Narcolepsy Type Research Articles

Improvements in daytime sleepiness and disrupted nighttime sleep with once-nightly sodium oxybate in people with narcolepsy type 1 and type 2: a plain language summary.

This is a plain language summary of a published article in the journal Sleep. Narcolepsy is a sleep condition that has 2 different subtypes: narcolepsy type 1 and narcolepsy type 2. These are called NT1 and NT2 for short. Sodium oxybate (SXB) is approved to treat excessive daytime sleepiness (EDS) and cataplexy. People with NT1 and NT2 both have EDS, but cataplexy is only present in people with NT1. Limited information is available about how SXB works in people with NT2. This is because previous trials have included only people with NT1 or people with unspecified narcolepsy. For more than 20years, the only available formulation of this medicine had to be given twice during the night. Many people with narcolepsy find that chronically waking up in the middle of the night for a second dose of SXB is disruptive to themselves or others in their household. People have also reported sleeping through alarm clocks, missing their second dose, and feeling worse the next day. Some people have accidentally taken the second dose too early, putting them at risk for serious adverse effects. These adverse effects may include slow breathing, low blood pressure, or sedation. The US Food and Drug Administration (FDA) approved a medicine called LUMRYZ™ (sodium oxybate) for extended-release oral suspension in May 2023. LUMRYZ is a once-nightly formulation of SXB (ON-SXB for short) and is taken as a single dose before bedtime. This medicine treats EDS and muscle weakness (also known as cataplexy) in people with narcolepsy. A clinical trial called REST-ON studied ON-SXB to find out if it was better at treating narcolepsy symptoms than a medicine with no active ingredients (placebo). This summary describes a study that tested whether ON-SXB was better than placebo at treating narcolepsy symptoms in people with NT1 or NT2. This study showed that compared to people who took placebo, people who took ON-SXB were able to stay awake longer during the day, felt less sleepy during the daytime, had less cataplexy, and had more improvements in their symptoms overall than people who took placebo. ON-SXB has been proven effective for people with NT1 or NT2. Unlike prior formulations of SXB, ON-SXB is taken once at bedtime, without requiring waking up in the middle of the night for a second dose.

Clinical features and mechanisms of neck myoclonus in narcolepsy

Study objectivesThe purpose of this study was to investigate the effects of neck myoclonus (NM) on sleep quality and daytime sleepiness in patients with narcolepsy (NT) and to further explore possible underlying mechanisms. MethodsWe included 72 patients with narcolepsy type 1 (NT1), 34 patients with narcolepsy type 2 (NT2) and 33 healthy controls. Patients underwent questionnaires, lumbar puncture procedure, polysomnography, and multiple sleep latency test (MSLT). Healthy controls underwent polysomnography and questionnaires. Orexin-A levels in the cerebrospinal fluid (CSF) were analyzed by radioimmunoassay. Three catecholamines, including dopamine, norepinephrine and epinephrine, in the CSF were measured by high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS). ResultsBoth the NT1 and NT2 groups displayed a higher level of NM incidence rate and index compared to the control group in PSG. NT1 displayed greater MSLT REM–-NM incidence rate and index than NT2. NM were often associated with arousal or awakening and body movements, which had a prominent influence on sleep quality in both narcoleptic patients and controls. There was a positive correlation between the NM index and the Pittsburgh Sleep Quality Index (PSQI), Stanford Sleepiness Scale (SSS) and Ullanlinna Narcolepsy Scale (UNS) scores in NT1 patients. In MSLT of NT1 patients, REM–NM index were positively correlated with the CSF dopamine levels, and there were elevated dopamine levels but reduced orexin-A levels in patients with REM–NM. ConclusionNM incidence rate and index were high in patients with narcolepsy, which had a huge effect on sleep quality and aggravated daytime sleepiness. NM should be considered pathological and viewed as a new sleep-related movement disorder. Orexin-A and dopamine may be involved in the development of NM.

Altered functional connectivity and spatiotemporal dynamics in individuals with sleep disorders.

