Disorders Of Hypersomnolence Research Articles

Diagnostic usefulness of 24‐h polysomnography for idiopathic hypersomnia co‐occurring with neurodevelopmental disorders: A case report

AbstractBackgroundAlthough central disorders of hypersomnolence (CDH) and attention‐deficit/hyperactivity disorder (ADHD) are frequently comorbid, they often remain underdiagnosed, leading to insufficient treatment and sociopsychological outcomes.Case PresentationHere, we present a case of a male in his late 20s with ADHD and autism spectrum disorder who exhibited symptoms suggestive of idiopathic hypersomnia (IH), a subtype of CDH. The patient experienced difficulty waking up and dropped out of university. Additionally, although methylphenidate extended‐release was prescribed, he often forgot to take his medication, resulting in difficulty waking up until late afternoon. No symptoms related to rapid eye movements sleep were observed. Considering the possibility of concurrent hypersomnia with neurodevelopmental disorders, we conducted 24‐h polysomnography (PSG). The results demonstrated total sleep time of 774.5 min (≥660 min). Together with other criteria, we diagnosed him as having IH. Following discharge and discussion with the patient, we provided sleep hygiene education for him, and he resumed day care attendance to establish a social routine.ConclusionIn cases where hypersomnia may co‐occur with neurodevelopmental disorders, active utilization of 24‐h PSG enables detailed evaluation of sleep–wake patterns and behaviors, facilitating effective guidance on sleep hygiene and promoting improvements in social rhythms and sociability.

Patient experiences of narcolepsy and idiopathic hypersomnia in the Nordics: a patient journey map.

Central disorders of hypersomnolence (CDH) are chronic diseases that significantly impact the lives of affected individuals. We aimed to explore the perspectives of individuals with narcolepsy type 1 (NT1), narcolepsy type 2 (NT2), and idiopathic hypersomnia (IH), and the challenges they encounter in their daily lives and within the healthcare systems in the Nordics. Interviews with patients (N = 41) and healthcare professionals (n = 14) and a patient survey (n = 70) were conducted in 2022 in Denmark, Sweden, Finland, and Norway to develop a patient journey map that visualises the patient with CDH journey and provides insights into the difficulties faced by these individuals. The patient journey mapping approach was chosen to focus on the processes and experiences of patients, highlighting the challenges they confront. Our findings revealed that the process of receiving a CDH diagnosis, as well as subsequent misdiagnoses and treatment, can be protracted and burdensome. CDH diagnoses remain poorly understood by neurologists, general practitioners, and the public, resulting in adverse consequences, with patients reporting a mean (standard deviation [SD]) time from symptom onset to diagnosis of 8.4 (5.11) years and a mean (SD) of 5.5 (4.17) productive hours lost/day. The available non-pharmaceutical support for patients with CDH, encompassing medical, psychological, educational, and professional assistance, was insufficient. The generalisability of the findings to one specific diagnosis is limited due to the collective analysis of the CDH. These findings are invaluable for identifying disruptions in the patient with CDH journeys and for designing improved pathways for those with NT1, NT2, and IH in the future.

Daytime sleepiness and BMI exhibit gender and age differences in patients with central disorders of hypersomnolence.

The aim of the present study was to examine gender and age-specific effects on subjective daytime sleepiness (as measured by the Epworth Sleepiness Scale), body weight and eating behaviour in patients with central disorders of hypersomnolence. Based on the European Narcolepsy Network database, we compared 1035 patients with narcolepsy type I and 505 patients with other central disorders of hypersomnolence ("narcoleptic borderland"), including narcolepsy type II (N = 308) and idiopathic hypersomnia (N = 174), using logistic regression and general linear models. In the entire study population, the Epworth Sleepiness Scale was higher in women (N = 735, mean age = 30 years, mean Epworth Sleepiness Scale = 16.6 ± SD 3.9) than in men (N = 805, mean age = 32 years, mean Epworth Sleepiness Scale = 15.8 ± SD 4.4). In women with narcolepsy type I (N = 475), both Epworth Sleepiness Scale and body mass index increased in parallel with age. In women of the narcoleptic borderland (N = 260), the Epworth Sleepiness Scale markedly peaked in their early 30s, while body mass index only started to rise at that age. This rise in body mass index following the Epworth Sleepiness Scale peak cannot be explained by sleepiness-induced uncontrolled eating, as self-reported uncontrolled eating was negatively associated with the Epworth Sleepiness Scale in this group. We propose that the narcoleptic borderland harbours a unique cluster of women in their fertile years with an unexplored aetiology requiring further investigation towards tailored interventions.

