Probabilistic Sleep Staging in MSLTs across Hypersomnia Disorders.

STUDY OBJECTIVES: This study aimed to identify novel markers of narcolepsy type 1 (NT1) using between-nap opportunity periods ('Lights On') and in-nap opportunity periods ('Lights Off') features of Multiple Sleep Latency Test (MSLT) recordings. We hypothesized that NT1 could be identified both from sleep-wake instability and patterns of sleepiness during wakefulness. Further, we explored if MSLTs from NT1 and narcolepsy type 2 (NT2) patients could be distinguished despite having the same diagnostic thresholds. METHODS: We analyzed 'Lights On' and 'Lights Off' periods of the MSLT, extracting 163 features describing sleepiness, microsleep, and sleep stage mixing using data from 177 patients with NT1, NT2, Idiopathic Hypersomnia (IH), and Subjective Hypersomnia (sH) from three sleep centers. These features were based on automated probabilistic sleep staging, also denoted as hypnodensities, using U-Sleep. Hypersomnias were differentiated using either or both features from 'Lights On' and 'Lights Off'. RESULTS: Patients with NT1 could be distinguished from NT2, IH, and sH using features solely from 'Lights On' periods with a sensitivity of 0.76 and specificity of 0.71. When using features from all periods of the MSLT, NT1 was distinguished from NT2 alone with a sensitivity of 0.77 and a specificity of 0.84. CONCLUSIONS: The findings of this study demonstrate microsleeps and sleep stage mixing as potential markers of the sleep attacks and unstable sleep-wake states common in NT1. Further, NT1 and NT2 could be frequently distinguished using 'Lights Off' features.

Association between sleep disturbances and suicidal behavior in adolescents: a systematic review and meta-analysis.

Introduction: Adolescents' health and well-being are seriously threatened by suicidal behaviors, which have become a severe social issue worldwide. Suicide is one of the leading causes of mortality for adolescents in low and middle-income countries, with approximately 67,000 teenagers committing suicide yearly. Although an association between sleep disturbances (SDs) and suicidal behaviors has been suggested, data are still scattered and inconclusive. Therefore, to further investigate this association, we conducted a meta-analysis to verify if there is a link between SDs and suicidal behaviors in adolescents without diagnosed psychiatric disorders. Methods: PubMed, CENTRAL, EMBASE, and PsycINFO were searched from inception to August 30th, 2024. We included studies reporting the estimation of suicidal behaviors in adolescents from 12 to 21 years of age, with SDs and healthy controls. The meta-analysis was based on odds ratio (OR, with a 95% confidence interval ([CI]), estimates through inverse variance models with random-effects. Results: The final selection consisted of 19 eligible studies from 9 countries, corresponding to 628,525 adolescents with SDs and 567,746 controls. We found that adolescents with SDs are more likely to attempt suicide (OR: 3.10; [95% CI: 2.43; 3.95]) and experience suicidal ideation (OR: 2.28; [95% CI 1.76; 2.94]) than controls. Conclusion: This meta-analysis suggests that SDs are an important risk factor for suicidal ideation and suicide attempts in healthy adolescents. The findings highlight the importance of early identification of SDs to prevent suicidal behaviors in this population. Systematic review registration: PROSPERO, identifier CRD42023415526.

Co-occurrence of anxiety and depressive symptoms, suicidal thoughts, and hopelessness in patients with narcolepsy type 1.

