Attention-Deficit/Hyperactivity Disorder (ADHD) Symptoms in Pediatric Narcolepsy: A Cross-Sectional Study

Association of Inattention, Hyperactivity, and Hypersomnolence in Two Clinic-Based Adult Cohorts

Objective: To assess the relationship between excessive daytime sleepiness (EDS), inattention, and hyperactivity/impulsivity in adults with ADHD and central hypersomnia. Method: Drug-free adult patients with ADHD (n = 100) or hypersomnia (n = 100) were evaluated using a structured clinical interview and self-report questionnaires on ADHD symptoms and EDS. Results: In all, 61% of patients with hypersomnia had clinically significant ADHD symptoms with 25% having an ADHD diagnosis (with both childhood and adulthood ADHD symptoms) and 36% ADHD-like symptoms, without history of childhood ADHD. EDS was reported in 47% of patients with ADHD, among whom 22% had a hypersomnolence disorder. Conclusion: We confirmed the high frequency of ADHD and ADHD-like symptoms in central hypersomnia, and of EDS and hypersomnolence in ADHD in adults. The nature of the link between EDS, inattention, and hyperactivity appears to be complex that may involve either a cause-effect relationship or intrinsic features of a similar neurodevelopmental dysfunction.

A Mobile App for Longterm Monitoring of Narcolepsy Symptoms: Design, Development, and Evaluation

BACKGROUND

Narcolepsy is a chronic sleep disorder with a broad variety of symptoms. Although narcolepsy is primarily characterized by excessive daytime sleepiness and cataplexy (loss of muscle control triggered by emotions), patients may suffer from hypnagogic hallucinations, sleep paralysis, and fragmented night sleep. However, the spectrum of narcolepsy also includes symptoms not related to sleep, such as cognitive or psychiatric problems. Symptoms vary greatly among patients and day-to-day variance can be considerable. Available narcolepsy questionnaires do not cover the whole symptom spectrum and may not capture symptom variability. Therefore, there is a clinical need for tools to monitor narcolepsy symptoms over time to evaluate their burden and the effect of treatment.

OBJECTIVE

This study aimed to describe the design, development, implementation, and evaluation of the Narcolepsy Monitor, a companion app for long-term symptom monitoring in narcolepsy patients.

METHODS

After several iterations during which content, interaction design, data management, and security were critically evaluated, a complete version of the app was built. The Narcolepsy Monitor allows patients to report a broad spectrum of experienced symptoms and rate their severity based on the level of burden that each symptom imposes. The app emphasizes the reporting of changes in relative severity of the symptoms. A total of 7 patients with narcolepsy were recruited and asked to use the app for 30 days. Evaluation was done by using in-depth interviews and user experience questionnaire.

RESULTS

We designed and developed a final version of the Narcolepsy Monitor after which user evaluation took place. Patients used the app on an average of 45.3 (SD 19.2) days. The app was opened on 35% of those days. Daytime sleepiness was the most dynamic symptom, with a mean number of changes of 5.5 (SD 3.7) per month, in contrast to feelings of anxiety or panic, which was only moved 0.3 (SD 0.7) times per month. Mean symptom scores were highest for daytime sleepiness (1.8 [SD 1.0]), followed by lack of energy (1.6 [SD 1.4]) and often awake at night (1.5 [SD 1.0]). The personal in-depth interviews revealed 3 major themes: (1) reasons to use, (2) usability, and (3) features. Overall, patients appreciated the concept of ranking symptoms on subjective burden and found the app easy to use.

CONCLUSIONS

The Narcolepsy Monitor appears to be a helpful tool to gain more insight into the individual burden of narcolepsy symptoms over time and may serve as a patient-reported outcome measure for this debilitating disorder.

Prevalence of attention deficit hyperactivity disorder symptoms in narcolepsy: a systematic review

OBJECTIVE

Narcolepsy is characterized by excessive daytime sleepiness and cataplexy. Attention deficit hyperactivity disorder (ADHD) is characterized by hyperactivity, inattention, and impulsivity. However, despite their differences, both narcolepsy and ADHD share the symptoms of sleep disturbance and excessive daytime sleepiness. Recent studies have suggested a link between the two disorders. The objective of systematic review was to assess the prevalence of ADHD symptoms in narcolepsy.

METHODS

We performed a systematic search of MEDLINE (inception to December 2018) and EMBASE (inception to December 2018) for English publications of human studies using the keywords "narcolepsy" and "ADHD".

RESULTS

Five studies examining a total of 328 patients met the eligibility criteria for this study examining the prevalence of ADHD symptoms in narcolepsy. The pooled prevalence of ADHD symptoms in narcolepsy was 33.0%. Two studies using the international classification of sleep disorders, second edition (ICSD-2) observed a pooled prevalence of ADHD symptoms in narcolepsy of 25.0%, while two other studies that relied on the ICSD-3 criteria observed a pooled prevalence of ADHD symptoms in narcolepsy of 36.4%.

CONCLUSIONS

The prevalence of ADHD symptoms was >30%, making it an important comorbidity of narcolepsy. Future studies should be performed to better assess the relationship between ADHD and narcolepsy.

Excessive Daytime Sleepiness Measurements in Children With Attention Deficit Hyperactivity Disorder

Attention deficit hyperactivity disorder (ADHD) is the most commonly diagnosed neurodevelopmental disorder in childhood. It is a heterogeneous disorder in terms of clinical presentation that is probably due to the frequent occurrence of comorbidity. Children with ADHD more frequently report sleep disorders (notably delayed sleep phase syndrome) and excessive daytime sleepiness (EDS) than typically developing children. The aim of this article is to propose a narrative review of the assessment of EDS in the context of ADHD with first a summary of the subjective and objective tools used to measure it. Secondly, perspectives in terms of electroencephalogram (EEG) markers and neurofeedback are proposed. Then, possibilities for new kinds of evaluation are discussed (virtual reality, ecological momentary assessment, etc.). Lastly, we discuss specific clinical situations with EDS in the context of ADHD as links with narcolepsy, the comorbidity with other psychiatric disorders, and the context of sluggish cognitive tempo.