Idiopathic hypersomnia (IH) is a sleep disorder characterized by highly disruptive symptoms. Like narcolepsy type 1, a well-characterized sleep disorder, individuals with IH suffer from excessive daytime sleepiness, though there is little overlap in metabolic or neural biomarkers across these two disorders. This lack of common pathophysiology, combined with the clear overlap in symptoms presents an ideal paradigm for better understanding the impact of IH on an individual's functional activity and organization, and potentially, the underlying pathophysiology. This study examines the observed functional connectivity in patients with IH, and patients with narcolepsy type 1 (NT1) against healthy control individuals. Static functional connectivity is compared, as are quasi-periodic patterns, acquired from the BOLD timecourse, for all groups. In addition to baseline data comparison, the study also included a post-nap condition, where the individuals included in this analysis napped for at least 10 minutes prior to the scanning session, to explore why individuals with IH do not feel refreshed after a nap like individuals with NT1 do. Assessing the groups' spatiotemporal patterns revealed key differences across both disorders and conditions: static connectivity revealed at baseline higher subcortical connectivity in the NT1 group. There was also observably less connectivity in the IH group both at baseline and post-nap, though none of these static analyses survived multiple comparisons correction to reach significance. The QPP results however found significant differences in the IH group in key networks, particularly the DAN/FPCN correlation is significantly different at baseline vs. post-nap, a trend not observed in either the control or NT1 groups. The DAN and FPCN are drastically altered both at baseline and post-nap when compared to the other groups, and may likely be a disorder-specific result. This study demonstrates that key networks for arousal are more heavily disrupted in IH patients, who are less affected by a nap, confirmed through both subject reporting and functional evidence through spatiotemporal patterns.

Sleep disorder syndromes of post-acute sequelae of SARS-CoV-2 (PASC) / Long Covid

IntroductionCOVID-19 infection has resulted in a high prevalence of a post-infectious syndrome, known as post-acute sequelae of SARS-CoV-2 (PASC) or “Long COVID”. PASC is a heterogeneous disease with a high prevalence of sleep disturbances, varying from an insomnia disorder to excessive daytime sleepiness. MethodsPatients seen in the Covid Survivorship Program at the Beth Israel Deaconess Medical Center Boston, USA, were screened for sleep disorders as part of a comprehensive multi-system evaluation. Those who screened positive were referred for a comprehensive sleep evaluation in a dedicated COVID-19-Sleep clinic, followed by diagnostic sleep testing and treatment. This report summarizes patients who completed an American Academy of Sleep Medicine (AASM) accredited facility-based diagnostic evaluation. International Classification of Sleep Disorders 3rd Edition-Revised criteria were met for all diagnoses. ResultsIn 42 patients with PASC, five categories of sleep disorder syndromes were observed following a sleep clinic evaluation, including obstructive sleep apnea, chronic insomnia disorder, primary hypersomnia, REM behavior disorder (RBD), and new onset circadian phase delay. Seven patients met criteria for idiopathic hypersomnia, and two had narcolepsy type 2. RBD patients were infected in three different waves; circadian disturbance patients were all infected in the winter wave of 2020/21, and the primary hypersomnolence group occurred during all waves, predominantly the initial wave of 2020. A peculiar form of insomnia was a persistent loss of sleep regularity. ConclusionsSpecific sleep symptoms/syndromes are reported in this select group of patients with PASC/Long Covid. As new onset sleep complaints are prevalent in PASC, we recommend a complete clinical and investigative sleep evaluation for persistent severe sleep symptoms following COVID-19 infection.

Narcolepsy and Idiopathic Daytime Hypersomnia: A Study of Cohort in the Chilean Population

Introduction: Central disorders with hypersomnolence (CDH) are a group of sleep disorders characterized by excessive daytime sleepiness (EDS) that can be related to REM-sleep dissociative symptoms. They have a low prevalence in the population and may not be explained by other medical conditions. Materials and methods: A cohort of 59 Chilean patients with the most common types of CDH were studied. Clinical data, and results of polysomnography (PSG) plus multiple sleep latency tests (MSLT) were analyzed.. Results: The median age of the cohort was 35.26 ± 13.23 years (69.5% female). Diagnosis of narcolepsy Type 1, narcolepsy Type 2, and idiopathic daytime hypersomnia, were determined in 54.2%, 23.7% and 22% of patients respectively. All patients reported EDS, while 57.6%, 81.4% and 78% reported cataplexy, sleep paralysis and hypnagogic/hypnopompic hallucinations respectively. Polysomnographic studies showed non relevant alterations in the majority of patients. The MLTS was abnormal in all patients, 78% of them with 2 or more sleep onset REM periods (SOREMP). In 52.5% of cases, the delay in final diagnosis was more than 5 years. About a third of patients had another sleep disorder that could not explain the severity of EDS. We observed a comorbidity with an immunological disorder in 30.5% of patients. Conclusion: The EDS is the main symptom in CDH. Related REM-sleep symptoms and MSLT alterations were the second most important features to establish final diagnosis. However, we observed a significant delay in CDH diagnosis in the majority of patients.