OBJECTIVE: To assesses the prevalence and co-occurrence of anxiety, depressive symptoms, suicidal thoughts, and hopelessness in patients with narcolepsy type 1 (NT1). PATIENTS/METHODS: In this cross-sectional study, 127 patients with NT1 (mean age 38.2 ± 15.5 years, 53.5 % female) and 131 controls (mean age 37.4 ± 14.3 years, 59.5 % female) matched for age, sex, and education, filled in the following validated questionnaires: Beck Depression Inventory-II (BDI), State-Trait Anxiety Inventory (STAI), and Beck Hopelessness Scale (BHS). Comparisons between groups and multivariable logistic regression analyses were performed. RESULTS: Patients with NT1 presented significantly higher scores in BDI, suicidal thoughts (BDI-item-9), STAI-trait, STAI-state, and BHS than controls. Adjusted for age, sex, and educational level, NT1 was significantly associated with depressive symptoms (BDI≥13; OR 3.23, 95%CI 1.71-6.10), trait anxiety symptoms (STAI-trait≥38; OR 1.91, 95%CI 1.14-3.21), co-occurrence of BDI≥13 with STAI-trait≥38 (OR 2.72, 95%CI 1.47-5.05), and with STAI-state≥38 (OR 2.24, 95%CI 1.17-4.30), and moderate to severe hopelessness (BHS≥9; OR 2.95, 95%CI 1.55-5.63). CONCLUSIONS: Patients with NT1 present a multidimensional psychiatric burden and comorbidity between symptoms of depression and anxiety and suicidal thoughts, a concern that deserves tailored interventions.

Self-Induced Stretch Syncope: An Unusual Non-Epileptic Paroxysmal Event. A Case Report and Literature Mini-Review.

Stretch syncope (SS) is a benign, uncommon, distinct condition described mainly in adolescent males. It is responsible for paroxysmal events started by stereotyped stretching actions with neck hyperextension, culminating in alteration of consciousness. Motor manifestations are often present and may be associated with a generalized slowing of the electroencephalographic activity, challenging the diagnosis. Despite a few cases reported in the literature, different mechanisms have been implied in the pathogenesis, involving both local and systemic hemodynamic phenomena. Here, we report on an 8-year-old girl with self-induced SS, providing new insights into the related neurophysiological profile and discussing the possible etiology. Our evidence of transient and dynamic vascular impairment supports the hypothesis of SS as a multifactorial disorder.

The actigraphic evaluation of daytime sleep in central disorders of hypersomnolence: comparison with polysomnography.

STUDY OBJECTIVES: The role of actigraphy in central disorders of hypersomnolence (CDH) is expanding but evidence of reliability with polysomnography (PSG) is scarce and provided only during nighttime. We explored the agreement between actigraphy and continuous 24-hour PSG at CDH diagnosis. METHODS: Forty-four consecutive drug-naïve patients (28 narcolepsy, 16 idiopathic hypersomnia) underwent actigraphy during 24 hours of free-running PSG, during multiple sleep latency test (MSLT) and 13 of them also during maintenance of wakefulness test (MWT). Daytime and nighttime sleep features and MSLT and MWT mean sleep latencies (mSL) were estimated with the actigraphic algorithms by Cole-Kripke (CK) Sadeh, and University of California San Diego (UCSD). Agreement to corresponding PSG measures was assessed with Bland Altman plots. RESULTS: Nighttime-total sleep time (TST) in narcolepsy was significantly underestimated with CK (bias 27.8 min, 95%CI 13.7-41.9) and Sadeh (bias 56.7 min, 95%CI 38.8/74.5). Daytime-TST was overestimated in IH and narcolepsy with all algorithms (CK: bias -42.2, 95%CI -67/-17.4; Sadeh: bias -30.2 min, 95%CI -52.7/-7.7; UCSD bias -86.9 min, 95%CI -118.2/-55.6). 24-hour-TST was overestimated by CK and UCSD in IH (CK: bias -58.5 min, 95%CI -105.5/-11.5; UCSD: bias -118.8 min, 95% CI -172.5/-65), and by UCSD in narcolepsy (bias -68.8 min, 95%CI -109.3/-38.2). In the entire cohort, actigraphy overestimated MSLT mSL but not MWT mSL. CONCLUSIONS: Conventional actigraphic algorithms overestimate 24-hour TST in IH and underestimate nighttime TST in narcolepsy. These discrepancies call for cautious application of actigraphy in the diagnostic process of CDH and the development of new quantitative signal analysis approaches.

