Microglia Density and Its Association With Disease Duration, Severity, and Orexin Levels in Patients With Narcolepsy Type 1

BACKGROUND AND OBJECTIVES

Narcolepsy type 1 (NT1) is due to the loss of hypothalamic neurons that produce orexin (ORX), by a suspected immune-mediated process. Rare postmortem studies are available and failed to detect any inflammation in the hypothalamic region, but these brains were collected years after the first symptoms. In vivo studies close to disease onset are lacking. We aimed to explore microglia density in the hypothalamus and thalamus in NT1 compared with controls using [18F]DPA-714 PET and to study in NT1 the relationships between microglia density in the hypothalamus and in other regions of interest (ROIs) with disease duration, severity, and ORX levels.

METHODS

Patients with NT1 and controls underwent a standardized clinical evaluation and [18F]DPA-714 PET imaging using a radiolabeled ligand specific to the 18 kDa translocator protein (TSPO). TSPO genotyping determined receptor affinity. Images were processed on peripheral module interface using standard uptake value (SUV) on ROIs: hypothalamus, thalamus, frontal area, cerebellum, and the whole brain. SUV ratios (SUVr) were calculated by normalizing SUV with cerebellum uptake.

RESULTS

A total of 41 patients with NT1 (21 adults, 20 children, 10 with recent disease onset <1 year) and 35 controls were included, with no significant difference between groups for [18F]DPA-714 binding (SUV/SUVr) in the hypothalamus and thalamus. Unexpectedly, significantly lower SUVr in the whole brain was found in NT1 compared with controls (0.97 ± 0.06 vs 1.08 ± 0.22, p = 0.04). The same finding between NT1 and controls in the whole brain was observed in those with high or mixed TSPO affinity (p = 0.03 and p = 0.04). Similar trend was observed in the frontal area in NT1 (0.96 ± 0.09 vs 1.09 ± 0.25, p = 0.05). In NT1, no association was found between SUVr in different ROIs and age, disease duration, severity, or ORX levels.

DISCUSSION

We found no evidence of in vivo increased microglia density in NT1 compared with controls, even close to disease onset, and even unexpectedly a decrease in the whole brain of these patients. These findings do not support the presence of neuroinflammation in the destruction process of ORX neurons.

TRIAL REGISTRATION INFORMATION

ClinicalTrials.org NCT03754348.

Effect of sodium oxybate on body mass index in pediatric patients with narcolepsy

STUDY OBJECTIVES

We examined body mass index (BMI) changes associated with sodium oxybate treatment (SXB) in pediatric patients with narcolepsy with cataplexy who participated in a double-blind, placebo-controlled, randomized withdrawal study and an open-label continuation period.

METHODS

Participants were aged 7-16 years at screening. SXB-naive participants titrated to twice-nightly dosing of SXB then entered a 2-week stable-dose period; participants taking SXB at study entry entered a 3-week stable-dose period. After a 2-week randomized withdrawal period, all participants entered an open-label safety period (OLP; main study duration: ≤ 52 weeks). Participants who completed the OLP were allowed to enter the open-label continuation period (an additional 1-2 years). BMI percentile categories were defined as underweight (< 5th), normal (5th to < 85th), overweight (≥ 85th to < 95th), and obese (≥ 95th).

RESULTS

Median BMI percentile decreased from baseline to OLP week 52 in SXB-naive participants who were normal weight at baseline (decreased from 77.0 to 35.0) or overweight/obese at baseline (98.0 to 86.7). Median BMI percentile decreased to a lesser extent in participants taking twice-nightly SXB at study entry who were normal weight at baseline (54.6 to 53.0) or overweight/obese at baseline (96.5 to 88.9). Shifts in BMI category from baseline to week 52 were sometimes noted. In SXB-naive participants, 9/10 (90.0%) who were overweight became normal weight, 7/25 (28.0%) who were obese became normal weight, 3/25 (12.0%) who were obese became overweight, and 1/16 (6.3%) who was normal weight became obese. In participants taking SXB at baseline, 5/8 (62.5%) who were overweight became normal weight, 3/6 (50.0%) who were obese became overweight, 1/14 (7.1%) who was normal weight became overweight, and 2/14 (14.3%) who were normal weight became underweight. Median BMI percentiles at months 6 and 12 of the open-label continuation period were similar to those at OLP end (OLP week 52). In SXB-naive participants, the evident BMI z-score decrease over time was relative to the screening values.

CONCLUSIONS

Decreases in BMI percentile and z-score, and downward shifts in BMI category, were observed within 1 year of SXB treatment in pediatric participants with narcolepsy with cataplexy. BMI decreases plateaued after approximately 1 year.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Name: A Multicenter Study of the Efficacy and Safety of Xyrem With an Open-Label Pharmacokinetic Evaluation and Safety Extension in Pediatric Subjects With Narcolepsy With Cataplexy; URL: https://clinicaltrials.gov/study/NCT02221869; Identifier: NCT02221869.

CITATION

Dauvilliers Y, Lammers GJ, Lecendreux M, et al. Effect of sodium oxybate on body mass index in pediatric patients with narcolepsy. J Clin Sleep Med. 2024;20(3):445-454.

NLS-3 (Levophacetoperane or (R,R) Phacetoperane): A Reverse Ester of Methylphenidate: A Literature Review

BACKGROUND

NLS-3 or (R, R) enantiomer of phacetoperane (levophacetoperane) is the reverse ester of methylphenidate, a well-documented psychostimulant marketed for the treatment of attention-deficit/hyperactivity disorder (ADHD) since the end of 1950s. Launched in Canada and Europe by Specia Rhône-Poulenc and Rhodia, marketed as Lidepran® (8228 R.P.), for the treatment of obesity and depression, phacetoperane became an increasingly popular psychiatric medication from 1959 to 1967. Previous data supported that the stimulant effect of phacetoperane differed from those of other medications acting on the catecholamine system (e.g., methylphenidate, amphetamine), with an advantage of benefit/risk balance.

METHOD

The goal of this study is to characterize the binding profile of NLS-3 using in vitro and in vivo assays and hypothesize potential therapeutic uses considering all available data.

RESULTS

A complete binding profile assay confirmed the potential benefit of phacetoperane with a higher benefit/risk compared to other stimulants. NLS-3 synthesis resulted from phenylketone, which is also used for the synthesis of methylphenidate. It differs from that used by Rhône-Poulenc SA laboratories, allowing the possibility of individualizing several enantiomers not synthesized previously. The present review also confirmed extensive clinical use of the compound in almost one thousand children and adolescents in large dose ranges with fewer side effects versus comparative treatments. Furthermore, levophacetoperane was found to be generally well-tolerated by the subjects.

CONCLUSION

NLS-3 could be a safer and more potent alternative to stimulants for patients with ADHD.

