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.

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

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

Association between cytokines and fatigue in patients with type 1 narcolepsy.

BACKGROUND: Fatigue is a frequent complaint among patients with narcolepsy. Studies have shown that inflammatory cytokines are associated with fatigue in neurological disorders; however, this association has not been identified in patients with type 1 narcolepsy. The purpose of this study was to investigate the potential relationship between cytokines and fatigue in patients with type 1 narcolepsy. METHODS: We investigated the association between 12 inflammatory cytokines and fatigue in 49 patients with type 1 narcolepsy. The Multidimensional Fatigue Inventory-20 was used to assess the fatigue severity. The associations of fatigue were identified using Spearman and Pearson correlation analyses. A linear regression analysis model was used to adjust the confounding factors and evaluate the associations of fatigue. RESULTS: Correlation analysis showed that the plasma interleukin (IL)-2 level (r = 0.409, p = 0.004) was positively correlated with fatigue in patients with narcolepsy type 1. After adjusting for confounding factors, the linear regression model revealed a positive association between the IL-2 level (ß = 1.148, p = 0.04) and fatigue in individuals diagnosed with type 1 narcolepsy. CONCLUSION: IL-2 levels show a positive correlation with fatigue in type 1 narcolepsy, suggesting its potential role in the pathophysiology of fatigue.

Altered reinforcement learning in Narcolepsy type I and other central disorders of hypersomnolence.

Cognitive impairments are described in central disorders of hypersomnolence (CDH), but studies remain very limited and largely focused on narcolepsy type 1 (NT1). The precise nature and origin of these cognitive impairments is poorly understood. Specifically, impaired decision making under ambiguity has been reported in NT1 and suggested to be caused by dysregulation of the direct projections of hypocretin neurons to the dopamine network. However, the decision-making tasks used previously embed different cognitive functions that are difficult to isolate. This study aims to test reinforcement learning in participants with NT1 and with other (non-hypocretin deficient) CDH in a task known to directly depend on the dopamine system. Participants with NT1 (N = 27), other CDH (N = 34, including narcolepsy type 2 and idiopathic hypersomnia, matched with NT1 participants for sleepiness severity), and healthy participants (N = 34) took part in the study. Results showed that all groups had normal and similar positive reinforcement learning, a pattern not suggestive of dopamine deficiency. However, both participants with NT1 and other CDH had decreased learning abilities to avoid losses. This decreased negative reinforcement learning in participants with CDH was associated with the alteration of vigilance. This study provides new insights into the nature of decision making impairment in people with CDH and suggests that these alterations could be minimized by restoring adequate vigilance.

Psychobehavioural profile in narcolepsy type 1 with and without REM sleep behaviour disorder.

REM sleep behaviour disorder (RBD) is common in narcolepsy type 1 (NT1). Abnormalities in the reward system have been observed in NT1, possibly related to impaired orexin projections towards the mesolimbic reward system, but also in RBD when associated with Parkinson's disease. Our study aimed to explore the psychobehavioural profile of NT1 patients with and without RBD compared with healthy controls (HC). Forty patients with NT1 were compared with 20 sex- and age-matched HC. All patients with NT1 underwent a video-polysomnography including a measure of REM sleep without atonia (RSWA). The following neuropsychobehavioural variables were assessed: apathy, impulsivity, depression, cognition, subjective and objective attention, sensation-seeking, and behavioural addictions. The patient population included 22 patients with NT1-RBD and 18 patients with NT1-noRBD. Compared with the healthy controls, patients with NT1 had higher scores of apathy, impulsivity, and depression; a lower score on global cognition, and poorer self-perceived attention. No differences were found between patients with NT1 with and without RBD in all neuropsychological variables, except for impaired objective attention in patients with NT1-RBD. In patients with NT1, a positive correlation was observed between RSWA and both apathy and impulsivity subscale. Moreover, in patients with NT1-RBD, RSWA was positively correlated with depression. Patients with NT1 showed higher depression, apathy, and impulsivity compared with controls. These measures correlate with the severity of RSWA, suggesting a transdiagnostic association between RBD and abnormalities of the reward system at least for patients with NT1.

ADHD in narcolepsy: A closer look at prevalence and ties.