Autism Spectrum Disorder and Narcolepsy: A Possible Connection That Deserves to Be Investigated

Narcolepsy in childhood-adolescence is characterized by a high occurrence of psychiatric comorbidities. The most frequent psychiatric disorders reported in these patients are attention deficit/hyperactivity disorder, depression, anxiety disorder, and schizophrenia. However, narcolepsy can be associated also with introversion, sorrowfulness, feelings of inferiority, impaired affectivity modulation, emotional lability, irritability, aggressiveness, and poor attention, that have been pooled by some authors under a definition of "narcoleptic personality." Some aspects of this "narcoleptic personality," and in particular introversion, impaired affectivity modulation, irritability, and poor attention, partially overlap with the clinical features of the individuals with autism spectrum disorder, considering also those that are not regarded as core autism symptoms. Till now, in literature the number of cases affected by both narcolepsy and autism spectrum disorder (seven patients) has been clearly too small to demonstrate the presence of a pathogenetic link between these two conditions, but this possible connection has not yet been adequately investigated, despite the presence of several points in common. The finding of a connection between narcolepsy and autism spectrum disorder could boost the study of possible etiopathogenetic mechanisms shared between these two apparently so distant disorders. Basing on the literature data summarized in this paper, in the diagnostic work-up of a child with narcolepsy it is essential to evaluate also the social-communicative behavior using standardized tools in order to detect the real recurrence of clinical features suggesting an autism spectrum disorder. At the same time, it appears necessary to screen in the individuals with autism spectrum disorder for the possible presence of evoking symptoms of narcolepsy.

Chinese version of narcolepsy severity scale: a validation study

BACKGROUND

The narcolepsy severity scale (NSS) was developed to measure the severity and consequences of symptoms in patients with narcolepsy. The scale has been validated in France, though no other studies have further validated this instrument. The current study aimed to present psychometric properties and describe the score distribution of the Chinese-NSS.

METHODS

One hundred twenty-two patients with narcolepsy (41 females and 81 males; mean age 26.14 ± 15.40 years) participated in the study. All patients completed the Chinese-NSS. Cronbach's α, item-total score correlations, exploratory factor analysis (EFA), and correlations between NSS total scores and clinical or sleep parameters were then calculated.

RESULTS

EFA yielded a three-factor model. Internal consistency was acceptable (Cronbach'sα = 0.799). The NSS total score had significant correlations with the Epworth sleepiness score (0.447), pediatric daytime sleepiness scale (0.318), the insomnia severity index (0.592), Beck depression inventory (0.593), EurQol five dimensions-utility (0.457), EurQol five dimensions -VAS (- 0.323), the sleep disturbance scale for children (0.440), the children depression inventory (0.553), and the pediatric quality of life inventory (0.555) total scores, demonstrating acceptable convergence as predicted.

CONCLUSIONS

The current study is the first validation study of the narcolepsy severity scale in an Asian population. The findings validated the Chinese-narcolepsy severity scale in a Chinese population with acceptable psychometric properties. There are minor differences between our results and those of the original study due to cultural differences.

Impaired social functioning in children with narcolepsy

Study Objectives

To explore impairments in social functioning in children with narcolepsy compared to healthy children.

Methods

Parents of 53 pediatric patients with narcolepsy type 1 and 64 matched healthy children completed the Social Responsiveness Scale (SRS) and the Child Behavior Checklist 6-18 (CBCL 6-18).

Results

Patients scored significantly higher on the total score of the SRS (median 56, interquartile range [IQR] 23.5) compared to controls (median 44.5, IQR 8.5, U = 797.0, p < 0.001). Patients also scored higher on the sum of the CBCL 6-18 subscales indicative of social functioning (Withdrawn/Depressed, Social Problems, and Thought Problems; median 183, IQR 30.5) compared to controls (median 155, IQR 13, U = 500.0, p < 0.001). A total of 24 patients (45.3%) reported at least mild-to-moderate difficulties in social functioning compared to seven controls (10.9%, χ2 = 17.165, p < 0.001). Eleven patients (20.8%) and only one control (1.6%) had T scores above 75, which points to severely impaired social functioning (χ2 = 11.602, p = 0.001). Within the patient group, girls reported mild-to-moderate difficulties in social functioning significantly more often compared to boys on the SRS (77.8% versus 28.6%, χ2 = 17.560, p < 0.001).

Conclusions

Impaired social functioning is common in children with narcolepsy type 1, especially in girls. Questionnaires such as the SRS and the CBCL 6-18 may help in early detection of social problems in pediatric narcolepsy. Recognition of these problems could be valuable in the management of young people with narcolepsy.

Fifteen-minute consultation: Managing sleep problems in children and young people with ADHD

Sleep difficulties are common in children and young people presenting with features of attention-deficit/hyperactivity disorder (ADHD). Sleep problems may be both an effect of and a contributor to ADHD symptomatology, as well as having a significant impact on both individual and family functioning and well-being. There are often complex interacting contributing factors. Assessment of children presenting with symptoms suggestive of possible ADHD should include routine enquiry about sleep. Ongoing management of children with diagnosed ADHD should include regular reassessment and review of sleep. When sleep difficulties are present, we discuss how to further assess these, including the role of investigations, and a structured management strategy.

Obesity and other medical comorbidities among NT1 patients after the Norwegian H1N1 influenza epidemic and vaccination campaign

Study Objectives

Narcolepsy type 1 (NT1) may be complicated by comorbidities. We aimed to study the extent of obesity and other medical comorbidities in a Norwegian population of NT1 patients with debut of symptoms after the 2009 H1N1 influenza epidemic and vaccination campaign. We also aimed to explore factors associated with obesity.

Methods

Ninety-one patients (48 children and 43 adults) were included in this cross-sectional study, 80 of whom were H1N1-vaccinated. All participants were hospitalized and underwent sleep investigation and physical examination, and completed a semi-structured clinical interview.