Narcolepsy risk loci outline role of T cell autoimmunity and infectious triggers in narcolepsy

Narcolepsy type 1 (NT1) is caused by a loss of hypocretin/orexin transmission. Risk factors include pandemic 2009 H1N1 influenza A infection and immunization with Pandemrix®. Here, we dissect disease mechanisms and interactions with environmental triggers in a multi-ethnic sample of 6,073 cases and 84,856 controls. We fine-mapped GWAS signals within HLA (DQ0602, DQB1*03:01 and DPB1*04:02) and discovered seven novel associations (CD207, NAB1, IKZF4-ERBB3, CTSC, DENND1B, SIRPG, PRF1). Significant signals at TRA and DQB1*06:02 loci were found in 245 vaccination-related cases, who also shared polygenic risk. T cell receptor associations in NT1 modulated TRAJ*24, TRAJ*28 and TRBV*4-2 chain-usage. Partitioned heritability and immune cell enrichment analyses found genetic signals to be driven by dendritic and helper T cells. Lastly comorbidity analysis using data from FinnGen, suggests shared effects between NT1 and other autoimmune diseases. NT1 genetic variants shape autoimmunity and response to environmental triggers, including influenza A infection and immunization with Pandemrix®.

Safety and efficacy of pitolisant in children aged 6 years or older with narcolepsy with or without cataplexy: a double-blind, randomised, placebo-controlled trial

BACKGROUND

Narcolepsy is a life-long disorder characterised by excessive daytime sleepiness and cataplexy, often arising in childhood or adolescence. Pitolisant, a selective histamine H3 receptor inverse agonist, has been approved in Europe and USA for adults with narcolepsy with or without cataplexy, with a favourable safety profile. This phase 3 study aimed to assess the safety and efficacy of pitolisant in children with narcolepsy with or without cataplexy.

METHODS

For this double-blind, randomised, placebo-controlled, multisite study, we recruited patients aged 6-17 years with narcolepsy with or without cataplexy in 11 sleep centres in five countries (Italy, France, Netherlands, Russia, and Finland). Participants were required to have a Pediatric Daytime Sleepiness Scale score of 15 or greater and to have not received psychostimulants for at least 14 days before enrolment; participants who needed anticataplectics (including sodium oxybate) were required to have been on a stable dose for at least 1 month. Participants were randomly assigned to treatment with pitolisant or placebo in a 2:1 ratio at the end of screening. Randomisation was stratified by study centre and treatment was allocated using an interactive web response system. After a 4-week screening period including a 2-week baseline period, patients entered in a 4-week individual up-titration scheme from 5 mg a day to a maximum of 40 mg a day of pitolisant or placebo; treatment was administered at a stable dose for 4 weeks, followed by a 1-week placebo period. For the primary analysis, we assessed pitolisant versus placebo using change in the Ullanlinna Narcolepsy Scale (UNS) total score from baseline to the end of double-blind period in the full analysis set, defined as all randomly allocated patients who received at least one dose of treatment and who had at least one baseline UNS value. A decrease in the UNS total score reflects a reduction in both excessive daytime sleepiness and cataplexy. All adverse events were assessed in the safety population, defined as all participants who took at least one dose of study medication. An open-label follow-up is ongoing. This study is registered at ClinicalTrials.gov, NCT02611687.

FINDINGS

Between June 6, 2016, and April 3, 2021, we screened 115 participants and 110 were randomly assigned (mean age 12·9 [SD 3·0] years, 61 [55%] male, and 90 [82%] with cataplexy; 72 assigned to pitolisant and 38 to placebo); 107 (70 receiving pitolisant and 37 receiving placebo) completed the double-blind period. The mean adjusted difference in UNS total score from baseline to the end of the double-blind period was -6·3 (SE 1·1) in the pitolisant group and -2·6 (1·4) in the placebo group (least squares mean difference -3·7; 95% CI -6·4 to -1·0, p=0·007). Treatment-emergent adverse events were reported in 22 (31%) of 72 patients in the pitolisant group and 13 (34%) of 38 patients in the placebo group. The most frequently reported adverse events (affecting ≥5% of patients) in either group were headache (14 [19%] in the pitolisant group and three [8%] in the placebo group) and insomnia (five [7%] in the pitolisant group and one [3%] in the placebo group).

INTERPRETATION

Pitolisant treatment resulted in an improvement in narcolepsy symptoms in children, although the UNS was not validated for use in children with narcolepsy when our study began. The safety profile was similar to that reported in adults but further studies are needed to confirm long-term safety.

FUNDING

Bioprojet.

French Sleepiness Scale for Adolescents-8 items: A discriminant and diagnostic validation

The objective of the present study was to validate the Short Version of French Sleepiness Scale for Adolescents (FSSA) with eight items (FSSA8).

METHODS

A total of 384 adolescents, aged between 12 and 18 years, completed the FSSA8. These included 269 nonclinical adolescents and 115 adolescents admitted for overnight polysomnography and Multiple Sleep Latency Test (MSLT) because of suspected hypersomnia (85 patients with narcolepsy and 30 with other sleep disorders). Item response theory (IRT) assumptions were tested and psychometric properties were analysed. Matching on sex ratio and age was conducted to estimate concurrent criterion, diagnostic validity and cut-offs.

RESULTS

IRT assumptions were validated confirming the one-dimensionality of the FSSA8. The latent continuum sleepiness for which the scale and its items are reliable encompassed most of the clinical subjects. FSSA8 is weakly correlated with MSLT. Distribution of scores for the nonclinical group and the clinical group differed significantly; the FSSA8 had very good screening validity in sleep disorders. The cut-off was seven points.

CONCLUSION

The FSSA8 appeared to be more reliable for patients than for nonclinical participants and to be a good tool for screening excessive daytime sleepiness in sleep 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.

Association of Parent-Rated Sleep Disturbances With Attention-Deficit/Hyperactivity Disorder Symptoms: 9-Year Follow-up of a Population-Based Cohort Study

OBJECTIVE

Symptoms of attention-deficit/hyperactivity disorder (ADHD) and sleep disturbances frequently co-occur, and can result in significant functional impairments that worsen quality of life. Despite a growing number of studies focusing on the association between sleep disturbances and ADHD symptoms over the last 20 years, the directionality of this association from childhood to early adulthood remains unclear.

METHOD

A sample of French parents (n = 1,055) were followed-up over a 9-year period. At children mean ages of 9, 13, and 18 years, parents were interviewed about their children's ADHD symptoms and sleep disturbances. Random-intercept cross-lagged panel models assessed the directionality of the association from childhood to early adulthood.

RESULTS

Parent-reported sleep disturbances at a mean age of 13 years predicted increased ADHD symptoms 5 years later. Additional analyses suggested that this effect might be limited to inattentive symptoms, and that ADHD symptoms at a mean age of 9 predicted increased sleep disturbances 4 years later.

CONCLUSION

The present study provides evidence of a directional longitudinal association between parent-reported sleep disturbances and ADHD symptoms from adolescence to early adulthood. Our results highlight the importance of identifying sleep disturbances and ADHD symptoms for the design of preventive interventions. Future studies investigating this association in children with a clinical diagnosis of ADHD have the potential to provide important information for clinical practice.

