Sleep Disturbances in Neurodevelopmental Disorders

Gestational low-dose BPA exposure impacts suprachiasmatic nucleus neurogenesis and circadian activity with transgenerational effects

Critical physiological processes such as sleep and stress that underscore health are regulated by an intimate interplay between the endocrine and nervous systems. Here, we asked how fetal exposure to the endocrine disruptor found in common plastics, bisphenol A (BPA), causes lasting effects on adult animal behaviors. Adult mice exposed to low-dose BPA during gestation displayed notable disruption in circadian activity, social interactions, and associated neural hyperactivity, with some phenotypes maintained transgenerationally. Gestational BPA exposure increased vasopressin+ neurons in the suprachiasmatic nucleus (SCN), the region that regulates circadian rhythms, of F1 and F3 generations. Mechanistically, BPA increased proliferation of hypothalamic neural progenitors ex vivo and caused precocious neurogenesis in vivo. Co-antagonism of both estrogen and androgen receptors was necessary to block BPA's effects on hypothalamic neural progenitors, illustrating a dual role for these endocrine targets. Together, gestational BPA exposure affects development of circadian centers, with lasting consequences across generations.

Sleep Disturbances and Sensory Sensitivities Co-Vary in a Longitudinal Manner in Pre-School Children with Autism Spectrum Disorders

Previous research has demonstrated that sleep disturbances are positively correlated with sensory sensitivities in children with ASD. Most of these studies, however, were based on cross-sectional analyses, where the relationship across symptom domains was examined at a single time-point. Here, we examined the development of 103 pre-school children with ASD over a 1–3-year period. The results revealed that spontaneous longitudinal changes in sleep disturbances were specifically correlated with changes in sensory sensitivities and not with changes in other sensory processing domains nor with changes in core ASD symptoms. These finding demonstrate a consistent longitudinal relationship between sleep disturbances and sensory sensitivities, which suggests that these symptoms may be generated by common or interacting underlying physiological mechanisms.

The chromatin remodeler ISWI acts during Drosophila development to regulate adult sleep

Sleep disruptions are among the most commonly reported symptoms across neurodevelopmental disorders (NDDs), but mechanisms linking brain development to normal sleep are largely unknown. From a Drosophila screen of human NDD-associated risk genes, we identified the chromatin remodeler Imitation SWItch/SNF (ISWI) to be required for adult fly sleep. Loss of ISWI also results in disrupted circadian rhythms, memory, and social behavior, but ISWI acts in different cells and during distinct developmental times to affect each of these adult behaviors. Specifically, ISWI expression in type I neuroblasts is required for both adult sleep and formation of a learning-associated brain region. Expression in flies of the human ISWI homologs SMARCA1 and SMARCA5 differentially rescues adult phenotypes, while de novo SMARCA5 patient variants fail to rescue sleep. We propose that sleep deficits are a primary phenotype of early developmental origin in NDDs and point toward chromatin remodeling machinery as critical for sleep circuit formation.

Neurodevelopmental Disorders Commonly Presenting with Sleep Disturbances

There are multiple disorders of neurodevelopment that present with co-occurring sleep disturbances. Many of these neurodevelopmental disorders (NDD) include sleep disturbances in their diagnostic criteria. Neurobiological, genetic, and environmental factors overlap to cause different sleep disorders in individuals with NDD. Caregivers often present reporting either insomnia or hypersomnia, and based on the clinical history and findings from diagnostic tests, an appropriate diagnosis can be made. It is crucial that clinicians understand the different presentations of sleep disturbances in individuals with NDD.

Iron Deficiency and Its Role in Sleep Disruption in Patients With Angelman Syndrome

OBJECTIVE

To determine if Angelman syndrome patients with sleep complaints have an increased risk of iron deficiency, and if iron therapy improves their sleep difficulties.

BACKGROUND

About two-thirds of Angelman syndrome patients experience sleep difficulties, which are likely multifactorial. Because iron deficiency can contribute toward restlessness in sleep, we investigated whether it might be a contributing factor in this special population.

METHODS

This retrospective study involved medical record review of Angelman syndrome patients <18 years old who had attended our multidisciplinary Angelman syndrome clinic and had sleep complaints. Serum ferritin levels were compared to age- and sex-matched controls. Sleep history and nocturnal polysomnogram findings of the Angelman syndrome patients were also characterized.

RESULTS

Nineteen Angelman syndrome patients (9 female, mean age 6.2±4.4 years) were identified. All 19 reported sleep difficulties. The mean serum ferritin level was 19.9±8.5 μg/L, while that in controls was 27.8±17.8 μg/L (P value .13). The odds ratio of iron deficiency in Angelman syndrome compared to controls was 4.17 (95% confidence interval 1.23-14.10), using normal serum ferritin level of 24 μg/L based on literature. Fifteen Angelman syndrome patients underwent nocturnal polysomnogram with 9/15 showing an elevated periodic limb movement index (overall mean 9.8±10.4). Seventeen of 19 received iron therapy. Twelve had follow-up after iron therapy, with parents reporting improved sleep quality. Eight had serum ferritin levels rechecked after iron therapy, showing a mean increase of 24±5.1 μg/L.

CONCLUSIONS

Sleep difficulties in Angelman syndrome, though multifactorial, may in part be related to iron deficiency. Treatment with iron improved sleep to a modest degree in this population.

Barriers and facilitators to treating insomnia in children with autism spectrum disorder and other neurodevelopmental disorders: Parent and health care professional perspectives

BACKGROUND/AIMS

Insomnia is highly prevalent in children with neurodevelopmental disorders (NDDs), yet little research exists on sleep treatment access, utilization, and provision in this population. This study explores barriers and facilitators to access, use, and provision of treatment for sleep problems as experienced by parents of children with NDDs, including Autism Spectrum Disorder (ASD), Attention-Deficit/Hyperactivity Disorder (ADHD), Cerebral Palsy (CP) and Fetal Alcohol Spectrum Disorder (FASD), and health care professionals who work with children with these conditions.

