Narcolepsy: an interface among neurology, immunology, sleep, and genetics.

Narcolepsy is a primary disorder of the central nervous system resulting from genetic, environmental, and immunological interactions defined as excessive daytime sleepiness plus cataplexy, hallucinations, sleep paralysis, and sleep fragmentation. The pathophysiology is not entirely known, but the interaction among genetic predisposition, environmental exposition, and immune component with consequent hypocretin-1 deficiency is the model to explain narcolepsy type I. The mechanism of narcolepsy type II is less understood. There is a delay of over ten years for the diagnosis of narcolepsy around the world. Patients with narcolepsy have many comorbidities with a negative impact on quality of life. The treatment of narcolepsy must contain an educational approach for the family, coworkers, and patients. Scheduled naps and sleep hygiene are essential to minimize the dose of medications. Much progress has been seen in the pharmacological treatment of narcolepsy with new stimulants, different presentations of oxybate, and recent studies with orexin agonists. Narcolepsy is a rare disease that needs to be more understood and highlighted to avoid delayed diagnosis and severe disabilities in patients.

A narcolepsia é um distúrbio primário do sistema nervoso central resultante das interações genéticas, ambientais e imunológicas definidas como sonolência diurna excessiva mais cataplexia, alucinações, paralisia do sono e fragmentação do sono. A fisiopatologia não é completamente conhecida, mas a interação entre predisposição genética, exposição ambiental e componente imunológico com consequente deficiência de hipocretina-1 é o modelo para explicar a narcolepsia tipo I. O mecanismo da narcolepsia tipo II é menos compreendido. Há um atraso de mais de dez anos para o diagnóstico da narcolepsia em todo o mundo. Pacientes com narcolepsia apresentam muitas comorbidades com impacto negativo na qualidade de vida. O tratamento da narcolepsia deve conter uma abordagem educativa para a família, colegas de trabalho e pacientes. Cochilos programados e higiene do sono são importantes para minimizar a dose dos medicamentos. Muito progresso foi observado no tratamento farmacológico da narcolepsia com novos estimulantes, diferentes apresentações de oxibato e estudos recentes com agonistas de orexina. A narcolepsia é uma doença rara que precisa ser mais compreendida e destacada para evitar atrasos no diagnóstico e incapacidades graves nos pacientes.

Making sense of narcolepsy: A qualitative exploration of how persons with narcolepsy perceive symptoms and their illness experience.

INTRODUCTION: Understanding how persons with narcolepsy conceptualize symptoms, daily impact and illness experience is key to facilitating dialogue between patients and healthcare professionals. These concepts are usually explored from the perspective of healthcare professionals/researchers and rarely from the perspective of those with narcolepsy. METHODS: 127 self-reported persons with narcolepsy were recruited from an Australian patient support group. A short demographic survey was completed. All agreed to participate in a subsequent 1:1 semi-structured interview. Saturation was reached after 24 interviews (mean age = 33 years (SD 11) with 44% reporting cataplexy). A multidisciplinary team of researchers/clinicians analyzed interview transcripts using thematic analysis. RESULTS: Participants perceived physical fatigue, sleepiness, and two separate experiences of 'falling asleep/sleep attacks' as distinct symptoms rather than a multidimensional construct (i.e. excessive daytime sleepiness). We also identified two experiences of cataplexy, one triggered by acute emotion and another by a stressor. Participants determined their narcolepsy to be 'well-managed' by the level of functional impairment rather than the frequency of any symptom. Almost all participants described experiencing anticipated stigma and internalized or 'self-' stigma, likely stemming from societal devaluation of sleep and the conflation of sleepiness with laziness. CONCLUSION: Descriptions of common symptoms often differed between participants and the existing literature. These differences likely impact patient-physician communication, with both parties utilizing the same terminology to communicate different concepts. The characterization of stigma in narcolepsy presents opportunities for future research exploring the impact and possible development of interventions to reduce the substantial psychological comorbidity in persons with narcolepsy.

The Burden of Narcolepsy in Adults: A Population Sampling Study Using Personal Media.