Adjustment to lockdown in children and adolescents with narcolepsy in France

STUDY OBJECTIVES

The goal of the current study was to explore the effect of a 2-month quarantine on children and adolescents with narcolepsy and to describe the changes in their sleep, mood, and metabolism during this period.

METHODS

The study involved 77 patients aged 7 to 23 years with a diagnosis of narcolepsy. Participants had to answer multiple-choice questions to characterize the changes and modifications in their own habits and state of health.

RESULTS

Participants reported changes in daytime sleep, nighttime sleep schedules, treatment intake, food intake, weight, and amount of screen time. Most patients reported deterioration in their memory and attention abilities as well as a decrease in their work efficiency. Mood appeared to be less affected, although it deteriorated in less than one-third of the participants who reported feeling sad more often.

CONCLUSIONS

The prolonged and complete lockdown seemed to have an effect on children and adolescents with narcolepsy, and changes are often considered by the participants to depend on or to determine an overall quality of adaptation to the situation. This study highlights the importance of maintaining and strengthening time markers in individuals with narcolepsy and should help to establish guidelines that would apply in future quarantine situations.

CITATION

de Laclause AP, Konofal E, Bokov P, Delclaux C, Lecendreux M. Adjustment to lockdown in children and adolescents with narcolepsy in France. J Clin Sleep Med. 2022;18(9):2247-2252.

Short Research Article: Impact of a prolonged lockdown on the symptoms of paediatric ADHD and common associated disorders

OBJECTIVE

Our objective is to explore the change in the severity of ADHD, ODD and anxiety during a two-month lockdown among children in France and the moderating role of behavioural regulation.

METHOD

In 235 children with ADHD, the symptom severity of ADHD, ODD and anxiety was investigated one and two months after the beginning of lockdown, and one month after its end. Behavioural regulation skills were estimated with the Behaviour Regulation Index.

RESULTS

ADHD, ODD and anxiety scores were increasing or decreasing depending on BRI.

CONCLUSION

Baseline behavioural regulation skills may act as a moderating factor for the persistence of ADHD, ODD and anxiety symptoms related to the lockdown.

Long-term safety and maintenance of efficacy of sodium oxybate in the treatment of narcolepsy with cataplexy in pediatric patients

STUDY OBJECTIVES

Evaluate long-term efficacy and safety of sodium oxybate (SXB) in children and adolescents (aged 7-16 years) with narcolepsy with cataplexy.

METHODS

A double-blind randomized withdrawal study was conducted. Prior to randomization, SXB-naive participants were titrated to an efficacious and tolerable dose of SXB; participants taking SXB entered on their established dose. Following a 2-week stable-dose period and 2-week, double-blind, randomized withdrawal period, participants entered an open-label period (OLP; ≤ 47 weeks). Efficacy measures during the OLP included number of weekly cataplexy attacks, cataplexy-free days, and Epworth Sleepiness Scale for Children and Adolescents (ESS-CHAD). Safety outcomes included treatment-emergent adverse events; assessments of depression, anxiety, and suicidality; and polysomnography.

RESULTS

Of 106 enrolled participants, 95 entered and 85 completed the OLP. In SXB-naive participants and participants previously taking SXB, efficacy of SXB established prior to the double-blind, randomized withdrawal period was maintained throughout the OLP for number of weekly cataplexy attacks (median [quartile 1, quartile 3] change from the stable-dose period to end of the OLP: 0.0 [-2.5, 4.9] and 0.0 [-3.4, 2.6], respectively) and ESS-CHAD scores (0.0 [-3.0, 2.5] and 1.0 [-3.0, 3.0], respectively). The median (quartile 1, quartile 3) number of cataplexy-free days per week was 2.3 (0.0, 6.0) in OLP week 1 and 3.8 (0.5, 5.5) in week 48. Treatment-emergent adverse events (≥ 5%) were enuresis, nausea, vomiting, headache, decreased weight, decreased appetite, nasopharyngitis, upper respiratory tract infection, and dizziness.

CONCLUSIONS

SXB demonstrated long-term maintenance of efficacy in pediatric narcolepsy with cataplexy, with a safety profile consistent with that observed in adults.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Name: A Multicenter Study of the Efficacy and Safety of Xyrem with an Open-Label Pharmacokinetic Evaluation and Safety Extension in Pediatric Subjects with Narcolepsy with Cataplexy; URL: https://clinicaltrials.gov/ct2/show/NCT02221869; Identifier: NCT02221869.

CITATION

Lecendreux M, Plazzi G, Dauvilliers Y, et al. Long-term safety and maintenance of efficacy of sodium oxybate in the treatment of narcolepsy with cataplexy in pediatric patients. J Clin Sleep Med. 2022;18(9):2217-2227.

Comorbid parasomnias in narcolepsy and idiopathic hypersomnia: more REM than NREM parasomnias

STUDY OBJECTIVES

To assess the frequency, determinants and clinical impact of clinical NREM and REM parasomnias in adult patients with narcolepsy type 1 (NT1), narcolepsy type 2 (NT2), and idiopathic hypersomnia (IH) compared to healthy controls.

METHODS

Familial and past and current personal parasomnias were assessed by questionnaire and medical interviews in 710 patients (220 NT1, 199 NT2, and 221 IH) and 595 healthy controls.

RESULTS

Except for sleep-related eating disorder (SRED), current NREM parasomnias were rare in all patient groups and controls. SRED was more frequent in NT1 patients (7.9%, vs. 1.8% in NT2 patients, 2.1% in IH patients and 1% in controls) and associated with disrupted nighttime sleep (odds ratio [OR] = 3.9) and nocturnal eating in full awareness (OR = 6.9) but not with sex. Clinical REM sleep behavior disorder (RBD) was more frequent in NT1 patients (41.4%, half being violent) than in NT2 patients (13.2%) and affected men more often than women (OR = 2.4). It was associated with disrupted nighttime sleep, depressive symptoms and antidepressant use. Frequent (>1/week) nightmares were reported by 39% of patients with NT1, 29% with NT2 and 27.8% with IH (vs. 8.3% in controls) and were associated with depressive symptoms in narcolepsy. No parasomnia (except sleep-related hallucinations) worsened daytime sleepiness.

CONCLUSIONS

In patients with central disorders of hypersomnolence, comorbid NREM parasomnias (except SRED) are rare and do not worsen sleepiness. In contrast, REM parasomnias are prevalent (especially in NT1) and associated with male sex, disrupted nighttime sleep, depressive symptoms and antidepressant use.

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.

European guideline and expert statements on the management of narcolepsy in adults and children

BACKGROUND AND PURPOSE

Narcolepsy is an uncommon hypothalamic disorder of presumed autoimmune origin that usually requires lifelong treatment. This paper aims to provide evidence-based guidelines for the management of narcolepsy in both adults and children.

METHODS

The European Academy of Neurology (EAN), European Sleep Research Society (ESRS), and European Narcolepsy Network (EU-NN) nominated a task force of 18 narcolepsy specialists. According to the EAN recommendations, 10 relevant clinical questions were formulated in PICO format. Following a systematic review of the literature (performed in Fall 2018 and updated in July 2020) recommendations were developed according to the GRADE approach.

