Complex movement disorders at disease onset in childhood narcolepsy with cataplexy

"Oh My Sleeping Child" … Narcolepsy Type 1 in a 22-Month-Old Boy

Pediatric narcolepsy is a complex disorder with unique diagnostic challenges. It is diagnosed with a combination of clinical presentation, polysomnogram with multiple sleep latency test (PSG with MSLT), and occasionally, hypocretin-1 (orexin) levels in the cerebrospinal fluid (CSF). This report describes a 22-month-old boy experiencing excessive daytime sleepiness (EDS) and frequent falls. The patient was subsequently diagnosed with narcolepsy using hypocretin-1 (orexin) levels. The intent of this report is to establish the utility of using hypocretin-1 (orexin) levels to diagnose narcolepsy type 1 in children who are too young to undergo PSG with MSLT. To our knowledge, there are no reports of narcolepsy in a patient this young. Early recognition and treatment of narcolepsy in children younger than age five may lead to a substantial impact on their cognitive development and minimize potential long- term complications.

Clinical Evaluation and Management of Narcolepsy in Children and Adolescents

While sleepiness is common among children, and particularly adolescents, profound sleepiness in the setting of apparently adequate sleep should prompt consideration of a central disorder of hypersomnolence. These disorders, which include narcolepsy, idiopathic hypersomnia, Kleine-Levin syndrome, and others, are likely underrecognized in the pediatric population. Narcolepsy in particular should be of interest to child neurologists as the unique signs and symptoms of this disease often prompt evaluation in pediatric neurology clinics. While sleepiness may appear to be a straightforward complaint, its evaluation requires a nuanced approach. Cataplexy, a hallmark of narcolepsy, can be confused for other neurologic conditions, though understanding its various manifestations makes it readily identifiable. Clinicians should be aware of these symptoms, as delay in diagnosis and misdiagnosis are common in childhood narcolepsy. While treatment options have been limited in the past, many new therapeutic options have become available and can result in significant improvement in symptoms. Given the age at presentation, paroxysmal and chronic features, diagnostic modalities, and available treatment options, the field of child neurology is well equipped to see patients with narcolepsy. In this review, I will focus on the presentation, evaluation, and management of pediatric patients with narcolepsy.

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.

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.

Central Disorders of Hypersomnolence

OBJECTIVE

The goals of this article are to describe the clinical approach to and management of patients with central disorders of hypersomnolence, and to understand and differentiate available diagnostic tools.

LATEST DEVELOPMENTS

Updated clinical practice guidelines for the treatment of central disorders of hypersomnolence and narcolepsy specifically highlight new treatment options. Approval for a lower-sodium oxybate formulation that contains 92% less sodium than the standard sodium oxybate for the treatment of narcolepsy and idiopathic hypersomnia adds to the number of medications available for these disorders, allowing for a more tailored management of symptoms.

ESSENTIAL POINTS

Central disorders of hypersomnolence are characterized by excessive daytime sleepiness that impacts daily functions. These disorders can be differentiated by obtaining a detailed clinical sleep history and by a thoughtful interpretation of sleep diagnostic testing. Tailoring treatment approaches to meet the needs of individuals and accounting for medical and psychiatric comorbidities may improve quality of life.

Narcolepsy and Idiopathic Hypersomnia

Narcolepsy types 1 and 2 and idiopathic hypersomnia are primary Central Nervous System (CNS) disorders of hypersomnolence characterized by profound daytime sleepiness and/or excessive sleep need. Onset of symptoms begins typically in childhood or adolescence, and children can have unique presentations compared with adults. Narcolepsy type 1 is likely caused by immune-mediated loss of orexin (hypocretin) neurons in the hypothalamus; however, the causes of narcolepsy type 2 and idiopathic hypersomnia are unknown. Existing treatments improve daytime sleepiness and cataplexy but there is no cure for these disorders.

Real-world treatment of pediatric narcolepsy with pitolisant: A retrospective, multicenter study

BACKGROUND

First symptoms of narcolepsy mostly present during childhood. Pharmacological management options in children are limited, also due to approval status. Pitolisant is an inverse histamine 3 receptor agonist and has been approved for the treatment of adult narcolepsy with or without cataplexy by EMA and FDA. Clinical experience indicates for a beneficial use also in children and adolescents. Our goal was to evaluate the effects and tolerability of pitolisant in narcolepsy children/adolescents in a real-world setting.

METHODS

This multicentre retrospective observational study included 55 patients with narcolepsy from three international narcolepsy centers (Germany, France and Italy) who were treated with pitolisant. Patients were eligible if they were at least 6 years old and diagnosed with narcolepsy type 1 or 2. Demographic and clinical characteristics, questionnaires, sleep medicine and laboratory data were collected.

RESULTS

55 children/adolescents (25 girls, 45.45%, 30 boys, 54.55%) aged 6-18 years, with narcolepsy (type 1 = 92.7%, type 2 = 7.3%), were treated with pitolisant. The mean pitolisant dose was 34.1 mg/d. Treatment was effective for excessive daytime sleepiness (EDS) and cataplexy: the pediatric Epworth Sleepiness Scale (ESS) score decreased from 19 to 13.5 (p < 0.001) and the weekly cataplexy frequency improved from 7.9 at baseline to 5.2 (p < 0.001). Treatment with pitolisant was well tolerated. Side effects were mild and mostly short-term. Insomnia was reported most frequently (5.5%).

CONCLUSION

First real-world results suggest that pitolisant treatment is effective in improving EDS and cataplexy in children with narcolepsy, and also is well tolerated.

"Unvoluntary" Movement Disorders: Distinguishing between Tics, Akathisia, Restless Legs, and Stereotypies

Tics, stereotypies, akathisia, and restless legs fall at different places on the spectrum of discrete, unwanted and potentially disabling motor routines. Unlike tremor, chorea, myoclonus, or dystonia, this subgroup of abnormal movements is characterized by the subject's variable ability to inhibit or release undesired motor patterns on demand. Though it may be sometimes clinically challenging, it is crucial to distinguish these "unvoluntary" motor behaviors because secondary causes and management approaches differ substantially. To this end, physicians must consider the degree of repetitiveness of the movements, the existence of volitional control, and the association with sensory symptoms, or cognitive-ideational antecedent. This review aims to summarize the current existing knowledge on phenomenology, diagnosis, and treatment of tics, stereotypies, akathisia, and restless leg syndrome.

