Narcolepsy in Children and Adults: A Guide to Improved Recognition, Diagnosis and Management

Challenges in the Management of Narcolepsy in a Resource Limited Setting: A Case Report

The management of Narcolepsy, from the initial presentation to the long-term management and follow-up, remains a challenging endeavor, especially in developing climes. Worldwide, it has been recognized as a medical condition that is frequently associated with initial misdiagnoses, and delays in definitive management, further highlighted, in resource-limited settings like Nigeria where issues are further compounded by social, cultural, and political factors. In this report, we aim to shed some light on the peculiar challenges encountered by clinicians in Nigeria, and in other similar settings, in the process of diagnosis and management of narcolepsy. We present a case of a 17-year-old male teenager with Narcolepsy Type 1 (NT1) who had been previously managed as a case of Juvenile Absence Epilepsy in various centers prior to presentation at our facility. The symptoms began two years prior to presentation at our outpatient clinic, and they were excessive daytime sleepiness, cataplexy, and sleep paralysis. The symptoms were corroborated by laboratory parameters - reduced mean sleep latency (conducted in an improvised sleep laboratory), and a low cerebrospinal fluid (CSF) hypocretin level. The patient was initially placed on Modafinil for excessive daytime sleepiness and a trial of Fluoxetine for the Cataplexy. However, due to the scarcity of Modafinil, behavioral modifications - scheduled sleep naps and sleep hygiene - were eventually employed. Narcolepsy is a debilitating illness, and consequently, the far-reaching effects of these challenges must be understood. It is important that concerted efforts be made towards improving the overall quality of care received by patients from the early identification to the treatment of narcolepsy in the Nigerian healthcare system.

Sleep Stage Transitions and Sleep-Dependent Memory Consolidation in Children with Narcolepsy-Cataplexy

Electroencephalographic sleep stage transitions and altered first REM sleep period transitions have been identified as biomarkers of type 1 narcolepsy in adults, but not in children. Studies on memory complaints in narcolepsy have not yet investigated sleep-dependent memory consolidation. We aimed to explore stage transitions; more specifically altered REM sleep transition and its relationship with sleep-dependent memory consolidation in children with narcolepsy. Twenty-one children with narcolepsy-cataplexy and twenty-three healthy control children completed overnight polysomnography and sleep-dependent memory consolidation tests. Overnight transition rates (number of transitions per hour), global relative transition frequencies (number of transitions between a stage and all other stages/total number of transitions × 100), overnight transitions to REM sleep (transition from a given stage to REM/total REM transitions × 100), and altered first REM sleep period transitions (transitions from wake or N1 to the first REM period) were computed. Narcoleptic children had a significantly higher overnight transition rate with a higher global relative transition frequencies to wake. A lower sleep-dependent memory consolidation score found in children with narcolepsy was associated with a higher overnight transition frequency. As observed in narcoleptic adults, 90.48% of narcoleptic children exhibited an altered first REM sleep transition. As in adults, the altered sleep stage transition is also present in children with narcolepsy-cataplexy, and a higher transition rate could have an impact on sleep-dependent memory consolidation. These potential biomarkers could help diagnose type 1 narcolepsy in children more quickly; however, further studies with larger cohorts, including of those with type 2 narcolepsy and hypersomnia, are needed.

Pediatric sleep: current knowledge, gaps, and opportunities for the future

This White Paper addresses the current gaps in knowledge, as well as opportunities for future studies in pediatric sleep. The Sleep Research Society's Pipeline Development Committee assembled a panel of experts tasked to provide information to those interested in learning more about the field of pediatric sleep, including trainees. We cover the scope of pediatric sleep, including epidemiological studies and the development of sleep and circadian rhythms in early childhood and adolescence. Additionally, we discuss current knowledge of insufficient sleep and circadian disruption, addressing the neuropsychological impact (affective functioning) and cardiometabolic consequences. A significant portion of this White Paper explores pediatric sleep disorders (including circadian rhythm disorders, insomnia, restless leg and periodic limb movement disorder, narcolepsy, and sleep apnea), as well as sleep and neurodevelopment disorders (e.g. autism and attention deficit hyperactivity disorder). Finally, we end with a discussion on sleep and public health policy. Although we have made strides in our knowledge of pediatric sleep, it is imperative that we address the gaps to the best of our knowledge and the pitfalls of our methodologies. For example, more work needs to be done to assess pediatric sleep using objective methodologies (i.e. actigraphy and polysomnography), to explore sleep disparities, to improve accessibility to evidence-based treatments, and to identify potential risks and protective markers of disorders in children. Expanding trainee exposure to pediatric sleep and elucidating future directions for study will significantly improve the future of the field.