RESULTS

A total of 10,247 references were evaluated, 308 studies were assessed and 155 finally included. The main recommendations can be summarized as follows: (i) excessive daytime sleepiness (EDS) in adults-scheduled naps, modafinil, pitolisant, sodium oxybate (SXB), solriamfetol (all strong); methylphenidate, amphetamine derivatives (both weak); (ii) cataplexy in adults-SXB, venlafaxine, clomipramine (all strong) and pitolisant (weak); (iii) EDS in children-scheduled naps, SXB (both strong), modafinil, methylphenidate, pitolisant, amphetamine derivatives (all weak); (iv) cataplexy in children-SXB (strong), antidepressants (weak). Treatment choices should be tailored to each patient's symptoms, comorbidities, tolerance and risk of potential drug interactions.

CONCLUSION

The management of narcolepsy involves non-pharmacological and pharmacological approaches with an increasing number of symptomatic treatment options for adults and children that have been studied in some detail.

European guideline and expert statements on the management of narcolepsy in adults and children

BACKGROUND AND AIM

Narcolepsy is an uncommon hypothalamic disorder of presumed autoimmune origin that usually requires lifelong treatment. This paper aims to provide evidence-based guidelines for the management of narcolepsy in both adults and children.

METHODS

The European Academy of Neurology (EAN), European Sleep Research Society (ESRS) and European Narcolepsy Network (EU-NN) nominated a task force of 18 narcolepsy specialists. According to the EAN recommendations, 10 relevant clinical questions were formulated in PICO format. Following a systematic review of the literature (performed in Fall 2018 and updated in July 2020) recommendations were developed according to the GRADE approach.

RESULTS

A total of 10,247 references were evaluated, 308 studies were assessed and 155 finally included. The main recommendations can be summarized as follows: (i) excessive daytime sleepiness in adults-scheduled naps, modafinil, pitolisant, sodium oxybate (SXB), solriamfetol (all strong), methylphenidate, amphetamine derivates (both weak); (ii) cataplexy in adults-SXB, venlafaxine, clomipramine (all strong) and pitolisant (weak); (iii) excessive daytime sleepiness in children-scheduled naps, SXB (both strong), modafinil, methylphenidate, pitolisant, amphetamine derivates (all weak); (iv) cataplexy in children-SXB (strong), antidepressants (weak). Treatment choices should be tailored to each patient's symptoms, comorbidities, tolerance and risk of potential drug interactions.

CONCLUSION

The management of narcolepsy involves non-pharmacological and pharmacological approaches with an increasing number of symptomatic treatment options for adults and children that have been studied in some detail.

Measurement of Narcolepsy Symptoms in School-Aged Children and Adolescents: The Pediatric Narcolepsy Severity Scale

OBJECTIVE

We validated the Narcolepsy Severity Scale (NSS) in adults with narcolepsy type 1 (NT1) to quantify the severity, frequency, and consequences of the 5 key narcolepsy symptoms over the last month, and we now developed the Pediatric NSS (NSS-P); thus, the aims of this study were to assess NSS-P psychometric properties, validity, and reliability, and to evaluate its responsiveness to treatment in a well-characterized sample of children and adolescents with NT1.

METHODS

The NSS was reformulated for children, and the item about driving was removed. The total score of the 14-item NSS-P ranges from 0 to 54, and higher scores reflect more severe disease. Children and adolescents (n = 209, 6-17 years of age) with NT1 diagnosed in 2 Reference Centers for Narcolepsy in France were consecutively asked to fill in the NSS-P. The scale was fully and correctly completed by 160 (10-18 years of age, 68 untreated). Moreover, 65 participants completed it twice (33 before/during treatment, and 32 under the same treatment). The NSS-P psychometric properties, score changes before/during treatment, and convergent validity with other clinical parameters were assessed.

RESULTS

The NSS-P showed adequate psychometric properties with significant item-total score correlations. Factor analysis indicated a 4-factor solution with good reliability. The NSS-P score was lower in treated than untreated patients with a mean difference of 3.71 ± 1.45, with a minimum clinically important difference between untreated and treated patients in the longitudinal sample estimated at 4 points. Four severity levels were defined (mild, moderate, severe, very severe) with between-group differences related to treatment. The NSS-P total score was associated with self-reported sleepiness, insomnia, and depressive symptoms. Its temporal stability was satisfactory.

DISCUSSION

We validated a brief instrument to assess NT1 symptom frequency, severity, and consequences in ≥10-year-old children and adolescents with 4 clinically relevant severity score ranges. This scale constitutes a relevant tool to improve and provide guidance for NT1 management in pediatric populations. The ease of administration, its good psychometric properties, and its sensitivity to detect symptom changes after treatment ensure future use of the NSS-P in clinical and research settings.

New 2013 incidence peak in childhood narcolepsy: more than vaccination?

Increased incidence rates of narcolepsy type-1 (NT1) have been reported worldwide after the 2009-2010 H1N1 influenza pandemic (pH1N1). While some European countries found an association between the NT1 incidence increase and the H1N1 vaccination Pandemrix, reports from Asian countries suggested the H1N1 virus itself to be linked to the increased NT1 incidence. Using robust data-driven modeling approaches, that is, locally estimated scatterplot smoothing methods, we analyzed the number of de novo NT1 cases (n = 508) in the last two decades using the European Narcolepsy Network database. We confirmed the peak of NT1 incidence in 2010, that is, 2.54-fold (95% confidence interval [CI]: [2.11, 3.19]) increase in NT1 onset following 2009-2010 pH1N1. This peak in 2010 was found in both childhood NT1 (2.75-fold increase, 95% CI: [1.95, 4.69]) and adulthood NT1 (2.43-fold increase, 95% CI: [2.05, 2.97]). In addition, we identified a new peak in 2013 that is age-specific for children/adolescents (i.e. 2.09-fold increase, 95% CI: [1.52, 3.32]). Most of these children/adolescents were HLA DQB1*06:02 positive and showed a subacute disease onset consistent with an immune-mediated type of narcolepsy. The new 2013 incidence peak is likely not related to Pandemrix as it was not used after 2010. Our results suggest that the increased NT1 incidence after 2009-2010 pH1N1 is not unique and our study provides an opportunity to develop new hypotheses, for example, considering other (influenza) viruses or epidemiological events to further investigate the pathophysiology of immune-mediated narcolepsy.