Sleep-Related Drug Therapy in Special Conditions: Children

Pharmacologic treatment of the most common pediatric sleep disorders lacks evidence, and alternative methods, which have been proved to alleviate the symptoms, are preferred in most cases. The implementation of specific guidelines is of great importance because sleep disorders in children are not rare and they can negatively affect children's development and their cognitive and social skills. This article summarizes the current therapeutic management of sleep disorders in children, bearing in mind the absence of evidence-based guidelines on this topic.

Narcolepsy in Children: Sleep disorders in children, A rapidly evolving field seeking consensus

Narcolepsy is a life-long sleep disorder with two distinct subtypes, narcolepsy type I and narcolepsy type II. It is now well recognized that the loss of hypocretin neurons underlies the pathogenesis of narcolepsy type I, however, the pathogenesis of narcolepsy type II is currently unknown. Both genetic and environmental factors play an important role in the pathogenesis of narcolepsy. There is increasing evidence that autoimmune processes may play a critical role in the loss of hypocretin neurons. Infections especially streptococcus and influenza have been proposed as a potential trigger for the autoimmune-mediated mechanism. Several recent studies have shown increased cases of pediatric narcolepsy following the 2009 H1N1 pandemic. The increased cases in Europe seem to be related to a specific type of H1N1 influenza vaccination (Pandemrix), while the increased cases in China are related to influenza infection. Children with narcolepsy can have an unusual presentation at disease onset including complex motor movements which may lead to delayed diagnosis. All classic narcolepsy tetrads are present in only a small proportion of children. The diagnosis of narcolepsy is confirmed by either obtaining cerebrospinal fluid hypocretin or overnight sleep study with the multiple sleep latency test (MSLT). There are limitations of using MSLT in young children such that a negative MSLT test cannot exclude narcolepsy. HLA markers have limited utility in narcolepsy, but it may be useful in young children with clinical suspicion of narcolepsy. For management, both pharmacologic and non-pharmacologic treatments are important in the management of narcolepsy. Pharmacotherapy is primarily aimed to address excessive daytime sleepiness and REM-related symptoms such as cataplexy. In addition to pharmacotherapy, routine screening of behavioral and psychosocial issues is warranted to identify patients who would benefit from bio-behavior intervention.

50th anniversary of the ESRS in 2022-JSR special issue

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.

Child Neurology: A Case Series of Heterogeneous Neuropsychiatric Symptoms and Outcome in Very Early-Onset Narcolepsy Type 1

Narcolepsy type 1 is a central disorder of hypersomnolence characterized by excessive daytime sleepiness, cataplexy (i.e., sudden loss of muscle tone during wakefulness triggered by emotions), and rapid eye movement sleep-related manifestations that can present with a peculiar phenotype when arising at a pediatric age. Several features of childhood-onset narcolepsy type 1 are also common in neuropsychiatric conditions; discrete neuropsychiatric comorbidity has also been demonstrated.Here we report on three children with very early narcolepsy type 1. All three patients had psychiatric features at time of symptom onset coupled with peculiar motor disturbances. The course of narcolepsy symptoms also paralleled neuropsychiatric symptoms, suggesting a possible intrinsic link between sleep and psychological features.Multidisciplinary management is mandatory for pediatric narcolepsy type 1 since prompt disease management addressing neuropsychiatric symptoms could lead to better clinical outcomes and quality of life.

Orexin/Hypocretin System Dysfunction in ESSENCE (Early Symptomatic Syndromes Eliciting Neurodevelopmental Clinical Examinations)

Early Symptomatic Syndromes Eliciting Neurodevelopmental Clinical Examinations (ESSENCE) is an umbrella term covering a wide range of neurodevelopmental difficulties and disorders. Thus, ESSENCE includes attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and other neurodevelopmental disorders (NDDs) and difficulties, with a variety of symptoms in cognitive, motor, sensory, social, arousal, regulatory, emotional, and behavioral developmental domains, frequently co-occurring and likely having partly common neurobiological substrates. The ESSENCE concept is a clinical paradigm that promotes organizing NDDs in everyday clinical practice according to their coexistence, symptom dimensions overlapping, and treatment possibilities. Despite increased knowledge regarding NDDs, the neurobiological mechanisms that underlie them and other ESSENCE-related problems, are not well understood. With its wide range of neural circuits and interactions with numerous neurotransmitters, the orexin/hypocretin system (Orx-S) is possibly associated with a variety of neurocognitive, psychobiological, neuroendocrine, and physiological functions and behaviors. Dysfunction of Orx-S has been implicated in various psychiatric and neurological disorders. This article provides an overview of Orx-S dysfunctions' possible involvement in the development, presentation, and maintenance of ESSENCE. We provide a focused review of current research evidence linking orexin neuropeptides with specific clinical NDDs symptoms, mostly in ADHD and ASD, within the Research Domain Criteria (RDoC) framework. We propose that Orx-S dysfunction might have an important role in some of these neurodevelopmental symptom domains, such as arousal, wakefulness, sleep, motor and sensory processing, mood and emotional regulation, fear processing, reward, feeding, attention, executive functions, and sociability. Our perspective is presented from a clinical point of view. Further, more thorough systematic reviews are needed as well as planning of extensive new research into the Orx-S's role in ESSENCE, especially considering RDoC elements.

Idling for Decades: A European Study on Risk Factors Associated with the Delay Before a Narcolepsy Diagnosis

PURPOSE

Narcolepsy type-1 (NT1) is a rare chronic neurological sleep disorder with excessive daytime sleepiness (EDS) as usual first and cataplexy as pathognomonic symptom. Shortening the NT1 diagnostic delay is the key to reduce disease burden and related low quality of life. Here we investigated the changes of diagnostic delay over the diagnostic years (1990-2018) and the factors associated with the delay in Europe.

PATIENTS AND METHODS

We analyzed 580 NT1 patients (male: 325, female: 255) from 12 European countries using the European Narcolepsy Network database. We combined machine learning and linear mixed-effect regression to identify factors associated with the delay.