Validation of the Russian version of Swiss Narcolepsy Scale for narcolepsy type 1 screening

Validation of the Russian version of Swiss Narcolepsy Scale for narcolepsy type 1 screening

CSF-profile and hypocretin levels in children with narcolepsy type 1 and 2

BackgroundNarcolepsy is a rare neurological disease caused by dysfunction of hypocretin-producing neurons. Hypocretin concentrations in the cerebrospinal fluid (CSF) of less than 110 pg/ml are considered pathological in adults. ObjectivesTo compare hypocretin levels of children with narcolepsy type 1, type 2 and disease control groups, in addition to a detailed CSF analysis, clinical and polysomnographic parameters. MethodsIn a retrospective, cross-sectional study, children diagnosed with narcolepsy based on clinical and polysomnographic parameters, who received a CSF analysis and hypocretin measurement, in addition to controls, were included. CSF was analyzed for the presence of cells, total protein, lactate, intrathecal synthesis of antibodies against measles, rubella and/or varicella zoster, and oligoclonal bands. All children had a complete sleep study including a multiple sleep latency test (MSLT). Results49 children with narcolepsy type 1, 15 children with type 2 and 37 children with other (suspected) neurological diseases were included. CSF routine analysis did not reveal any differences between the three groups. All children with narcolepsy type 1 had hypocretin levels of less than 110 pg/ml (range: 10–101 pg/ml). Hypocretin levels in type 2 patients ranged from 43 to 436 pg/ml (median 157 pg/ml). The median hypocretin level in the control cohort was 365 pg/ml (range: 153–583 pg/ml). In 4 children with narcolepsy type 2 the diagnosis was changed to narcolepsy level 1 because of a CSF hypocretin level of less than 110 pg/ml according to the recently proposed criteria, which consider the measurement of hypocretin in CSF. ConclusionChildren with narcolepsy type 1 showed significantly lower CSF hypocretin levels than children with narcolepsy type 2 and controls. As suggested by the recently published narcolepsy criteria, hypocretin levels of less than 110 pg/ml should be used as an additional criterion for the presence of narcolepsy type 1 in children.

Weight Loss With Once-nightly Sodium Oxybate for the Treatment of Narcolepsy: Analysis From the Phase III Randomized study Evaluating the efficacy and SafeTy of a ONce nightly formulation of sodium oxybate (REST-ON) Trial

Individuals with narcolepsy are more likely to be obese than the general population. Changes in weight-related measures with extended-release, once-nightly sodium oxybate (ON-SXB) and characteristics of participants with ≥5% weight loss were assessed in a Randomized study Evaluating the efficacy and SafeTy of a ONce nightly formulation of sodium oxybate (REST-ON) trial post hoc analysis. REST-ON (NCT02720744) was a Phase III, double-blind, placebo-controlled, multicenter, randomized clinical trial. Participants aged ≥16 years with narcolepsy type 1 (NT1) or NT2 received ON-SXB or placebo for 13 weeks (week 1, 4.5 g; weeks 2-3, 6 g; weeks 4-8, 7.5 g; and weeks 9-13, 9 g). Weight and body mass index were measured at baseline and study end. Weights were similar between groups at baseline (mean [SD]; ON-SXB, 81.2 [20.8] kg; N = 107 [NT1, n = 80; NT2, n = 27]; placebo, 82.1 [22.5] kg; N = 105 [NT1, n = 82; NT2, n = 23]). At week 13 (9 g), mean (SD) weight decreased 1.3 (3.6) kg with ON-SXB and increased 0.2 (2.6) kg with placebo; 17.8% (19/107; NT1, n = 14; NT2, n = 5) of participants receiving ON-SXB had ≥5% weight loss versus 3.8% receiving placebo (4/105; NT1, n = 3; NT2, n = 1; P = 0.001). At week 13, least squares mean (SE) body mass index change from baseline was ‒0.51 (0.13) kg/m2 with ON-SXB and 0.08 (0.13) kg/m2 with placebo (least squares mean difference [95% CI], -0.59 [-0.95 to -0.23] kg/m2; P = 0.001). Excessive daytime sleepiness improved for both groups with ON-SXB, the ≥5% weight-loss subgroup exhibited larger improvement in the Maintenance of Wakefulness Test and Epworth Sleepiness Scale versus the other subgroup (weight loss <5%, no change, or weight gain) (Maintenance of Wakefulness Test, P = 0.019; Epworth Sleepiness Scale score, P < 0.001). Narcolepsy is often associated with obesity, which may increase cardiometabolic risks. ON-SXB, an effective treatment for excessive daytime sleepiness and cataplexy, may be preferred in overweight or obese individuals to provide a more tailored treatment approach. NCT02720744.