Cross-sectional case-control study of the relationships between pharyngeal compliance and heart rate variability indices in childhood obstructive sleep apnoea

A combination of noradrenergic and antimuscarinic agents reduces the apnea-hypopnea index (AHI) in adult patients with obstructive sleep apnoea (OSA) via reduced upper airway collapsibility, suggesting that a shift in the sympathovagal balance improves OSA. The objectives of our present case-control study were to assess heart rate variability (HRV) indices in the stages of sleep in children with and without OSA to evaluate OSA-induced sleep HRV modifications and to assess whether increased collapsibility measured during wakefulness is associated with reduced sympathetic activity during non-rapid eye movement (NREM) sleep. Three groups of 15 children were matched by sex, age, z-score of body mass index and ethnicity: non-OSA (obstructive AHI [OAHI] <2 events/hr), mild (OAHI ≥2 to <5 events/hr) or moderate-severe (OAHI ≥5 events/hr) OSA. Pharyngeal compliance was measured during wakefulness using acoustic pharyngometry. HRV indices (time and frequency domain variables) were calculated on 5-min electrocardiography recordings from polysomnography during wakefulness, NREM and REM sleep in periods free of any event. As compared to children without OSA, those with OSA (n = 30) were characterised by increased compliance and no physiological parasympathetic tone increase in REM sleep. Children with increased pharyngeal compliance (n = 21) had a higher OAHI due to higher AHI in NREM sleep, whereas their sympathetic tone was lower than that of those with normal compliance (n = 24). In conclusion, children with increased pharyngeal compliance exhibit decreased sympathetic tone associated with increased AHI in NREM sleep. Therapeutics directed at sympathovagal balance modifications should be tested in childhood OSA.

Narcolepsy with cataplexy: Does age at diagnosis change the clinical picture?

Objective

To compare symptoms and sleep characteristics in patients diagnosed with narcolepsy‐cataplexy (NC) before and after the age of 18 years.

Methods

De novo patients with NC diagnosis completed a standardized questionnaire and interview, followed by a sleep study. The clinical and sleep measures were compared between patients diagnosed before (46 children, median age: 12 year old) and after (46 adults, median age: 28.5 year old) 18 years of age.

Results

The frequency of obesity (54% vs 17%), night eating (29% vs 7%), parasomnia (89% vs 43%), sleep talking (80% vs 34%), and sleep drunkenness (69% vs 24%) were higher in children than in adults, the frequency of sleep paralysis was lower (20% vs 55%) but the frequency of cataplexy and the severity of sleepiness were not different. Children scored higher than adults at the attention‐deficit/hyperactivity disorder (ADHD) scale. Depressive feelings affected not differently children (24%) and adults (32%). However, adults had lower quality of life than children. There was no difference between groups for insomnia and fatigue scores. Quality of life was essentially impacted by depressive feelings in both children and adults. Obstructive apnea‐hypopnea index (OAHI) was lower in children with higher mean and minimal oxygen saturation than in adults. No between‐group differences were found at the multiple sleep latency test. The body mass index (z‐score) was correlated with OAHI (r = .32).

Conclusion

At time of NC diagnosis, children have more frequent obesity, night eating, parasomnia, sleep talking, drunkenness, and ADHD symptoms than adults, even if sleepiness and cataplexy do not differ. These differences should be considered to ensure a prompt diagnosis.

0950 Effects of Sodium Oxybate (SXB) on Body Mass Index (BMI) in Pediatric Patients With Narcolepsy

Introduction

Obesity is a common comorbidity of pediatric narcolepsy. SXB is a standard of care for cataplexy and excessive daytime sleepiness in narcolepsy. BMI decreases have been observed with SXB treatment. We examined BMI changes by BMI percentile category at study entry in pediatric participants.

Methods

Participants were aged 7-17 years with narcolepsy with cataplexy. SXB-naive participants were titrated to an optimal SXB dose, then entered a 2-week stable-dose period; participants taking SXB at study entry entered a 3-week stable-dose period. After a 2-week, placebo-controlled, double-blind, randomized-withdrawal period, all participants entered an open-label safety period (total study duration: ≤1 year). Weight categories were defined using BMI percentiles at study entry based on growth charts from the Centers for Disease Control. BMI percentile was categorized as: underweight (&lt;5%ile), normal (≥5%ile to &lt;85%ile), overweight (≥85%ile to&lt;95%ile), obese (≥95%ile).

Results

Among SXB-naive participants, median (Q1, Q3) BMI percentile decreased with SXB treatment in participants who were categorized as normal-weight and overweight/obese at baseline (normal-weight, n=16: 76.5 [57.8, 82.4] at baseline, 35.0 [20.5, 62.6] at week 52; overweight/obese, n=35: 97.6 [93.6, 99.1] at baseline, 86.7 [72.5, 97.9] at week 52). Of participants who were normal-weight at baseline, 15/16 remained normal-weight at week 52. Of participants who were overweight at baseline, 9/10 were normal-weight at week 52. Of participants who were obese at baseline, 7/25 were normal-weight, 3/25 were overweight, and 15/25 remained obese at week 52. Among participants taking SXB at study entry, BMI percentile decreased, but to a lesser degree. Decreased weight or weight loss was reported as an adverse event in 13 participants (11 SXB-naive; 1 participant withdrew). Four participants became underweight during the study but returned to normal-weight by study end.

Conclusion

Decreases in BMI percentile and category were observed with SXB treatment in pediatric participants with narcolepsy.

Support

Jazz Pharmaceuticals

FC13-11 - Effectiveness of mazindol in children with ADHD : open-label study

Mazindol is a central nervous system stimulant, which blocks reuptake of dopamine and norepinephrine. Mazindol (1–6 mg/d) has previously been studied in the treatment of excessive daytime sleepiness with relative therapeutic benefit. Our hypothesis suggests that mazindol may be effective for the treatment of Attention Deficit Hyperactivity Disorder symptoms.

Based on clinical assessments after oral administration of mazindol to 24 children (9–12 years) with ADHD (according to DSM-IVTR criteria), this open-label study evaluates the efficacy, safety and tolerability of mazindol (1 mg/d, 7 days). Safety evaluations included routine hematology, electrocardiograms, blood pressure, and pulse rate. Efficacy rating measurements included ADHD-RS score (primary outcome measure), CPRS-R:L, CGI-S and CGI-I (secondary outcome measures). This clinical trial reports data obtained from 21 boys (10 ± 1 years).

Based on primary outcome (ADHD-RS), change in ADHD-RS mean total score after one week of mazindol was −24.6 (p < 0.0001) ; greater than a 90% improvement from baseline. Change in CPRS-R:L (80 items) mean total score after one week of mazindol was −55.5 (p < 0.0001); CGI-S after one week of mazindol was -3,02 (p< 0.01). Adverse events were mild to moderate in severity and decreased appetite, weight loss, headache, and abdominal pain were most common (95%).

Changes in laboratory values, ECG, blood pressure, pulse rate and body weight were not clinically meaningful. Blood pressure and pulse rate were unchanged (p > 0.05) after one week of treatment.

This preliminary investigation suggests that mazindol is still a new well-tolerated and active psychostimulant for the treatment of ADHD in children.

A 9-Year Follow-Up of Attention-Deficit/Hyperactivity Disorder in a Population Sample

BACKGROUND

Prior follow-up studies of attention-deficit/hyperactivity disorder (ADHD) have mostly been from North America. They have provided a good deal of information about ADHD, but whether these results generalize to population samples and to other countries is not certain. Most prior studies have also not assessed predictors of possible new onsets of ADHD in non-ADHD youth or the validity of subthreshold forms of the disorder.