RESULTS

The mean age at EDS onset and diagnosis of our patients was 20.9±11.8 (mean ± standard deviation) and 30.5±14.9 years old, respectively. Their mean and median diagnostic delay was 9.7±11.5 and 5.3 (interquartile range: 1.7-13.2 years) years, respectively. We did not find significant differences in the diagnostic delay over years in either the whole dataset or in individual countries, although the delay showed significant differences in various countries. The number of patients with short (≤2-year) and long (≥13-year) diagnostic delay equally increased over decades, suggesting that subgroups of NT1 patients with variable disease progression may co-exist. Younger age at cataplexy onset, longer interval between EDS and cataplexy onsets, lower cataplexy frequency, shorter duration of irresistible daytime sleep, lower daytime REM sleep propensity, and being female are associated with longer diagnostic delay.

CONCLUSION

Our findings contrast the results of previous studies reporting shorter delay over time which is confounded by calendar year, because they characterized the changes in diagnostic delay over the symptom onset year. Our study indicates that new strategies such as increasing media attention/awareness and developing new biomarkers are needed to better detect EDS, cataplexy, and changes of nocturnal sleep in narcolepsy, in order to shorten the diagnostic interval.

The Genetics of Sleep Disorders in Children: A Narrative Review

Sleep is a universal, highly preserved process, essential for human and animal life, whose complete functions are yet to be unravelled. Familial recurrence is acknowledged for some sleep disorders, but definite data are lacking for many of them. Genetic studies on sleep disorders have progressed from twin and family studies to candidate gene approaches to culminate in genome-wide association studies (GWAS). Several works disclosed that sleep-wake characteristics, in addition to electroencephalographic (EEG) sleep patterns, have a certain degree of heritability. Notwithstanding, it is rare for sleep disorders to be attributed to single gene defects because of the complexity of the brain network/pathways involved. Besides, the advancing insights in epigenetic gene-environment interactions add further complexity to understanding the genetic control of sleep and its disorders. This narrative review explores the current genetic knowledge in sleep disorders in children, following the International Classification of Sleep Disorders-Third Edition (ICSD-3) categorisation.

Hypothalamus and amygdala functional connectivity at rest in narcolepsy type 1

INTRODUCTION

functional and structural MRI studies suggest that the orexin (hypocretin) deficiency in the dorso-lateral hypothalamus of narcoleptic patients would influence both brain metabolism and perfusion and would cause reduction in cortical grey matter. Previous fMRI studies have mainly focused on cerebral functioning during emotional processing. The aim of the present study was to explore the hemodynamic behaviour of spontaneous BOLD fluctuation at rest in patients with Narcolepsy type 1 (NT1) close to disease onset.

METHODS

Fifteen drug naïve children/adolescents with NT1 (9 males; mean age 11.7 ± 3 years) and fifteen healthy children/adolescents (9 males; mean age 12.4 ± 2.8 years) participated in an EEG-fMRI study in order to investigate the resting-state functional connectivity of hypothalamus and amygdala. Functional images were acquired on a 3 T system. Seed-based functional connectivity analyses were performed using SPM12. Regions of Interest were the lateral hypothalamus and the amygdala.

RESULTS

compared to controls, NT1 patients showed decreased functional connectivity between the lateral hypothalamus and the left superior parietal lobule, the hippocampus and the parahippocampal gyrus. Decreased functional connectivity was detected between the amygdala and the post-central gyrus and several occipital regions, whereas it was increased between the amygdala and the inferior frontal gyrus, claustrum, insula, and putamen.

CONCLUSION

in NT1 patients the abnormal connectivity between the hypothalamus and brain regions involved in memory consolidation during sleep, such as the hippocampus, may be linked to the loss of orexin containing neurons in the dorsolateral hypothalamus. Moreover, also functional connectivity of the amygdala seems to be influenced by the loss of orexin-containing neurons. Therefore, we can hypothesize that dysfunctional interactions between regions subserving the maintenance of arousal, memory and emotional processing may contribute to the main symptom of narcolepsy.

Narcolepsy type 1 features across the life span: age impact on clinical and polysomnographic phenotype

STUDY OBJECTIVES

Narcolepsy type 1 (NT1) is a chronic neurological disorder typically arising during adolescence and young adulthood. Recent studies demonstrated that NT1 presents with age-specific features, especially in children. With this study we aimed to describe and to compare the clinical pictures of NT1 in different age groups.

METHODS

In this cross-sectional, multicenter study, 106 untreated patients with NT1 enrolled at the time of diagnosis underwent clinical evaluation, a semistructured interview (including the Epworth Sleepiness Scale), nocturnal video-polysomnography, and the Multiple Sleep Latency Test. Patients were enrolled in order to establish 5 age-balanced groups (childhood, adolescence, adulthood, middle age, and senior).

RESULTS

The Epworth Sleepiness Scale score showed a significant increase with age, while self-reported diurnal total sleep time was lower in older and young adults, with the latter also complaining of automatic behaviors in more than 90% of patients. Children reported the cataplexy attacks to be more frequent (> 1/d in 95% of patients). "Recalling an emotional event," "meeting someone unexpectedly," "stress," and "anger" were more frequently reported in adult and older adult patients as possible triggers of cataplexy. Neurophysiological data showed a higher number of sleep-onset rapid eye movement periods on the Multiple Sleep Latency Test in adolescent compared to senior patients and an age-progressive decline in sleep efficiency.

CONCLUSIONS

Daytime sleepiness, cataplexy features and triggers, and nocturnal sleep structure showed age-related difference in patients with NT1; this variability may contribute to diagnostic delay and misdiagnosis.

Narcolepsy and psychosis: A systematic review

OBJECTIVE

Narcolepsy is a rare sleep disorder in which psychotic-like symptoms can present diagnostic and therapeutic challenges. We aimed to review the association between, and medical management of, narcolepsy and psychosis in children and adults.

METHODS

We reviewed the full text of 100 papers from 187 identified by a PubMed search on narcolepsy plus any of these keywords: psychosis, schizophrenia, delusion, side effects, safety, and bipolar disorder.

RESULTS

Three relevant groups are described. (i) In typical narcolepsy, psychotic-like symptoms include predominantly visual hallucinations at the sleep-wake transition (experienced as "not real") and dissociation because of intrusion of rapid eye movement (REM) sleep phenomena into wakefulness. (ii) Atypical patients ("the psychotic form of narcolepsy") experience more severe and vivid, apparently REM-related hallucinations or dream/reality confusions, which patients may rationalize in a delusion-like way. (iii) Some patients have a comorbid schizophrenia spectrum disorder with psychotic symptoms unrelated to sleep. Psychostimulants used to treat narcolepsy may trigger psychotic symptoms in all three groups. We analyzed 58 published cases from groups 2 and 3 (n = 17 and 41). Features that were reported significantly more frequently in atypical patients include visual and multimodal hallucinations, sexual and mystical delusions, and false memories. Dual diagnosis patients had more disorganized symptoms and earlier onset of narcolepsy.