Association between human leukocyte antigen class II-DR-DQ and narcolepsy: a case control study.

Narcolepsy is a neurologic disorder characterized by irresistible sleep attacks. Although its etiology is unknown, it is strongly associated with genetic variances in the human leukocyte antigen (HLA) complex. We investigated the association of HLA class II-DR-DQ alleles in a sample of patients with narcolepsy-cataplexy (narcolepsy type 1; NT1) and patients with narcolepsy without cataplexy (narcolepsy type 2; NT2) with a control group. Additionally, we compared demographic, clinical, and laboratory characteristics of patients with narcolepsy with or without the DQB1*06:02 allele. This case control study included 21 patients with NT1 (56.8%), 16 patients with NT2 (43.2%), and 100 controls. Sequence-based typing identified HLA-DRB1 alleles, and HLA-DQB1 typing was done using PCR-Sequence-Specific Oligonucleotide. Allele and haplotype frequencies were calculated by direct counting. Nocturnal polysomnography and Multiple Sleep Latency Test were performed in all participants. In the NT1 group, only one allele had a significantly higher frequency than in the NT2 group: DQB1*06:02 (61.9% vs. 18.8%;). Compared to controls, DQB1*06:02 (61.9% vs. 18.0% in controls) and DRB1*15:01(47.6% vs. 8.0%), had higher frequencies in patients with NT1. Multiple analyses showed that patients with NT1 had an increased chance of being HLA-DQB1*06:02 positive. HLA-DRB1*15:01-DQA1*01:02-DQB1*06:02 haplotype is associated with NT1 in our Brazilian patients. PSG was identified in DQB1*06:02 positive subgroup REM sleep latency (REML) ≤ 15 minutes, and all patients had two or more sleep-onset REM periods (SOREMPs) at MSLT. This study showed a strong association between HLA DQB1*06:02 and the haplotype HLA-DRB1*15:01-DQA1*01:02-DQB1*06:02 in patients with NT1. Patients with DQB1*0602 allele showed shorter REMLs at PSG. These results reinforce the suggestion of DQB1 genotyping as relevant to narcolepsy screening.

Insights from a 10-year Australasian idiopathic hypersomnia patient data registry study.

Idiopathic hypersomnia (IH) is a disorder of central hypersomnolence that results in excessive daytime sleepiness in the absence of another identifying cause. Case studies from sleep clinic patients may not be a fair representation of the wider IH population. This study aims to better characterize patients diagnosed with IH in Australia and New Zealand using online patient-driven survey data. A retrospective analysis of 686 participants from the Hypersomnolence Australia Patient Data Registry diagnosed with either IH (n = 554), narcolepsy type 1 (NT1, n = 54) or narcolepsy type 2 (NT2, n = 78) between January 2013 and October 2022 was performed. Participants with IH reported additional sleep disorders such as OSA (16.4%) and restless legs syndrome (7.9%) and notable comorbidities included depression (46.2%) and anxiety (50%). There was a mean delay in diagnosis of 10 years in participants with IH, when compared to symptom onset. IH presents with unique but also overlapping symptomatology with NT2, with similar reporting of long daytime naps, unrefreshed sleep and automatic behavior. Modafinil was the most common medication (45.5%) used by participants with IH followed by dexamphetamine (44.2%). Most participants with IH reported receiving physician advice regarding positive lifestyle changes but recommend that newly diagnosed patients be given more advice about medication use. This study demonstrates a delay in IH diagnosis when compared to symptom onset and overlapping features of IH and NT2. It also highlights the heterogeneous presentation of IH and the value of large patient registries in future research.