OBJECTIVE: To obtain insight in the spectrum of narcolepsy symptoms and associated burden in a large cohort of patients. METHODS: We used the Narcolepsy Monitor, a mobile app, to easily rate the presence and burden of 20 narcolepsy symptoms. Baseline measures were obtained and analyzed from 746 users aged between 18 and 75 years with a reported diagnosis of narcolepsy. RESULTS: Median age was 33.0 years (IQR 25.0-43.0), median Ullanlinna Narcolepsy Scale 19 (IQR 14.0-26.0), 78% reported using narcolepsy pharmacotherapy. Excessive daytime sleepiness (97.2%) and lack of energy were most often present (95.0%) and most often caused a high burden (79.7% and 76.1% respectively). Cognitive symptoms (concentration 93.0%, memory 91.4%) and psychiatric symptoms (mood 76.8%, anxiety/panic 76.4%) were relatively often reported to be present and burdensome. Conversely, sleep paralysis and cataplexy were least often reported as highly bothersome. Females experienced a higher burden for anxiety/panic, memory, and lack of energy. CONCLUSIONS: This study supports the notion of an elaborate narcolepsy symptom spectrum. Each symptom's contribution to the experienced burden varied, but lesser-known symptoms did significantly add to this as well. This emphasizes the need to not only focus treatment on the classical core symptoms of narcolepsy.

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.

Validation of the Brazilian Portuguese version of the Stanford cataplexy questionnaire.

INTRODUCTION: Cataplexy is a sudden and involuntary episode of loss of muscle tone during wakefulness. Cataplexy cannot be easily recognized when clinical features are atypical or when the physician is unfamiliar with its characteristics. The unstructured clinical interview is the only standard diagnostic method, but the use of a targeted questionnaire can help in the diagnosis of cataplexy. METHODS: The Stanford cataplexy questionnaire is a self-administered 51-question questionnaire. This validation consisted of an initial translation and back-translation of the questionnaire from English into Brazilian Portuguese, followed by a pilot study with 10 participants for the cultural adaptation of the scale. RESULTS: 155 consecutive patients aged 18-85 completed the questionnaire. The Brazilian version of the Stanford cataplexy questionnaire showed similar results to the original version with good metric properties (area under the curve), high internal consistency (Cronbach's alpha equal to 0.87), good reliability and reproducibility. CONCLUSIONS: The Brazilian Portuguese version of the Stanford Cataplexy questionnaire presented good accuracy satisfactory psychometric properties in identifying cataplexy.

The role of orexinergic system in the regulation of cataplexy.

Loss of orexin/hypocretin causes serious sleep disorder; narcolepsy. Cataplexy is the most striking symptom of narcolepsy, characterized by abrupt muscle paralysis induced by emotional stimuli, and has been considered pathological activation of REM sleep atonia system. Clinical treatments for cataplexy/narcolepsy and early pharmacological studies in narcoleptic dogs tell us about the involvement of monoaminergic and cholinergic systems in the control of cataplexy/narcolepsy. Muscle atonia may be induced by activation of REM sleep-atonia generating system in the brainstem. Emotional stimuli may be processed in the limbic systems including the amygdala, nucleus accumbens, and medial prefrontal cortex. It is now considered that orexin/hypocretin prevents cataplexy by modulating the activity of different points of cataplexy-inducing circuit, including monoaminergic/cholinergic systems, muscle atonia-generating systems, and emotion-related systems. This review will describe the recent advances in understanding the neural mechanisms controlling cataplexy, with a focus on the involvement of orexin/hypocretin system, and will discuss future experimental strategies that will lead to further understanding and treatment of this disease.

Narcolepsies, update in 2023.

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

Pharmacological options for narcolepsy: are they the way forward?

INTRODUCTION: Narcolepsy is an under-recognized, rare neurologic disorder of hypersomnolence that is associated with increased mortality and medical and psychiatric co-morbidities. Narcolepsy exerts a substantial economic burden on patients and society. There is currently no cure, and life-long symptomatic therapy is needed. Available drugs do not modify the disease course. AREAS COVERED: This manuscript provides an overview of narcolepsy symptoms, diagnosis, pathophysiology, current pharmacotherapies, and emerging treatments. Gaps and unresolved issues in diagnosis and management of narcolepsy are discussed to answer whether pharmacological options are the way forward. EXPERT OPINION: Diagnostic criteria for narcolepsy (ICSD-3) need revision and greater clarity. Improved recognition of cataplexy and other symptoms through educational outreach, new biomarkers, improved test scoring through artificial intelligence algorithms, and use of machine learning may facilitate earlier diagnosis and treatment. Pharmacological options need improved symptomatic therapy in addition to targeted therapies that address the loss of hypocretin signaling. Optimal narcolepsy care also needs a better understanding of the pathophysiology, recognition of the different phenotypes in narcolepsy, identification of at-risk individuals and early recognition of symptoms, better diagnostic tools, and a database for research and disease monitoring of treatment, side-effects, and comorbidities.