Narcolepsy and rapid eye movement sleep.

Since the first description of narcolepsy at the end of the 19th Century, great progress has been made. The disease is nowadays distinguished as narcolepsy type 1 and type 2. In the 1960s, the discovery of rapid eye movement sleep at sleep onset led to improved understanding of core sleep-related disease symptoms of the disease (excessive daytime sleepiness with early occurrence of rapid eye movement sleep, sleep-related hallucinations, sleep paralysis, rapid eye movement parasomnia), as possible dysregulation of rapid eye movement sleep, and cataplexy resembling an intrusion of rapid eye movement atonia during wake. The relevance of non-sleep-related symptoms, such as obesity, precocious puberty, psychiatric and cardiovascular morbidities, has subsequently been recognized. The diagnostic tools have been improved, but sleep-onset rapid eye movement periods on polysomnography and Multiple Sleep Latency Test remain key criteria. The pathogenic mechanisms of narcolepsy type 1 have been partly elucidated after the discovery of strong HLA class II association and orexin/hypocretin deficiency, a neurotransmitter that is involved in altered rapid eye movement sleep regulation. Conversely, the causes of narcolepsy type 2, where cataplexy and orexin deficiency are absent, remain unknown. Symptomatic medications to treat patients with narcolepsy have been developed, and management has been codified with guidelines, until the recent promising orexin-receptor agonists. The present review retraces the steps of the research on narcolepsy that linked the features of the disease with rapid eye movement sleep abnormality, and those that do not appear associated with rapid eye movement sleep.

Navigating narcolepsy: exploring coping strategies and their association with quality of life in patients with narcolepsy type 1.

Narcolepsy type 1 (NT1) is a chronic neurological disorder characterized by symptoms such as excessive daytime sleepiness, sudden sleep episodes, disrupted nocturnal sleep, cataplexy, sleep paralysis, and hypnagogic hallucinations, which significantly impact the overall well-being and quality of life of individuals. While psychological factors have gained attention, there is limited research on the coping strategies employed by patients with NT1 and their association with quality of life. This study aimed to compare coping strategies in patients with NT1 and controls, as well as assess the relationship between coping strategies and quality of life in patients with NT1. A total of 122 individuals diagnosed with NT1 and 138 controls were enrolled in this cross-sectional study. Participants completed questionnaires assessing coping strategies and health-related quality of life. A Mann-Whitney U test was conducted to compare the use of different coping strategies by patients with NT1 and controls. Spearman's rho correlation was performed to examine the association between coping strategies and quality of life in the NT1 group. Results showed that patients with NT1 exhibited differences in the use of coping strategies compared to controls. They reported lower use of active coping, planning, instrumental, and emotional social support, and higher use of behavioral and mental disengagement. Denial and behavioral disengagement were significantly and negatively associated with quality of life. Identifying coping strategies and their association with quality of life may aid in the development of tailored interventions aimed at improving the adoption of effective coping strategies and reducing the use of maladaptive coping strategies.

Theory of Mind impairment in childhood narcolepsy type 1: a case-control study.