CONCLUSION

Epidemiological studies tentatively suggest a possible association between narcolepsy and schizophrenia only for very early-onset cases, which could be related to the partially overlapping neurodevelopmental changes observed in these disorders. We propose a clinical algorithm for the management of cases with psychotic-like or psychotic features.

CAT-CAD: A Computer-Aided Diagnosis Tool for Cataplexy

Narcolepsy with cataplexy is a severe lifelong disorder characterized, among others, by sudden loss of bilateral face muscle tone triggered by emotions (cataplexy). A recent approach for the diagnosis of the disease is based on a completely manual analysis of video recordings of patients undergoing emotional stimulation made on-site by medical specialists, looking for specific facial behavior motor phenomena. We present here the CAT-CAD tool for automatic detection of cataplexy symptoms, with the double aim of (1) supporting neurologists in the diagnosis/monitoring of the disease and (2) facilitating the experience of patients, allowing them to conduct video recordings at home. CAT-CAD includes a front-end medical interface (for the playback/inspection of patient recordings and the retrieval of videos relevant to the one currently played) and a back-end AI-based video analyzer (able to automatically detect the presence of disease symptoms in the patient recording). Analysis of patients’ videos for discovering disease symptoms is based on the detection of facial landmarks, and an alternative implementation of the video analyzer, exploiting deep-learning techniques, is introduced. Performance of both approaches is experimentally evaluated using a benchmark of real patients’ recordings, demonstrating the effectiveness of the proposed solutions.

The Impacts of Age and Sex in a Mouse Model of Childhood Narcolepsy

Narcolepsy is a sleep disorder caused by selective death of the orexin neurons that often begins in childhood. Orexin neuron loss disinhibits REM sleep during the active period and produces cataplexy, episodes of paralysis during wakefulness. Cataplexy is often worse when narcolepsy develops in children compared to adults, but the reason for this difference remains unknown. We used orexin-tTA; TetO DTA mice to model narcolepsy at different ages. When doxycycline is removed from the diet, the orexin neurons of these mice express diphtheria toxin A and die within 2-3 weeks. We removed doxycycline at 4 weeks (young-onset) or 14 weeks (adult-onset) of age in male and female mice. We implanted electroencephalography (EEG) and electromyography (EMG) electrodes for sleep recordings two weeks later and then recorded EEG/EMG/video for 24 h at 3 and 13 weeks after removal of doxycycline. Age-matched controls had access to doxycycline diet for the entire experiment. Three weeks after doxycycline removal, both young-onset and adult-onset mice developed severe cataplexy and the sleep-wake fragmentation characteristic of narcolepsy. Cataplexy and maintenance of wake were no worse in young-onset compared to adult-onset mice, but female mice had more bouts of cataplexy than males. Orexin neuron loss was similarly rapid in both young- and adult-onset mice. As age of orexin neuron loss does not impact the severity of narcolepsy symptoms in mice, the worse symptoms in children with narcolepsy may be due to more rapid orexin neuron loss than in adults.

Recognizing the Symptom Spectrum of Narcolepsy to Improve Timely Diagnosis: A Narrative Review

Narcolepsy is a chronic sleep disorder with a strong negative impact on quality of life, especially when untreated. Diagnostic delay is a persistent problem, with obvious detrimental effects on patients. A diagnosis of narcolepsy may be delayed because of its broad symptom presentation which is much more encompassing than the classical "tetrad" of sleepiness, cataplexy, hallucinations, and sleep paralysis. Furthermore, symptoms can vary over time. Presentation of symptoms can also be markedly different between children and adults. Finally, common sleep-related comorbidities increase the risk of narcolepsy being masked by overlapping symptoms or treatment. In this review, we provide a detailed description of the broad and dynamic symptom spectrum of narcolepsy, with specific attention to the different manifestations in both adults and children. The overarching goal is to help not only sleep specialists, but general practitioners, pediatricians, and other caregivers with early recognition and prompt diagnosis of this severe but treatable disorder.

Sleep disorders and the hypothalamus

As early as the 1920s, pathological studies of encephalitis lethargica allowed Von Economo to correctly identify hypothalamic damage as crucial for the profound associated sleep-related symptoms that helped define the condition. Only over the last 3 decades, however, has the key role of the hypothalamus in sleep-wake regulation become increasingly recognized. As a consequence, a close relation between abnormal sleep symptomatology and hypothalamic pathology is now widely accepted for a variety of medical disorders. Narcolepsy is discussed in some detail as the cardinal primary sleep disorder that is caused directly and specifically by hypothalamic pathology, most notably destruction of hypocretin (orexin)-containing neurons. Thereafter, various conditions are described that most likely result from hypothalamic damage, in part at least, producing a clinical picture resembling (symptomatic) narcolepsy. Kleine-Levin syndrome is a rare primary sleep disorder with intermittent symptoms, highly suggestive of hypothalamic involvement but probably reflecting a wider pathophysiology. ROHHAD (rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation) and Prader-Willi syndrome are also covered as hypothalamic syndromes with prominent sleep-related symptoms. Finally, sleep issues in several endocrine disorders are briefly discussed.

Early detection of Niemann-pick disease type C with cataplexy and orexin levels: continuous observation with and without Miglustat

Study objectives

Niemann-Pick type C (NPC) is an autosomal recessive and congenital neurological disorder characterized by the accumulation of cholesterol and glycosphingolipids. Symptoms include hepatosplenomegaly, vertical supranuclear saccadic palsy, ataxia, dystonia, and dementia. Some cases frequently display narcolepsy-like symptoms, including cataplexy which was reported in 26% of all NPC patients and was more often recorded among late-infantile onset (50%) and juvenile onset (38%) patients. In this current study, we examined CSF orexin levels in the 10 patients of NPC with and without cataplexy, which supports previous findings.

Methods

Ten patients with NPC were included in the study (5 males and 5 females). NPC diagnosis was biochemically confirmed in all 10 patients, from which 8 patients with NPC1 gene were identified. We compared CSF orexin levels among NPC, narcoleptic and idiopathic hypersomnia patients.