The therapeutic potential of opioids in narcolepsy type 1: A systematic literature review and questionnaire study.

OBJECTIVE: Narcolepsy type 1 is a primary sleep disorder caused by deficient hypocretin transmission leading to excessive daytime sleepiness and cataplexy. Opioids have been suggested to increase the number of hypocretin-producing neurons. We aimed to assess opioid use and its self-reported effect on narcolepsy type 1 symptom severity through a literature review and questionnaire study. METHODS: We systematically reviewed literature on opioid use in narcolepsy. We also recruited 100 people with narcolepsy type 1 who completed an online questionnaire on opioid use in the previous three years. The main questionnaire topics were the indication for use, and the possible effects on narcolepsy symptom severity. Structured follow-up interviews were conducted when opioid use was reported. RESULTS: The systematic literature review mainly showed improvements in narcolepsy symptom severity. Recent opioid use was reported by 16/100 questionnaire respondents, who had used 20 opioids (codeine: 7/20, tramadol: 6/20, oxycodone: 6/20, fentanyl: 1/20). Narcolepsy symptom changes were reported in 11/20. Positive effects on disturbed nocturnal sleep (9/20), excessive daytime sleepiness (4/20), hypnagogic hallucinations (3/17), cataplexy (2/18), and sleep paralysis (1/13) were most pronounced for oxycodone (4/6) and codeine (4/7). CONCLUSIONS: Opioids were relatively frequently used compared to a similarly young general Dutch sample. Oxycodone and, to a lesser extent, codeine were associated with self-reported narcolepsy symptom severity improvements. Positive changes in disturbed nocturnal sleep and daytime sleepiness were most frequently reported, while cataplexy effects were less pronounced. Randomised controlled trials are now needed to verify the potential of opioids as therapeutic agents for narcolepsy.

[Sleep paralysis during naptime as initial symptom of narcolepsy]. / Parálisis de sueño durante la siesta como síntoma inicial de narcolepsia.

INTRODUCTION: Narcolepsy is a disease of unknown etiology, with a very low prevalence (0.02-0.16% in adults, although it must be higher, given the underdiagnosis), characterized by the presence of excessive daytime sleepiness, hypnagogic and/or hypnopompic hallucinations, sleep paralysis and/or cataplexy (if present, we speak of type 1 narcolepsy and, if not, type 2 narcolepsy), whose average diagnostic delay is between 10 and 15 years. CASE REPORT: A 16-year-old male who consulted after visiting different specialists for presenting sleep paralysis during naps, which cause him fear and occasional objects falling from his hands (diagnosed as possible myoclonus). In the anamnesis we were surprised by the presence of sleep paralysis immediately after the start of the naps and, in the directed anamnesis, these sudden movements caused by emotions were compatible with cataplexies, so we performed a nocturnal polysomnographic study and a multiple sleep latency test. With evolution came hypnopompic hallucinations and fragmented nocturnal sleep, as well as occasional daytime sleepiness (thus completing the typical symptomatic tetrad of type 1 narcolepsy with cataplexy). CONCLUSION: Knowledge of this disease is important, considering it as a differential diagnosis in patients with episodes of intractable sleepiness, send these patients to expert doctors in sleep disorders and doing a good anamnesis, performing the necessary complementary tests for the diagnosis of this underdiagnosed disease for its correct management, which is decisive for improving the quality of life of these patients.