METHOD

Transcripts from online focus groups and interviews, conducted separately with parents of children with NDDs (n = 43) and health care professionals (n = 44), were qualitatively analyzed using content analysis for key themes.

RESULTS

Barriers included limited access to/availability of treatment, lack of knowledge/training, NDD-specific factors (e.g., symptoms, medications, and comorbidities), parent factors (e.g., capacity to implement treatment, exhaustion), and the challenging, intensive nature of sleep treatment. Facilitators included positive beliefs and attitudes, education, support, and ability to modify treatments for NDD symptoms. Barriers and facilitators were similar across all four NDDs.

CONCLUSIONS

Results highlight a need for more education about sleep in NDDs and to develop accessible interventions, as well as the potential of a transdiagnostic approach to sleep treatment in this population.

Sleep characteristics and problems of 2-year-olds with Williams syndrome: relations with language and behavior

Background

Sleep problems have been shown to have a negative impact on language development and behavior for both typically developing children and children with a range of neurodevelopmental disorders. The relation of sleep characteristics and problems to language and behavior for children with Williams syndrome (WS) is unclear. The goal of this study was to address these relations for 2-year-olds with WS. Associations of nonverbal reasoning ability, nighttime sleep duration, and excessive daytime sleepiness with language ability and behavior problems were considered.

Method

Ninety-six 2-year-olds with genetically confirmed classic-length WS deletions participated. Parents completed the Pediatric Sleep Questionnaire, which includes a Sleep-Related Breathing Disorder (SRBD) scale with a subscale measuring excessive daytime sleepiness, to assess sleep characteristics and problems. Parents also completed the Child Behavior Checklist (CBCL) and the MacArthur-Bates Communicative Development Inventory: Words and Sentences to assess behavior problems and expressive vocabulary, respectively. Children completed the Mullen Scales of Early Learning to measure nonverbal reasoning and language abilities.

Results

Parents indicated that children slept an average of 10.36 h per night (SD = 1.09, range 7.3–13.3), not differing significantly from the mean reported by Bell and Zimmerman (2010) for typically developing toddlers (p = .787). Sixteen percent of participants screened positive for SRBD and 30% for excessive daytime sleepiness. Children who screened positive for SRBD had significantly more behavior problems on all CBCL scales than children who screened negative. Children with excessive daytime sleepiness had significantly more attention/hyperactivity, stress, and externalizing problems than those who did not have daytime sleepiness. Individual differences in parent-reported nighttime sleep duration and directly measured nonverbal reasoning abilities accounted for unique variance in expressive language, receptive language, and internalizing problems. Individual differences in parent-reported daytime sleepiness accounted for unique variance in externalizing problems.

Conclusions

The relations of nighttime sleep duration, positive screens for SRBD, and excessive daytime sleepiness to language and behavior in toddlers with WS parallel prior findings for typically developing toddlers. These results highlight the importance of screening young children with WS for sleep problems. Studies investigating the efficacy of behavioral strategies for improving sleep in children with WS are warranted.

Supplementary Information

The online version contains supplementary material available at 10.1186/s11689-020-09336-z.

Sleep health practices and sleep knowledge among healthcare professionals in Dutch paediatric rehabilitation

BACKGROUND

Sleep disorders are highly prevalent in children with neurodisabilities, yet they seem under-recognized in paediatric rehabilitation settings. The aim of this study was to assess among two groups of healthcare professionals (HCPs) working in paediatric rehabilitation: (1) sleep health practices and (2) knowledge about sleep physiology, sleep disorders and sleep hygiene.

METHODS

We performed a cross-sectional sleep survey among medical and non-medical HCPs and the general population. Participants (30 rehabilitation physicians [RPs], 54 allied health professionals [AHPs] and 63 controls) received an anonymous 30-item survey consisting of three domains: (1) general information, (2) application of sleep health practices and (3) sleep knowledge.

RESULTS

RPs address sleep issues more frequently in clinical practice than AHPs. Sleep interventions mostly consist of giving advice about healthy sleep practices and are given by the majority of HCPs. While RPs demonstrated the highest scores on all knowledge domains, total sleep knowledge scores did not exceed 50% correct across groups, with AHPs and controls showing equal scores. Sleep hygiene rules closest to bedtime and related to the sleep environment were best known, whereas those related to daytime practices were rarely mentioned across all groups. A small minority of HCPs (RPs 20%; AHPs 15%) believed to possess sufficient sleep knowledge to address sleep in clinical practice. No association was found between self-perceived knowledge and sleep knowledge scores among HCPs.

CONCLUSIONS

Sleep should become a standard item for review during routine health assessments in paediatric rehabilitation settings. HCPs' limited exposure to sleep education may result in feelings of incompetence and inadequate sleep knowledge levels, affecting their sleep health practices. Appropriate sleep training programs should be implemented to empower HCPs with knowledge, skills and confidence, needed to recognize and treat sleep disorders in children with neurodisabilities, as well as to be able to guide parents.

Melatonin treatment of repetitive behavioral deficits in the Cntnap2 mouse model of autism spectrum disorder

Nighttime light pollution is linked to metabolic and cognitive dysfunction. Many patients with autism spectrum disorders (ASD) show disturbances in their sleep/wake cycle, and may be particularly vulnerable to the impact of circadian disruptors. In this study, we examined the impact of exposure to dim light at night (DLaN, 5 lx) in a model of ASD: the contactin associated protein-like 2 knock out (Cntnap2 KO) mice. DLaN was sufficient to disrupt locomotor activity rhythms, exacerbate the excessive grooming and diminish the social preference in Cntnap2 mutant mice. On a molecular level, DLaN altered the phase and amplitude of PER2:LUC rhythms in a tissue-specific manner in vitro. Daily treatment with melatonin reduced the excessive grooming of the mutant mice to wild-type levels and improved activity rhythms. Our findings suggest that common circadian disruptors such as light at night should be considered in the management of ASD.