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.

Major alteration of motor control during rapid eye movements sleep in mice models of sleep disorders.

Alteration of motor control during rapid eye movements (REM) sleep has been extensively described in sleep disorders, in particular in isolated REM sleep behavior disorder (iRBD) and narcolepsy type 1 (NT1). NT1 is caused by the loss of orexin/hypocretin (ORX) neurons. Unlike in iRBD, the RBD comorbid symptoms of NT1 are not associated with alpha-synucleinopathies. To determine whether the chronic absence of ORX neuropeptides is sufficient to induce RBD symptoms, we analyzed during REM sleep the EMG signal of the prepro-hypocretin knockout mice (ORX-/-), a recognized mouse model of NT1. Then, we evaluated the severity of motor alterations by comparing the EMG data of ORX-/- mice to those of mice with a targeted suppression of the sublaterodorsal glutamatergic neurotransmission, a recognized rodent model of iRBD. We found a significant alteration of tonic and phasic components of EMG during REM sleep in ORX-/- mice, with more phasic events and more REM sleep episodes without atonia compared to the control wild-type mice. However, these phasic events were fewer, shorter, and less complex in ORX-/- mice compared to the RBD-like ORX-/- mice. We thus show that ORX deficiency, as seen in NT1, is sufficient to impair muscle atonia during REM sleep with a moderate severity of alteration as compared to isolated RBD mice. As described in NT1 patients, we report a major interindividual variability in the severity and frequency of RBD symptoms in ORX-deficient mice.

Knowledge of Narcolepsy Among Physicians in Makkah Region, Saudi Arabia: A Cross-Sectional Study.

Background Narcolepsy is a chronic sleep disorder that is characterized by excessive daytime sleepiness and cataplexy. It has been increasingly diagnosed over the years, impacting productivity and employment rates. Awareness of healthcare providers is crucial for the early identification and management of this condition. Objectives This study assessed physicians' knowledge of narcolepsy in the Makkah region of Saudi Arabia. Method This cross-sectional study was conducted from February to November 2023. An online self-administered questionnaire has been used to target physicians working in the Makkah region of Saudi Arabia. The utilized questionnaire assessed demographic and professional data as well as the participants' knowledge of narcolepsy. Statistical analysis was performed using RStudio (R version 4.3.1.). Statistical differences in knowledge were assessed using Pearson's chi-squared and Fisher's exact tests. Factors associated with knowledge of narcolepsy were investigated through univariable and multivariable regression analyses expressed using beta coefficients and 95% confidence intervals (95% CIs). Statistical significance was considered at p < 0.05. Results A total of 226 physicians participated in this study. Male physicians (54.4%, n = 123), practicing in governmental hospitals (77.9%, n = 176) and residing in Makkah City (43.4%, n = 98) were predominant. Non-surgical specialties represented 73.5% (n = 166) of the sample. Around 81% (n = 184) of the participants were aware of narcolepsy, with a significant difference according to professional status (p = 0.045). The majority of physicians have correctly identified narcolepsy as a sleep disorder (78.3%, n = 177), but only 32.3% (n = 73) have identified its typical onset age group and recognized that there are two types of narcolepsy. Almost half of the respondents indicated a lack of knowledge about the diagnostic criteria for narcolepsy in the DSM-5 (52.2%, n = 118). Only 27.4% (n = 62) recognized the correct diagnostic criteria. Half of the sample (51.3%, n = 116) recognized the use of multiple sleep latency tests for the diagnosis. For factors associated with higher participants' knowledge, non-surgical specialties showed significantly higher knowledge scores compared to surgical specialties (beta = 0.91, 95% CI, 0.13 to 1.7, p = 0.024). Conclusion This study has revealed a significant lack of knowledge about narcolepsy among physicians inMakkah region. This raises concerns about the timely identification, proper understanding, and accurate diagnosis of patients with narcolepsy. Adequate understanding of narcolepsy is crucial to avoid its misdiagnosis or delays in receiving appropriate treatment and support, ultimately impacting their quality of life.