Results

Six NPC patients with cataplexy had low or intermediate orexin levels. In 4 cases without cataplexy, their orexin levels were normal. In 5 cases with Miglustat treatment, their symptoms stabilized or improved. For cases without Miglustat treatment, their conditions worsened generally. The CSF orexin levels of NPC patients were significantly higher than those of patients with narcolepsy-cataplexy and lower than those of patients with idiopathic hypersomnia, which was considered as the control group with normal CSF orexin levels.

Discussion

Our study indicates that orexin level measurements can be an early alert of potential NPC. Low or intermediate orexin levels could further decrease due to reduction in the neuronal function in the orexin system, accelerating the patients’ NPC pathophysiology. However with Miglustat treatment, the orexin levels stabilized or improved, along with other general symptoms. Although the circuitry is unclear, this supports that orexin system is indeed involved in narcolepsy-cataplexy in NPC patients.

Conclusion

The NPC patients with cataplexy had low or intermediate orexin levels. In the cases without cataplexy, their orexin levels were normal. Our study suggests that orexin measurements can serve as an early alert for potential NPC; furthermore, they could be a marker of therapy monitoring during a treatment.

Can a Peer Support the Process of Self-Management in Narcolepsy? A Qualitative Narrative Analysis of a Narcoleptic Patient

INTRODUCTION

Narcolepsy type 1 (NT1) is a chronic and rare sleep disorder typically arising during adolescence and young adulthood. The main symptoms are excessive daytime sleepiness and cataplexy, a prototypical fall down elicited by huge emotions. Social relationships, school, work, and general health perception are frequently impaired in patients, who often show lower quality-of-life scores. We report which management strategies a young patient (DMG) adopted to cope with NT1 during his growth, avoiding exhibiting serious impairments to his global functioning.

METHODS

A clinical psychologist explores the history of the patient's disease and the self-acquired strategies used to cope with the symptoms. The patient's global adaptation to the disease, stress-related managing skills, and overall well-being are assessed by standardized scales [Illness Behavior Questionnaire (IBQ); Coping Orientations to Problems Experienced (COPE); and Psychological General Well-Being Index (PGWBI)]. We conducted a qualitative analysis of the patient's narration of his illness according to the procedure of the Grounded Theory. The MAXQDA software program was used to code the verbatim transcript.

RESULTS

From the qualitative analysis of the interview, three thematic cores emerged: 1) the disease history; 2) the patient's friendship with AD, a friend of his age diagnosed with NT1 since childhood; 3) the strategies used to deal with his symptoms before the diagnosis of NT1 and the related treatment. From the psychometric tests, the patient presents good coping strategies in dealing with stressful problems and events based mainly on acceptance and positive reinterpretation of the stressful situation.

CONCLUSION

This case shows that comparing peers of the same age and suffering from the same illness improve the patient's self-management ability to cope and live well with NT1.

Giving a voice to cataplectic experience: recollections from patients with narcolepsy type 1

STUDY OBJECTIVES

The objective of this study was to assess the narratives from the recalled accounts of cataplexy attacks of patients with narcolepsy type 1 (NT1).

METHODS

Twenty-two drug-naive adult patients meeting the International Classification of Sleep Disorders criteria for the diagnosis of NT1 referring to the Narcolepsy Center of the University of Bologna in the year 2017 underwent a semistructured interview focusing on their personal experiences during the cataplectic attacks. Verbatim transcripts were analyzed by thematic analysis of elementary contexts using T-LAB software.

RESULTS

The thematic analysis performed on the entire body text showed 3 clusters that explained 36.2%, 34.1%, and 29.7% of the variance, respectively: a cluster related to situations that trigger attacks of cataplexy, a cluster to bodily sensations, and another control strategies during episodes. The thematic content highlighted a tendency to disregard emotional experiences, thus affecting the ability to name, recognize, and regulate critical emotions.

CONCLUSIONS

The study showed that patients with NT1 spoke of their cataplectic attacks in terms of self-reported bodily experiences, trigger situations, and their management. Therefore, patients may have developed strategies of symptom management focused on emotion avoidance and/or inhibition.

Therapy for Cataplexy

Purpose of the review

Cataplexy, an involuntary loss of muscle activity triggered by strong emotions is the most impressive symptom in narcolepsy. This review gives an overview of the current understanding of cataplexy and its available treatment options.

Recent findings

With the discovery of hypocretin/orexin, the understanding of the pathophysiology of cataplexy advanced in the past decades. In the recent years, with the development of new anticataplectic agents (e.g., Pitolisant) symptomatic treatment of cataplexy has further improved. Abrupt cessation of anticataplectic medication especially antidepressants increase the risk of status cataplecticus, a virtually continuous series of long-lasting cataplectic attacks.

Summary

Cataplexies still remain an under-recognized phenomenon due to missing diagnostic measures. Treatment for cataplexy still remains symptomatic but new agents with better tolerability and usability are continuously developed. New therapeutic actions either targeting the autoimmune mechanisms underlying orexin cell death or substituting orexin action are promising treatments for the near future.

Sleep and neurological autoimmune diseases

Neurological autoimmune diseases are characterized by an inappropriate immune response that by mistake targets the nervous system. As a result, patients experiment a number of neurological manifestations that may include insomnia, excessive daytime sleepiness, cataplexy, central hypoventilation, and REM sleep behavior disorder. Polysomnographic evaluation may reveal disorganized sleep architecture involving both NREM and REM sleep, and REM sleep intrusions into wakefulness. The study of sleep disorders in the setting of autoimmune diseases (e.g., narcolepsy, anti-IgLON5 disease, paraneoplastic neurological syndromes) shows that an abnormal immune-mediated (humoral or cellular) response target the neuronal structures (e.g., brainstem, hypothalamus) and neurotransmitters systems (e.g., hypocretin) that regulate sleep resulting in sleep impairment. It is a window to examine the link between the autoimmune system and the sleep regulation at the molecular, cellular, and anatomic level.