TITLE: Parálisis de sueño durante la siesta como síntoma inicial de narcolepsia.Introducción. La narcolepsia es una enfermedad de etiología desconocida, de prevalencia muy baja (el 0,02-0,16% en adultos, aunque debe ser mayor, dado el infradiagnóstico), caracterizada por la presencia de somnolencia diurna excesiva, alucinaciones hipnagógicas y/o hipnopómpicas, parálisis de sueño y/o cataplejía (si está presente, se habla de narcolepsia de tipo 1 y, si no, de narcolepsia de tipo 2), cuya media de retraso diagnóstico se sitúa entre los 10 y los 15 años. Caso clínico. Varón de 16 años que consulta tras visitar a distintos especialistas por presentar parálisis de sueño durante las siestas, que le producen miedo y ocasional caída de objetos de las manos (diagnosticadas como posibles mioclonías). En la anamnesis nos sorprendió la presencia de parálisis de sueño inmediatamente tras el inicio de las siestas y, en la anamnesis dirigida, esos movimientos bruscos provocados por emociones eran compatibles con cataplejías, por lo que realizamos un estudio polisomnográfico nocturno y un test de latencias múltiples del sueño. Con la evolución aparecieron alucinaciones hipnopómpicas y sueño fragmentado nocturno, así como ocasional somnolencia diurna (se completó así la tétrada sintomatológica típica de la narcolepsia con cataplejía de tipo 1). Conclusión. Es importante el conocimiento de esta enfermedad, plantearla como diagnóstico diferencial en pacientes con episodios de somnolencia incoercible, realizar la derivación a consultas especializadas en trastornos de sueño y una buena anamnesis dirigida, e indicar las pruebas complementarias necesarias para el diagnóstico de esta enfermedad infradiagnosticada para su correcto manejo, tan determinante para la mejora de la calidad de vida de estos pacientes.

A multicenter, double-blind, placebo-controlled, randomized, Phase 1b crossover trial comparing two doses of ulotaront with placebo in the treatment of narcolepsy-cataplexy.

BACKGROUND: Ulotaront (SEP-363856) is a novel agonist at trace amine-associated receptor 1 and serotonin 5-HT1A receptors in clinical development for the treatment of schizophrenia. Previous studies demonstrated ulotaront suppresses rapid eye movement (REM) sleep in both rodents and healthy volunteers. We assessed acute and sustained treatments of ulotaront on REM sleep and symptoms of cataplexy and alertness in subjects with narcolepsy-cataplexy. METHODS: In a multicenter, double-blind, placebo-controlled, randomized, 3-way crossover study, ulotaront was evaluated in 16 adults with narcolepsy-cataplexy. Two oral doses of ulotaront (25 mg and 50 mg) were administered daily for 2 weeks and compared with matching placebo (6-treatment sequence, 3-period, 3-treatment). RESULTS: Acute treatment with both 25 mg and 50 mg of ulotaront reduced minutes spent in nighttime REM compared to placebo. A sustained 2-week administration of both doses of ulotaront reduced the mean number of short-onset REM periods (SOREMPs) during daytime multiple sleep latency test (MSLT) compared to placebo. Although cataplexy events decreased from the overall mean baseline during the 2-week treatment period, neither dose of ulotaront statistically separated from placebo (p = 0.76, 25 mg; p = 0.82, 50 mg), and no significant improvement in patient and clinician measures of sleepiness from baseline to end of the 2-week treatment period occurred in any treatment group. CONCLUSIONS: Acute and sustained treatment with ulotaront reduced nighttime REM duration and daytime SOREMPs, respectively. The effect of ulotaront on suppression of REM did not demonstrate a statistical or clinically meaningful effect in narcolepsy-cataplexy. REGISTRATION: ClinicalTrials.gov identifier: NCT05015673.

Progressive narcolepsy: how to deal with intermediate hypocretin-1 values?

According to the International Classification of Sleep Disorders, third edition guidelines, the diagnosis of narcolepsy type 1 is based on the association of excessive daytime sleepiness plus either cataplexy and electrophysiological criteria, or a cerebrospinal fluid hypocretin-1 concentration below 110 pg/mL. This threshold remains debated, and recent works have proposed alternative values in the intermediate (110 to 200 pg/mL) zone. We report the case of a patient who presented with typical clinical symptoms of narcolepsy type 1 developing over six years but in whom initial polysomnography and multiple sleep latency test were negative and cerebrospinal fluid hypocretin-1 was intermediate (132 pg/mL). Cerebrospinal fluid hypocretin-1 reassessment four years later found a dramatic decrease, < 50 pg/mL, and the multiple sleep latency test proved to be abnormal, eventually allowing to confirm the diagnosis. This case highlights the importance of reassessing patients with intermediate hypocretin-1 values and contributes to the debate on the determination of alternative cerebrospinal fluid hypocretin1 thresholds for narcolepsy type 1 diagnosis. CITATION: Ricordeau F, Bridoux A, Raverot V, Peter-Derex L. Progressive narcolepsy: how to deal with intermediate hypocretin-1 values? J Clin Sleep Med. 2023;19(7):1375-1378.

