanistic role of orexin in sleep and cardiovascular health in humans. The current review assesses the role of orexin in both sleep and sympathetic regulation from a translational perspective, spanning animal and human studies. The review concludes with future research directions necessary to fully elucidate the mechanistic role for orexin in sleep and sympathetic regulation in humans.

Exploring Addictive Online Behaviors in Patients with Narcolepsy Type 1

BACKGROUND

Narcolepsy type 1 (NT1) is a rare neurological sleep disorder caused by the loss of neurons that produce hypocretin-a peptide that plays a crucial role in addictive behaviors. We aimed to compare, for the first time, levels of problematic online gaming, problematic social media use, and compulsive Internet use between NT1 patients and healthy controls (HC), and to evaluate the association between anxiety, depression, and emotion dysregulation with addictive online behaviors in NT1 patients.

METHODS

A total of 43 patients with NT1 and 86 sex- and age-matched HC participated in an online cross-sectional survey.

RESULTS

NT1 patients did not differ from HC in terms of problematic social media use and compulsive Internet use but displayed higher levels of problematic online gaming compared to HC. Higher levels of emotion dysregulation were significantly associated with higher levels of problematic social media use and compulsive Internet use, while none of the tested factors were associated with problematic online gaming.

CONCLUSION

NT1 patients and HC had similar levels of problematic social media use and compulsive Internet use, but NT1 patients showed higher levels of problematic online gaming. Emotion dysregulation might be an intervention target for reducing compulsive Internet use and problematic social media use.

Not Only Excessive Daytime Sleepiness but Also Depression Symptoms, Chronological Age and Onset-Age Were Associated with Impulsivity in Narcolepsy Type 1 Patients

Objective

To detect the factors associated with total and subscales impulsivity scores in narcolepsy and further explore the non-linear relationship between these factors and impulsivity score.

Methods

One hundred and fifty-eight narcolepsy type 1 (NT1) patients were involved in this cross-sectional study. Patients completed questionnaires evaluating impulsivity symptoms (Barratt impulse scale-11, BIS-11), depression symptoms (Center for Epidemiologic Studies Depression Scale for Children, CES-DC or Self-Rating Depression Scale, SDS) and sleepiness (Epworth Sleepiness Scale, ESS). Parameters from polysomnography and multiple sleep latency test were also collected. Linear regression analysis was performed to detect the factors associated with total and subscales impulsivity scores. Then, generalized additive models and smooth curve fitting were performed to explore the non-linear relationship between chronological age and impulsivity scores.

Results

Factors associated with higher total impulsivity score were higher ESS, older onset and adolescents. Factors associated with higher attentional impulsivity score were higher ESS, older onset and adolescents. Factors associated with higher motor impulsivity score were higher ESS, younger onset and depression symptoms. Factors associated with higher non-planning impulsivity score were adolescents, older onset and depression symptoms. A non-linear relationship between age and impulsivity scores (total impulsivity score, attentional impulsivity score and non-planning impulsivity score) was detected in NT1 patients.

Conclusion

Not only excessive daytime sleepiness but also onset-age, depression symptoms and chronological age were associated with impulsivity in NT1 patients. The non-linear relationship between age and impulsivity scores suggested brain and mental development alterations in NT1 patients.

Increased very low frequency pulsations and decreased cardiorespiratory pulsations suggest altered brain clearance in narcolepsy

Background

Narcolepsy is a chronic neurological disease characterized by daytime sleep attacks, cataplexy, and fragmented sleep. The disease is hypothesized to arise from destruction or dysfunction of hypothalamic hypocretin-producing cells that innervate wake-promoting systems including the ascending arousal network (AAN), which regulates arousal via release of neurotransmitters like noradrenalin. Brain pulsations are thought to drive intracranial cerebrospinal fluid flow linked to brain metabolite transfer that sustains homeostasis. This flow increases in sleep and is suppressed by noradrenalin in the awake state. Here we tested the hypothesis that narcolepsy is associated with altered brain pulsations, and if these pulsations can differentiate narcolepsy type 1 from healthy controls.

Methods

In this case-control study, 23 patients with narcolepsy type 1 (NT1) were imaged with ultrafast fMRI (MREG) along with 23 age- and sex-matched healthy controls (HC). The physiological brain pulsations were quantified as the frequency-wise signal variance. Clinical relevance of the pulsations was investigated with correlation and receiving operating characteristic analysis.