A Review of Sleep Disturbances among Infants and Children with Neurodevelopmental Disorders

Sleep problems are common among children with neurodevelopmental disorders (NDDs). We review sleep disturbance in three major NDDs: autism spectrum disorder, Down syndrome, and fetal alcohol spectrum disorder (FASD). We review associations with functional impairment, discuss how patterns of sleep disturbance inform understanding of etiology, and theorize about mechanisms of impairment. Sleep disturbance is a transdiagnostic feature of NDDs. Caregivers report high rates of sleep problems, including difficulty falling or staying asleep. Polysomnography data reveal differences in sleep architecture and increased rates of sleep disorders. Sleep disturbance is associated with functional impairment and stress among families. Further research is needed to elucidate mechanisms of impairment and develop more effective interventions. Despite significant sleep disturbance in FASD, limited research is available.

Composite Sleep Problems Observed Across Smith-Magenis Syndrome, MBD5-Associated Neurodevelopmental Disorder, Pitt-Hopkins Syndrome, and ASD

Caregivers of preschool and elementary school age children with Smith-Magenis syndrome (SMS), MBD5-associated neurodevelopmental disorder (MAND), and Pitt-Hopkins syndrome (PTHS) were surveyed to assess sleep disturbance and to identify disorder-specific sleep problems. Because of overlapping features of these rare genetic neurodevelopmental syndromes, data were compared to reports of sleep disturbance in children with autism spectrum disorder (ASD). While similarities were observed with ASD, specific concerns between disorders differed, including mean nighttime sleep duration, daytime sleepiness, night wakings, parasomnias, restless sleep, and bedwetting. Overall, sleep disturbance in PTHS is significant but less severe than in SMS and MAND. The complexity of these conditions and the challenges of underlying sleep disturbance indicate the need for more support, education, and ongoing management of sleep for these individuals.

Psychological distress and positive gain in mothers of children with autism, with or without other children with neurodevelopmental disorders

Although a wealth of literature has focused on the parenting experiences of mothers of children with autism spectrum disorder (ASD), there is a lack of research about mothers who are parenting a child with ASD, and who have other children with neurodevelopmental disorders. In this matched-comparison study, 10 mothers of a child with ASD and other typically developing children (ASD-TD) were compared to 10 mothers of a child with ASD who also had other children with neurodevelopmental disorders (ASD-NDD). Mothers completed self-report measures of mental health and positive gain. Results indicated no significant between-group differences for mental health, although mothers in the ASD-NDD group reported increased positive gain compared to mothers in the ASD-TD group. Further research is needed to understand practical support needs and theory development.

Cumulative incidence and relative risk of sleep problems among children and adolescents with newly diagnosed neurodevelopmental disorders: A nationwide register-based study

We estimated the absolute and relative risk of sleep problems in children and adolescents with newly diagnosed neurodevelopmental disorders. This was a population-based cohort study of individuals born in Denmark in 1993-2014 and followed in nationwide registers in 2011-2016. We estimated the 5-year cumulative incidence of sleep problems in incident cases of attention-deficit/hyperactivity disorder (ADHD; n = 12,844), autism spectrum disorder (ASD; n = 8,073), oppositional defiant disorder/conduct disorder (ODD/CD; n = 2,234) and epilepsy (n = 3,709). Hazard ratios (HRs) for sleep problems were estimated by Cox regression. The 5-year risk of sleep problems was highest in ADHD (29.2%; 95% CI, 28.4-30.1), ASD (24.2%; 95% CI, 23.1-25.3) and ODD/CD (27.1% 95% CI, 25.0%-29.2%) and lowest in epilepsy (11.3%; 95% CI, 10.2%-12.6%). For ADHD and ASD, sleep problems were more common in females than in males. Furthermore, sleep problems were predicted by high parental socioeconomic status and varied with the geographical region of residence, suggesting that different clinical practices exist across Denmark and that sleep problems may be more likely to go undetected in families of lower socioeconomic position. Compared with individuals without these disorders, the likelihood of sleep problems was increased in individuals with ADHD (HR, 33.81; 95% CI, 32.78-34.87), ASD (HR, 16.77; 95% CI, 16.15-17.41), ODD/CD (HR, 14.73; 95% CI, 13.88-15.64) and epilepsy (HR, 6.01; 95% CI, 5.67-6.37). After mutual adjustment for comorbidity, HRs were attenuated, especially in ASD, ODD/CD and epilepsy when adjusted for ADHD, suggesting that the increased risk of sleep problems in individuals with ASD, ODD/CD and epilepsy is driven largely by comorbid ADHD.

Characterization of sleep habits and medication outcomes for sleep disturbance in children and adults with Angelman syndrome

The objectives of this study were to characterize the sleep habits of 50 clinically referred individuals with Angelman syndrome (AS) and to retrospectively compare the effectiveness/tolerability of the three most commonly prescribed sleep medications in the sample. An experienced physician assigned a Clinical Global Impressions-Severity scale (CGI-S) score for each subject's AS-specific symptoms. Caregivers completed the Child Sleep Habits Questionnaire (CSHQ; screen for sleep problems in school-aged [4-10 years] children), a screening assessment for sleep problems. Caregivers provided information about medication trials targeting disturbed sleep, with the physician assigning a CGI-Improvement scale (CGI-I) score for each trial. Linear regression showed significant negative association between age and CSHQ score. In their lifetime, 72% of participants had taken a medication for sleep, most commonly melatonin, clonidine and trazodone. The majority continued these for 6 months or longer. With these medications, many demonstrated significant improvement in sleep disturbances, with no difference in odds of improvement between medications. Disturbed sleep was common in this cohort and significantly worse in younger-aged participants. The majority received at least one medication trial for disturbed sleep and each of the most commonly prescribed medication was effective for a substantial percentage of participants. Most participants remained on medication for at least 6 months, suggesting favorable tolerability.