International Swiss Primary Hypersomnolence and Narcolepsy Cohort Study (iSPHYNCS): the impact of psychiatric comorbidities on daily life in central disorders of hypersomnolence-a vicious circle.

Presence of psychiatric comorbidities is well documented in narcolepsy type-1 (NT1) but there are limited data on patients with 'other central disorders of hypersomnolence' (OCH). This study aimed to investigate frequency of psychiatric comorbidities in patients with NT1 and OCH, and to evaluate their impact on quality of life and sleep as an additive factor in combination with hypersomnolence-related symptoms. This study was conducted within the scope of the international Swiss Primary Hypersomnolence and Narcolepsy Cohort Study (iSPHYNCS), which aims to find new biomarkers in central disorders of hypersomnolence (CDH). Study participants underwent Mini International Neuropsychiatric Interview and completed questionnaires related to quality of life and sleep. Comparative analysis was conducted to investigate group differences, and multivariable regression models were used to reveal the impact of psychiatric comorbidities. Among a total of 90 patients, 26 were diagnosed with NT1 and 64 with OCH. In all, 38 patients showed at least one psychiatric disorder, 27% of NT1 and 48% of OCH, with female dominance (50% in females versus 23% in males, p < 0.02). Major depressive episodes (n = 29) were most common, followed by suicidality (n = 13). Patients with a psychiatric diagnosis were more fatigued (β = 0.70, p < 0.05), apathic (β = -5.41, p < 0.002), had more disturbed sleep (β = 0.55, p < 0.02), worse sleep (β = 1.89, p < 0.001) and general health (β = -12.55, p < 0.02) quality. Comorbid psychiatric disorders are frequent in patients with CDH and worsen the impact of hypersomnolence-related symptoms on daily activities regardless of the type of CDH. Psychiatric comorbidities may create a vicious circle with fatigue and avoidance of physical activities, which aggravates hypersomnolence-related symptoms.

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

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. 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. Nighttime-total sleep time (TST) in narcolepsy was significantly underestimated with CK (bias 27.8min, 95%CI 13.7-41.9) and Sadeh (bias 56.7min, 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 -30.2min, 95%CI -52.7/-7.7; UCSD bias -86.9min, 95%CI -118.2/-55.6). 24-hour-TST was overestimated by CK and UCSD in IH (CK: bias -58.5min, 95%CI -105.5/-11.5; UCSD: bias -118.8min, 95% CI -172.5/-65), and by UCSD in narcolepsy (bias -68.8min, 95%CI -109.3/-38.2). In the entire cohort, actigraphy overestimated MSLT mSL but not MWT mSL. 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.

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.

Allowing ad libitum sleep during overnight polysomnography impacts Multiple Sleep Latency Test results in patients being assessed for hypersomnolence.

The Multiple Sleep Latency Test (MSLT) is a key diagnostic component in the diagnosis of central disorders of hypersomnolence. Due to time constraints, it is common practice to wake patients at a standard time from overnight polysomnography (PSG) prior to the MSLT. This has the potential to influence MSLT results due to sleep deprivation. We describe the impact of allowing ad libitum sleep on the night prior to the MSLT in patients being assessed for hypersomnolence. 580 consecutive patients undergoing PSG/MSLT for assessment of hypersomnolence were analyzed: 290 either side of a change in laboratory protocol which allowed patients ad libitum sleep during the PSG, rather than being woken at a pre-specified time. Baseline characteristics, PSG and MSLT results were compared between the groups. Groups were similar at baseline, other than there being more females in the ad libitum group. After adjusting for confounding variables, ad libitum patients had later sleep offset time (+58.7 minutes; p<0.001), longer PSG total sleep time (+47.8 minutes; p<0.001), longer MSLT mean sleep latency (+1.3 minutes; p=0.002) and 23% fewer MSLT with mean sleep latency less than 8 minutes (p=0.004) when compared with patients who were woken at a standard time. The common practice of waking patients from their PSG at a standard time has the potential to curtail sleep and impact MSLT results by reducing mean sleep latency. Patients being assessed for hypersomnolence should be allowed ad libitum sleep during the PSG on the night prior to their MSLT.