Results

We find that variance and fractional variance in the very low frequency (MREG_vlf) band are greater in NT1 compared to HC, while cardiac (MREG_card) and respiratory band variances are lower. Interestingly, these pulsations differences are prominent in the AAN region. We further find that fractional variance in MREG_vlf shows promise as an effective bi-classification metric (AUC = 81.4%/78.5%), and that disease severity measured with narcolepsy severity score correlates with MREG_card variance (R = −0.48, p = 0.0249).

Conclusions

We suggest that our novel results reflect impaired CSF dynamics that may be linked to altered glymphatic circulation in narcolepsy type 1.

The flow of fluid surrounding and inside the human brain is thought to be caused by the movement of brain vessels, breathing and heart rate. These so called brain pulsations are linked to clearing waste from the brain. This process is increased during sleep and suppressed while we are awake. Narcolepsy is a neurological disease where the brain areas regulating being awake and asleep are affected. The diagnosis requires time-consuming hospital tests and is often delayed which has a prolonged negative impact on the patients. Here, we use brain imaging to investigate whether brain pulsations are altered in patients with narcolepsy, and if they can be utilized to differentiate patients with narcolepsy from healthy individuals. We find that narcolepsy affects all brain pulsations, and these findings show promise as an additional diagnostic tool that could help detect the disease earlier.

Järvelä et al. investigate if narcolepsy is associated with altered brain pulsations using ultrafast fMRI. They find differences in the brain pulsations between narcolepsy type 1 patients and healthy controls that may link to altered brain clearance in narcolepsy, have diagnostic potential and correlate with the severity of narcolepsy.

Towards an automatic narcolepsy detection on ambiguous sleep staging and sleep transition dynamics joint model

Objective.Mixing/dissociation of sleep stages in narcolepsy adds to the difficulty in automatic sleep staging. Moreover, automatic analytical studies for narcolepsy and multiple sleep latency test (MSLT) have only done automatic sleep staging without leveraging the sleep stage profile for further patient identification. This study aims to establish an automatic narcolepsy detection method for MSLT.Approach.We construct a two-phase model on MSLT recordings, where ambiguous sleep staging and sleep transition dynamics make joint efforts to address this issue. In phase 1, we extract representative features from electroencephalogram (EEG) and electrooculogram (EOG) signals. Then, the features are input to an EasyEnsemble classifier for automatic sleep staging. In phase 2, we investigate sleep transition dynamics, including sleep stage transitions and sleep stages, and output likelihood of narcolepsy by virtue of principal component analysis (PCA) and a logistic regression classifier. To demonstrate the proposed framework in clinical application, we conduct experiments on 24 participants from our hospital, considering ten patients with narcolepsy and fourteen patients with MSLT negative.Main results.Applying the two-phase leave-one-subject-out testing scheme, the model reaches an accuracy, sensitivity, and specificity of 87.5%, 80.0%, and 92.9% for narcolepsy detection. Influenced by disease pathology, accuracy of automatic sleep staging in narcolepsy appears to decrease compared to that in the non-narcoleptic population.Significance.This method can automatically and efficiently distinguish patients with narcolepsy based on MSLT. It probes into the amalgamation of automatic sleep staging and sleep transition dynamics for narcolepsy detection, which would assist clinic and neuroelectrophysiology specialists in visual interpretation and diagnosis.

Low carnitine palmitoyltransferase 1 activity is a risk factor for narcolepsy type 1 and other hypersomnia

Study Objectives

Narcolepsy type 1 (NT1) is associated with metabolic abnormalities but their etiology remains largely unknown. The gene for carnitine palmitoyltransferase 1B (CPT1B) and abnormally low serum acylcarnitine levels have been linked to NT1. To elucidate the details of altered fatty acid metabolism, we determined levels of individual acylcarnitines and evaluated CPT1 activity in patients with NT1 and other hypersomnia.

Methods

Blood samples from 57 NT1, 51 other hypersomnia patients, and 61 healthy controls were analyzed. The levels of 25 major individual acylcarnitines were determined and the C0/(t[C16] + t[C18]) ratio was used as a CPT1 activity marker. We further performed transcriptome analysis using independent blood samples from 42 NT1 and 42 healthy controls to study the relevance of fatty acid metabolism. NT1-specific changes in CPT1 activity and in expression of related genes were investigated.