Narcolepsy type 1 is a central disorder of hypersomnolence characterized by excessive daytime sleepiness, cataplexy and other rapid eye movement sleep-related manifestations. Neurophysiological studies suggest that narcolepsy type 1 patients may experience impairment in emotional processing due to structural and functional changes in limbic structures and associated areas. However, the only study exploring narcolepsy behavioural responses found no impairment in the ability to recognize emotions, possibly due to compensatory mechanisms. The present study was designed to fill this gap in the literature by investigating the behavioural impairment related to emotional processing focusing on an advanced socio-cognitive skill, namely Theory of Mind, in paediatric narcolepsy type 1 patients. Twenty-two narcolepsy type 1 children and adolescents (six female; age range: 8.0-13.5) and 22 healthy controls matched for age and sex (six female; age range: 8.9-13.0) underwent a neuropsychological evaluation to assess socio-economic status, verbal abilities, working memory, social anxiety and Theory of Mind via a verbal task (i.e. Strange Stories task) and a visual task (i.e. Silent Films). Narcolepsy type 1 patients were also evaluated for disease severity. Patients exhibited impairment in Theory of Mind skills, as assessed both through both verbal (controls median = 8; patients median = 5; P = 0.009) and visual tasks (controls median = 8; patients median = 6; P = 0.003), compared to healthy controls. Correlation analyses showed that verbal and visual Theory of Mind was negatively related to narcolepsy severity (ρ = -0.45, P = 0.035 and ρ = -0.52, P = 0.012), and daytime sleepiness (ρ = -0.48, P = 0.025 and ρ = -0.45, P = 0.038). Our study shows a selective impairment in the Theory of Mind domain in children and adolescents with narcolepsy type 1. In addition, our results highlight a link between symptom severity and Theory of Mind, suggesting that lower Theory of Mind levels are associated with higher symptom severity. Further, longitudinal studies are needed to disentangle the direction of this relation and to disambiguate if narcolepsy severity impaired children's Theory of Mind or if Theory of Mind skills modulate the severity of narcolepsy symptoms by providing a greater ability to avoid cataplexy.

Sex disparities in clinical features and burden of narcolepsy type 1.

To investigate potential sex-related differences in patients with narcolepsy type 1, we carried out an analysis of baseline data from 93 women and 89 men with narcolepsy type 1 who participated in the TElemedicine for NARcolepsy (TENAR) trial. The following data were considered: sociodemographics; diagnostic (disease history, polysomnography, orexin, human leukocyte antigen) and clinical features, including sleepiness (Epworth Sleepiness Scale), cataplexy and other narcolepsy symptoms; disease severity (Narcolepsy Severity Scale); pharmacological treatment; depressive symptoms (Beck Depression Inventory); and self-reported relevance of eight narcolepsy-related issues. We found that, compared with men, significantly more women reported automatic behaviours (55.4% versus 40%) and had higher Epworth Sleepiness Scale (median 10 versus 9) and Beck Depression Inventory scores (median 10.5 versus 5), and there was a trend for a higher Narcolepsy Severity Scale total score in women (median 19 versus 18, p = 0.057). More women than men were officially recognized as having a disability (38% versus 22.5%) and considered 5/8 narcolepsy-related issues investigated as a relevant problem. More severe sleepiness and a greater narcolepsy-related burden in women could mirror sex differences present in the general population, or may be related to suboptimal management of narcolepsy type 1 or to more severe depressive symptoms in women. Future studies and guidelines should address these aspects.

Eating disorders in narcolepsy type 1: Evidence from a cross-sectional Italian study.

Narcolepsy type 1 is a chronic central disorder of hypersomnolence, and it is frequently accompanied by overweight, but the association between narcolepsy type 1 and eating disorders is controversial. Our study aims to compare patients with narcolepsy type 1 and controls on the symptomatology of eating disorders and to evaluate the association between clinical factors. This is a cross-sectional study, with consecutive recruitment of patients with narcolepsy type 1 attending the Outpatient Clinic for Narcolepsy at the IRCCS Istituto delle Scienze Neurologiche di Bologna (Italy) for routine follow-up visits. Healthy subjects from general populations were recruited as controls. Patients underwent a questionnaire-based assessment using the Eating Disorder Examination Questionnaire (EDE-Q), Binge Eating Scale (BES), Italian Night Eating Questionnaire (I-NEQ), Epworth Sleepiness Scale (ESS), and Narcolepsy Severity Scale (NSS). One hundred and thirty-eight patients with narcolepsy type 1 and 162 controls were enrolled. This study showed that individuals with narcolepsy type 1 reported higher scores on the EDE-Q, I-NEQ, and a higher body mass index (BMI) than the controls. The logistic regression analysis results, with EDE-Q positivity as a dependent variable, demonstrate a significant association with antidepressant drugs, female sex, and the use of sodium oxybate. We found an association between antidepressant drug consumption, the NSS total score, and female sex with BES positivity as the dependent variable. The logistic regression analysis for I-NEQ positivity found an association with antidepressant drug use. This study shows that patients with narcolepsy type 1 frequently present with comorbid eating disorder symptomatology, mainly night eating syndrome. Investigating the possible presence of eating disorders symptomatology through questionnaires is fundamental during the assessment of patients with narcolepsy type 1.