Pattern of sleep disorders among children with autism spectrum disorder

BackgroundSleep disorders (SDs) are among many co-morbid medical conditions that affect children with autism spectrum disorder (ASD). Raising awareness and improving the standard of care for children diagnosed with ASD may result from identifying SDs among them. This study aims to evaluate patterns of SDs among Sudanese children diagnosed with ASD.MethodUsing the Childhood Sleep Habit Questionnaire (CSHQ) to gather data on sleep disorders and SPSS version 26.0 for data analysis, a descriptive cross-sectional study was carried out in the five main autistic centres in Khartoum state covering all registered patients with ASD between April and June 2022. Ninety-two children diagnosed with ASD were enrolled in this study after the purpose of the research was explained and consent was obtained from their guardians. A p-value < 0.05 was considered to indicate statistical significance.ResultsThe mean age was 6.90 (± 2.6) years with a boys-to-girls ratio of 2.17:1. The prevalence of SDs (at least one sleep condition almost daily) was 95.65%. Sleep onset 71 (77.2%), limit setting 32 (32.6%), resistant onset to sleep 48 (52.2%), and combined 52 (56.5%) insomnia affected the majority of children. Additionally, there were significant associations between sex and Limit-setting insomnia, advanced sleep phase disorder, and narcolepsy type 2 (P values = 0.033, 0.009, and 0.037, respectively). Additionally, there was a significant association between age and sleep-related breathing disorders-snoring (p value = 0.031).ConclusionThe frequency of SDs is significant among children diagnosed with ASD from Sudan, and certain SDs are associated with age and sex. Subsequent studies are required to develop national guidelines for the prevalence, presentation, screening, and treatment of SDs in children diagnosed with ASD.

Exploring the association between hypocretin-1 levels and bone mineral content in patients with narcolepsy: A cross-sectional study

IntroductionRecent studies suggest the existence of a physiologic basis for bone rarefaction and increased risk for fractures. This study aimed to address anthropometric differences between patients with narcolepsy type 1 (NT1) and type 2 (NT2) and discrepancies in bone mineral content (BMC) as a function of hypocretin-1 (Hcrt-1) measured in cerebrospinal fluid (CSF). MethodsWe have evaluated 31 adult patients (aged 18–65 years) with NT1 and 18 patients with NT2, comparing the groups in terms of anthropometric variables – body mass index (BMI) and waist-to-hip ratio (WHR) – and percentage of bone mineral content (%BMC), measured by bioelectrical impedance analysis (BIA). Statistical analysis assessed the effects of Hcrt-1 levels on CSF, dietary intake, and medication use over these variables. Statistical significance was achieved with a confidence interval of 95 % and p < 0.05. ResultsPatients with NT1 presented with higher BMI (32.04 ± 6.95 vs. 25.38 ± 4.26 kg/m2; p < 0.01) and WHR (0.89 ± 0.09 vs. 0.83 ± 0.09; p = 0.02) compared to NT2, in detriment of %BMC, which was lower for NT1 (4.1 ± 1.02 vs. 4.89 ± 0.59; p < 0.01). Hcrt-1 in CSF showed a positive correlation with %BMC (r = +0.48, p < 0.01) and a negative correlation with anthropometric features (BMI: r = −0.54, p < 0.01; WHR: r = −0.37, p = 0.01). There was a correlation between WHR and diary caloric intake (r = +0.42, p < 0.01). ConclusionThe evaluation of patients with narcolepsy presupposes a syndromic approach comprising symptoms that go far beyond excessive daytime sleepiness. The integrated follow-up, including nutritional profile and anthropometric features, should add value in reducing morbidity in this population.