METHODS

1,012 families were recruited at baseline, when a telephone interview assessed a child in the 6-12 years age range. The interview covered symptoms of ADHD, conduct disorder, and oppositional defiant disorder as well as family living situation, school performance, sleep disturbance, eating habits, use of supplemental iron, and history of ADHD treatment. Nine years later, the persistence of ADHD and its impairments and the emergence of new conditions were assessed. DSM-5 diagnostic criteria were used to diagnose ADHD.

RESULTS

492 of the 1,012 participants seen at baseline were followed up 9 years later, at a mean age of 18 years. At follow-up, 16.7% of the children diagnosed with ADHD at baseline met full criteria for ADHD and 11.1% met criteria for subthreshold ADHD, yielding a persistence rate of 27.8%. Among children not diagnosed with ADHD at baseline, 1.1% met criteria for ADHD at follow-up. The persistence of ADHD and new onsets of ADHD were predicted by several baseline clinical features and by a family history of ADHD.

CONCLUSIONS

We replicated predictors of the persistence of ADHD found in prior studies and provide new data about predictors of new ADHD onsets in the population. Our findings about subthreshold ADHD support a dimensional conceptualization of the disorder, highlighting the potential clinical utility of a subthreshold diagnostic category. This study also contributes to the ongoing debate regarding adult-onset ADHD.

Practitioner Review: Current best practice in the use of parent training and other behavioural interventions in the treatment of children and adolescents with attention deficit hyperactivity disorder

BACKGROUND

Behavioural interventions are recommended for use with children and young people with attention deficit hyperactivity disorder (ADHD); however, specific guidance for their implementation based on the best available evidence is currently lacking.

METHODS

This review used an explicit question and answer format to address issues of clinical concern, based on expert interpretation of the evidence with precedence given to meta-analyses of randomised controlled trials.

RESULTS

On the basis of current evidence that takes into account whether outcomes are blinded, behavioural intervention cannot be supported as a front-line treatment for core ADHD symptoms. There is, however, evidence from measures that are probably blinded that these interventions benefit parenting practices and improve conduct problems which commonly co-occur with ADHD, and are often the main reason for referral. Initial positive results have also been found in relation to parental knowledge, children's emotional, social and academic functioning - although most studies have not used blinded outcomes. Generic and specialised ADHD parent training approaches - delivered either individually or in groups - have reported beneficial effects. High-quality training, supervision of therapists and practice with the child, may improve outcomes but further evidence is required. Evidence for who benefits the most from behavioural interventions is scant. There is no evidence to limit behavioural treatments to parents with parenting difficulties or children with conduct problems. There are positive effects of additive school-based intervention for the inattentive subtype. Targeting parental depression may enhance the effects of behavioural interventions.

CONCLUSIONS

Parent training is an important part of the multimodal treatment of children with ADHD, which improves parenting, reduces levels of oppositional and noncompliant behaviours and may improve other aspects of functioning. However, blinded evidence does not support it as a specific treatment for core ADHD symptoms. More research is required to understand how to optimise treatment effectiveness either in general or for individual patients and explore potential barriers to treatment uptake and engagement. In terms of selecting which intervention formats to use, it seems important to acknowledge and respond to parental treatment preferences.

Lauflumide (NLS-4) Is a New Potent Wake-Promoting Compound

Psychostimulants are used for the treatment of excessive daytime sleepiness in a wide range of sleep disorders as well as in attention deficit hyperactivity disorder or cognitive impairment in neuropsychiatric disorders. Here, we tested in mice the wake-promoting properties of NLS-4 and its effects on the following sleep as compared with those of modafinil and vehicle. C57BL/6J mice were intraperitoneally injected with vehicle, NLS-4 (64 mg/kg), or modafinil (150 mg/kg) at light onset. EEG and EMG were recorded continuously for 24 h after injections and vigilance states as well as EEG power densities were analyzed. NLS-4 at 64 mg/kg induced significantly longer wakefulness duration than modafinil at 150 mg/kg. Although no significant sleep rebound was observed after sleep onset for both treatments as compared with their vehicles, modafinil-treated mice showed significantly more NREM sleep when compared to NLS-4. Spectral analysis of the NREM EEG after NLS-4 treatment indicated an increased power density in delta activity (0.75–3.5 Hz) and a decreased power in theta frequency range (6.25–7.25 Hz), while there was no differences after modafinil treatment. Also, time course analysis of the delta activity showed a significant increase only during the first 2 time intervals of sleep after NLS-4 treatment, while delta power was increased during the first 9 time intervals after modafinil. Our results indicate that NLS-4 is a highly potent wake-promoting drug with no sign of hypersomnia rebound. As opposed to modafinil, recovery sleep after NLS-4 treatment is characterized by less NREM amount and delta activity, suggesting a lower need for recovery despite longer drug-induced wakefulness.

Exploring the clinical features of narcolepsy type 1 versus narcolepsy type 2 from European Narcolepsy Network database with machine learning

Narcolepsy is a rare life-long disease that exists in two forms, narcolepsy type-1 (NT1) or type-2 (NT2), but only NT1 is accepted as clearly defined entity. Both types of narcolepsies belong to the group of central hypersomnias (CH), a spectrum of poorly defined diseases with excessive daytime sleepiness as a core feature. Due to the considerable overlap of symptoms and the rarity of the diseases, it is difficult to identify distinct phenotypes of CH. Machine learning (ML) can help to identify phenotypes as it learns to recognize clinical features invisible for humans. Here we apply ML to data from the huge European Narcolepsy Network (EU-NN) that contains hundreds of mixed features of narcolepsy making it difficult to analyze with classical statistics. Stochastic gradient boosting, a supervised learning model with built-in feature selection, results in high performances in testing set. While cataplexy features are recognized as the most influential predictors, machine find additional features, e.g. mean rapid-eye-movement sleep latency of multiple sleep latency test contributes to classify NT1 and NT2 as confirmed by classical statistical analysis. Our results suggest ML can identify features of CH on machine scale from complex databases, thus providing 'ideas' and promising candidates for future diagnostic classifications.

Kleine-Levin syndrome is associated with LMOD3 variants

Kleine-Levin syndrome (KLS) is a rare periodic hypersomnia with associated behavioural abnormalities but with often favourable prognosis. There is excess risk of KLS in first-degree relatives, suggesting a strong genetic contribution. So far, no mutation is identified in KLS and comprehensive genetic analysis of affected individuals is lacking. Here we performed whole genome single-nucleotide polymorphism (SNP) genotyping and exome sequencing in a large family with seven affected members. The identified gene with a mutation was resequenced in 38 sporadic KLS patients and the expression of the gene product was mapped in the mouse brain. Linkage analysis mapped the disease locus to chromosome 3 and exome analysis identified a heterozygous missense variant in LMOD3 (p.E142D) in the linkage interval. The variant was found to segregate in all affected and one presumably unaffected member of the family. Resequencing LMOD3 in 38 other KLS patients and their families revealed three other low frequency or rare missense variants in seven cases that were inherited with incomplete penetrance. LMOD3 is expressed in the brain and colocalized with major structures involved in the regulation of vigilance states. LMOD proteins are structural proteins and seem to be developmentally regulated. Our findings suggest that KLS might be a structural/neurodevelopmental brain disease.