Narcolepsy secondary to anti-Ma2 encephalitis: two case reports.

Recent studies suggest that sleep disorders are present in two-thirds of patients with autoimmune encephalitis. In anti-Ma2 encephalitis, hypersomnia appears to be frequent. However, only few cases of type 1 narcolepsy have been reported to date with anti-Ma2 encephalitis. We report 2 new cases of patients with narcolepsy secondary to anti-Ma2 encephalitis. Patient 1, a 68-year-old man, had narcolepsy type 1, including sleep attacks, cataplexy, abnormal Multiple Sleep Latency Tests and hypocretin-1 deficiency (< 50 ng/L) in the cerebrospinal fluid (CSF), associated with a cerebellar syndrome. Anti-Ma2 antibodies were present in the serum and CSF and antivoltage-gated potassium channel antibodies in the serum. He benefited from a treatment with pitolisant. Patient 2, a 42-year-old man, had narcolepsy type 2, including hypersomnolence, no cataplexy, intermediate CSF levels of hypocretin-1 (138 ng/L), abnormal Multiple Sleep Latency Tests, and a limbic encephalitis presentation. Anti-Ma2 antibodies were present in the serum and CSF, and anti-Ma1 antibodies were in the CSF. For both, repeated polysomnographies were necessary to establish the precise diagnosis of central hypersomnia, emphasizing the importance of carrying out sleep investigations in a tertiary neurology center with sleep medicine expertise in patients with anti-Ma2 encephalitis. CITATION: Brunet de Courssou J-B, Testard P, Sallansonnet-Froment M, et al. Narcolepsy secondary to anti-Ma2 encephalitis: two case reports. J Clin Sleep Med. 2023;19(4):837-841.

Rapid eye movement sleep duration during the multiple sleep latency test to diagnose hypocretin-deficient narcolepsy.

STUDY OBJECTIVES: To assess the performances of alternative measures of the multiple sleep latency test (MSLT) to identify hypocretin-deficiency in patients with a complaint of hypersomnolence, including patients with narcolepsy. METHODS: MSLT parameters from 374 drug-free patients with hypersomnolence, with complete clinical and polysomnographic (PSG) assessment and cerebrospinal hypocretin-1 measurement were collected. Conventional (sleep latency, number of sleep onset REM-SOREM-periods) and alternative (sleep duration, REM sleep latency and duration, sleep stage transitions) MSLT measures were compared as function of hypocretin-1 levels (≤110 vs > 110 pg/mL). We performed receiver-operating characteristics analyses to determine the best thresholds of MSLT parameters to identify hypocretin-deficiency in the global population and in subgroups of patients with narcolepsy (i.e. typical cataplexy and/or positive PSG/MSLT criteria, n = 223). RESULTS: Patients with hypocretin-deficiency had shorter mean sleep and REM sleep latencies, longer mean sleep and REM sleep durations and more direct REM sleep transitions during the MSLT. The current standards of MSLT/PSG criteria identified hypocretin-deficient patients with a sensitivity of 0.87 and a specificity of 0.69, and 0.81/0.99 when combined with cataplexy. A mean REM sleep duration ≥ 4.1 min best identified hypocretin-deficiency in patients with hypersomnolence (AUC = 0.932, sensitivity 0.87, specificity 0.86) and ≥ 5.7 min in patients with narcolepsy (AUC = 0.832, sensitivity 0.77, specificity 0.82). CONCLUSION: Compared to the current neurophysiological standard criteria, alternative MSLT parameters would better identify hypocretin-deficiency among patients with hypersomnolence and those with narcolepsy. We highlighted daytime REM sleep duration as a relevant neurophysiological biomarker of hypocretin-deficiency to be used in clinical and research settings.

Anxiety and depression in patients with narcolepsy.