The reported prevalence of attention deficit hyperactivity disorder (ADHD) in narcolepsy varies considerably, while the associated factors remain inadequately established. A systematic search of studies published in PubMed, EMBASE, and the Cochrane Library was performed from inception to March 2023. Ten studies with 839 patients with narcolepsy were included in the study. Utilizing a random effects model, the pooled prevalence of ADHD in narcolepsy was 25% (95% CI, 14-38%). Notably, patients with narcolepsy type 2 showed a significantly higher prevalence of ADHD than that of narcolepsy type 1 (46% vs. 20%, p = 0.045). Furthermore, the rate of ADHD was notably elevated in narcolepsy compared with the healthy controls (odds ratio 9.59, 95% CI, 4.06-22.63, p < 0.001). Several factors such as excessive daytime sleepiness (EDS), fatigue, insomnia severity, and the quality of life were significantly associated with ADHD in narcolepsy (all ps < 0.05). These findings highlight the importance of monitoring and managing ADHD in narcolepsy, and provide a clue to help reducing ADHD by intervening in these associated factors.

Narcolepsy and psychiatric disorders: A bidirectional Mendelian randomization study.

Since the introduction of the concept of narcolepsy, there has been a proliferation of discussions about its association with psychiatry. To elucidate the causal role of narcolepsy in the three psychiatric disorders [i.e., schizophrenia (SCZ), major depressive disorder (MDD), and attention-deficit hyperactivity disorder (ADHD)], we applied a bidirectional Mendelian randomization study using two stages (discovery stage and validation stage) and data from three different genome-wide association studies of narcolepsy. The estimates from different stages were combined using fixed-effects meta-analysis. Our findings suggest that narcolepsy is associated with an increased risk of SCZ. Conversely, MDD may be causally related to narcolepsy. A causal relationship between narcolepsy and ADHD was excluded.

Once-nightly sodium oxybate (FT218) improved symptoms of disrupted nighttime sleep in people with narcolepsy: a plain language summary.

WHAT IS THIS SUMMARY ABOUT?: This is a plain language summary of a published article in the journal CNS Drugs. Narcolepsy is a rare sleep condition. Most people with narcolepsy experience disrupted nighttime sleep and have poor quality of sleep. Sometimes these symptoms are not easily diagnosed as a symptom of narcolepsy. Sodium oxybate is an approved treatment for narcolepsy. The only version of sodium oxybate that was available until 2023 required people to take their sodium oxybate at bedtime and then again in the middle of the night. The US Food and Drug Administration (FDA for short) has approved a once-nightly bedtime dose of sodium oxybate (ON-SXB for short, also known as FT218 or LUMRYZ™) to treat symptoms of narcolepsy in adults. These symptoms are daytime sleepiness and cataplexy, which is an episode of sudden muscle weakness. The once-nightly bedtime dose of ON-SXB removes the need for a middle-of-the-night dose of sodium oxybate. The REST-ON clinical study compared ON-SXB to a placebo (a substance that contains no medicine) to determine if it was better at treating symptoms of disrupted nighttime sleep associated with narcolepsy. This summary looks at whether; ON-SXB was better than placebo at treating symptoms of disrupted nighttime sleep. WHAT WERE THE RESULTS?: Compared to people who took placebo, people who took ON-SXB had fewer number of changes from deeper to lighter sleep stages and woke up less during the night. They also reported that they slept better at night and felt more refreshed when waking up in the morning. People with narcolepsy sometimes take alerting agents to help with sleepiness during the day, but alerting agents can cause difficulty sleeping at night. This study showed that people who took ON-SXB had better nighttime sleep even if they were taking alerting agents during the day. The most common side effects of ON-SXB included dizziness, nausea (feeling sick to your stomach), vomiting, headache, and bedwetting. WHAT DO THE RESULTS MEAN?: A once-nightly bedtime dose of ON-SXB is a narcolepsy treatment option for people without the need for a middle-of-the-night dose of sodium oxybate.

Narcolepsy type 1 and Sydenham chorea - Report of 3 cases and review of the literature.