Emerging psychiatric disorders in Kleine-Levin syndrome

In Kleine-Levin syndrome (KLS), episodes of hypersomnia and cognitive, psychiatric and behavioural disturbances alternate with asymptomatic periods in adolescents. We evaluated whether psychiatric disorders would emerge during asymptomatic periods in a naturalistic, uncontrolled clinical cohort. Patients with primary KLS underwent psychiatric interviews at diagnosis and every year for 1-10 years, leading to diagnosis of former and present comorbid psychiatric disorders. Among the 115 patients (65.2% male and aged 16.1 ± 4.8 years at KLS onset), 19 (16.5%) had a history of psychiatric disorder prior to KLS onset, which persisted afterwards in 10. Twenty-five (21%) patients developed a new, comorbid psychiatric disorder 1-6 years after KLS onset, during 'asymptomatic' periods, including mood disorders (n = 14; including major depressive episodes, n = 8; recurrent depressive episodes, n = 2; bipolar I disorder, n = 1; dysthymic disorder, n = 1; adjustment disorder with depressive mood, n = 1; and mood disorder not otherwise specified, n = 1), anxiety disorders (n = 7), eating disorders (n = 2), psychotic disorders not otherwise specified (n = 2), schizoaffective disorder (n = 1) and cannabis dependence (n = 1). Six patients attempted suicide: two before and two after KLS onset, and two during episodes. Female sex, longer disease course, longer time incapacitated (356 ± 223 versus 155 ± 186 days) and more frequent psychiatric symptoms during episodes (but no family or personal history of psychiatric disorders) were associated with emerging psychiatric disorders. Contrary to the alleged benignity of KLS and normality between episodes, one KLS patient in five suffers from emerging psychiatric disorders. These disorders may depend on personal vulnerability and, most probably, on psychiatric symptoms during episodes.

Mazindol: a risk factor for pulmonary arterial hypertension?

Mazindol is an imidazo-isoindole derivative, a tricyclic compound and a non-amphetamine central nervous system stimulant that blocks dopamine and norepinephrine reuptake. Mazindol was withdrawn from the US and European markets in 1999 for reasons unrelated to its efficacy or safety around a time when other anorexic drugs were found to be associated with the development of pulmonary arterial hypertension (PAH). Despite the use of mazindol for decades, reports of PAH due to mazindol intake have been extremely rare. Recent interest on mazindol has emerged for the treatment of narcolepsy and attention-deficit/hyperactivity disorder. Therefore, an updated understanding of the potential benefits and risks of mazindol in these patient populations is warranted.

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.

Narcolepsy Type 1 Is Associated with a Systemic Increase and Activation of Regulatory T Cells and with a Systemic Activation of Global T Cells

Narcolepsy is a rare neurologic disorder characterized by excessive daytime sleepiness, cataplexy and disturbed nocturnal sleep patterns. Narcolepsy type 1 (NT1) has been shown to result from a selective loss of hypothalamic hypocretin-secreting neurons with patients typically showing low CSF-hypocretin levels (<110 pg/ml). This specific loss of hypocretin and the strong association with the HLA-DQB1*06:02 allele led to the hypothesis that NT1 could be an immune-mediated pathology. Moreover, susceptibility to NT1 has recently been associated with several pathogens, particularly with influenza A H1N1 virus either through infection or vaccination. The goal of this study was to compare peripheral blood immune cell populations in recent onset pediatric NT1 subjects (post or non-post 2009-influenza A H1N1 vaccination) to healthy donors. We demonstrated an increased number of central memory CD4+ T cells (CD62L+ CD45RA-) associated to an activated phenotype (increase in CD69 and CD25 expression) in NT1 patients. Percentage and absolute count of regulatory T cells (Tregs) in NT1 patients were increased associated with an activated phenotype (increase in GITR and LAP expression), and of activated memory phenotype. Cytokine production by CD4+ and CD8+ T cells after activation was not modified in NT1 patients. In H1N1 vaccinated NT1 patients, absolute counts of CD3+, CD8+ T cells, and B cells were increased compared to non-vaccinated NT1 patients. These results support a global T cell activation in NT1 patients and thus support a T cell-mediated autoimmune origin of NT1, but do not demonstrate the pathological role of H1N1 prophylactic vaccination. They should prompt further studies of T cells, particularly of Tregs (such as suppression and proliferation antigen specific assays, and also T-cell receptor sequencing), in NT1.

Comorbidity between central disorders of hypersomnolence and immune-based disorders

Objective:

To assess and compare the frequencies of personal and family history of autoimmune diseases (AID), autoinflammatory disorders (ID), and allergies in a population of patients, adults and children, with narcolepsy type 1 (NT1), narcolepsy type 2 (NT2), and idiopathic hypersomnia (IH), 3 central hypersomnia disorders, and healthy controls.

Methods:

Personal and family history of AID, ID, and allergies were assessed by questionnaire and medical interview in a large cohort of 450 consecutive adult patients (206 NT1, 106 NT2, 138 IH) and 95 pediatric patients (80 NT1) diagnosed according to the third International Classification of Sleep Disorders criteria in national reference centers for narcolepsy in France and 751 controls (700 adults, 51 children) from the general population.

Results:

Ten adults with NT1 (4.9%) had a comorbid AID vs 3.4% of adult controls, without between-group differences in adjusted models. AID frequency did not differ between children with NT1 and controls. Conversely, compared with controls, AID frequency was higher in adults with NT2 (p = 0.002), whereas ID (p = 0.0002) and allergy (p = 0.003) frequencies were higher in adults with IH. A positive family history of AID was found in the NT1 group and of ID in the IH group.

Conclusions:

NT1 is not associated with increased risk of comorbid immune disorders, in favor of a potentially unique pathophysiology. Conversely, compared with controls, the frequency of autoimmune diseases was higher in adults with NT2, whereas allergies and autoinflammatory disorders were more common in adults with IH, suggesting an immune dysregulation mechanism in these conditions.

French consensus. Hypersomnolence: Evaluation and diagnosis

Sleepiness is one of the most frequently reported complaints in adults and children during specialised sleep consultations. It is responsible for an alteration that can be severe in quality of life, a lowering of academic or professional performance, and domestic or work accidents. Hypersomnolence is the first cause of road accidents on the highway, responsible for a third of fatal accidents. Furthermore its presence is associated with an increased risk of morbi-mortality related to cardiovascular and neurodegenerative pathologies. Hence, its represents a real public health issue. Recent revisions in international classifications have clarified confusing terminology, and the complaint of hypersomnia has now been replaced by the terms hypersomnolence or excessive sleepiness. It is clinically defined as an excessive quantity of sleep over 24hours, and/or by an alteration in the quality of arousal defined as incapacity to maintain a satisfactory level of vigilance during the day or in the morning on awakening (defined as sleep inertia). The evaluation of sleepiness requires a rigorous clinical approach, completed by subjective and objective measurements. The Epworth Sleep Scale, Multiple Sleep Latency Tests and the Maintenance of Wakefulness Test are the most studied and used in clinical practice. However, to date, no gold standard measurement of excessive sleepiness exists, and there are no quantifiable biological markers. It is therefore important to optimise our evaluation tools, improve our pathophysiological understanding of sleepiness, and define genetic and environmental risk factors.