Late Diagnosis of Narcolepsy With Cataplexy: A Novel Case of Cataplectic Facies Presenting in an Elderly Woman

None

Cataplectic facies is an unusual feature described in children with narcolepsy and cataplexy. The typical manifestations of cataplectic facies consist of repetitive mouth opening, tongue protrusion, and ptosis. An interesting observation is that the usual emotional triggers associated with cataplexy such as laughter and joking are not always present, thus hampering diagnosis of the underlying syndrome. Cataplectic facies is thought to be a phenomenon observed in the early stages of narcolepsy type 1 and is thought to disappear by the time the patient reaches puberty. We present a unique case of an elderly woman with narcolepsy type 1 demonstrating cataplectic facies. The novel circumstances of this case highlight that facial cataplexy can present later in life, in contrast with previous descriptions that report resolution of cataplectic facies before puberty. Wider recognition of these features throughout the life course may aid in accurate diagnosis and thereby ensure swift access to appropriate treatment.

Validation of Multiple Sleep Latency Test for the diagnosis of pediatric narcolepsy type 1

Objective

To validate polysomnographic markers (sleep latency and sleep-onset REM periods [SOREMPs] at the Multiple Sleep Latency Test [MSLT] and nocturnal polysomnography [PSG]) for pediatric narcolepsy type 1 (NT1) against CSF hypocretin-1 (hcrt-1) deficiency and presence of cataplexy, as no criteria are currently validated in children.

Methods

Clinical, neurophysiologic, and, when available, biological data (HLA-DQB1*06:02 positivity, CSF hcrt-1 levels) of 357 consecutive children below 18 years of age evaluated for suspected narcolepsy were collected. Best MSLT cutoffs were obtained by receiver operating characteristic (ROC) curve analysis by contrasting among patients with available CSF hcrt-1 assay (n = 228) with vs without CSF hcrt-1 deficiency, and further validated in patients without available CSF hcrt-1 against cataplexy (n = 129).

Results

Patients with CSF hcrt-1 deficiency were best recognized using a mean MSLT sleep latency ≤8.2 minutes (area under the ROC curve of 0.985), or by at least 2 SOREMPs at the MSLT (area under the ROC curve of 0.975), or the combined PSG + MSLT (area under the ROC curve of 0.977). Although specificity and sensitivity of reference MSLT sleep latency ≤8 minutes and ≥2 SOREMPs (nocturnal SOREMP included) was 100% and 94.87%, the combination of MSLT sleep latency and SOREMP counts did not improve diagnostic accuracy. Age or sex also did not significantly influence these results in our pediatric population.

Conclusions

At least 2 SOREMPs or a mean sleep latency ≤8.2 minutes at the MSLT are valid and reliable markers for pediatric NT1 diagnosis, a result contrasting with adult NT1 criteria.

Classification of evidence

This study provides Class III evidence that for children with suspected narcolepsy, polysomnographic and MSLT markers accurately identify those with narcolepsy type 1.

Clinical neurophysiology of CNS hypersomnias

Central nervous system hypersomnias (narcolepsy type 1 and type 2, idiopathic hypersomnia, and Kleine-Levin syndrome) are orphan sleep disorders in which the predominant symptom is excessive daytime sleepiness. The evaluation of sleepiness requires rigorous clinical and neurophysiologic approaches that may include the Epworth Sleepiness Scale, multiple sleep latency tests, and the maintenance of wakefulness test. However, to date, no gold standard measurement of excessive sleepiness exists, and there are no quantifiable biologic markers. The main pathophysiologic feature of central hypersomnias is thought to reflect a deficiency of arousal systems, rather than an overactivity of sleep systems or an imbalance between those systems. Impaired neurotransmission of hypocretin/orexin (neuropeptides of the lateral hypothalamus) is involved in the neurobiology of narcolepsy with cataplexy (NT1). NT1 is a well-characterized disorder, due to the destruction of hypocretin/orexin neurons by a probable autoimmune process. The biologic hallmarks of the other central hypersomnias remain unknown, and neurophysiologic biomarkers are still of major importance for the diagnosis and characterization of those disorders.

The clinical characteristics of cataplectic attack in narcolepsy type 1

OBJECTIVE

Cataplexy is a pathognomonic symptom of narcolepsy type 1. This study was conducted to clarify the clinical characteristics of cataplexy by staging, and to further analyse the correlations of clinical features and cataplectic stages in patients with narcolepsy type 1 (NT1).

METHODS

We experimentally triggered patients with NT1 into cataplexy while under video-polysomnography (v-PSG) monitoring in the sleep lab. The most serious cataplectic attack from each patient was analysed. Each cataplectic episode was segmented into four stages according to the v-PSG. Correlations were analysed between cataplectic stages in pairs, and between cataplectic stages and other clinical features.

RESULTS

We observed 81 cataplectic episodes in 21 patients with diverse triggers, including humorous or exciting videos, tickling, recalling horrible memories and exercising. Nine patients (43%) went through complete cataplectic attacks while the others experienced partial attacks. Four cataplectic stages (ie, triggering, resisting, atonic, and recovering) were identified according to clinical and electromyograms characteristics. Resisting stage is predominant (56.4%) in cataplexy, while atonic stage is most related with the total duration of cataplexy. The Epworth Sleepiness Scale score (ESS) has a positive correlation with the total duration of cataplexy. Both duration of cataplexy and ESS score are negatively correlated with disease course. However, medication history seems have no influence on either cataplexy duration or ESS score.

CONCLUSION

Four-stage segmentation shows the dynamic process of the cataplectic attack, which is different from the traditional classification of complete or partial cataplexy. Resisting stage is necessary for every cataplexy and might reflect the compensation mechanism, while atonic stage may be omitted in some patients. The severity of narcolepsy reduces with the extension of natural course regardless of medication history.

Fluctuation of primary motor cortex excitability during cataplexy in narcolepsy

Objective

Cataplexy is a complicated and dynamic process in narcolepsy type 1 (NT1) patients. This study aimed to clarify the distinct stages during a cataplectic attack and identify the changes of the primary motor cortex (PMC) excitability during these stages.

Methods

Thirty-five patients with NT1 and 29 healthy controls were recruited to this study. Cataplectic stages were distinguished from a cataplectic attack by video-polysomnogram monitoring. Transcranial magnetic stimulation motor-evoked potential (TMS-MEP) was performed to measure the excitability of PMC during quiet wakefulness, laughter without cataplexy, and each cataplectic stage.