Results

CPT1 activity was lower in patients with NT1 (p = 0.00064) and other hypersomnia (p = 0.0014) than in controls. Regression analysis revealed that CPT1 activity was an independent risk factor for NT1 (OR: 1.68; p = 0.0031) and for other hypersomnia (OR: 1.64; p = 0.0042). There was a significant interaction between obesity (BMI &lt;25, ≥25) and the SNP rs5770917 status such that nonobese NT1 patients without risk allele had better CPT1 activity (p = 0.0089). The expression levels of carnitine-acylcarnitine translocase (CACT) and CPT2 in carnitine shuttle were lower in NT1 (p = 0.000051 and p = 0.00014, respectively).

Conclusions

These results provide evidences that abnormal fatty acid metabolism is involved in the pathophysiology of NT1 and other hypersomnia.

The Impact of Sleep Pattern in School/Work Performance During the COVID-19 Home Quarantine in Patients With Narcolepsy

Objectives

Narcolepsy patients were observed improvements in their academic performance during the COVID-19 home quarantine. Therefore, we aim to investigate the influence of sleep behavioral changes on school/work performance in narcolepsy patients during the home quarantine.

Methods

Patients admitted to Shandong Provincial Qianfoshan Hospital from Jan 1, 2017 to Jan 1, 2021 who were diagnosed with narcolepsy were studied by online questionnaires in two different periods (during and 1 year after the COVID-19 home quarantine), including five aspects: (1) changes in school/work performance (percentile ranking in class/Sheehan Disability Scale 1, SDS1); (2) daytime functions; (3) clinical symptoms; (4) psychological moods; (5) medication situations.

Results

A total of 46 narcolepsy patients 34 (73.9%) narcolepsy type 1, 12 (26.1%) narcolepsy type 2 with average age of 20.76 ± 8.99 years and an equal number of age and gender matched control subjects were enrolled. During the COVID-19 home quarantine, the narcolepsy patients were found that they altered sleep patterns, including later get up time (P < 0.001), longer total sleep time (TST, P = 0.001), better sleep quality (PSQI, P = 0.001), and lower anxiety level (P = 0.005). Their school/work performance improved parallelly [with better percentile ranking (P = 0.001) and lower SDS1 scores (P = 0.002)]. The results of multiple linear stepwise regression analysis showed a linear regression relationship between TST [efficient (95%) −7.356 (−13.570 to 1.143)], SDS1 score [efficient (95%) 6.580 (2.346–10.815), P = 0.004] and the percentile ranking after adjusting for potential effects. Both the improvements of sleep behavior and school/work performance disappeared after the end of COVID-19 home quarantine. No similar fluctuation was found in the control group.

Discussion

Changes in sleep pattern during the COVID-19 home quarantine, such as longer sleep time and later wake-up time, can reduce the degree of daytime sleepiness and increase the degree of daytime wakefulness of narcolepsy patients, which can alleviate the impact of the disease on school/work performance.

Once-nightly sodium oxybate (FT218) demonstrated improvement of symptoms in a phase 3 randomized clinical trial in patients with narcolepsy

STUDY OBJECTIVES

To assess the efficacy and safety of FT218, a novel once-nightly formulation of sodium oxybate (ON-SXB), in patients with narcolepsy in the phase 3 REST-ON trial.

METHODS

Narcolepsy patients aged ≥16 years were randomized 1:1 to uptitration of ON-SXB (4.5, 6, 7.5, and 9 g) or placebo. Three coprimary endpoints were change from baseline in mean sleep latency on the Maintenance of Wakefulness Test, Clinical Global Impression-Improvement rating, and weekly cataplexy attacks at 9, 7.5, and 6 g. Secondary endpoints included change from baseline on the Epworth Sleepiness Scale. Safety included adverse drug reactions and clinical laboratory assessments.

RESULTS

In total, 222 patients were randomized; 212 received ≥1 dose of ON-SXB (n = 107) or placebo (n = 105). For the three coprimary endpoints and Epworth Sleepiness Scale, all three doses of ON-SXB demonstrated clinically meaningful, statistically significant improvement versus placebo (all p < 0.001). For ON-SXB 9 g versus placebo, increase in mean sleep latency was 10.8 versus 4.7 min (Least squares mean difference, LSMD [95% CI], 6.13 [3.52 to 8.75]), 72.0% versus 31.6% were rated much/very much improved on Clinical Global Impression-Improvement (OR [95% CI], 5.56 [2.76 to 11.23]), change in mean weekly number of cataplexy attacks was -11.5 versus -4.9 (LSMD [95% CI], -6.65 [-9.32 to -3.98]), and change in Epworth Sleepiness Scale was -6.5 and -2.7 (LSMD [95% CI], -6.52 [-5.47 to -2.26]). Common adverse reactions included nausea, vomiting, headache, dizziness, and enuresis.