Neurofeedback for Attention-Deficit/Hyperactivity Disorder: Meta-Analysis of Clinical and Neuropsychological Outcomes From Randomized Controlled Trials

OBJECTIVE

We performed meta-analyses of randomized controlled trials to examine the effects of neurofeedback on attention-deficit/hyperactivity disorder (ADHD) symptoms and neuropsychological deficits in children and adolescents with ADHD.

METHOD

We searched PubMed, Ovid, Web of Science, ERIC, and CINAHAL through August 30, 2015. Random-effects models were employed. Studies were evaluated with the Cochrane Risk of Bias tool.

RESULTS

We included 13 trials (520 participants with ADHD). Significant effects were found on ADHD symptoms rated by assessors most proximal to the treatment setting, that is, the least blinded outcome measure (standardized mean difference [SMD]: ADHD total symptoms = 0.35, 95% CI = 0.11-0.59; inattention = 0.36, 95% CI = 0.09-0.63; hyperactivity/impulsivity = 0.26, 95% CI = 0.08-0.43). Effects were not significant when probably blinded ratings were the outcome or in trials with active/sham controls. Results were similar when only frequency band training trials, the most common neurofeedback approach, were analyzed separately. Effects on laboratory measures of inhibition (SMD = 0.30, 95% CI = -0.10 to 0.70) and attention (SMD = 0.13, 95% CI = -0.09 to 0.36) were not significant. Only 4 studies directly assessed whether learning occurred after neurofeedback training. The risk of bias was unclear for many Cochrane Risk of Bias domains in most studies.

CONCLUSION

Evidence from well-controlled trials with probably blinded outcomes currently fails to support neurofeedback as an effective treatment for ADHD. Future efforts should focus on implementing standard neurofeedback protocols, ensuring learning, and optimizing clinically relevant transfer.

[Narcolepsy in sleepy obese children. Two case reports]

Narcolepsy is a disabling disorder, characterized by excessive daytime sleepiness, irresistible sleep attacks, and partial or complete cataplexy. Many cases of obesity and precocious puberty have been reported in narcoleptic children, suggesting that the deficiency of hypocretin in narcolepsy could also be implicated in appetite stimulation. We report the observations of two young girls, who were referred for obesity and who developed narcolepsy accompanied by an abrupt weight gain. In both cases, specific drugs promoted wakefulness and overweight stabilization. Narcolepsy has to be suspected in sleepy obese children and not misdiagnosed as obstructive apnea. A nocturnal polysomnography with multiple sleep latency tests should be performed to confirm the diagnosis and begin specific treatment that is effective for sleep disorders and weight gain.

Narcolepsy-Associated HLA Class I Alleles Implicate Cell-Mediated Cytotoxicity

STUDY OBJECTIVES

Narcolepsy with cataplexy is tightly associated with the HLA class II allele DQB1*06:02. Evidence indicates a complex contribution of HLA class II genes to narcolepsy susceptibility with a recent independent association with HLA-DPB1. The cause of narcolepsy is supposed be an autoimmune attack against hypocretin-producing neurons. Despite the strong association with HLA class II, there is no evidence for CD4+ T-cell-mediated mechanism in narcolepsy. Since neurons express class I and not class II molecules, the final effector immune cells involved might include class I-restricted CD8+ T-cells.

METHODS

HLA class I (A, B, and C) and II (DQB1) genotypes were analyzed in 944 European narcolepsy with cataplexy patients and in 4,043 control subjects matched by country of origin. All patients and controls were DQB1*06:02 positive and class I associations were conditioned on DQB1 alleles.

RESULTS

HLA-A*11:01 (OR = 1.49 [1.18-1.87] P = 7.0*10(-4)), C*04:01 (OR = 1.34 [1.10-1.63] P = 3.23*10(-3)), and B*35:01 (OR = 1.46 [1.13-1.89] P = 3.64*10(-3)) were associated with susceptibility to narcolepsy. Analysis of polymorphic class I amino-acids revealed even stronger associations with key antigen-binding residues HLA-A-Tyr(9) (OR = 1.32 [1.15-1.52] P = 6.95*10(-5)) and HLA-C-Ser(11) (OR = 1.34 [1.15-1.57] P = 2.43*10(-4)).

CONCLUSIONS

Our findings provide a genetic basis for increased susceptibility to infectious factors or an immune cytotoxic mechanism in narcolepsy, potentially targeting hypocretin neurons.

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

STUDY OBJECTIVES

To evaluate the frequency, severity, and associations of symptoms of attention-deficit/hyperactivity disorder (ADHD) in children with narcolepsy with and without cataplexy.

DESIGN

Cross-sectional survey.

SETTINGS

Four French national reference centers for narcolepsy.

PATIENTS

One hundred eight consecutively referred children aged younger than 18 y with narcolepsy, with (NwC, n = 86) or without cataplexy (NwoC, n = 22), and 67 healthy controls.

INTERVENTIONS

The participants, their families, and sleep specialists completed a structured interview and questionnaires about sleep, daytime sleepiness, fatigue, and ADHD symptoms (ADHD-rating scale based upon Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision [DSM-IV-TR] symptoms), and use of psychostimulants for the treatment of narcolepsy (administered in 68.2%). Polysomnographic measures were collected.

MEASUREMENTS AND RESULTS

Clinically significant levels of ADHD symptoms were found in 4.8% of controls compared with 35.3% in patients with NwoC (P < 0.001) and 19.7% in patients with NwC (P < 0.01). Total ADHD scores were 6.4 (95% confidence interval [CI]: 4.5, 9.0) in controls compared with 14.2 (95% CI: 10.6, 18.9; P < 0.001), in patients with NwoC and 12.2 (95% CI: 9.8, 15.3; P < 0.01) in patients with NwC; subscores of inattention and hyperactivity/impulsivity were also significantly higher in both narcolepsy groups compared with controls. No difference was found between the NwC and NwoC groups for any ADHD measure. ADHD symptom severity was associated with increased levels of sleepiness, fatigue, and insomnia. Compared with the 34 untreated patients, the 73 patients treated with psychostimulants (modafinil in 91%) showed a trend toward lower narcolepsy symptoms but not lower ADHD symptoms.

CONCLUSIONS

Pediatric patients with narcolepsy have high levels of treatment-resistant attention-deficit/hyperactivity disorder (ADHD) symptoms. The optimal treatment for ADHD symptoms in these patients warrants further evaluation in longitudinal intervention studies.