Biomarkers of neurodegeneration in isolated and antidepressant-related rapid eye movement sleep behavior disorder.

BACKGROUND AND PURPOSE: This study compared the features of isolated rapid eye movement (REM) sleep behavior disorder (iRBD) and antidepressant-related REM sleep behaviour disorder (RBD) with the aim of highlighting markers that might distinguish the two entities. METHODS: The observational cohort study included RBD patients with and without antidepressant use (antiD+ and antiD- patients, respectively), without cognitive impairment and parkinsonism. Clinical features of RBD, subtle motor and non-motor symptoms of parkinsonism, sleep architecture, REM atonia index, dopamine transporter-single photon emission computed tomography (DAT-SPECT) and skin biopsies for the intraneuronal alpha-synuclein (α-syn), were evaluated in the baseline work-up. RESULTS: Thirty-nine patients, 10 antiD+ and 29 antiD-, were included. AntiD+ patients (more frequently female) reported more psychiatric symptoms, less violent dream enactment, and less frequent hyposmia. Dermal α-syn was detected in 93.1% of antiD- versus 30% of antiD+ patients (p = 0.00024). No differences appeared in other motor and non-motor symptoms, Movement Disorder Society-Unified Parkinson's Disease Rating Scale part III score, DAT-SPECT, or polysomnographic features. CONCLUSIONS: Patients with antidepressant-related RBD have clinical and neuropathological features suggesting a lower risk of evolution than those with iRBD.

Long sleep time and excessive need for sleep: State of the art and perspectives.

The mechanisms underlying the individual need for sleep are unclear. Sleep duration is indeed influenced by multiple factors, such as genetic background, circadian and homeostatic processes, environmental factors, and sometimes transient disturbances such as infections. In some cases, the need for sleep dramatically and chronically increases, inducing a daily-life disability. This "excessive need for sleep" (ENS) was recently proposed and defined in a European Position Paper as a dimension of the hypersomnolence spectrum, "hypersomnia" being the objectified complaint of ENS. The most severe form of ENS has been described in Idiopathic Hypersomnia, a rare neurological disorder, but this disabling symptom can be also found in other hypersomnolence conditions. Because ENS has been defined recently, it remains a symptom poorly investigated and understood. However, protocols of long-term polysomnography recordings have been reported by expert centers in the last decades and open the way to a better understanding of ENS through a neurophysiological approach. In this narrative review, we will 1) present data related to the physiological and pathological variability of sleep duration and their mechanisms, 2) describe the published long-term polysomnography recording protocols, and 3) describe current neurophysiological tools to study sleep microstructure and discuss perspectives for a better understanding of ENS.

Role of Daytime Continuous Polysomnography in the Diagnosis of Pediatric Narcolepsy Type 1.