Results

In children, 16 females (70%) and 10 males (40%) were classified as overweight or obese. Twenty children (42%) had a co-existing medical disorder. Medical comorbidity was significantly positively associated with BMI in children (p = .032). In adults, 19 females (58%) and 7 males (70%) were classified as overweight or obese. Twenty-six adults (61%) had a co-existing medical disorder. We found no factors significantly associated with BMI in adults. On a fatigue scale from 0 to 100, lower scores indicating more fatigue, we found a mean (SD) total fatigue score of 50 (17) in children and 39 (16) in adults.

Conclusion

In a cohort of predominantly H1N1-vaccinated NT1 patients, we found a high prevalence of overweight or obesity. Half of the cohort presented with one or more additional medical comorbidities, and patients reported a clinically relevant degree of fatigue. Our findings highlight the importance of carefully monitoring patients with NT1 with regard to the development of obesity, which is a significant risk factor for cardiovascular disorders.

Academic and professional paths of narcoleptic patients: the Narcowork study

OBJECTIVE/BACKGROUND

To study educational and professional pathways of narcoleptic patients and examine demographic, disease-related and environmental factors associated with a better academic and professional prognosis.

PATIENTS/METHODS

In sum, 69 narcoleptic patients (51 narcolepsy type 1 and 18 narcolepsy type 2, age 42.5 ± 18.2 years) were enrolled in this pilot monocentric cross-sectional study with a comparison group (80 age- and sex-matched controls) between October 2017 and July 2018 in Lyon Center for Sleep Medicine. They completed questionnaires about their academic and professional trajectories and specific scales of quality of life (EuroQol quality of life scale EQ-5D-3L), depression (beck depression inventory, BDI), sleepiness (Epworth Sleepiness Scale, ESS) and narcoleptic symptoms severity (narcolepsy severity scale, NSS).

RESULTS

No difference in grade repetition or final obtained diploma was observed between patients and controls, but patients evaluated their academic curricula as more difficult (45.5% vs 16.9%, p = 0.0007), complained for more attentional deficits (75% vs 22.1%, p < 0.0001), and had needed more educational reorientation (28.6% vs 9.9%, p = 0.01). Even if no difference was observed in occupational category and professional status, patients expressed significantly less satisfaction about their work. Patients had more signs of depression [OR severe depression = 4.4 (1.6-12.6), p = 0.02] and their quality of life was significantly decreased (67.3 ± 18.4 vs 80.6 ± 13.2, p = 0.0007) as compared to controls. Multivariate analysis showed that a more favorable professional career was associated with a better quality of life.

CONCLUSIONS

Educational and professional pathways do not seem to be significantly impaired in narcoleptic patients, but their experience and quality of life are affected. These findings may allow to reassure patients and should lead to a more comprehensive management of the disease.

CLINICAL TRIAL REGISTRATION

Narcowork, https://clinicaltrials.gov/ct2/show/NCT03173378, N° NCT03173378.

Shorter REM latency in children with attention-deficit/hyperactivity disorder

The discrepancies in prior research about the actual sleep problems underlying attention-deficit/hyperactivity disorder (ADHD) demand more studies of children with this disorder. This study aimed to compare the subjective and objective sleep characteristics of 20 children with ADHD (DSM-IV criteria) and 20 typically developing children (aged 7-11 years). We assessed the children using sleep questionnaires and polysomnography recordings and analysed differences between the two groups using two-tailed Mann-Whitney U exact tests and Rosenthal's r as effect size measure. We also assessed associations between sleep measures and psychopathology using Spearman's correlation coefficients. No significant difference was found between the groups in almost any objective sleep variable, except for shorter REM latency in the ADHD group. Children with ADHD also showed significantly higher levels of daytime sleepiness and greater general sleep problems than control children, as reported by their parents, after discarding the primary sleep problems commonly associated with ADHD. Significant correlations were found between psychopathology and sleep measures. Our findings might support the link between narcolepsy-like sleep phenotype and ADHD. However, longitudinal research combining objective and subjective assessments should further explore the involvement of other variables, such as ADHD subtypes, medication, and comorbid symptoms in this relationship.

[Can ADHD have an adulthood onset?]

ADHD is the most common psychiatric disorder of childhood. It is considered to be a neurodevelopmental disorder that may persist from chilhood into adulthood. In childood it is associated with several outcomes such as inattention, hyperactivity and impulsivity. Symptoms may change as a person gets older with an increased risk of developing psychiatric comorbidities such as depression, anxiety and substance addiction. However, recent studies diverge from the traditional perspective. These authors hypothesized that ADHD may appear in adulthood, not as a continuation of child ADHD, but some limitations have to be considered. Firstly, ADHD often goes unrecognized throughout childhood. Secondly, families may help the children to develop compensation strategies and adaptative behaviors. The purpose of this report is to better investigate these different and innovative clinical results and understand if adult ADHD could really be considered as a distinct, different pathology, as a late-onset disorder. We conducted a brief review of literature and included the most recent scientific longitudinal follow-up cohort studies. We conclude that, while adult ADHD is still considered a continuation from childhood, many questions of late-onset ADHD remain and further research is necessary to better understand and explain the etiology, the development, the clinical impact, and the psychotherapeutic and pharmacologic treatment of this late-onset disorder.

Prevalence and Correlates of Hypersomnolence Symptoms in US Teens

OBJECTIVE

Recent attention to pervasive sleep deficits in US adolescents has focused on sleep patterns and insomnia, but there are limited data on the prevalence and correlates of hypersomnolence symptoms.

METHOD

The sample included 6,483 adolescents 13 to 18 years of age who were interviewed directly and had parent reports in the National Comorbidity Survey Replication Adolescent Supplement (NCS-A), a nationally representative sample of US youth. Information on sleep patterns/symptoms that were collected in the interview was used to determine the population prevalence of DSM-5 criterion A-defined hypersomnolence and component symptoms. Logistic regression analyses were used to examine associations between sleepiness and sub-symptoms of hypersomnolence with weekday/weekend bedtime, sleep duration, mental disorders, and psychotropic medication use.