OBJECTIVES/BACKGROUND: Narcolepsy type 1 (NT1) is an immune-mediated disorder characterized by excessive daytime sleepiness, cataplexy, low levels of hypocretin-1 in the cerebrospinal fluid, and a strong association with the HLA DQB1*06:02 allele. There is evidence for streptococcal infections as one pathogenic factor that may lead to NT1 as part of a multifactorial pathogenesis. Elevated titers of Antistreptolysin-O antibodies and increased inflammatory activity in response to streptococci antigens have been described in patients with NT1. Sydenham chorea (SC) results from a post-streptococcal autoimmune process targeting basal ganglia neurons. Despite this common trigger, SC has been interpreted as a misdiagnosis in a few described cases of patients who were first diagnosed with SC and later with NT1. Our goal was to analyze the association between SC and NT1. PATIENTS/METHODS: We reviewed the literature and report three patients from three European sleep centers who were diagnosed with both SC and NT1 within a few months. RESULTS: We describe the cases of one male (age 10) and two female (age 22 and 10) patients. CONCLUSIONS: We argue that in those cases both diagnoses are justified, unlike reports of previous cases in which SC was considered a misdiagnosis in patients with NT1. It remains, however, unclear if the conditions occur independently or if there is an overlap disorder- an SC-like subtype of narcolepsy with a particular sequence of symptoms. Further studies need to clarify the causality of the relationship and the pathophysiology of the reported rare association.

Solriamfetol: A Review in Excessive Daytime Sleepiness Associated with Narcolepsy and Obstructive Sleep Apnoea.

Solriamfetol (SUNOSI®) is an oral selective dopamine and norepinephrine reuptake inhibitor approved in the EU and the USA for improving wakefulness in adults with excessive daytime sleepiness (EDS) associated with narcolepsy or obstructive sleep apnoea (OSA). In phase III studies, 12 weeks' therapy with solriamfetol within the recommended dosage range for narcolepsy (75 mg or 150 mg once daily) or OSA (37.5 mg, 75 mg or 150 mg once daily) provided early and sustained reductions in excessive sleepiness and improvements in wakefulness relative to placebo. These effects were generally sustained through 52 weeks. The drug's effectiveness in adults with EDS associated with narcolepsy is supported by results from real-world studies. Solriamfetol demonstrated a consistent safety and tolerability profile across clinical studies, with commonly reported adverse reactions generally occurring within 2 weeks of treatment initiation and mostly resolving within 2 weeks. Thus, solriamfetol represents a useful treatment option for adults with EDS associated with narcolepsy or OSA.

Excessive daytime sleepiness (EDS) is a common condition in which an individual is unable to stay awake during periods when they typically would be awake. Dopamine and norepinephrine are among the chemical messengers involved in sleep­wake regulation. Solriamfetol (SUNOSI^®), a selective dopamine and norepinephrine reuptake inhibitor, is a once-daily oral treatment approved in the EU and the USA for improving wakefulness in adults with EDS associated with narcolepsy or obstructive sleep apnoea (OSA). In such patients, solriamfetol reduced excessive sleepiness and improved wakefulness compared with placebo over 12 weeks. Onset was rapid and generally sustained through 52 weeks. The safety and tolerability profile of solriamfetol was consistent over the short and longer term; the most common adverse reactions were headache, decreased appetite, nausea, anxiety and insomnia in adults with narcolepsy and nausea and decreased appetite in those with OSA. Thus, solriamfetol represents a useful treatment option for adults with EDS associated with narcolepsy or OSA.

A unique association? A narcolepsy type 1 case comorbid with Primary Biliary Cholangitis.

The aim of the study was to present a woman affected of a narcolepsy with cataplexy (narcolepsy type 1) comorbid with an asymptomatic Primary Biliary Cholangitis (PBC). The HLA haplotype was DRB1*15:01, DQA1*01:02, DQB1*06:02. The allele DQB1*06:02 has been considered until now protective for PBC and dual pathology has not been published. We think the important clinical message of the Case would be of continuing to monitor adults with narcolepsy type 1 for late complications that may be associated with other autoimmune conditions. Clinicians should be aware of the relationship between Narcolepsy and PBC. This highlights the need for screening and management in these individuals.

A series of 7 cases of patients with narcolepsy with hypocretin deficiency without the HLA DQB1*06:02 allele.