The pulse of sleep: novel interventions in understanding the sleep-cardiovascular connection: a literature review.

Sleep disorders represent common complaints in different medical illnesses. They encompass a risk for diverse inflammatory, metabolic, and cardiovascular diseases. Sleep disorders include disorders of hypersomnolence, insomnia, parasomnias, sleep-related movement disorders, circadian rhythm sleep-wake-disorders, and sleep-related breathing disorders, each one of which was associated with increased cardiovascular disease risk in a different mechanism. In this review, the authors address the most recent research on the correlation between sleep and CVD. The literature on sleep disorders and their potential links to various cardiovascular diseases was reviewed in narrative form. For the published papers up to June 2023, the authors searched the databases of PubMed and Google Scholar. Literature demonstrating the relationship between these illnesses, pathophysiological mechanisms, diagnosis, and various therapeutic approaches was included. Sleep disorders were significantly linked to heart rate variability, hypertension, and obesity, which can eventually result in cardiovascular consequences and affect mortality and morbidity. The disruption in sleep cycles, which can be noticed in different sleep disorders, can obviously result in blood pressure, heart rate, and other cardiac functions. The clinical assessment acts as the cornerstone in the diagnosis of different spectrums of sleep disorders. The management of sleep disorders ranges from cognitive-behavioral therapy to continuous positive airway pressure (CPAP). Additional research on the topic is needed to pinpoint any potential links and pathological processes. To improve clinical treatment and preventive measures, further observational studies should emphasize the reliability of early diagnostic signs.

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.

Idiopathic hypersomnia: a kind of sleep disorder that cannot be ignored

Idiopathic hypersomnia(IH) is a chronic central disorders of hypersomnolence that manifests as excessive daytime sleepiness occurring despite normal or prolonged sleep time. Due to the individual heterogeneity of disease, the high overlap of clinical, poor repeatability of polysomnography monitoring results and the lack of clear disease biomarkers, clinical diagnosis and differential diagnosis are still difficult. This article summarizes the update of diagnostic criteria, clinical manifestations, diagnosis and treatment strategies of IH, in order to receive attention, increase the recognition rate of clinical diagnosis, reduce the misdiagnosis rate and missed diagnosis rate.

PET Study of Microglial Activation in Kleine-Levin Syndrome.

Kleine-Levin syndrome (KLS) is a rare recurrent hypersomnolence disorder associated with cognitive and behavioral disturbances, of unknown origin, but inflammatory mechanisms could be involved. We aimed to explore in vivo microglia activation using [18F]DPA-714 PET imaging in patients with KLS compared with controls, and during symptomatic vs asymptomatic periods. Patients with KLS and controls underwent a standardized clinical evaluation and PET imaging, using a radiolabeled ligand specific to the 18 kDa translocator protein. Images were processed on the PMOD (peripheral module) interface using a standard uptake value (SUV). Five regions of interest (ROIs) were analyzed: hypothalamus, thalamus, frontal area, cerebellum, and whole brain. SUV ratios (SUVr) were calculated by normalizing SUV with cerebellum uptake. Images of 17 consecutive patients with KLS (7 during episodes, 10 out of episodes) and 14 controls were analyzed. We found no SUV/SUVr difference between KLS and controls, between patients in and out episodes in all ROIs, and no correlation between SUVr and episode duration at the time of PET scan. No association was found between SUVr and sex, disease duration, or orexin levels. Our findings do not support the presence of neuroinflammation in KLS. Further research is needed to identify relevant biomarkers in KLS.

Pediatric Narcolepsy Type 1: A State-of-the-Art Review

Narcolepsy is a chronic central disorder of hypersomnolence most frequently arising during childhood/adolescence. This review article examined the literature concerning the etiology, prevalence, clinical course, and treatment of children with type 1 narcolepsy (NT1). Core symptoms of pediatric NT1 include excessive daytime sleepiness (EDS) and cataplexy, together with disrupted night sleep, sleep paralysis, and hypnagogic and hypnopompic hallucinations that can also occur. This disease frequently presents several comorbidities, such as obesity and precocious puberty, conditions ranging from psychological distress to psychiatric disorders, and cognitive aspects that further worsen the clinical picture. NT1 impairs the quality of life of children, thus calling for an early diagnosis and adequate treatment. To date, pharmacological treatments have been registered for childhood NT1 and can improve symptoms. Non-pharmacological approaches are also essential to improve patients’ well-being, ranging from behavioral treatments (e.g., planned napping) to psychosocial interventions (e.g., school programs). Multidisciplinary treatment management and early diagnosis are key factors in order to allow for adequate quality of life and development in children with NT1.