Transient neonatal sleep fragmentation results in long-term neuroinflammation and cognitive impairment in a rabbit model

Sleep fragmentation is an increase in sleep-wake transitions without an overall decrease in total sleep time. Sleep fragmentation is well documented during acute and chronic hospitalization and can result in delirium and memory problems in children. Sleep fragmentation is also often noted in neurodevelopmental disorders. However, it is unclear how sleep fragmentation independent of disease affects brain development and function. We hypothesized that acute sleep fragmentation during the neonatal period in otherwise healthy animals would result in neuroinflammation and would be associated with abnormalities in cognitive development. The orbital shaker method was used to fragment sleep for 72 h in postnatal day 3 New Zealand white rabbit kits (fragmentation group). To control for maternal separation, the sham group was separated from the dam and maintained in the same conditions without undergoing sleep fragmentation. A naïve control group remained with the dam. Kits underwent behavioral testing with novel object recognition and spontaneous alternation T-maze tests at 2-3 weeks post-fragmentation and were sacrificed 3-50 days after fragmentation. Sleep fragmentation resulted in acute and chronic changes in microglial morphology in the hippocampus and cortex, and regional differences in mRNA expression of pro- and anti-inflammatory cytokines at 3, 7 and 50 days post-fragmentation. Impaired novel object recognition and a longer latency in T-maze task completion were noted in the fragmented kits. This was in spite of normalization of sleep architecture noted at 2 months of age in these kits. The results indicate that transient neonatal sleep fragmentation results in short-term and long-term immune alterations in the brain, along with diminished performance in cognitive tasks long-term.

Sleep problems and associations with psychopathology and cognition in young people with 22q11.2 deletion syndrome (22q11.2DS)

BACKGROUND

Young people with 22q11.2 deletion syndrome (22q11.2DS) are at high risk for neurodevelopmental disorders. Sleep problems may play a role in this risk but their prevalence, nature and links to psychopathology and cognitive function remain undescribed in this population.

METHOD

Sleep problems, psychopathology, developmental coordination and cognitive function were assessed in 140 young people with 22q11.2DS (mean age = 10.1, s.d. = 2.46) and 65 unaffected sibling controls (mean age = 10.8, s.d.SD = 2.26). Primary carers completed questionnaires screening for the children's developmental coordination and autism spectrum disorder.

RESULTS

Sleep problems were identified in 60% of young people with 22q11.2DS compared to 23% of sibling controls (OR 5.00, p < 0.001). Two patterns best-described sleep problems in 22q11.2DS: restless sleep and insomnia. Restless sleep was linked to increased ADHD symptoms (OR 1.16, p < 0.001) and impaired executive function (OR 0.975, p = 0.013). Both patterns were associated with elevated symptoms of anxiety disorder (restless sleep: OR 1.10, p = 0.006 and insomnia: OR 1.07, p = 0.045) and developmental coordination disorder (OR 0.968, p = 0.0023, and OR 0.955, p = 0.009). The insomnia pattern was also linked to elevated conduct disorder symptoms (OR 1.53, p = 0.020).

CONCLUSIONS

Clinicians and carers should be aware that sleep problems are common in 22q11.2DS and index psychiatric risk, cognitive deficits and motor coordination problems. Future studies should explore the physiology of sleep and the links with the neurodevelopment in these young people.

Low-Dose Perampanel Rescues Cortical Gamma Dysregulation Associated With Parvalbumin Interneuron GluA2 Upregulation in Epileptic Syngap1+/- Mice

BACKGROUND

Loss-of-function SYNGAP1 mutations cause a neurodevelopmental disorder characterized by intellectual disability and epilepsy. SYNGAP1 is a Ras GTPase-activating protein that underlies the formation and experience-dependent regulation of postsynaptic densities. The mechanisms that contribute to this proposed monogenic cause of intellectual disability and epilepsy remain unresolved.

METHODS

We established the phenotype of the epileptogenesis in a Syngap1^+/- mouse model using 24-hour video electroencephalography (vEEG)/electromyography recordings at advancing ages. We administered an acute low dose of perampanel, a Food and Drug Administration-approved AMPA receptor (AMPAR) antagonist, during a follow-on 24-hour vEEG to investigate the role of AMPARs in Syngap1 haploinsufficiency. Immunohistochemistry was performed to determine the region- and location-specific differences in the expression of the GluA2 AMPAR subunit.

RESULTS

A progressive worsening of the epilepsy with emergence of multiple seizure phenotypes, interictal spike frequency, sleep dysfunction, and hyperactivity was identified in Syngap1^+/- mice. Interictal spikes emerged predominantly during non-rapid eye movement sleep in 24-hour vEEG of Syngap1^+/- mice. Myoclonic seizures occurred at behavioral-state transitions both in Syngap1^+/- mice and during an overnight EEG from a child with SYNGAP1 haploinsufficiency. In Syngap1^+/- mice, EEG spectral power analyses identified a significant loss of gamma power modulation during behavioral-state transitions. A significant region-specific increase of GluA2 AMPAR subunit expression in the somas of parvalbumin-positive interneurons was identified.

CONCLUSIONS

Acute dosing with perampanel significantly rescued behavioral state-dependent cortical gamma homeostasis, identifying a novel mechanism implicating Ca²⁺-impermeable AMPARs on parvalbumin-positive interneurons underlying circuit dysfunction in SYNGAP1 haploinsufficiency.