RESULTS

Of the sample, 41.5% reported feeling sleepy during the daytime and 11.7% met criteria for hypersomnolence. The prevalence of hypersomnolence varied depending on age (p < .001) and was more common in adolescent girls (odds ratio [OR] 1.40, 95% CI 1.09-1.78). Excessive sleepiness and hypersomnolence symptoms were associated with shorter sleep duration and delayed bedtimes on weekdays and weekends Hypersomnolence was significantly associated with insomnia (OR 2.45, 95% CI 1.87-3.21) and mental disorders (OR 1.99, 95% CI 1.42-2.77). After accounting for insomnia, hypersomnolence was no longer associated with use of psychotropic medication (OR 1.61, 95% CI 0.97-2.66).

CONCLUSION

Of adolescents with adequate sleep duration, 11.7% still reported symptoms of hypersomnolence. The strong association between hypersomnolence and insomnia suggests that sleep disorders in adolescents can fluctuate between over- and under-sleeping. Potential mechanisms underpinning the strong associations between sleep disturbances and mental disorders should be further pursued and could provide insight into prevention efforts.

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.

Childhood narcolepsy and autism spectrum disorders: four case reports

BACKGROUND

Childhood narcolepsy is associated with various emotional, behavioural and cognitive dysfunctions as well as with psychiatric and neurodevelopmental disorders: anxiety, depression, attention deficit hyperactivity disorder and psychosis. A relationship between these conditions is unclear - comorbidity or similar pathophysiological mechanisms can be suggested.

OBJECTIVE

We reported four children with narcolepsy type 1 (NT1) and autism spectrum disorder (ASD) - Asperger syndrome (AS).

RESULTS AND CONCLUSION

To the best of our knowledge co-occurrence of NT1 and AS has not been described in the literature as noted in this report.

Clinical Characteristics and Burden of Illness in Pediatric Patients with Narcolepsy

BACKGROUND

Narcolepsy is a chronic and lifelong neurologic disorder with onset commonly occurring in childhood or adolescence, and affecting approximately 0.025% to 0.05% of the general population. The primary symptom is excessive daytime sleepiness, which is accompanied by cataplexy in 70% of patients. Other common symptoms include sleep paralysis, hallucinations upon falling asleep or waking, and disrupted nocturnal sleep. Narcolepsy is associated with a considerable burden of illness (BOI), which has been well characterized in adults, and is exacerbated by delays in symptom recognition, diagnosis, and intervention.

METHODS

This review describes the specific characteristics and BOI of pediatric narcolepsy, using a wide range of published research data.

RESULTS

Pediatric narcolepsy presents distinct challenges in diagnosis and management. Narcolepsy symptoms often initially manifest differently in children and adolescents versus adults, which may pose diagnostic dilemmas. Children often respond to sleepiness with irritability, hyperactivity, and poor attention, which may be misinterpreted as misbehavior or neurocognitive sequelae of other conditions. Pediatric cataplexy symptoms may include subtle and unusual facial expressions or choreic-like movements, which are not observed in adults. Insufficient sleep and circadian rhythm disorders presenting with excessive daytime sleepiness are common in adolescents, potentially confounding narcolepsy diagnosis. Pediatric narcolepsy is also associated with comorbidities including rapid weight gain, precocious puberty, and attention deficit hyperactivity disorder, and increased risk for deficits in social functioning, depression, and anxiety. School performance is also typically impaired, requiring special education services.

CONCLUSIONS

Thus, the discrete BOI of pediatric narcolepsy underscores the need for prompt and accurate diagnosis, and appropriate treatment of this disorder.

Associations Between Neuropsychological, Neurobehavioral and Emotional Functioning and Either Narcolepsy or Idiopathic Hypersomnia in Children and Adolescents

STUDY OBJECTIVES

Narcolepsy and idiopathic hypersomnia are chronic neurological sleep disorders characterized by hypersomnolence or excessive daytime sleepiness. This review aims to systematically examine the scientific literature on the associations between narcolepsy and idiopathic hypersomnia and their effect on intellectual functioning, academic achievement, behavior, and emotion.

METHODS

Published studies that examined those associations in children and adolescents were included. Studies in which children or adolescents received a clinical diagnosis, and in which the associated function was measured with at least one objective instrument were included. Twenty studies published between 1968 and 2017 were eligible for inclusion in this review.

RESULTS

There does not appear to be a clear association between intellectual functioning and narcolepsy or idiopathic hypersomnia; however, limited research is an obstacle to obtaining generalizability. The variability in results from studies investigating associations between academic achievement and these two hypersomnolence disorders suggests that further research using standardized and validated assessment instruments is required to determine if there is an association. Behavior and emotion appear to be significantly affected by narcolepsy. Only two studies included populations of children and adolescents with idiopathic hypersomnia.

CONCLUSIONS

Further research using larger populations of children and adolescents with narcolepsy or idiopathic hypersomnia while utilizing standardized and validated instruments is required, because the effect of these conditions of hypersomnolence varies and is significant for each individual.

Narcolepsy and Psychiatric Disorders: Comorbidities or Shared Pathophysiology?

Narcolepsy and psychiatric disorders have a significant but unrecognized relationship, which is an area of evolving interest, but unfortunately, the association is poorly understood. It is not uncommon for the two to occur co-morbidly. However, narcolepsy is frequently misdiagnosed initially as a psychiatric condition, contributing to the protracted time to accurate diagnosis and treatment. Narcolepsy is a disabling neurodegenerative condition that carries a high risk for development of social and occupational dysfunction. Deterioration in function may lead to the secondary development of psychiatric symptoms. Inversely, the development of psychiatric symptoms can lead to the deterioration in function and quality of life. The overlap in pharmaceutical intervention may further enhance the difficulty to distinguish between diagnoses. Comprehensive care for patients with narcolepsy should include surveillance for psychiatric illness and appropriate treatment when necessary. Further research is necessary to better understand the underlying pathophysiology between psychiatric disease and narcolepsy.

Pediatric Sleep Disorders

PURPOSE OF REVIEW

This article provides an overview of the clinical features, diagnosis, and treatment of insomnia, restless legs syndrome, periodic limb movements of sleep, parasomnias, narcolepsy, and sleep-related breathing disorders among children and adolescents.