BACKGROUND AND OBJECTIVES: Narcolepsy type 1 (NT1) is still largely underdiagnosed or diagnosed too late in children. Difficulties in obtaining rapid and reliable diagnostic evaluations of the condition in clinical practice partially explain this problem. Predictors of NT1 include cataplexy and sleep-onset REM periods (SOREMPs), documented during nocturnal polysomnography (N-PSG) or through the multiple sleep latency test (MSLT), although low CSF hypocretin-1 (CSF hcrt-1) is the definitive biological disease marker. Obtaining reliable MSLT results is not always feasible in children; therefore, this study aimed to validate daytime continuous polysomnography (D-PSG) as an alternative diagnostic tool. METHODS: Two hundred consecutive patients aged younger than 18 years (112 with NT1; 25 with other hypersomnias, including narcolepsy type 2 and idiopathic hypersomnia; and 63 with subjective excessive daytime sleepiness) were randomly split into 2 groups: group 1 (n = 133) for the identification of diagnostic markers and group 2 (n = 67) for the validation of the detected markers. The D-PSG data collected included the number of spontaneous naps, total sleep time, and the number of daytime SOREMPs (d-SOREMP). D-PSG data were tested against CSF hcrt-1 deficiency (NT1 diagnosis) as the gold standard using receiver operating characteristic (ROC) curve analysis in group 1. ROC diagnostic performances of single and combined D-PSG parameters were tested in group 1 and validated in group 2. RESULTS: In group 1, the areas under the ROC curve (AUCs) were 0.91 (95% CI 0.86-0.96) for d-SOREMPs, 0.81 (95% CI 0.74-0.89) for the number of spontaneous naps, and 0.70 (95% CI 0.60-0.79) for total sleep time. A d-SOREMP count ≥1 (sensitivity of 95% and specificity of 72%), coupled with a diurnal total sleep time above 60 minutes (sensitivity of 89% and specificity of 91%), identified NT1 in group 1 with high reliability (area under the ROC curve of 0.93, 95% CI 0.88-0.97). These results were confirmed in the validation group with an AUC of 0.88 (95% CI 0.79-0.97). DISCUSSION: D-PSG recording is an easily performed, cost-effective, and reliable tool for identifying NT1 in children. Further studies should confirm its validity with home D-PSG monitoring. These alternative procedures could be used to confirm NT1 diagnosis and curtail diagnostic delay.

Work productivity and activity impairment in patients with narcolepsy type 1.

The aim of this study was to assess work productivity and activity impairments and to explore their association with excessive daytime sleepiness, body mass index (BMI), depression, and anxiety in patients with narcolepsy type 1. We carried out a cross-sectional study in which patients with narcolepsy type 1 and matched controls for sex, age, and education were assessed for occupational features, EDS (Epworth Sleepiness Scale), BMI, depression (Beck Depression Inventory), anxiety (State-Trait Anxiety Inventory), and Work Productivity and Activity Impairment (WPAI). Different statistical approaches were used to investigate differences between groups and correlations between WPAI scores and clinical features. The 127 patients with narcolepsy type 1 (mean age 38.2 ± 15.5, 91.3% taking drugs for narcolepsy) and 131 controls (mean age of 37.4 ± 14.3) included did not differ in terms of occupational features, except for hours worked/week (29.9 in patients vs. 34.9 in controls) and officially recognised disability (30.7% vs. 5.3%). Impairment in all WPAI scores was approximately three times greater in patients. Narcolepsy was associated with work time missed in 27.4% of patients, while 93.2% to 95.5% of them had some impairment while working or during daily activities (vs. 37.5-46.8% of controls). Correlations with WPAI scores were found for excessive daytime sleepiness only in patients, and for both depression and anxiety in patients and controls, with a stronger correlation for activity impairment in patients. These results suggest that, despite treatment, narcolepsy type 1 was associated with extensive impairment especially regarding job effectiveness and daily activities. Future studies should investigate risk factors and effects of interventions on these outcomes.

Exploring the emotional and behavioural profile in paediatric narcolepsy type 1: A case-control study.