We analysed the co-existence of psychopathology in patients with narcolepsy at our centre. We performed an observational retrospective descriptive analysis of patients with a diagnosis of narcolepsy, with and without psychopathology, who attended our sleep disorders unit from October 2012 to October 2021. A total of 51patients with narcolepsy (mean [SD] age 41.10 [14.71] years; 23 [45.1%] males and 28 [54.90%] females) were included. In all, 27 patients (52.94%) and 24 patients (47.06%) had narcolepsy with and without cataplexy, respectively. Of the total, 18 (33.33%) had a mood disorder: 18 with anxiety disorder (33.33%). Of these patients 14 (27.45%) had major depression, two (4%) had attempted suicide, one (2%) had manic outbreak, and one (2%) had substance abuse. Of the 18 patients with anxiety and depression, 10 (55.55%) and eight (44.44%) had narcolepsy with and without cataplexy, respectively. In the comparative analysis, a statistically significant relationship was found between younger age and the presence of anxiety. The prevalence of anxiety and depression in patients with narcolepsy was triple that of the general population, especially in younger patients. Psychopathology precedes the diagnosis of narcolepsy in most patients, not being reactive to diagnosis. This high prevalence suggests a possible biological relationship between both disorders, which should be assessed with larger studies.

Estudio WAKE de vida real en pacientes con narcolepsia con cataplejía tratados con pitolisant no respondedores a tratamientos previos / Real-life WAKE study in narcolepsy patients with cataplexy treated with pitolisant and unresponsive to previous treatments

Introducción: La narcolepsia de tipo 1 es una enfermedad incapacitante que requiere tratamiento continuo, que no siempre es eficaz. El pitolisant es un nuevo fármaco con un mecanismo de acción diferente que ofrece una nueva opción de tratamiento. El objetivo del estudio fue analizar la efectividad y la seguridad del pitolisant en pacientes con narcolepsia de tipo 1 que no hubieran respondido o tolerado previamente los tratamientos habituales. Pacientes y métodos: Estudio observacional descriptivo multicéntrico de vida real que incluyó a pacientes diagnosticados de narcolepsia de tipo 1 no respondedores a tratamientos previos que iniciaron tratamiento con pitolisant. El estudio evaluó tres momentos: el inicio del tratamiento, la estabilización del tratamiento con pitolisant y los tres meses posteriores. Resultados: En 32 pacientes incluidos (media de edad, 44 años; 37,5% de mujeres), la media de la escala de somnolencia de Epworth se redujo de 17,1 a 13,5; un 47,8% de los pacientes mejoró subjetivamente de su cataplejía; un 65% de los pacientes mejoró su impresión clínica global a criterio médico y a criterio del paciente; y se redujo la media de medicamentos consumidos de 2,0 a 1,4. El efecto adverso más frecuente fue el insomnio, en un 43,8% de los pacientes. De los 32 pacientes, 23 mantuvieron el tratamiento durante los tres meses de seguimiento. Conclusiones: En pacientes con narcolepsia de tipo 1 que no responden a o no toleran los tratamientos disponibles, el pitolisant puede mejorar su situación clínica y reducir su consumo de medicamentos. Son necesarios estudios de mayor nivel de evidencia para confirmar estos resultados.(AU)

INTRODUCTION: Type 1 narcolepsy is a disabling disease that requires continuous treatment, which is not always effective. Pitolisant is a new drug with a different mechanism of action that offers a new treatment option. The objective of the study was to analyse the effectiveness and safety of pitolisant in patients with type 1 narcolepsy that did not respond to or tolerate previous standard treatments. PATIENTS AND METHODS: Real-life multicentre descriptive observational study that included patients diagnosed with type 1 narcolepsy who did not respond to or tolerate previous treatments and started treatment with pitolisant. The study evaluated three different moments: the start of treatment, the stabilization of treatment with pitolisant and the three months after. RESULTS: In 32 patients included (mean age, 44 years; 37.5% women) the mean of the Epworth Sleepiness Scale was reduced from 17.1 to 13.5; 47.8% of the patients improved from their cataplexy; 65% of the patients improved their clinical global impression at the physician’s and at the patient’s discretion and the mean number of medications consumed was reduced from 2.0 to 1.4. The most frequent adverse effect was insomnia in 43.8% of patients. Of the 32 patients, 23 continued with the treatment during the 3-month follow-up period. CONCLUSIONS: In patients with type I narcolepsy who do not respond to or do not tolerate the available treatments, pitolisant can improve their clinical situation and reduce their medication consumption. Studies with a higher level of evidence are needed to confirm these results.(AU)

Pfizer/BioNTech SARS-CoV-2 vaccine as a potential trigger for the development of narcolepsy: a case report.