Phenotypic profiling of mGlu7 knockout mice reveals new implications for neurodevelopmental disorders

Neurodevelopmental disorders are characterized by deficits in communication, cognition, attention, social behavior and/or motor control. Previous studies have pointed to the involvement of genes that regulate synaptic structure and function in the pathogenesis of these disorders. One such gene, GRM7, encodes the metabotropic glutamate receptor 7 (mGlu₇ ), a G protein-coupled receptor that regulates presynaptic neurotransmitter release. Mutations and polymorphisms in GRM7 have been associated with neurodevelopmental disorders in clinical populations; however, limited preclinical studies have evaluated mGlu₇ in the context of this specific disease class. Here, we show that the absence of mGlu₇ in mice is sufficient to alter phenotypes within the domains of social behavior, associative learning, motor function, epilepsy and sleep. Moreover, Grm7 knockout mice exhibit an attenuated response to amphetamine. These findings provide rationale for further investigation of mGlu₇ as a potential therapeutic target for neurodevelopmental disorders such as idiopathic autism, attention deficit hyperactivity disorder and Rett syndrome.

Clinical Validity of the PROMIS Pediatric Sleep Measures across Populations of Children with Chronic Illnesses and Neurodevelopment Disorders

OBJECTIVE

To examine the clinical validity of the Patient Reported Outcome Measurement Information System (PROMIS) Pediatric Sleep Disturbance (SD) and Sleep-Related Impairment (SRI) short forms.

METHODS

Youth (8-17 years) from clinical populations with known SDs (sleep clinic n = 126, autism n = 276, asthma n = 82, asthma + eczema n = 68) and the general population (n = 902) completed the PROMIS Pediatric SD and SRI 8-item short forms, along with established measures of sleep (Children's Report of Sleep Patterns, Sleep Habits Survey), PROMIS Pediatric Fatigue, and parent-reported clinical indicators (does child have sleep problem, use melatonin, use prescription sleep medication).

RESULTS

Confirmatory factor analyses demonstrated factorial invariance for all clinical groups. Significant differences between the general population and clinical groups were found for SD and SRI (medium to large effect sizes). Convergent validity was demonstrated through separate hierarchical regression models that showed significant associations between parent-reported clinical indicators and SD and SRI, above and beyond clinical group, as well as moderate to strong correlations between the PROMIS sleep measures and both established measures of sleep and fatigue.

CONCLUSIONS

The PROMIS Pediatric SD and SRI short forms provide clinicians and researchers a brief, accurate, and valid way to measure patient-reported sleep outcomes in pediatric populations.

Identification of a molecular basis for the juvenile sleep state

Across species, sleep in young animals is critical for normal brain maturation. The molecular determinants of early life sleep remain unknown. Through an RNAi-based screen, we identified a gene, pdm3, required for sleep maturation in Drosophila. Pdm3, a transcription factor, coordinates an early developmental program that prepares the brain to later execute high levels of juvenile adult sleep. PDM3 controls the wiring of wake-promoting dopaminergic (DA) neurites to a sleep-promoting region, and loss of PDM3 prematurely increases DA inhibition of the sleep center, abolishing the juvenile sleep state. RNA-Seq/ChIP-Seq and a subsequent modifier screen reveal that pdm3 represses expression of the synaptogenesis gene Msp300 to establish the appropriate window for DA innervation. These studies define the molecular cues governing sleep behavioral and circuit development, and suggest sleep disorders may be of neurodevelopmental origin.

Learning support strategies for learners with neurodevelopmental disorders: Perspectives of recently qualified teachers

Background

Inclusive education envisages the improvement of the quality of education for all learners. This further implies that schools must adjust all systems of teaching and learning to accommodate all learners regardless of their diverse needs. The reduction of educational inequalities through inclusive practices is aimed at supporting the accomplishment of academic outcomes for all. Learners presenting with neurodevelopmental disorders (NDDs) place specific requirements on teachers, particularly when they find themselves in mainstream classrooms.

Objectives

This study focused on the learning support strategies used by recently qualified teachers in accommodating learners with NDDs in mainstream classrooms in the Gauteng province of South Africa.

Method

A qualitative approach was used to explore the support strategies used by recently qualified teachers in mainstream classrooms when dealing with learners with NDDs. Purposive sampling was used to select six recently qualified teachers from different mainstream classroom. Data were collected using semi-structured interviews, observations and critical incident reports.

Results

The findings revealed that teachers employ a variety of support strategies such as cooperative learning, peer learning, ability grouping, extensive visual aids and curriculum differentiation in an attempt to support learners. The support provided by the teachers was evident in their performance as learners with NDD were able to learn and understand the lessons irrespective for their barrier to learning.

Conclusion

Contrary to literature findings that teachers do not support learners with diverse needs because of lack of skills, training and knowledge, this study revealed that recently qualified teachers employ a variety of support strategies to support learners with NDDs. However, it appeared that these support strategies were rather general teaching and learning strategies. More support strategies should be applied to help learners with NDD in the mainstream classroom.

An eHealth insomnia intervention for children with neurodevelopmental disorders: Results of a usability study

BACKGROUND

Sleep problems, particularly insomnia, are highly prevalent in children with neurodevelopmental disorders (NDD) and can negatively affect health and development. eHealth interventions may increase access to evidence-based care for insomnia for children with NDD, as programs are rare in most communities. Better Nights, Better Days (BNBD) is an online, parent-implemented intervention for pediatric insomnia in typically developing 1- to 10-year-olds.

AIMS

The present study examined whether parents of children with NDD perceived the original BNBD to be usable, acceptable, and feasible, and what modifications might be necessary to adapt it for children with NDD.

METHODS AND PROCEDURES

Twenty Canadian parents/caregivers of children aged 4-10 years with NDD and insomnia implemented the BNBD intervention with their children, and completed usability questionnaires. Questionnaire data were analyzed quantitatively (descriptive statistics) and qualitatively (thematic analysis).

OUTCOMES AND RESULTS

Participants reported the intervention to be usable, useful, acceptable, and feasible. Several modifications were suggested to make the intervention more appropriate and acceptable for use with children with NDD.

CONCLUSIONS AND IMPLICATIONS

Results support a largely transdiagnostic approach to treating sleep in children with NDD, and will inform the development of BNBD for Children with Neurodevelopmental Disorders (BNBD-NDD).