Abnormal Regional Spontaneous Neural Activity and Functional Connectivity in Unmedicated Patients with Narcolepsy Type 1: A Resting-State fMRI Study

BACKGROUND

Previous Resting-state functional magnetic resonance imaging (fMRI) studies have mainly focused on cerebral functional alteration in processing different emotional stimuli in patients with narcolepsy type 1 (NT1), but were short of exploration of characteristic brain activity and its remote interaction patterns. This study aimed to investigate the spontaneous blood oxygen fluctuations at rest and to elucidate the neural mechanisms underlying neuropsychiatric behavior.

METHOD

A total of 18 unmedicated patients with NT1 and matched healthy individuals were recruited in a resting-state fMRI study. Magnetic resonance imaging (MRI) data were first analyzed using fractional low-frequency amplitude of low-frequency fluctuation (fALFF) to detect changes in local neural activity, and regions with group differences were taken as regions of interest (ROIs). Secondly, functional connectivity (FC) analysis was used to explore altered connectivity between ROIs and other areas. Lastly, the relationship between functional brain activity and neuropsychiatric behaviors was analyzed with correlation analysis.

RESULTS

fALFF analysis revealed enhanced neural activity in bilateral fusiform gyrus (FFG), right precentral gyrus, and left postcentral gyrus (PoCG) in the NT1 group. The patients indicated reduced activity in the bilateral temporal pole middle temporal gyrus (TPOmid), left caudate nucleus (CAU), left parahippocampus, left precuneus (PCUN), right amygdala, and right anterior cingulate and paracingulate gyri. ESS score was negatively correlated with fALFF in the right FFG. The NT1 group revealed decreased connectivity between left TPOmid and right PoCG, the bilateral middle frontal gyrus, left superior frontal gyrus, medial, and right supramarginal gyrus. Epworth Sleepiness Scale (ESS) was negatively correlated with FC of the left TPOmid with left putamen (PUT) in NT1. Compared with healthy controls (HCs), enhanced FC of the left CAU with right FFG was positively associated with MSLT-SOREMPs in patients. Furthermore, increased FC of the left PCUN with right PoCG was positively correlated with SDS score.

CONCLUSIONS

We found that multiple functional activities related to the processing of emotional regulation and sensory information processing were abnormal, and some were related to clinical characteristics. fALFF in the left postcentral or right precentral gyrus may be used as a biomarker of narcolepsy, whereas fALFF in the right fusiform and the FC strength of the left temporal pole middle temporal gyrus with the putamen may be clinical indicators to assess the drowsiness severity of narcolepsy.

Secondary Narcolepsy as Worsening Sign in a Pediatric Case of Optic Pathway Glioma

Narcolepsy, a neurologic disorder that leads to excessive daytime sleepiness, may represent a rare consequence of neoplastic lesions involving the sellar/parasellar and hypothalamic regions, the anatomical areas responsible for wakefulness. Optic pathway gliomas represent the most common neoplasm of these regions and present an excellent overall survival, while long-term neurologic impairments, such as visual loss, endocrinopathies, or sleep disorders, are the principal causes of morbidity. In this case report, we describe a non-NF1 patient suffering from a very extensive optical pathway glioma, who several years after the diagnosis in a radiological condition of stable disease, presented with severe narcolepsy, a rare complication, that led to the death of the patient.

pitolisant, a novel histamine-3 receptor competitive antagonist, and inverse agonist, in the treatment of excessive daytime sleepiness in adult patients with narcolepsy