CONCLUSIONS

ON-SXB significantly improved narcolepsy symptoms; its safety profile was consistent with SXB. ON-SXB conferred efficacy with a clearly beneficial single nighttime dose.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov: NCT02720744, https://clinicaltrials.gov/ct2/show/NCT02720744.

Narcolepsy: a model interaction between immune system, nervous system, and sleep-wake regulation

Narcolepsy is a rare chronic neurological disorder characterized by an irresistible excessive daytime sleepiness and cataplexy. The disease is considered to be the result of the selective disruption of neuronal cells in the lateral hypothalamus expressing the neuropeptide hypocretin, which controls the sleep-wake cycle. Diagnosis and management of narcolepsy represent still a substantial medical challenge due to the large heterogeneity in the clinical manifestation of the disease as well as to the lack of understanding of the underlying pathophysiological mechanisms. However, significant advances have been made in the last years, thus opening new perspective in the field. This review describes the current knowledge of clinical presentation and pathology of narcolepsy as well as the existing diagnostic criteria and therapeutic intervention for the disease management. Recent evidence on the potential immune-mediated mechanisms that may underpin the disease establishment and progression are also highlighted.

Effect of FT218, a Once-Nightly Sodium Oxybate Formulation, on Disrupted Nighttime Sleep in Patients with Narcolepsy: Results from the Randomized Phase III REST-ON Trial

BACKGROUND

Sodium oxybate has been recognized as a gold standard for the treatment of disrupted nighttime sleep due to narcolepsy. Its short half-life and immediate-release formulation require patients to awaken 2.5-4 h after their bedtime dose to take a second dose. A novel extended-release, once-nightly sodium oxybate formulation (ON-SXB; FT218) is under US Food and Drug Administration review for the treatment of adults with narcolepsy.

OBJECTIVE

A phase III trial of ON-SXB in individuals with narcolepsy type 1 (NT1) or 2 (NT2) [the REST-ON trial; NCT02720744] has been conducted and the primary results reported elsewhere. Secondary objectives from REST-ON were to assess the efficacy of ON-SXB on disrupted nighttime sleep; the results of this analysis are reported here.

METHODS

In the double-blind, phase III REST-ON trial, patients aged ≥ 16 years were randomly assigned 1:1 to ON-SXB (1 week, 4.5 g; 2 weeks, 6 g; 5 weeks, 7.5 g; 5 weeks, 9 g) or placebo. Secondary endpoints included polysomnographic measures of sleep stage shifts and nocturnal arousals and patient-reported assessments of sleep quality and refreshing nature of sleep at 6, 7.5, and 9 g; post hoc analyses included changes in time spent in each sleep stage, delta power, and assessments in stimulant-use subgroups for prespecified endpoints.

RESULTS

In total, 190 participants (n = 97, ON-SXB; n = 93, placebo) were included in the efficacy analyses. All three ON-SXB doses demonstrated a clinically meaningful, statistically significant decrease vs placebo in the number of transitions to wake/N1 from N1, N2, and rapid eye movement (REM) stages (all doses p < 0.001) and the number of nocturnal arousals (p < 0.05 ON-SXB 6 g; p < 0.001 7.5 and 9 g). Sleep quality and refreshing nature of sleep were significantly improved with all three ON-SXB doses vs placebo (p < 0.001). Post hoc analyses revealed a significant reduction in time spent in N1 (p < 0.05 ON-SXB 6 g; p < 0.001 7.5 and 9 g) and REM (all p < 0.001) and increased time spent in N3 with ON-SXB vs placebo (all p < 0.001), with a significant increase in delta power (p < 0.01 ON-SXB 6 g; p < 0.05 7.5 g; p < 0.001 9 g) and increased REM latency (ON-SXB 7.5 g vs placebo; p < 0.05). Significant improvements in disrupted nighttime sleep were observed regardless of concomitant stimulant use.