The value of using ELISA to detect orexin-A in cerebrospinal fluid in the diagnosis of narcolepsy.

Orexin in cerebrospinal fluid (CSF) is a neuropeptide synthesized by a cluster of neurons in the lateral hypothalamus. It mainly functions to maintain arousal, regulate feeding, and participate in reward mechanisms. Radioimmunoassay (RIA) and enzyme-linked immunosorbent assay (ELISA) can detect CSF orexin. At present, RIA is widely used but is limited by various conditions, which is not conducive to its widespread development. We aimed to determine whether ELISA can replace RIA in detecting orexin in CSF. We investigated the results of 20 patients with central disorders of hypersomnolence, including 11 with narcolepsy type 1, 2 with narcolepsy type 2, 5 with idiopathic hypersomnia, and 2 with other causes of somnolence. RIA and ELISA were used to detect CSF orexin, and P values <.05 were considered to be significant. In the narcolepsy and non-narcolepsy type 1 groups, there was no correlation between the RIA and ELISA results (P > .05). In the narcolepsy type 1 group, the ELISA and RIA results were significantly different (P < .05), but this was not observed in the non-narcolepsy type 1 group (P > .05). The accuracy of ELISA to detect CSF orexin was lower than that of RIA (P < .05). ELISA cannot replace RIA in the measurement of CSF orexin, and RIA is recommended as the first choice when narcolepsy is suspected.

Cardiovascular Implications of Sleep Disorders Beyond Sleep Apnea.

Sleep is crucial for human health and life. There is still limited attention to the association between sleep disorders beyond sleep apnea and cardiovascular (CV) health. We investigated the current evidence between non-respiratory sleep disorders and CV health. Current evidence suggests an important association between sleep duration, circadian rhythm, insomnia, disorders of hypersomnolence and CV health. Sleep-related movement disorders exhibit a moderate association with CV health. Further research is needed to explore the effects of each sleep disorder on CV health. Given the close association between non-respiratory sleep disorders and CV health, it is crucial to recognize and address sleep disorders in patients with a high CV risk.

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.

0661 Slow Wave Alterations During Nocturnal Sleep in Hypersomnolence Disorder

0661 Slow Wave Alterations During Nocturnal Sleep in Hypersomnolence Disorder

The Swiss Primary Hypersomnolence and Narcolepsy Cohort Study: feasibility of long-term monitoring with Fitbit smartwatches in central disorders of hypersomnolence and extraction of digital biomarkers in narcolepsy.

The Swiss Primary Hypersomnolence and Narcolepsy Cohort Study (SPHYNCS) is a multicenter research initiative to identify new biomarkers in central disorders of hypersomnolence (CDH). Whereas narcolepsy type 1 (NT1) is well characterized, other CDH disorders lack precise biomarkers. In SPHYNCS, we utilized Fitbit smartwatches to monitor physical activity, heart rate, and sleep parameters over 1 year. We examined the feasibility of long-term ambulatory monitoring using the wearable device. We then explored digital biomarkers differentiating patients with NT1 from healthy controls (HC). A total of 115 participants received a Fitbit smartwatch. Using a adherence metric to evaluate the usability of the wearable device, we found an overall adherence rate of 80% over 1 year. We calculated daily physical activity, heart rate, and sleep parameters from 2 weeks of greatest adherence to compare NT1 (n = 20) and HC (n = 9) participants. Compared to controls, NT1 patients demonstrated findings consistent with increased sleep fragmentation, including significantly greater wake-after-sleep onset (p = .007) and awakening index (p = .025), as well as standard deviation of time in bed (p = .044). Moreover, NT1 patients exhibited a significantly shorter REM latency (p = .019), and sleep latency (p = .001), as well as a lower peak heart rate (p = .008), heart rate standard deviation (p = .039) and high-intensity activity (p = .009) compared to HC. This ongoing study demonstrates the feasibility of long-term monitoring with wearable technology in patients with CDH and potentially identifies a digital biomarker profile for NT1. While further validation is needed in larger datasets, these data suggest that long-term wearable technology may play a future role in diagnosing and managing narcolepsy.

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.

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.