Narcolepsy is a debilitating sleep disorder that presents with excessive daytime sleepiness (EDS) and cataplexy, which is a sudden paralysis of muscle tone triggered by strong emotions such as laughing. It is also associated with many other disorders, including psychiatric disorders, neurologic illnesses, and medication side effects. Common causes of delayed and incorrect diagnoses of these conditions include lack of physician familiarity with narcolepsy symptoms and comorbidities which mask narcolepsy signs and symptoms. Current pharmacologic therapies include Modafinil and Armodafinil for EDS and sodium oxybate for cataplexy. This review discusses the epidemiology, pathophysiology, risk factors, presentation, treatment of narcolepsy, and the role of a novel drug, Pitolisant, in the treatment of EDS in adults with narcolepsy. Pitolisant is a histamine-3 receptor (H3R), competitive antagonist, and inverse agonist, acting through the histamine system to regulate wakefulness. It is a novel drug approved in August 2019 by the FDA, is not classified as a controlled substance, and is approved for use in Europe and the United States to treat EDS and cataplexy in narcolepsy. Recent phase II and III trials have shown that Pitolisant helps reduce the ESS score and cataplexy. In summary, based on comparative studies, recent evidence has shown that Pitolisant is non-inferior to Modafinil in the treatment of EDS but superior to Modafinil in reducing cataplexy.

Narcolepsia na Infância: A Atuação Multidisciplinar com a Psicologia do Sono do Diagnóstico ao Tratamento em um Relato de Caso

Resumo A narcolepsia, distúrbio neurológico crônico caracterizado pela sonolência diurna excessiva, pode ser associada à cataplexia, fragmentação do sono, alucinações relacionadas ao sono e paralisia do sono. Frequentemente, é confundida com outros transtornos, como Transtorno do Déficit de Atenção com Hiperatividade (TDAH), epilepsia e até esquizofrenia, assim, por vezes, é diagnosticada inadequadamente. Objetiva-se relatar o diagnóstico diferencial bem-sucedido da narcolepsia na infância e suas dificuldades, realizado por uma equipe multidisciplinar, enfocando a atuação da psicologia do sono em avaliação e intervenção. Um menino de 10 anos foi recebido no Ambulatório de Narcolepsia e Apneia do Sono Infantil (AMBNAP), alocado no Hospital Universitário Onofre Lopes da Universidade Federal do Rio Grande do Norte (UFRN) com queixas de sonolência diurna excessiva, sono fragmentado e episódios de perda de tônus muscular. Foi submetido a entrevistas psiquiátrica e psicológica pormenorizadas, a exames, aplicação de escalas específicas para rastreio e diagnóstico de transtornos de sono e diário de sono, solicitação de recursos de mídia e de relatório escolar e avaliação neurológica. A partir da investigação multidisciplinar, o diagnóstico foi de Narcolepsia e Síndrome da Apneia Obstrutiva do Sono (SAOS). O paciente foi submetido a técnicas da Terapia Cognitivo-Comportamental (TCC) e segue em acompanhamento, apresentando resultados satisfatórios. Este estudo evidencia que uma equipe multidisciplinar especializada na área de sono atuando em conjunto com a Psicologia do Sono oportuniza o diagnóstico e intervenções precoces eficazes para o tratamento do distúrbio do sono na infância.

Narcolepsy Presentation in Diverse Populations: an Update

Purpose of Review

We performed a literature search to generate incidence and prevalence rates of narcolepsy in diverse populations based on current available data.

Recent Findings

With an onset in childhood, narcolepsy often has a delayed diagnosis due to symptoms of excessive daytime sleepiness not being recognized or being misdiagnosed. Clinical, electrophysiological, and biological tests are needed in order to diagnose narcolepsy. At the same time, the discovery of the link with the immunoregulatory human leukocyte antigen complex and the adverse events in relation to the H1N1 pandemic vaccines have shuffled the epidemiological numbers.

Summary

In this meta-review, we pooled incidence rates and prevalence rates reported in 30 countries or from 209 sets of data. Findings are reported per age, continent, and proxy race/ethnicity as well as period (i.e., before/after the pandemic). This meta-review showed that narcolepsy occurs in 0.87-1.21 of the world population, with specifically NT1 being investigated. Its pooled incidence rate in vaccinated samples is 1.58. There is furthermore an underreporting of narcolepsy in ethnic/race and gender minorities, of childhood narcolepsy type 2 and potential comorbid conditions masking the clinical complaints and hence timely diagnosis.