Narcolepsy is a rare condition in Israel. Currently, the incidence of narcolepsy following SARS-CoV-2 vaccination in Israel is unknown. We are reporting a case report of a 51-year-old woman of Ashkenazi Jewish descent who was evaluated for complaints of excessive daytime sleepiness and relative functional decline that immediately followed receipt of the Pfizer/BioNTech SARS-CoV-2 vaccination. Evaluation of patient-reported data with polysomnography and multiple sleep latency test was consistent with narcolepsy with cataplexy, meeting the criteria for a diagnosis of type 1 narcolepsy. Further investigation included human leukocyte antigen testing. Prior studies have demonstrated genetic, immunological, and environmental factors associated with narcolepsy following other vaccinations. This case is a valuable contribution to the literature as there are no prior reports of type 1 narcolepsy following SARS-CoV-2 vaccination in the State of Israel. CITATION: Mahamid A, Bornstein RJ, Amir H. Pfizer/BioNTech SARS-CoV-2 vaccine as a potential trigger for the development of narcolepsy: a case report. J Clin Sleep Med. 2022;18(10):2503-2506.

Intermediate hypocretin-1 cerebrospinal fluid levels and typical cataplexy: their significance in the diagnosis of narcolepsy type 1.

STUDY OBJECTIVES: The diagnosis of narcolepsy type 1 (NT1) is based upon the presence of cataplexy and/or a cerebrospinal fluid (CSF) hypocretin-1/orexin-A level ≤ 110 pg/mL. We determined the clinical and diagnostic characteristics of patients with intermediate hypocretin-1 levels (111-200 pg/mL) and the diagnostic value of cataplexy characteristics in individuals with central disorders of hypersomnolence. METHODS: Retrospective cross-sectional study of 355 people with known CSF hypocretin-1 levels who visited specialized Sleep-Wake Centers in the Netherlands. For n = 271, we had full data on cataplexy type ("typical" or "atypical" cataplexy). RESULTS: Compared to those with normal hypocretin-1 levels (>200 pg/mL), a higher percentage of individuals with intermediate hypocretin-1 levels had typical cataplexy (75% or 12/16 vs 9% or 8/88, p < .05), and/or met the diagnostic polysomnographic (PSG) and Multiple Sleep Latency Test (MSLT) criteria for narcolepsy (50 vs 6%, p < .001). Of those with typical cataplexy, 88% had low, 7% intermediate, and 5% normal hypocretin-1 levels (p < .001). Atypical cataplexy was also associated with hypocretin deficiency but to a lesser extent. A hypocretin-1 cutoff of 150 pg/mL best predicted the presence of typical cataplexy and/or positive PSG and MSLT findings. CONCLUSION: Individuals with intermediate hypocretin-1 levels or typical cataplexy more often have outcomes fitting the PSG and MSLT criteria for narcolepsy than those with normal levels or atypical cataplexy. In addition, typical cataplexy has a much stronger association with hypocretin-1 deficiency than atypical cataplexy. We suggest increasing the NT1 diagnostic hypocretin-1 cutoff and adding the presence of clearly defined typical cataplexy to the diagnostic criteria of NT1. Clinical trial information: This study is not registered in a clinical trial register, as it has a retrospective database design.

Narcolepsy.

This article addresses the clinical presentation, diagnosis, pathophysiology and management of narcolepsy type 1 and 2, with a focus on recent findings. A low level of hypocretin-1/orexin-A in the cerebrospinal fluid is sufficient to diagnose narcolepsy type 1, being a highly specific and sensitive biomarker, and the irreversible loss of hypocretin neurons is responsible for the main symptoms of the disease: sleepiness, cataplexy, sleep-related hallucinations and paralysis, and disrupted nocturnal sleep. The process responsible for the destruction of hypocretin neurons is highly suspected to be autoimmune, or dysimmune. Over the last two decades, remarkable progress has been made for the understanding of these mechanisms that were made possible with the development of new techniques. Conversely, narcolepsy type 2 is a less well-defined disorder, with a variable phenotype and evolution, and few reliable biomarkers discovered so far. There is a dearth of knowledge about this disorder, and its aetiology remains unclear and needs to be further explored. Treatment of narcolepsy is still nowadays only symptomatic, targeting sleepiness, cataplexy and disrupted nocturnal sleep. However, new psychostimulants have been recently developed, and the upcoming arrival of non-peptide hypocretin receptor-2 agonists should be a revolution in the management of this rare sleep disease, and maybe also for disorders beyond narcolepsy.