STUDY OBJECTIVES: We report data collected from 2 reference European sleep centers on a series of patients with narcolepsy with hypocretin-1 deficiency and absence of the human leukocyte antigens (HLA) DQB1*06:02 allele. METHODS: Clinical data, HLA DQ markers, and cerebrospinal fluid assessments were collected retrospectively from Caucasian patients with a diagnosis of narcolepsy type 1 with cerebrospinal fluid hypocretin-1 deficiency (< 110 pg/ml) and absence of the HLA DQB1*06:02 allele, with follow-up with at least 1 visit within the last 4 years, consecutively admitted to 2 European sleep centers (Lugano, Switzerland and Montpellier, France). RESULTS: Seven patients (3 of 29 patients in Lugano and 4 of 328 in Montpellier) were diagnosed with narcolepsy with hypocretin-1 deficiency and absence of HLA DQB1*06:02 (ie, 2% of patients with narcolepsy type 1). Regarding the HLA-DQB1 genotyping, 4 cases were positive for HLA DQB1*03:01, 1 for DQB1*03:02, and 3 for DQB1*02:01. Three patients had atypical cataplexy and 1 had no cataplexy. Only 2 patients had both a mean sleep latency of less than 8 minutes and more than 2 sleep onset rapid eye movement periods on the Multiple Sleep Latency Test, indicative of a less severe condition. CONCLUSIONS: Although rare, this series of 7 cases confirms that hypocretin-deficient narcolepsy should not be excluded in the absence of HLA DQB1*06:02, especially if patients are carriers of other high-risk HLA-DQB1 alleles (DQB1*03:01, *03:02, *02:01). These data support the hypothesis that narcolepsy type 1 is a wider disease spectrum linked to the loss of hypocretin peptide. CITATION: Miano S, Barateau L, De Pieri M, et al. A series of 7 cases of patients with narcolepsy with hypocretin deficiency without the HLA DQB1*06:02 allele. J Clin Sleep Med. 2023;19(12):2053-2057.

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.

[Multidrug resistant narcolepsy]. / Narcolepsia multirresistente.

INTRODUCTION: Narcolepsy type 1 is a focal degenerative disease of the hypothalamus that selectively affects orexin (hypocretin)-producing neurons. It presents multiple clinical manifestations, both in wakefulness and in sleep. The symptoms are often so disruptive that they cause enormous suffering and impair patients' quality of life. Although a non-pharmacological approach is sometimes sufficient, the vast majority of patients need medication for adequate clinical management. CASE REPORT: A male who, at 43 years of age, began to present acutely with excessive daytime sleepiness and episodes of cataplexy. After a thorough examination, he was diagnosed with narcolepsy type 1. Throughout the course of the disease, he was prescribed antidepressants, neurostimulants and sodium oxybate, in monotherapy or in combination. The response to pharmacological treatment was insufficient and accompanied by numerous side effects. Following the introduction of pitolisant, there was a marked improvement in his symptoms and a reduction in the dose of the other drugs and their adverse effects was achieved. CONCLUSION: A number of measures are now available to address the cardinal symptoms of the disease, although there are still cases that are resistant to anti-narcoleptic treatment. Drugs with mechanisms of action that act upon receptors in the histaminergic system can be very useful in these cases.

TITLE: Narcolepsia multirresistente.Introducción. La narcolepsia de tipo 1 es una enfermedad degenerativa focal del hipotálamo que afecta selectivamente a las neuronas productoras de orexina (hipocretina). Presenta múltiples manifestaciones clínicas, tanto en vigilia como en sueño. Con frecuencia, los síntomas son tan disruptivos que ocasionan enorme sufrimiento y deterioro de la calidad de vida de los pacientes. Aunque en ocasiones es suficiente con un abordaje no farmacológico, la gran mayoría de los enfermos necesita medicación para un adecuado control clínico. Caso clínico. Varón que a los 43 años comenzó a presentar de forma aguda excesiva somnolencia diurna y episodios de cataplejía. Tras un exhaustivo estudio se le diagnosticó narcolepsia de tipo 1. A lo largo de la evolución de la enfermedad se le prescribieron antidepresivos, neuroestimulantes y oxibato sódico, en monoterapia o en combinación. La respuesta al tratamiento farmacológico fue insuficiente y se acompañó de numerosos efectos secundarios. Tras la introducción de pitolisant se objetivó una franca mejoría de los síntomas, y se consiguió reducir la dosis de los otros fármacos y de sus efectos adversos. Conclusión. Son numerosas las medidas disponibles en la actualidad para abordar los síntomas cardinales de la enfermedad, aunque siguen existiendo casos resistentes al tratamiento antinarcoléptico. Los fármacos con mecanismos de acción sobre receptores del sistema histaminérgico pueden resultar de gran utilidad en estos casos.