RECENT FINDINGS

Pediatric presentations of sleep disorders differ from adult presentations, making diagnosis challenging. Specific clinical syndromes, such as cataplexy in children with narcolepsy type 1, can have an altogether different presentation compared to adult-onset symptoms, contributing to diagnostic delays and potential misdiagnoses. More broadly, research shows strong associations between sleep and daytime cognition, mood, and behavior among children with and without neurologic conditions and thus suggests a need to identify and treat sleep problems to optimize daytime functioning.

SUMMARY

Addressing sleep problems in children with neurologic conditions and neurodevelopmental disorders improves quality of life for patients and their families and, in many cases, reduces neurologic disease burden.

Sleep disorders in patients with ADHD: impact and management challenges

Attention deficit/hyperactivity disorder (ADHD) is one of the most commonly diagnosed disorders in childhood, enduring through adolescence and adulthood and presenting with symptoms of inattention, hyperactivity, and/or impulsivity and significantly impairing functioning. Primary sleep disorders such as sleep-disordered breathing, restless leg syndrome, circadian rhythm sleep disorder, insomnia, and narcolepsy are commonly comorbid in these individuals but not often assessed and are therefore often left untreated. Sleep disturbances in individuals with ADHD can result in significant functional impairments that affect mood, attention, behavior, and ultimately school/work performance and quality of life. Previous reviews have described findings related to sleep but have neglected to examine potential impacts of these sleep disorders and ADHD on daytime functioning. This review investigates empirical findings pertaining to sleep abnormalities and related cognitive, behavioral, emotional, and physical impairments in individuals with ADHD and comorbid primary sleep disorders across the life span. It discusses implications to management and highlights existing limitations and recommended future directions.

Correlates to Problem Behaviors in Pediatric Narcolepsy: A Pilot Study

STUDY OBJECTIVE

Excessive daytime sleepiness, the hallmark of narcolepsy, predisposes patients to serious performance decrements in multiple areas of function. Psychosocial dysfunction has been demonstrated in adults and children with narcolepsy. Several factors could influence psychosocial functioning in children. The objective of this study was to examine neurobehavioral problems in children with narcolepsy and to define associations with these problem behaviors.

METHODS

A cross-sectional study was performed where the Child Behavior Checklist (CBCL) was completed by guardians of children (age 18 years or younger) in whom narcolepsy with or without cataplexy was diagnosed (based on the International Classification of Sleep Disorders, Second Edition) between July 2008 and October 2014. Spearman correlations (continuous variables) and Wilcoxon rank-sum tests (categorical variables) were performed for the CBCL findings and narcolepsy factors previously shown to influence psychosocial functioning.

RESULTS

The participants' current age correlated significantly with multiple CBCL scales. Caregivers of younger participants reported higher total psychosocial problems and externalizing problems. In addition, caregivers of younger participants reported higher scores on indices measuring inattention, withdrawal, thought problems, aggression, and rule-breaking behaviors. Values of P < .001 were found for total psychosocial problems, externalizing behaviors, and thought problems (negative correlations of 0.66, 0.65, and 0.64, respectively).

CONCLUSIONS

Patients with pediatric narcolepsy have high rates of attention and emotional/behavior problems. These problems strongly correlated with age. Younger children expressed higher emotional, behavioral, and attention problems. Sleep physicians need to be aware of and assess the mental and behavioral health of their pediatric patients with narcolepsy.

Is adult-onset attention deficit/hyperactivity disorder frequent in clinical practice?

Recent population-based longitudinal studies concluded that most adults with attention deficit/hyperactivity disorder (ADHD) symptoms would not have a childhood history of ADHD, leading to the concept of adult-onset ADHD. In a large, well-characterized clinical population of 446 adults with a primary complaint of ADHD, we reported a low frequency of adult-onset ADHD (6.9%), being a primary isolated condition in 2.8%. They had less severe symptoms and tendencies for higher hypersomnolence disorder comorbidity than patients with typical childhood-onset ADHD. Our findings reinforce the requirement to exclude other disorders that might overlap with ADHD or mimic ADHD symptoms in adulthood onset patients.

Attention deficit hyperactivity disorder symptom severity and sleep problems in adult participants of the Netherlands sleep registry

BACKGROUND

We examined whether current overall attention deficit hyperactivity disorder (ADHD), inattention, or hyperactivity symptom severities are associated with the current presence and persistent history of sleep problems.

METHODS

N = 942 participants of the Netherlands Sleep Registry filled out online several validated questionnaires. Regression analyses were performed to assess the association between (1) current overall ADHD symptom severity and the current presence of sleep problems, (2) current ADHD symptom-severity groups and the persistent history of sleep problems, and (3) current inattention or hyperactivity symptom severities and the current presence of sleep problems.

RESULTS

(1) Current overall ADHD symptom severity was associated with the odds of suffering from probable obstructive sleep apnea syndrome (OSAS), restless legs syndrome (RLS), periodic limb movement disorder (PLMD), insomnia disorder (ID) with predominant difficulties initiating sleep (DIS) and maintaining sleep (DMS), but not with the odds of suffering from narcolepsy or ID with predominant early-morning awakening (EMA). Current overall ADHD symptom severity was also associated with an extreme evening chronotype but not with short sleep. (2) The group with the most severe current ADHD symptoms was more likely to have a history of persistent OSAS, RLS, and ID. (3) The severity of symptoms of hyperactivity, but not of inattention, was specifically associated with probable RLS, PLMD, ID with DIS or DMS, and short sleep. Inattention symptom severity was only related to the probability of being an extreme evening chronotype.

CONCLUSION

ADHD severity, especially the severity of hyperactivity, is associated with the current presence and persistent history of sleep problems.

Attention impairments and ADHD symptoms in adult narcoleptic patients with and without hypocretin deficiency

BACKGROUND

Attentional complaints are common in narcolepsy patients and can overlap with daytime sleepiness features. Few studies attempted to characterize attentional domains in narcolepsy leading to controversial results. We aimed to assess the impact of hypocretin deficiency on attentional functioning by comparing performances on the attention network test (ANT) of narcoleptic patients with hypocretin deficiency (narcolepsy type 1-NT1) versus patients without hypocretin deficiency (narcolepsy type 2-NT2) and healthy controls. We also addressed frequency and severity of psychopathological symptoms and their influence on performances on ANT.