Narcolepsy type 1 (NT1) is a central disorder of hypersomnolence often arising in childhood and adolescence. NT1 has a significant, but poorly defined, psychological impact. We aimed to investigate the psycho-social functioning of children and adolescents with NT1. We performed a cross-sectional, child and parent-reported questionnaire survey in 37 children and adolescents (6-17 years) with NT1, compared with age- and sex-matched controls. Questionnaires (SSHS, ESS-CHAD, CDI, MASC, CBCL, CRS-R, and SNAP-IV) evaluated various aspects of behavioural and emotional profiles, sleep habits, and daytime sleepiness. Subsequently, NT1 intra-group analysis was performed to investigate the effect of sex (males vs females) and pharmacological treatment (treated vs non-treated) on psychological features. The NT1 questionnaires total scores were then correlated with the clinical characteristics (age, body mass index [BMI], ESS-CHAD score, cerebrospinal hypocretin-1 [Hcrt-1] levels, and diagnostic delay). Patients with NT1 showed a higher tendency to depressive symptoms, anxiety, somatisation, inattention, hyperactivity, oppositional/defiant problems, and other maladaptive behaviours compared with controls. Among NT1 patients, females showed a higher propensity to anxiety, and non-treated patients displayed higher depressive symptoms. Psychological symptoms increased with age, BMI, and daytime sleepiness in patients with NT1, while a younger age was associated with more frequent somatisation symptoms. Lower cerebrospinal Hcrt-1 levels correlated with poorer social competencies, daily activities, and inattention. Diagnostic delay was associated with a higher impact of depressive symptoms and behavioural problems. NT1 in children and adolescents is associated with poorer functioning in multiple psychological domains calling for a multidisciplinary approach and monitoring to reduce disease burden and to prevent psychiatric consequences.

Phenomenology and psychiatric correlates of pseudocataplexy.

STUDY OBJECTIVES: Pseudocataplexy is a rare functional neurological disorder that mimics cataplexy, pathognomonic for narcolepsy type 1 (NT1). We describe the psychiatric comorbidity and personality traits of patients with pseudocataplexy versus NT1 cases. METHODS: The case-control observational study enrolled consecutive patients with pseudocataplexy and a control group of age-matched consecutive NT1 patients. The diagnostic work-up included a structured interview, 48-hour polysomnography, multiple sleep latency test, cataplexy provoking test, and hypocretin-1 measurement in cerebrospinal fluid.All participants were administered Beck Depression Inventory, State-Trait Anxiety Inventory, Patient Health Questionnaire-15 (PHQ-15), Personality Inventory for DSM-5 brief form, and quality of life (QoL) measurement by 36-item Short Form health survey (SF-36). RESULTS: Fifteen patients with pseudocataplexy and 30 with NT1 were included. Despite the suspicion of possible cataplexy, none of the pseudocataplexy participants fulfilled international diagnostic criteria for NT1. Pseudocataplexy patients presented higher rates of moderate state anxiety (40% vs. 10%, p=0.018), medium level of somatic symptoms, defined by PHQ-15 score >10 (66.7% vs. 16.7%, p=0.003), and a trend towards moderate-to-severe depressive symptoms (33.3% vs. 10%, p=0.054) compared to NT1. No significant differences in personality traits emerged. Pseudocataplexy patients had worse QoL profile in almost all SF-36 domains including physical (mean±SD: 37.7±9.88 vs. 51.13±7.81, p<0.001) and mental (mean±SD: 33.36±12.69 vs.42.76±11.34, p=0.02) summary scores. CONCLUSIONS: Patients with pseudocataplexy present more severe psychiatric symptoms and a lower QoL profile in comparison with patients with NT1. The severe somatoform and affection impairment in pseudocataplexy may explain the poorer QoL and should require a tailored therapeutic approach.

Mutations in human DNA methyltransferase DNMT1 induce specific genome-wide epigenomic and transcriptomic changes in neurodevelopment.