Oral Orexin Receptor 2 Agonist in Narcolepsy Type 1.

BACKGROUND: Narcolepsy type 1 is caused by severe loss or lack of brain orexin neuropeptides. METHODS: We conducted a phase 2, randomized, placebo-controlled trial of TAK-994, an oral orexin receptor 2-selective agonist, in patients with narcolepsy type 1. Patients with confirmed narcolepsy type 1 according to clinical criteria were randomly assigned to receive twice-daily oral TAK-994 (30 mg, 90 mg, or 180 mg) or placebo. The primary end point was the mean change from baseline to week 8 in average sleep latency (the time it takes to fall asleep) on the Maintenance of Wakefulness Test (range, 0 to 40 minutes; normal ability to stay awake, ≥20 minutes). Secondary end points included the change in the Epworth Sleepiness Scale (ESS) score (range, 0 to 24, with higher scores indicating greater daytime sleepiness; normal, <10) and the weekly cataplexy rate. RESULTS: Of the 73 patients, 17 received TAK-994 at a dose of 30 mg twice daily, 20 received 90 mg twice daily, 19 received 180 mg twice daily, and 17 received placebo. The phase 2 trial and an extension trial were terminated early owing to hepatic adverse events. Primary end-point data were available for 41 patients (56%); the main reason for missing data was early trial termination. Least-squares mean changes to week 8 in average sleep latency on the MWT were 23.9 minutes in the 30-mg group, 27.4 minutes in the 90-mg group, 32.6 minutes in the 180-mg group, and -2.5 minutes in the placebo group (difference vs. placebo, 26.4 minutes in the 30-mg group, 29.9 minutes in the 90-mg group, and 35.0 minutes the 180-mg group; P<0.001 for all comparisons). Least-squares mean changes to week 8 in the ESS score were -12.2 in the 30-mg group, -13.5 in the 90-mg group, -15.1 in the 180-mg group, and -2.1 in the placebo group (difference vs. placebo, -10.1 in the 30-mg group, -11.4 in the 90-mg group, and -13.0 in the 180-mg group). Weekly incidences of cataplexy at week 8 were 0.27 in the 30-mg group, 1.14 in the 90-mg group, 0.88 in the 180-mg group, and 5.83 in the placebo group (rate ratio vs. placebo, 0.05 in the 30-mg group, 0.20 in the 90-mg group, and 0.15 in the 180-mg group). A total of 44 of 56 patients (79%) receiving TAK-994 had adverse events, most commonly urinary urgency or frequency. Clinically important elevations in liver-enzyme levels occurred in 5 patients, and drug-induced liver injury meeting Hy's law criteria occurred in 3 patients. CONCLUSIONS: In a phase 2 trial involving patients with narcolepsy type 1, an orexin receptor 2 agonist resulted in greater improvements on measures of sleepiness and cataplexy than placebo over a period of 8 weeks but was associated with hepatotoxic effects. (Funded by Takeda Development Center Americas; TAK-994-1501 and TAK-994-1504 ClinicalTrials.gov numbers, NCT04096560 and NCT04820842.).

Clinician Preferences for Oxybate Treatment for Narcolepsy: Survey and Discrete Choice Experiment.