METHODS

Twenty-one NT1 patients, fifteen NT2 patients and twenty-two healthy controls underwent the ANT, which allows assessing three separate attentional processes (alerting, orienting and executive control), and a psychometric assessment including questionnaires on attention-deficit hyperactivity disorder (ADHD), obsessive-compulsive disorder, anxiety and depression symptoms.

RESULTS

NT1 and NT2 patients presented with slower reaction times compared to controls. NT1 patients exhibited an impairment of alerting network relative to NT2 and healthy controls, while orienting and executive control networks efficiency were comparable between groups. NT1 and NT2 displayed higher severity of ADHD inattentive domain than controls, NT1 patients also displayed higher severity of ADHD hyperactive domain and depressive symptoms. In NT1, ADHD and depressive symptoms were positively correlated.

CONCLUSIONS

Despite a shared slowing of reaction times in both NT1 and NT2, a selective impairment of alerting network was present only in hypocretin deficient patients. Clinicians should carefully consider attentional deficits and psychopathological symptoms, including ADHD symptoms, in the clinical assessment and management of patients with narcolepsy.

The development of a health-related quality-of-life instrument for young people with narcolepsy: NARQoL-21

BACKGROUND

Narcolepsy is a lifelong sleep disorder with a prevalence of between 0.03% and 0.06% and onset at around puberty. It is associated with psychiatric comorbidities and cognitive difficulties. No valid and reliable condition-specific health-related quality-of-life (HrQoL) instrument has been developed for this population.

METHODS

A questionnaire based on four mixed-gender age-defined focus group discussions and a patient panel analysis was administered to young people with narcolepsy and a control group. External reliability was measured by a test-retest procedure and internal reliability was measured using Cronbach's alpha. Convergent validity with the KIDSCREEN-10 index was assessed using with intraclass correlation coefficients (ICC) and receiver operating characteristic (ROC) curves. Factor analysis techniques were used to identify suitable items and confirm the factor structure. Baseline values were assessed for convergent validity, ceiling effects, agreement and sensitivity. Comparison with KIDSCREEN-10 was made on the basis of area under the curve (AUC).

RESULTS

One hundred young people with narcolepsy and 95 control subjects returned questionnaires. The factor structure revealed two main factors with five domains and 21 questions, which was confirmed with confirmatory factor analysis. The domains of the NARQoL-21 showed good independence while the floor and ceiling effects were acceptable. The external reliability (0.928), convergent validity (rs = 0.769) and internal consistency (Cronbach's alpha = 0.886) were excellent. A Bland-Altman plot revealed some proportional bias. Good discriminant validity was detected for control/patient (Cohen's d = 2.114). ROC analysis showed significantly better AUC for NARQoL-21 (0.939) than KIDSCREEN (0.877). A cut-off score equivalent to KIDSCREEN-10 for suboptimal HrQoL which maximized sensitivity (84%) and specificity (92%) was found at NARQoL-21 score below 42.

CONCLUSIONS

Establishing the validity of a disease-specific HrQoL instrument in a population of people with a rare condition poses significant challenges. The mixed-methods approach adopted here has resulted in a questionnaire of 21 items with good discrimination and convergent validity, and excellent internal and external reliability, allowing precise and stable measurements. The cut-off score can be useful to identify patients with very poor HrQoL and thus improve the design of treatment options. Further testing in a longitudinal cohort is recommended in order to establish responsiveness.

Insomnia, parasomnias, and narcolepsy in children: clinical features, diagnosis, and management

Sleep problems are frequently encountered as presenting complaints in child neurology clinical practice. They can affect the functioning and quality of life of children, particularly those with primary neurological and neurodevelopmental disorders, since coexisting sleep problems can add substantially to neurocognitive and behavioural comorbidities. Additionally, symptoms of some sleep disorders such as parasomnias and narcolepsy can be confused with those of other neurological disorders (eg, epilepsy), posing diagnostic challenges for paediatric neurologists. The understanding of the neurophysiology of sleep disorders such as insomnia, parasomnias, and narcolepsy is still evolving. There is a complex relation between the sleeping brain and its waking function. The interplay among genetic factors, alterations in neurotransmitters, electrophysiological changes, and environmental factors potentially contribute to the genesis of these sleep disorders.

Depression and Hypersomnia: A Complex Association

Hypersomnolence is a clinically defined syndrome characterized by the association of prolonged nocturnal sleep, impaired arousal quality, and sleep inertia. Hypersomnolence is the major feature of central hypersomnias and is frequently reported in various mood disorders, such as major depressive disorder, bipolar disorder, or seasonal affective disorder. Assessment of hypersomnolence is challenging in depressed patients, with objective tests often in the normal range despite a high level of sleepiness complaint. On the other hand, many patients with central hypersomnias reported depressive symptoms. The self-assessment of mood symptoms in patients with central hypersomnias may overdiagnose depression with an overlap between both conditions.

Intravenous Immunoglobulin Therapy in Pediatric Narcolepsy: A Nonrandomized, Open-Label, Controlled, Longitudinal Observational Study

STUDY OBJECTIVES

Previous case reports of intravenous immunoglobulins (IVIg) in pediatric narcolepsy have shown contradictory results.

METHODS

This was a nonrandomized, open-label, controlled, longitudinal observational study of IVIg use in pediatric narcolepsy with retrospective data collection from medical files obtained from a single pediatric national reference center for the treatment of narcolepsy in France. Of 56 consecutively referred patients with narcolepsy, 24 received IVIg (3 infusions administered at 1-mo intervals) in addition to standard care (psychostimulants and/or anticataplectic agents), and 32 continued on standard care alone (controls).