CONCLUSIONS

The clinically beneficial, single nighttime dose of ON-SXB significantly improved disrupted nighttime sleep in patients with narcolepsy.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov NCT02720744.

Current Understanding of Narcolepsy 1 and its Comorbidities: What Clinicians Need to Know

Narcolepsy is a chronic neurologic disorder associated with the dysregulation of the sleep–wake cycle that often leads to a decreased quality of life and results in a considerable health burden. There is often a delay to diagnosis of narcolepsy, mainly due to the lack of recognition of this disorder. One of the main factors hindering the diagnosis of narcolepsy is the association of comorbidities, which include other sleep disorders, psychiatric disorders, cardiovascular disorders, and metabolic disorders. The signs and symptoms of these comorbidities often overlap with those of narcolepsy, and some of the medications used for their treatment may obscure the symptoms of narcolepsy, leading to a delay in diagnosis. This review is targeted to clinicians unaccustomed to working with sleep disorders and aims to increase recognition and improve the management of narcolepsy.

Disrupted nighttime sleep and sleep instability in narcolepsy

STUDY OBJECTIVES

This review aimed to summarize current knowledge about disrupted nighttime sleep (DNS) and sleep instability in narcolepsy, including self-reported and objective assessments, potential causes of sleep instability, health consequences and functional burden, and management.

METHODS

One hundred two peer-reviewed publications from a PubMed search were included.

RESULTS

DNS is a key symptom of narcolepsy but has received less attention than excessive daytime sleepiness and cataplexy. There has been a lack of clarity regarding the definition of DNS, as many sleep-related symptoms and conditions disrupt sleep quality in narcolepsy (eg, hallucinations, sleep paralysis, rapid eye movement sleep behavior disorder, nightmares, restless legs syndrome/periodic leg movements, nocturnal eating, sleep apnea, depression, anxiety). In addition, the intrinsic sleep instability of narcolepsy results in frequent spontaneous wakings and sleep stage transitions, contributing to DNS. Sleep instability likely emerges in the setting of orexin insufficiency/deficiency, but its exact pathophysiology remains unknown. DNS impairs quality of life among people with narcolepsy, and more research is needed to determine its contributions to cardiovascular risk. Multimodal treatment is appropriate for DNS management, including behavioral therapies, counseling on sleep hygiene, and/or medication. There is strong evidence showing improvement in self-reported sleep quality and objective sleep stability measures with sodium oxybate, but rigorous clinical trials with other pharmacotherapies are needed. Treatment may be complicated by comorbidities, concomitant medications, and mood disorders.

CONCLUSIONS

DNS is a common symptom of narcolepsy deserving consideration in clinical care and future research.

CITATION

Maski K, Mignot E, Plazzi G, Dauvilliers Y. Disrupted nighttime sleep and sleep instability in narcolepsy. J Clin Sleep Med. 2022;18(1):289-304.

Calcium, Magnesium, Potassium, and Sodium Oxybates Oral Solution: A Lower-Sodium Alternative for Cataplexy or Excessive Daytime Sleepiness Associated with Narcolepsy

Lower-sodium oxybate (LXB) is an oxybate medication approved to treat cataplexy or excessive daytime sleepiness (EDS) in patients with narcolepsy 7 years of age and older in the United States. LXB was developed as an alternative to sodium oxybate (SXB), because the incidence of cardiovascular comorbidities is higher in patients with narcolepsy and there is an elevated cardiovascular risk associated with high sodium consumption. LXB has a unique formulation of calcium, magnesium, potassium, and sodium ions, containing 92% less sodium than SXB. Whereas the active oxybate moiety is the same for LXB and SXB, their pharmacokinetic profiles are not bioequivalent; therefore, a phase 3 trial in participants with narcolepsy was conducted for LXB. This review summarizes the background on oxybate as a therapeutic agent and its potential mechanism of action on the gamma-aminobutyric acid type B (GABA_B) receptor at noradrenergic and dopaminergic neurons, as well as at thalamocortical neurons. The rationale leading to the development of LXB as a lower-sodium alternative to SXB and the key efficacy and safety data supporting its approval for both adult and pediatric patients with narcolepsy are also discussed. LXB was approved in August 2021 in the United States for the treatment of idiopathic hypersomnia in adults. Potential future developments in the field of oxybate medications may include novel formulations and expanded indications for other diseases.