Results

Based on the video and electromyogram observations, a typical cataplectic attack (CA) process is divided into four stages: triggering (CA1), resisting (CA2), atonic (CA3), and recovering stages (CA4). Compared with healthy controls, NT1 patients showed significantly decreased intracortical facilitation during quiet wakefulness. During the laughter stage, both patients and controls showed increased MEP amplitude compared with quiet wakefulness. The MEP amplitude significantly increased even higher in CA1 and 2, and then dramatically decreased in CA3 accompanied with prolonged MEP latency compared with the laughter stage and quiet wakefulness. The MEP amplitude and latency gradually recovered during CA4.

Interpretation

This study identifies four stages during cataplectic attack and reveals the existence of a resisting stage that might change the process of cataplexy. The fluctuation of MEP amplitude and MEP latency shows a potential participation of PMC and motor control pathway during cataplexy, and the increased MEP amplitude during CA1 and 2 strongly implies a compensatory mechanism in motor control that may resist or avoid cataplectic attack.

The neurobiological basis of narcolepsy

Narcolepsy is the most common neurological cause of chronic sleepiness. The discovery about 20 years ago that narcolepsy is caused by selective loss of the neurons producing orexins (also known as hypocretins) sparked great advances in the field. Here, we review the current understanding of how orexin neurons regulate sleep-wake behaviour and the consequences of the loss of orexin neurons. We also summarize the developing evidence that narcolepsy is an autoimmune disorder that may be caused by a T cell-mediated attack on the orexin neurons and explain how these new perspectives can inform better therapeutic approaches.

The neuronal network of laughing in young patients with untreated narcolepsy

OBJECTIVE

To investigate the neuronal correlates of spontaneous laughter in drug-naive pediatric patients with narcolepsy type I (NT1) compared to healthy controls by means of blood oxygen level-dependent (BOLD) MRI.

METHODS

Twenty-one children/adolescents with recent onset of NT1 and 21 age- and sex-matched healthy controls were studied with fMRI while viewing funny videos using a naturalistic paradigm. Whole-brain hemodynamic correlates of spontaneous laughter were investigated in each group and compared by use of appropriate second-level general linear model analyses. If recorded, cataplexy events were treated as the effect of no interest at the single-participant level. Correlations analyses between these contrasts and behavioral findings were performed.

RESULTS

Emotion-induced laughter occurred in 16 patients (294 events) and 21 controls (357 events). In controls, laughter-related BOLD increases involved a widespread cortical and subcortical network including the bilateral motor and premotor areas, cingulated cortex, insula, and amygdala. In NT1, laughter induced BOLD signal increments in the motor cortex, right thalamus, and left subthalamic nucleus/zona incerta (STN/ZI). STN/ZI and thalamic changes were significantly higher during fMRI sessions with laughter without cataplexy compared to sessions in which laughter was associated with cataplexy.

CONCLUSION

Laughter expression in individuals with NT1 involves different brain circuits compared to controls by means of overactivation of cortical and subcortical regions belonging to the volitional control of laughter. The activation of the STN/ZI region observed predominantly in patients with NT1 during laugh episodes without cataplexy suggests that the ZI could act to prevent cataplexy.

A 10-Year Longitudinal Observational Study Of Cataplexy In A Cohort Of Narcolepsy Type 1 Patients

PURPOSE

Narcolepsy type 1 (NT1) is thought to have a chronic persistent course. This study aimed to assess the natural course of cataplexy in patients with NT1 at 2, 6, and 10 years after stabilizing symptoms. Other secondary objectives included assessing sleep quality, body mass index (BMI), and comorbidities at recruitment and 10 years later.

PATIENTS AND METHODS

Cataplexy symptoms, the Epworth sleepiness scale (ESS), sleep quality (assessed using the Pittsburgh sleep quality index [PSQI]), BMI, and comorbid conditions were prospectively monitored in 38 patients with NT1. The study sample comprised 38 patients with narcolepsy (males=27). The mean ages at disease onset and recruitment were 17.7 ± 5.6 years and 24.3 ± 8.6 years, respectively.

RESULTS

In 42% of the cohort, the anti-cataplectic medications were stopped at the end of the study without disturbing symptoms of cataplexy. Additionally, there was an apparent significant reduction in the frequency of cataplexy over time. The mean ESS score decreased by more than 4 points from 19.4 ± 2.9 to 15 ± 4.3 (p<0.001) while on the same pharmacotherapy. The number of patients with a PSQI score of <5 (indicating good sleep quality) increased from 6 (15.8%) to 15 (39.5%) (p=0.004). The BMI increased from 30 ± 5.1 to 33.3 ± 6 kg/m² (p=0.001). No changes were documented in comorbidities.

CONCLUSION

The findings suggest that the course of NT1 is not stable. Over a 10-year period, cataplexy symptoms improved or disappeared in a large proportion of patients, and there was an improvement in daytime sleepiness and nighttime sleep quality. More prospective studies that repeatedly monitor CSF-HCRT are needed to confirm the current findings.

Red Flags for early referral of people with symptoms suggestive of narcolepsy: a report from a national multidisciplinary panel

OBJECTIVE

Narcolepsy is a lifelong disease, manifesting with excessive daytime sleepiness and cataplexy, arising between childhood and young adulthood. The diagnosis is typically made after a long delay that burdens the disease severity. The aim of the project, promoted by the "Associazione Italiana Narcolettici e Ipersonni" is to develop Red Flags to detect symptoms for early referral, targeting non-sleep medicine specialists, general practitioners, and pediatricians.

MATERIALS AND METHODS

A multidisciplinary panel, including patients, public institutions, and representatives of national scientific societies of specialties possibly involved in the diagnostic process of suspected narcolepsy, was convened. The project was accomplished in three phases. Phase 1: Sleep experts shaped clinical pictures of narcolepsy in pediatric and adult patients. On the basis of these pictures, Red Flags were drafted. Phase 2: Representatives of the scientific societies and patients filled in a form to identify barriers to the diagnosis of narcolepsy. Phase 3: The panel produced suggestions for the implementation of Red Flags.

RESULTS

Red Flags were produced representing three clinical pictures of narcolepsy in pediatric patients ((1) usual sleep symptoms, (2) unusual sleep symptoms, (3) endocrinological signs) and two in adult patients ((1) usual sleep symptoms, (2) unusual sleep symptoms). Inadequate knowledge of symptoms at onset by medical doctors turned out to be the main reported barrier to diagnosis.