RESULTS

For two patients in each group, medical files were unavailable. Of the 22 IVIg patients, all had cerebrospinal fluid (CSF) hypocretin ≤ 110 pg/mL and were HLA-DQB1*06:02 positive. Of the 30 control patients, 29 were HLA-DQB1*06:02 positive and of those with available CSF measurements, all 12 had hypocretin ≤ 110 pg/mL. Compared with control patients, IVIg patients had shorter disease duration, shorter latency to sleep onset, and more had received H1N1 vaccination. Mean (standard deviation) follow-up length was 2.4 (1.1) y in the IVIg group and 3.9 (1.7) y in controls. In multivariate-adjusted linear mixed-effects analyses of change from baseline in Ullanlinna Narcolepsy Scale (UNS) scores, high baseline UNS, but not IVIg treatment, was associated with a reduction in narcolepsy symptoms. On time-to-event analysis, among patients with high baseline UNS scores, control patients achieved a UNS score < 14 (indicating remission) less rapidly than IVIg patients (adjusted hazard ratio 0.18; 95% confidence interval: 95% confidence interval: 0.03, 0.95; p = 0.043). Shorter or longer disease duration did not influence treatment response in any analysis.

CONCLUSIONS

Overall, narcolepsy symptoms were not significantly reduced by IVIg. However, in patients with high baseline symptoms, a subset of IVIg-treated patients achieved remission more rapidly than control patients.

COMMENTARY

A commentary on this article appears in this issue on page 363.

Listening to the Patient Voice in Narcolepsy: Diagnostic Delay, Disease Burden, and Treatment Efficacy

STUDY OBJECTIVES

Describe common symptoms, comorbidities, functional limitations, and treatment responsiveness among patients with narcolepsy. Investigate the effect of pediatric onset of narcolepsy symptoms on time to diagnosis of narcolepsy and presence of comorbid depression.

METHODS

Cross-sectional survey of 1,699 people in the United States with self-reported diagnosis of narcolepsy. We utilized mixed-methods data analyses to report study findings.

RESULTS

Most participants reported receiving a diagnosis of narcolepsy more than 1 y after symptom onset. We found that the strongest predictor of this delayed diagnosis was pediatric onset of symptoms (odds ratio = 2.4, p < 0.0005). Depression was the most common comorbidity but we detected no association with pediatric onset of narcolepsy symptoms. Overall, participants reported that fatigue and cognitive difficulties were their most burdensome symptoms in addition to sleepiness and cataplexy. The majority of participants reported residual daytime fatigue and/or sleepiness despite treatment. Most participants reported they could not perform at work or school as well as they would like because of narcolepsy symptoms.

CONCLUSIONS

This study provides unique insight into the narcolepsy disease experience. The study quantifies the problem of diagnostic delay for narcolepsy patients in the United States and highlights that symptoms are more likely to be missed if they develop before 18 y of age. These results suggest that narcolepsy awareness efforts should be aimed at parents, pediatric health care providers, school professionals, and children/adolescents themselves. Disease burden is high because of problems with fatigue, cognition, and persistence of residual symptoms despite treatment.

Narcolepsy

Narcolepsy is a chronic sleep disorder that has a typical onset in adolescence and is characterized by excessive daytime sleepiness, which can have severe consequences for the patient. Problems faced by patients with narcolepsy include social stigma associated with this disease, difficulties in obtaining an education and keeping a job, a reduced quality of life and socioeconomic consequences. Two subtypes of narcolepsy have been described (narcolepsy type 1 and narcolepsy type 2), both of which have similar clinical profiles, except for the presence of cataplexy, which occurs only in patients with narcolepsy type 1. The pathogenesis of narcolepsy type 1 is hypothesized to be the autoimmune destruction of the hypocretin-producing neurons in the hypothalamus; this hypothesis is supported by immune-related genetic and environmental factors associated with the disease. However, direct evidence in support of the autoimmune hypothesis is currently unavailable. Diagnosis of narcolepsy encompasses clinical, electrophysiological and biological evaluations, but simpler and faster procedures are needed. Several medications are available for the symptomatic treatment of narcolepsy, all of which have quite good efficacy and safety profiles. However, to date, no treatment hinders or slows disease development. Improved diagnostic tools and increased understanding of the pathogenesis of narcolepsy type 1 are needed and might lead to therapeutic or even preventative interventions.

Hypersomnolence, Hypersomnia, and Mood Disorders

Relationships between symptoms of hypersomnolence, psychiatric disorders, and hypersomnia disorders (i.e., narcolepsy and idiopathic hypersomnia) are complex and multidirectional. Hypersomnolence is a common complaint across mood disorders; however, patients suffering from mood disorders and hypersomnolence rarely have objective daytime sleepiness, as assessed by the current gold standard test, the Multiple Sleep Latency Test. An iatrogenic origin of symptoms of hypersomnolence, and sleep apnea syndrome must be considered in a population of psychiatric patients, often overweight and treated with sedative drugs. On the other hand, psychiatric comorbidities, especially depression symptoms, are often reported in patients with hypersomnia disorders, and an endogenous origin cannot be ruled out. A great challenge for sleep specialists and psychiatrists is to differentiate psychiatric hypersomnolence and a central hypersomnia disorder with comorbid psychiatric symptoms. The current diagnostic tools seem to be limited in that condition, and further research in that field is warranted.

Classics in Chemical Neuroscience: Methylphenidate

As the first drug to see widespread use for the treatment of attention deficit hyperactivity disorder (ADHD), methylphenidate was the forerunner and catalyst to the modern era of rapidly increasing diagnosis, treatment, and medication development for this condition. During its often controversial history, it has variously elucidated the importance of dopamine signaling in memory and attention, provoked concerns about pharmaceutical cognitive enhancement, driven innovation in controlled-release technologies and enantiospecific therapeutics, and stimulated debate about the impact of pharmaceutical sales techniques on the practice of medicine. In this Review, we will illustrate the history and importance of methylphenidate to ADHD treatment and neuroscience in general, as well as provide key information about its synthesis, structure-activity relationship, pharmacological activity, metabolism, manufacturing, FDA-approved indications, and adverse effects.