Role of Per3, a circadian clock gene, in embryonic development of mouse cerebral cortex

Per3 is one of the primary components of circadian clock system. While circadian dysregulation is known to be involved in the pathogenesis of several neuropsychiatric diseases. It remains largely unknown whether they participate in embryonic brain development. Here, we examined the role of clock gene Per3 in the development of mouse cerebral cortex. In situ hybridization analysis revealed that Per3 is expressed in the developing mouse cortex. Acute knockdown of Per3 with in utero electroporation caused abnormal positioning of cortical neurons, which was rescued by RNAi-resistant Per3. Per3-deficient cells showed abnormal migration phenotypes, impaired axon extension and dendritic arbor formation. Taken together, Per3 was found to play a pivotal role in corticogenesis via regulation of excitatory neuron migration and synaptic network formation.

Pharmacologic Treatments for Sleep Disorders in Children: A Systematic Review

Sleep problems are common in children, especially those with neurodevelopmental disorders, and can lead to consequences in behavior, functioning, and quality of life. We systematically reviewed the efficacy and harms of pharmacologic treatments for sleep disorders in children and adolescents. We searched MEDLINE, Cochrane library databases, and PsycINFO through June 2018. We included 22 placebo-controlled randomized controlled trials (1-13 weeks' duration), involving 1758 children (mean age 8.2 years). Single randomized controlled trials of zolpidem and eszopiclone in children with attention-deficit/hyperactivity disorder (ADHD) showed no improvement in sleep or ADHD ratings. Clinical Global Impression Improvement/Severity scores significantly improved with zolpidem ( P = .03 and P = .006, respectively). A single, small randomized controlled trial of diphenhydramine reported small improvements in sleep outcomes (8-10 minutes' better sleep latency and duration) after 1 week. In 19 randomized controlled trials, melatonin significantly improved sleep latency (median 28 minutes; range 11-51 minutes), sleep duration (median 33 minutes; range 14-68 minutes), and wake time after sleep onset (range 12-43 minutes), but not number of awakenings per night (range 0-2.7). Function and behavior improvement varied. Improvement in sleep was greatest in children with autism or other neurodevelopmental disorders, and smaller in adolescents and children with chronic delayed sleep onset. Adverse events were infrequent with melatonin, but more frequent than placebo in children taking eszopiclone or zolpidem. These findings show that melatonin was useful in improving some sleep outcomes in the short term, particularly those with comorbid ASD and neurodevelopmental disorders. Other drugs and outcomes are inadequately studied.

Potential Circadian Rhythms in Oligodendrocytes? Working Together Through Time

Oligodendrocytes (OL) are the only myelinating cells of the central nervous system thus interferences, either environmental or genetic, with their maturation or function have devastating consequences. Albeit so far neglected, one of the less appreciated, nevertheless possible, regulators of OL maturation and function is the circadian cycle. Yet, disruptions in these rhythms are unfortunately becoming a common "disorder" in the today's world. The temporal patterning of behaviour and physiology is controlled by a circadian timing system based in the anterior hypothalamus. At the molecular level, circadian rhythms are generated by a transcriptional/translational feedback system that regulates transcription and has a major impact on cellular function(s). Fundamental cellular properties/functions in most cell types vary with the daily circadian cycle: OL are unlikely an exception! To be clear, the presence of circadian oscillators or the cell-specific function(s) of the circadian clock in OL has yet to be defined. Furthermore, we wish to entertain the idea of links between the "thin" evidence on OL intrinsic circadian rhythms and their interjection(s) at different stages of lineage progression as well as in supporting/regulating OL crucial function: myelination. Individuals with intellectual and developmental syndromes as well as neurodegenerative diseases present with a disrupted sleep/wake cycle; hence, we raise the possibility that these disturbances in timing can contribute to the loss of white matter observed in these disorders. Preclinical and clinical work in this area is needed for a better understanding of how circadian rhythms influence OL maturation and function(s), to aid the development of new therapeutic strategies and standards of care for these patients.

Paediatric neurodisability and sleep disorders: clinical pathways and management strategies

Sleep disorders are common in children with neurodisability. Their presentation is often complex. This complexity of presentation can make sleep disorders in children with neurodisability daunting to diagnose and manage. Both parents and healthcare professionals have identified sleep disorders as a healthcare outcome that they prioritise in children with neurodisability. We aim to explore the challenges of diagnosing sleep problems, discuss common difficulties with sleep in children with neurodisability and will touch on how to set up a service to support and manage sleep, working through case examples.

Sleep/Wake Disruption in a Mouse Model of BLOC-1 Deficiency

Mice lacking a functional Biogenesis of Lysosome-related Organelles Complex 1 (BLOC-1), such as those of the pallid line, display cognitive and behavioural impairments reminiscent of those presented by individuals with intellectual and developmental disabilities. Although disturbances in the sleep/wake cycle are commonly lamented by these individuals, the underlying mechanisms, including the possible role of the circadian timing system, are still unknown. In this paper, we have explored sleep/circadian malfunctions and underlying mechanisms in BLOC-1-deficient pallid mice. These mutants exhibited less sleep behaviour in the beginning of the resting phase than wild-type mice with a more broken sleeping pattern in normal light-dark conditions. Furthermore, the strength of the activity rhythms in the mutants were reduced with significantly more fragmentation and lower precision than in age-matched controls. These symptoms were accompanied by an abnormal preference for the open arm in the elevated plus maze in the day and poor performance in the novel object recognition at night. At the level of the central circadian clock (the suprachiasmatic nucleus, SCN), loss of BLOC-1 caused subtle morphological changes including a larger SCN and increased expression of the relative levels of the clock gene Per2 product during the day but did not affect the neuronal activity rhythms. In the hippocampus, the pallid mice presented with anomalies in the cytoarchitecture of the Dentate Gyrus granule cells, but not in CA1 pyramidal neurones, along with altered PER2 protein levels as well as reduced pCREB/tCREB ratio during the day. Our findings suggest that lack of BLOC-1 in mice disrupts the sleep/wake cycle and performance in behavioural tests associated with specific alterations in cytoarchitecture and protein expression.