DNA methyltransferase type 1 (DNMT1) is a major enzyme involved in maintaining the methylation pattern after DNA replication. Mutations in DNMT1 have been associated with autosomal dominant cerebellar ataxia, deafness and narcolepsy (ADCA-DN). We used fibroblasts, induced pluripotent stem cells (iPSCs) and induced neurons (iNs) generated from patients with ADCA-DN and controls, to explore the epigenomic and transcriptomic effects of mutations in DNMT1. We show cell type-specific changes in gene expression and DNA methylation patterns. DNA methylation and gene expression changes were negatively correlated in iPSCs and iNs. In addition, we identified a group of genes associated with clinical phenotypes of ADCA-DN, including PDGFB and PRDM8 for cerebellar ataxia, psychosis and dementia and NR2F1 for deafness and optic atrophy. Furthermore, ZFP57, which is required to maintain gene imprinting through DNA methylation during early development, was hypomethylated in promoters and exhibited upregulated expression in patients with ADCA-DN in both iPSC and iNs. Our results provide insight into the functions of DNMT1 and the molecular changes associated with ADCA-DN, with potential implications for genes associated with related phenotypes.

Auxological and endocrine findings in narcolepsy type 1: seventeen-year follow-up from a pediatric endocrinology center.

Introduction: Narcolepsy Type 1 (NT1) is a rare hypersomnia of central origin linked to hypocretin deficiency, most frequently arising at pediatric age. NT1 could be associated with endocrine comorbidities involving the neuroendocrine axis, predominantly obesity, and Central Precocious Puberty (CPP). The primary aim of this study is the evaluation of endocrine and auxological parameters at diagnosis and during follow-up in patients with NT1, treated with Sodium Oxybate (SO) or not. Methods: We retrospectively evaluated the auxological, biochemical, and radiological parameters of 112 patients referred to our Center between 2004-2022. The design of our study is cross-sectional at the time of diagnosis followed by a longitudinal follow-up. Results: Our study confirms an increased frequency of CPP and obesity in patients with NT1. At first evaluation, obesity was found in 31.3% of patients, while overweight was found in 25.0%. A diagnosis of CPP was made in 19.6% of patients. Interestingly, this group showed a significantly lower level of CSF-hypocretin (hrct-1) at diagnosis compared to others. We found an improvement in BMI SDS in the SO-treated group compared to untreated patients, and this trend persisted also at 36 months of follow-up (0.0 ± 1.3 vs 1.3 ± 0.4; p<0.03). Sixty-three patients reached their final height, with a median SDS of 0.6 ± 1.1 in boys and 0.2 ± 1.2 in girls. Discussion: To our knowledge, these are the first results regarding the final height in a large series of pediatric patients with NT1, with a normal range of IGF1-SDS levels and stature SDS.

Narcolepsy risk loci outline role of T cell autoimmunity and infectious triggers in narcolepsy.

Narcolepsy type 1 (NT1) is caused by a loss of hypocretin/orexin transmission. Risk factors include pandemic 2009 H1N1 influenza A infection and immunization with Pandemrix®. Here, we dissect disease mechanisms and interactions with environmental triggers in a multi-ethnic sample of 6,073 cases and 84,856 controls. We fine-mapped GWAS signals within HLA (DQ0602, DQB1*03:01 and DPB1*04:02) and discovered seven novel associations (CD207, NAB1, IKZF4-ERBB3, CTSC, DENND1B, SIRPG, PRF1). Significant signals at TRA and DQB1*06:02 loci were found in 245 vaccination-related cases, who also shared polygenic risk. T cell receptor associations in NT1 modulated TRAJ*24, TRAJ*28 and TRBV*4-2 chain-usage. Partitioned heritability and immune cell enrichment analyses found genetic signals to be driven by dendritic and helper T cells. Lastly comorbidity analysis using data from FinnGen, suggests shared effects between NT1 and other autoimmune diseases. NT1 genetic variants shape autoimmunity and response to environmental triggers, including influenza A infection and immunization with Pandemrix®.