Sleep Problems in Children with Attention Deficit/Hyperactivity Disorder: Current Status of Knowledge and Appropriate Management

Attention deficit hyperactivity disorder (ADHD) affects approximately 5 % of children and adolescents, and sleep problems are common in these patients. There is growing evidence informing the significant importance of sleep problems in youth with ADHD. The sleep problems in children with ADHD include specific sleep disorders and sleep disturbances due to comorbid psychiatric disorders or ADHD medications. The specific sleep disorders of ADHD children include behaviorally based insomnia, sleep-disordered breathing, and restless legs syndrome/periodic limb movement disorder. Current practices on the management of sleep problems for ADHD children are based mostly on expert consensus, whereas more evidence-based literature can be found only recently. Assessment of the sleep conditions in ADHD children before initiation of pharmacotherapy is the currently recommended guideline, and good sleep hygiene can be considered as the first-line treatment option. In addition to modifying the dose regimens, formulation, or alternative stimulants when sleep problems are encountered in ADHD children, atomoxetine, once daily guanfacine extended release, and melatonin are potential choices for ADHD children with more severe sleep problems. In this review, we aimed to provide the most updated information, preferably based on meta-analyses, systemic review, and randomized controlled trials published in the latest 3 years, in order to be clinically useful for practitioners and clinicians.

Psychosocial Profile and Quality of Life in Children With Type 1 Narcolepsy: A Case-Control Study

STUDY OBJECTIVES

To investigate behavioral aspects and quality of life in children and adolescents with type 1 narcolepsy (NT1).

METHODS

We performed a case-control study comparing 29 patients with NT1 versus sex- and age-matched patients with idiopathic epilepsy (n = 39) and healthy controls (n = 39). Behavior and quality of life were evaluated by self-administered questionnaires (Child Behavior Checklist, Pediatric Quality of Life Inventory). Patient groups were contrasted and scale results were correlated with clinical and polysomnographic parameters, and cerebrospinal fluid hypocretin-1 levels.

RESULTS

Young patients with NT1 showed increased internalizing problems associated with aggressive behavior. Emotional profile in patients with NT1 positively correlated with age at onset, diagnostic delay, and subjective sleepiness, whereas treatment and disease duration were associated with fewer behavioral problems (attention problems, aggressive behavior, and attention deficit/hyperactivity disorder). Psychosocial health domains of pediatric NT1 were worse than in healthy controls, whereas the physical health domains were comparable.

CONCLUSIONS

Young NT1 patients show a discrete pattern of altered behavioral, thought, and mood profile in comparison with healthy controls and with idiopathic epilepsy patients thus suggesting a direct link with sleepiness. Further studies investigating behavior in patients with idiopathic hypersomnia or type 2 narcolepsy are needed to disentangle the role of REM sleep dysfunction and hypocretin deficiency in psychiatric disorders. Symptoms of withdrawal, depression, somatic complaints, thought problems, and aggressiveness were common, NT1 children perceived lower school competencies than healthy children, and their parents also reported worse psychosocial health. Our data suggest that early effective treatment and disease self-awareness should be promoted in NT1 children for their positive effect on behavior and psychosocial health.

Sleep-Related Disorders in Children with Attention-Deficit Hyperactivity Disorder: Preliminary Results of a Full Sleep Assessment Study

BACKGROUND AND METHODS

We present the preliminary results of a prospective case-control sleep study in children with a diagnosis of attention-deficit hyperactivity disorder (ADHD). A deep sleep assessment including sleep questionnaires, sleep habits, a video-polysomnographic recording with full high-density electroencephalography (EEG) and cardiorespiratory polygraphy, multiple sleep latency test, and 1-week actigraphic recording were performed to verify whether children with ADHD may be classified into one of the following five phenotypes: (1) hypoarousal state, resembling narcolepsy, which may be considered a "primary" form of ADHD; (2) delayed sleep onset insomnia; (3) sleep-disordered breathing; (4) restless legs syndrome and/or periodic limb movements; and (5) sleep epilepsy and/or EEG interictal epileptiform discharges.

RESULTS

Fifteen consecutive outpatients with ADHD were recruited (two female, mean age 10.6 ± 2.2, age range 8-13.7 years) over 6 months. The narcolepsy-like sleep phenotype was observed in three children, the sleep onset insomnia phenotype was observed in one child, mild obstructive sleep apnea was observed in three children, sleep hyperkinesia and/or PLMs were observed in five children, while IEDs and or nocturnal epilepsy were observed in three children. Depending on the sleep phenotype, children received melatonin, iron supplementation, antiepileptic drugs, or stimulants.

CONCLUSIONS

Our study further highlights the need to design an efficient sleep diagnostic algorithm for children with ADHD, thereby more accurately identifying cases in which a full sleep assessment is indicated.

Treatment Options for Narcolepsy

Narcolepsy type 1 and narcolepsy type 2 are central disorders of hypersomnolence. Narcolepsy type 1 is characterized by excessive daytime sleepiness and cataplexy and is associated with hypocretin-1 deficiency. On the other hand, in narcolepsy type 2, cerebrospinal fluid hypocretin-1 levels are normal and cataplexy absent. Despite major advances in our understanding of narcolepsy mechanisms, its current management is only symptomatic. Treatment options may vary from a single drug that targets several symptoms, or multiple medications that each treats a specific symptom. In recent years, narcolepsy treatment has changed with the widespread use of modafinil/armodafinil for daytime sleepiness, antidepressants (selective serotonin and dual serotonin and noradrenalin reuptake inhibitors) for cataplexy, and sodium oxybate for both symptoms. Other psychostimulants can also be used, such as methylphenidate, pitolisant and rarely amphetamines, as third-line therapy. Importantly, clinically relevant subjective and objective measures of daytime sleepiness are required to monitor the treatment efficacy and to provide guidance on whether the treatment goals are met. Associated symptoms and comorbid conditions, such as hypnagogic/hypnopompic hallucinations, sleep paralysis, disturbed nighttime sleep, unpleasant dreams, REM- and non REM-related parasomnias, depressive symptoms, overweight/obesity, and obstructive sleep apnea, should also be taken into account and managed, if required. In the near future, the efficacy of new wake-promoting drugs, anticataplectic agents, hypocretin replacement therapy and immunotherapy at the early stages of the disease should also be evaluated.