Establishment of Vietnamese human induced pluripotent stem cell-derived Orexin-A neurons

Narcolepsy type 1 is a neurological disorder that severely affects sleep control due to a decrease in orexin neurons. Although research on neurological diseases, including narcolepsy, is vital for advancing science and improving human life, progress is hindered by the challenge of obtaining human brain samples as well as the difficulty in culturing neuronal cell lines. To overcome this obstacle, we generated Orexin-A neurons from human induced pluripotent stem cells (hiPSCs) by utilising a differentiation medium supplemented with N-acetyl-D-mannosamine (ManNAc) and Bone morphogenetic protein 4 (BMP4). The cells obtained from our study were characterised using immunofluorescence staining, real-time PCR, and competitive ELISA technique. The results show that our research successfully generated a hiPSC line with pluripotent stem cell characteristics. Furthermore, Orexin-A neurons derived from hiPSCs showed positive results for NCAM1 and TUBB3 markers, an increase in HCRT gene expression, and the capacity to secrete Orexin-A. These promising findings suggest that our hiPSC-derived Orexin-A neurons could serve as a foundation for cell-based disease modelling and further investigations into the underlying mechanisms of related neurological disorders.

Validation and performance of the sleep inertia questionnaire in central disorders of hypersomnolence

BackgroundOptimal measurement tools for problematic sleep inertia, common in some central disorders of hypersomnolence (CDH), have not yet been determined. We evaluated the performance of the Sleep Inertia Questionnaire (SIQ) in CDH, and how well it distinguished hypersomnolent groups from controls, and IH (idiopathic hypersomnia) from narcolepsy type 1 (NT1). MethodsThis prospective, bi-centric study included 63 control, 84 IH, 16 NT1, 18 narcolepsy type 2 (NT2), and 88 subjective excessive daytime sleepiness (sEDS) participants, using ICSD-3 criteria. 126 (47.2 %) participants were on any medication at the time of SIQ completion. We assessed construct validity of SIQ scores, and sleep inertia duration (SID), and compared them across diagnoses, controlling for age and center. We derived cutpoints to distinguish hypersomnolent patients from controls and IH from NT1. Sensitivity analyses for depression, chronotype, and medication were performed. ResultsThe SIQ sum and composite score were significantly lower in controls than in other groups (p < 0.0001), demonstrating outstanding ability to distinguish patients from controls (AUCs 0.92), without differences among hypersomnolent groups. SID (AUC 0.76) was significantly shorter in controls than in all hypersomnolent groups except NT1, and was shorter in NT1 than in IH or sEDS. Optimal SIQ sum cutpoint was 42 (J = 0.71) for patients versus controls. Optimal SID cutpoint in distinguishing IH from NT1 was 25 min (J = 0.39). ConclusionThe SIQ has excellent ability to distinguish hypersomnolent patients from healthy controls, after controlling for depression, eveningness, and medication. SID is best at distinguishing IH from NT1.

Ageing-related modification of sleep and breathing in orexin-knockout narcoleptic mice.

Narcolepsy type-1 (NT1) is a lifelong sleep disease, characterised by impairment of the orexinergic system, with a typical onset during adolescence and young adulthood. Since the wake-sleep cycle physiologically changes with ageing, this study aims to compare sleep patterns between orexin-knockout (KO) and wild type (WT) control mice at different ages. Four groups of age-matched female KO and WT mice (16 weeks of age: 8 KO-YO and 9 WT-YO mice; 87 weeks of age: 13 KO-OLD and 12 WT-OLD mice) were implanted with electrodes for discriminating wakefulness, rapid-eye-movement sleep (REMS), and non-REMS (NREMS). Mice were recorded for 48 h in their home cages and for 7 more hours into a plethysmographic chamber to characterise their sleep-breathing pattern. Regardless of orexin deficiency, OLD mice spent less time awake and had fragmentation of this behavioural state showing more bouts of shorter length than YO mice. OLD mice also had more NREMS bouts and less frequent NREMS apneas than YO mice. Regardless of age, KO mice showed cataplexy-like episodes and shorter REMS latency than WT controls and had a faster breathing rate and an increased minute ventilation during REMS. KO mice also had more wakefulness, NREMS and REMS bouts, and a shorter mean length of wakefulness bouts than WT controls. Our experiment indicated that the lack of orexins as well as ageing importantly modulate the sleep and breathing phenotype in mice. The narcoleptic phenotype caused by orexin deficiency in female mice was substantially preserved with ageing.