Oxytocin and Prader-Willi Syndrome

In the chapter, we explore the relationship between the peptide hormone, oxytocin (OT), and behavioral and metabolic disturbances observed in the genetic disorder Prader-Willi Syndrome (PWS). Phenotypic and genotypic characteristics of PWS are described, as are the potential implications of an abnormal OT system with respect to neural development including the possible effects of OT dysfunction on interactions with other regulatory mediators, including neurotransmitters, neuromodulators, and hormones. The major behavioral characteristics are explored in the context of OT dysfunction, including hyperphagia, impulsivity, anxiety and emotion dysregulation, sensory processing and interoception, repetitive and restrictive behaviors, and dysfunctional social cognition. Behavioral overlaps with autistic spectrum disorders are discussed. The implications of OT dysfunction on the mechanisms of reward and satiety and their possible role in informing behavioral characteristics are also discussed. Treatment implications and future directions for investigation are considered.

Practitioner Review: Treatment of chronic insomnia in children and adolescents with neurodevelopmental disabilities

BACKGROUND

Sleep disturbances, in particular insomnia, represent a common problem in children with neurodevelopmental disabilities (NDDs). Currently, there are no approved medications for insomnia in children by the US Food and Drug Administration or European Medicines Agency and therefore they are prescribed off-label. We critically reviewed pediatric literature on drugs as well as nonpharmacological (behavioral) interventions used for sleep disturbances in children with NDDs.

METHODS

PubMed, Ovid (including PsycINFO, Ovid MEDLINE^® , and Embase), and Web of Knowledge databases were searched through February 12, 2017, with no language restrictions. Two authors independently and blindly performed the screening.

RESULTS

Good sleep practices and behavioral interventions, supported by moderate-to-low level evidence, are the first recommended treatments for pediatric insomnia but they are often challenging to implement. Antihistamine agents, such as hydroxyzine or diphenhydramine, are the most widely prescribed sedatives in the pediatric practice but evidence supporting their use is still limited. An increasing body of evidence supports melatonin as the safest choice for children with NDDs. Benzodiazepines are not recommended in children and should only be used for transient insomnia, especially if daytime anxiety is present. Only few studies have been carried out in children's and adolescents' zolpidem, zaleplon, and eszopiclone, with contrasting results. Limited evidence supports the use of alpha-agonists such as clonidine to improve sleep onset latency, especially in attention deficit/hyperactivity disorder subjects. Tricyclic antidepressants, used in adults with insomnia, are not recommended in children because of their safety profile. Trazodone and mirtazapine hold promise but require further studies.

CONCLUSIONS

Here, we provided a tentative guide for the use of drugs for insomnia in children with NDDs. Well-controlled studies employing both objective polysomnography and subjective sleep measures are needed to determine the efficacy, effectiveness, and safety of the currently prescribed pediatric sleep medicines in children with NDDs.

Devices for Ambulatory Monitoring of Sleep-Associated Disorders in Children with Neurological Diseases

Good sleep quality is essential for a child's wellbeing. Early sleep problems have been linked to the later development of emotional and behavioral disorders and can negatively impact the quality of life of the child and his or her family. Sleep-associated conditions are frequent in the pediatric population, and even more so in children with neurological problems. Monitoring devices can help to better characterize sleep efficiency and sleep quality. They can also be helpful to better characterize paroxysmal nocturnal events and differentiate between nocturnal seizures, parasomnias, and obstructive sleep apnea, each of which has a different management. Overnight ambulatory detection devices allow for a tolerable, low cost, objective assessment of sleep quality in the patient's natural environment. They can also be used as a notification system to allow for rapid recognition and prompt intervention of events like seizures. Optimal monitoring devices will be patient- and diagnosis-specific, but may include a combination of modalities such as ambulatory electroencephalograms, actigraphy, and pulse oximetry. We will summarize the current literature on ambulatory sleep devices for detecting sleep disorders in children with neurological diseases.

Understanding and managing sleep disruption in children with fetal alcohol spectrum disorder

Accumulating evidence has revealed high rates of sleep disruption among children with fetal alcohol spectrum disorder (FASD). Multiple animal and clinical studies have found a clear association between sleep problems and prenatal alcohol exposure, and recent research is beginning to characterize the types and extent of sleep disruption in FASD. Nevertheless, sleep disruption in children with FASD often goes unrecognized or is treated without referring to an evidence base. Children's disrupted sleep interferes with parental sleep and increases caregiver burden, which is of particular importance for families raising children with FASD, a group with very high levels of caregiving stress. The literature supporting an association between sleep problems and deficits in emotional, behavioral, and cognitive function in children is compelling, but needs further investigation in children with FASD. This paper will review the current state of knowledge on sleep in FASD and recommend a rational approach to sleep interventions for affected children and their families.

Sleep Disorders in Childhood Neurogenetic Disorders

enetic advances in the past three decades have transformed our understanding and treatment of many human diseases including neurogenetic disorders. Most neurogenetic disorders can be classified as "rare disease," but collectively neurogenetic disorders are not rare and are commonly encountered in general pediatric practice. The authors decided to select eight relatively well-known neurogenetic disorders including Down syndrome, Angelman syndrome, Prader-Willi syndrome, Smith-Magenis syndrome, congenital central hypoventilation syndrome, achondroplasia, mucopolysaccharidoses, and Duchenne muscular dystrophy. Each disorder is presented in the following format: overview, clinical characteristics, developmental aspects, associated sleep disorders, management and research/future directions.

Sleep phenotypes in infants and toddlers with neurogenetic syndromes

BACKGROUND

Although sleep problems are well characterized in preschool- and school-age children with neurogenetic syndromes, little is known regarding the early emergence of these problems in infancy and toddlerhood. To inform syndrome-specific profiles and targets for intervention, we compared parent-reported sleep problems in infants and toddlers with Angelman syndrome (AS), Williams syndrome (WS), and Prader-Willi syndrome (PWS) with patterns observed among same-aged typically developing (TD) controls.