CONCLUSIONS

This report will hopefully enhance knowledge and awareness of narcolepsy among non-specialists in sleep medicine in order to reduce the diagnostic delay that burdens patients in Italy. Similar initiatives could be promoted across Europe.

Impaired histaminergic neurotransmission in children with narcolepsy type 1

OBJECTIVE

Narcolepsy is a sleep disorder characterized in humans by excessive daytime sleepiness and cataplexy. Greater than fifty percent of narcoleptic patients have an onset of symptoms prior to the age of 18. Current general agreement considers the loss of hypothalamic hypocretin (orexin) neurons as the direct cause of narcolepsy notably cataplexy. To assess whether brain histamine (HA) is also involved, we quantified the cerebrospinal fluid (CSF) levels of HA and tele-methylhistamine (t-MeHA), the direct metabolite of HA between children with orexin-deficient narcolepsy type 1 (NT1) and controls.

METHODS

We included 24 children with NT1 (12.3 ± 3.6 years, 11 boys, 83% cataplexy, 100% HLA DQB1*06:02) and 21 control children (11.2 ± 4.2 years, 10 boys). CSF HA and t-MeHA were measured in all subjects using a highly sensitive liquid chromatographic-electrospray/tandem mass spectrometric assay. CSF hypocretin-1 values were determined in the narcoleptic patients.

RESULTS

Compared with the controls, NT1 children had higher CSF HA levels (771 vs 234 pmol/L, P < 0.001), lower t-MeHA levels (879 vs 1924 pmol/L, P < 0.001), and lower t-MeHA/HA ratios (1.1 vs 8.2, P < 0.001). NT1 patients had higher BMI z-scores (2.7 ± 1.6 vs 1.0 ± 2.3, P = 0.006) and were more often obese (58% vs 29%, P = 0.05) than the controls. Multivariable analyses including age, gender, and BMI z-score showed a significant decrease in CSF HA levels when the BMI z-score increased in patients (P = 0.007) but not in the controls. No association was found between CSF HA, t-MeHA, disease duration, age at disease onset, the presence of cataplexy, lumbar puncture timing, and CSF hypocretin levels.

CONCLUSIONS

Narcolepsy type 1 children had a higher CSF HA level together with a lower t-MeHA level leading to a significant decrease in the t-MeHA/HA ratios. These results suggest a decreased HA turnover and an impairment of histaminergic neurotransmission in narcoleptic children and support the use of a histaminergic therapy in the treatment against narcolepsy.

Sleep-Related Drug Therapy in Special Conditions: Children

Sleep disorders in children may lead to neurodevelopmental and neurocognitive deficits; it is important to diagnose and treat them properly. Apart from the existing challenges in diagnosis, another drawback is that few therapies are currently approved. In this article, a comprehensive summary of the most common pediatric sleep disorders, along with the various pharmacologic and nonpharmacologic approaches for their management, is presented. Special attention has been paid to the currently available treatment options for pediatric insomnia, obstructive sleep apnea, parasomnias, narcolepsy, and restless legs syndrome, and comparisons are made with the corresponding treatment options for sleep disorders in adults.

Automatic detection of cataplexy

OBJECTIVE

Although being the most specific symptom of narcolepsy type 1 (NT1), cataplexy is currently investigated by clinical interview only, with potential diagnostic pitfalls. Our study aimed at testing the accuracy of an automatic video detection of cataplexy in NT1 patients vs. non-cataplectic subjects undergoing a standardized test with emotional stimulation.

METHODS

Fifteen drug-naive NT1 patients and 15 age- and sex-balanced non-cataplectic subjects underwent a standardized video recording procedure including emotional stimulation causing laughter. Video recordings were visually inspected by human scorers to detect three typical cataplexy facial motor patterns (ptosis, mouth opening and head drop), and then analysed by SHIATSU (Semantic-based HIearchical Automatic Tagging of videos by Segmentation using cUts). Expert-based and automatic attack detection was compared in NT1 patients and non-cataplectic subjects.

RESULTS

All NT1 patients and none of the non-cataplectic subjects displayed cataplexy during emotional stimulation. Automatic detection correlated well with experts' assessments in NT1 with an overall accuracy of 81%. In non-cataplectic subjects, automatic detection falsely identified cataplexy in two out of 15 (13.3%) subjects who showed active eyes closure during intense laughter as a confounder with ptosis.

CONCLUSIONS

Automatic cataplexy detection by applying SHIATSU to a standardized test for video documentation of cataplexy is feasible, with an overall accuracy of 81% compared to human examiners. Further studies are warranted to enlarge the range of elementary motor patterns detected, analyse their temporal/spatial relations and quantify cataplexy for diagnostic purposes.

A retrospective analysis of clinical characteristics of childhood narcolepsy

AIM

Narcolepsy, encompassing excessive daytime sleepiness (EDS), cataplexy, sleep paralysis and hypnogogic hallucinations, was previously considered rare in childhood. Recently, cases of childhood narcolepsy have increased significantly and the reasons for this may include the increasing awareness of narcolepsy as well as the H1N1 vaccination. The aim of this study was to describe the clinical characteristics of childhood narcolepsy, specifically focusing on cataplexy subtypes that may facilitate early recognition of narcolepsy.

METHODS

We retrospectively reviewed and analyzed the medical records of 33 children diagnosed with narcolepsy at the Hospital for Sick Children, in Toronto, Ontario. All patients were seen prior to 18 years of age and symptoms were self-reported by parents and/or children themselves.

RESULTS

At presentation, 32 of 33 children reported EDS and 28 of 33 reported cataplexy. Among the 28 patients with cataplexy, 18 of 28 reported cataplexy referred to as 'cataplectic facies' (e.g., facial hypotonia and/or tongue protrusion) while 10 of 28 patients reported characteristic cataplexy, defined as bilateral loss of muscle tone. Children with cataplectic facies reported higher BMI z-scores compared to those with characteristic cataplexy, 1.8 and 0.8, respectively. Children with cataplectic facies also tended to be younger than those with characteristic cataplexy, 9.2 and 11.8 years of age, respectively. Cataplectic facies appear to be related to narcolepsy close to disease onset.

CONCLUSIONS

Children, especially young, obese children, presenting with a history of EDS with associated facial hypotonia or tongue protrusion raises the index of suspicion of narcolepsy and should prompt a referral to a specialized sleep facility to establish the diagnosis.