INTRODUCTION: Immediate-release sodium oxybate (SXB) has been Food and Drug Administration (FDA)-approved to treat narcolepsy since 2002; in 2020, a mixed-salt oxybates formulation was also approved. Both are taken at bedtime with a second dose taken 2.5-4 h later. A third oxybate option, an investigational extended-release SXB, may soon be available. This study was undertaken to understand clinicians' preferences between these 3 different oxybate treatments. METHODS: Clinicians in active clinical practice for 3-35 years and experience treating patients with narcolepsy were recruited. A 30-min web-based survey quantified narcolepsy disease-state attitudes, treatment perceptions, and satisfaction with oxybates on 9-point scales. A discrete choice experiment (DCE) of 12 choice sets, with 2 hypothetical treatment profiles in each, was used to capture clinician preferences about overall oxybate therapy preference, impact on patient quality of life (QoL), and patient anxiety/stress. Attributes associated with current therapies and those expected to be available in the near future were included in the design. RESULTS: The clinicians surveyed (n = 100) indicated that narcolepsy has a negative impact on patient QoL (mean rating, 7.7) and rated impact on QoL and treatment efficacy as the most important aspects of a narcolepsy treatment (mean rating, 7.3-7.7). Clinicians with experience prescribing oxybates had moderately high satisfaction with SXB and mixed-salt oxybates efficacy (mean ratings, 6.5-6.9) and safety (mean ratings, 6.1-6.7) and lower satisfaction with nightly dosing frequency (mean rating, 5.9 and 6.3, respectively). In the DCE, dosing frequency was the most important attribute driving overall product choice, patient QoL, and reducing patient anxiety/stress (relative attribute importance, 46.1, 41.7, and 44.0, respectively), with once nightly preferred over twice nightly. CONCLUSION: Clinicians indicated a significantly higher preference for the once-at-bedtime dosing schedule versus twice nightly in selecting oxybate therapies overall and when aiming to improve patient QoL or reduce patient anxiety.

Current medications for narcolepsy include immediate-release sodium oxybate and mixed-salt oxybates. People taking these oxybates for narcolepsy take 1 dose at bedtime and must wake up 2.5­4 h later for the second dose. An investigational sodium oxybate, designed as a single bedtime dose, has been tentatively approved by the US Food and Drug Administration. This study used a 30-min web-based survey to learn what clinicians think about narcolepsy and narcolepsy medicines. A discrete choice experiment was used to identify which properties of current/future oxybate medicines are most important in a narcolepsy treatment. In this exercise, relevant properties of current/future oxybate medicines were mixed and matched to create hypothetical medicine profiles. Clinicians selected from these profiles which medication they preferred overall, which would improve patient quality of life, and which would reduce patient anxiety when thinking about taking the treatment. Clinicians were moderately satisfied with the effectiveness and safety of current narcolepsy medications. They strongly preferred oxybate treatments with fewer nightly doses and agreed that waking up for the second oxybate dose causes stress for patients. In the discrete choice experiment, the number of doses each night was the product characteristic that had the biggest impact on clinicians picking a medicine for narcolepsy. This was true for overall medicine choice, choosing a medicine that would improve patient quality of life, and choosing one that would reduce patient anxiety/stress. If granted marketing approval, extended-release sodium oxybate will be a once-at-bedtime option that may overcome challenges with current oxybate therapies.

DNMT1-associated sensory neuropathy and cerebellar ataxia: A novel variant and review of genotype-phenotype correlation.

AIM: Hereditary sensory neuropathy (HSN) 1E is a neurodegenerative disorder caused by pathogenic variants in DNA methyltransferase 1 (DNMT1). It is characterised by sensorineural deafness, sensory neuropathy and cognitive decline. Variants in DNMT1 are also associated with autosomal dominant cerebellar ataxia, deafness and narcolepsy. METHODS: A 42-year-old man presented with imbalance, lancinating pain, numerous paucisymptomatic injuries, progressive deafness since his mid-20s, mild cognitive decline and apathy. Examination revealed abnormalities of eye movements, distal sensory loss to all modalities, areflexia without weakness and lower limb ataxia. MRI brain and FDG-PET scan demonstrated biparietal and cerebellar atrophy/hypometabolism. Whole exome sequencing detected a heterozygous likely pathogenic missense variant in DNMT1, c.1289G > A, p.Cys430Tyr. Cochlear implant was performed at 44 years for the bilateral high frequency sensorineural hearing loss with improvement in hearing and day-to-day function. RESULTS AND CONCLUSION: We describe a novel variant in DNMT1 and confirm that an overlapping HSN1E-cerebellar phenotype can occur. Only one prior case of cochlear implant in HSN1E has been reported to date but this case adds to that literature, suggesting that cochlear implant can be successful in such patients. We further explore the clinical and radiological signature of the cognitive syndrome associated with this disorder.