CSF dynamics of orexin and β-amyloid42 levels in narcolepsy and Alzheimer’s disease patients: a controlled study

β-amyloid42 (Aβ42) in Alzheimer’s disease (AD) and orexin in narcolepsy are considered crucial biomarkers for diagnosis and therapeutic targets. Recently, orexin and Aβ cerebral dynamics have been studied in both pathologies, but how they interact with each other remains further to be known. In this study, we investigated the reliability of using the correlation between orexin-A and Aβ42 CSF levels as a candidate marker to explain the chain of events leading to narcolepsy or AD pathology. In order to test the correlation between these biomarkers, patients diagnosed with AD (n = 76), narcolepsy type 1 (NT1, n = 17), narcolepsy type 2 (NT2, n = 23) and healthy subjects (n = 91) were examined. Patients and healthy subjects underwent lumbar puncture between 8:00 and 10:00 am at the Neurology Unit of the University Hospital of Rome “Tor Vergata”. CSF levels of Aβ42, total-tau, phosphorylated-tau, and orexin-A were assessed. The results showed that CSF levels of Aβ42 were significantly lower (p < 0.001) in AD (332.28 ± 237.36 pg/mL) compared to NT1 (569.88 ± 187.00 pg/mL), NT2 (691.00 ± 292.63 pg/mL) and healthy subjects (943.68 ± 198.12 pg/mL). CSF orexin-A levels were statistically different (p < 0.001) between AD (148.01 ± 29.49 pg/mL), NT1 (45.94 ± 13.63 pg/mL), NT2 (104.92 ± 25.55 pg/mL) and healthy subjects (145.18 ± 27.01 pg/mL). Moderate-severe AD patients (mini mental state examination < 21) showed the highest CSF orexin-A levels, whereas NT1 patients showed the lowest CSF orexin-A levels. Correlation between CSF levels of Aβ42 and orexin-A was found only in healthy subjects (r = 0.26; p = 0.01), and not in narcolepsy or AD patients. This lack of correlation in both diseases may be explained by the pathology itself since the correlation between these two biomarkers is evident only in the healthy subjects. This study adds to the present literature by further documenting the interplay between orexinergic neurotransmission and cerebral Aβ dynamics, possibly sustained by sleep.

Serum N-Glycan Profiling of Patients with Narcolepsy Type 1 Using LC-MS/MS.

The neurological condition known as narcolepsy type 1 (NT1) is an uncommon condition marked by extreme daytime sleepiness, cataplexy, sleep paralysis, hallucinations, disrupted nocturnal sleep, and low or undetectable levels of orexin in the CSF fluid. NT1 has been hypothesized to be an immunological disorder; its treatment is currently only symptomatic, and misdiagnosis is not uncommon. This study compares the N-glycome of NT1 patients with healthy controls in search of potential glycan biomarkers using LC-MS/MS. A total of 121 candidate N-glycans were identified, 55 of which were isomeric N-glycan structures and 65 were not. Seventeen N-glycan biomarker candidates showed significant differences between the NT1 and control cohorts. All of the candidate glycan biomarkers were isomeric except HexNAc6Hex7Fuc0NeuAc1 (6701) and HexNAc6Hex7Fuc1NeuAc2 (6712). Therefore, with isomeric and nonisomeric structures, a total of 20 candidate N-glycan biomarkers are reported in this study, and interestingly, all are either sialylated or sialylated-fucosylated and upregulated in NT1 relative to the control. The distribution levels of all the identified N-glycans show that the sialylated glycan type is the most abundant in NT1 and is majorly disialylated, although the trisialylated subtype is three-fold higher in NT1 compared to the healthy control. The first isomers of HexNAc5Hex6Fuc0NeuAc3 (5603), HexNAc6Hex7Fuc0NeuAc2 (6702), and HexNAc6Hex7Fuc1NeuAc4 (6714) expressed a high level of fold changes (FC) of 1.62, 2.19, and 2.98, respectively. These results suggest a different N-glycome profile of NT1 and a relationship between sialylated glycan isomers in NT1 disease development or progression. The revelation of N-glycan expression alterations in this study may improve NT1 diagnostic methods, understanding of NT1 pathology, and the development of new targeted therapeutics.