METHODS

Mothers of 80 children (18 AS, 19 WS, 19 PWS, and 24 TD) completed the Brief Infant Sleep Questionnaire. Primary dependent variables included (1) sleep onset latency, (2) total sleep duration, (3) daytime and nighttime sleep duration, and (4) sleep problem severity, as measured by both maternal impression and National Sleep Foundation guidelines.

RESULTS

Sleep problems are relatively common in children with neurogenetic syndromes, with 41% of mothers reporting problematic sleep and 29% of children exhibiting abnormal sleep durations as per national guidelines. Across genetic subgroups, problems are most severe in children with AS and WS, particularly in relation to nighttime sleep duration. Although atypical sleep is characteristically reported in each syndrome later in development, infants and toddlers with PWS exhibited largely typical patterns, potentially indicating delayed onset of sleep problems in concordance with other medical features of PWS.

CONCLUSIONS

Our findings suggest that sleep problems in neurogenetic syndromes emerge as early as infancy and toddlerhood, with variable profiles across genetic subgroups. This work underscores the importance of early sleep screenings as part of routine medical care of neurosyndromic populations and the need for targeted, syndrome-sensitive treatment.

Aberrant Proteostasis of BMAL1 Underlies Circadian Abnormalities in a Paradigmatic mTOR-opathy

Tuberous sclerosis complex (TSC) is a neurodevelopmental disorder characterized by mutations in either the TSC1 or TSC2 genes, whose products form a critical inhibitor of the mechanistic target of rapamycin (mTOR). Loss of TSC1/2 gene function renders an mTOR-overactivated state. Clinically, TSC manifests with epilepsy, intellectual disability, autism, and sleep dysfunction. Here, we report that mouse models of TSC have abnormal circadian rhythms. We show that mTOR regulates the proteostasis of the core clock protein BMAL1, affecting its translation, degradation, and subcellular localization. This results in elevated levels of BMAL1 and a dysfunctional clock that displays abnormal timekeeping under constant conditions and exaggerated responses to phase resetting. Genetically lowering the dose of BMAL1 rescues circadian behavioral phenotypes in TSC mouse models. These findings indicate that BMAL1 deregulation is a feature of the mTOR-activated state and suggest a molecular mechanism for mitigating circadian phenotypes in a neurodevelopmental disorder.

Sleep in Children with Autism Spectrum Disorder

The purposes of this paper are to provide an overview of the state of the science of sleep in children with autism spectrum disorder (ASD), present hypotheses for the high prevalence of insomnia in children with ASD, and present a practice pathway for promoting optimal sleep. Approximately two thirds of children with ASD have chronic insomnia, and to date, the strongest evidence on promoting sleep is for sleep education, environmental changes, behavioral interventions, and exogenous melatonin. The Sleep Committee of the Autism Treatment Network (ATN) developed a practice pathway, based on expert consensus, to capture best practices for screening, identification, and treatment for sleep problems in ASD in 2012. An exemplar case is presented to integrate key constructs of the practice pathway and address arousal and sensory dysregulation in a child with ASD and anxiety disorder. This paper concludes with next steps for dissemination of the practice pathway and future directions for research of sleep problems in ASD.

Sleep in Angelman syndrome: A review of evidence

Sleep problems are reported to be extremely prevalent in individuals with developmental disabilities. The consensus guidelines for Angelman syndrome (AS) consider abnormal sleep-wake cycles and diminished need for sleep as associated features. We report an integrative research review and a meta-analysis of studies with sleep as the primary aim of investigation in an AS sample. 14 studies met eligibility criteria with half of them being surveys. Thirteen of the 17 conceptually formed sleep disorder item-groups showed to be significant for individuals with AS. There is evidence that arousal during sleep, somnolence and possibly short sleep duration are the primary sleep problems in individuals with AS. According to the results of this review and meta-analyses, there is clear evidence for sleep problems in individuals with AS. Individual effect sizes remain overall small, but nevertheless findings suggest disorders of arousal and sleepiness to be distinctive. In light of these findings, other sleep complaints in individuals with AS should be carefully examined. Consistent standards for research on sleep in individuals with AS are critical for new lines of investigation.

Normal sleep on mechanical ventilation in adult patients with congenital central alveolar hypoventilation (Ondine's curse syndrome)

Background

The purpose of this study was to describe the sleep structure (especially slow wave sleep) in adults with congenital central hypoventilation syndrome (CCHS), a rare genetic disease due to mutations in the PHOX2B gene. Fourteen patients aged 23 (19.0; 24.8) years old (median [1^rst-3rd quartiles]) with CCHS underwent a sleep interview and night-time attended polysomnography with their ventilatory support. Their sleep variables were compared to those collected in 15 healthy control subjects matched for age, sex and body mass index.

Results

The latency to N3 sleep was shorter in patients (26.3 min [24.0; 30.1]) than in controls (49.5 min [34.3; 66.9]; P = 0.005), and sleep onset latency tended to be shorter in patients (14.0 min [7.0; 20.5]) than in controls (33.0 min [18.0; 49.0]; P = 0.052). Total sleep time, sleep stage percentages, sleep fragmentation as well as respiratory and movement index were within normal ranges and not different between groups.

Conclusions

Normal sleep in adult patients with CCHS and adequate ventilator support indicates that the PHOX2 gene mutations do not affect brain sleep networks. Consequently, any complaint of disrupted sleep should prompt clinicians to look for the usual causes of sleep disorders, primarily inadequate mechanical ventilation. Shorter N3 latency may indicate a higher need for slow wave sleep, to compensate for the abnormal respiratory-related cortical activity during awake quiet breathing observed in patients with CCH.

Angelman syndrome: Current and emerging therapies in 2016

Angelman syndrome (AS) is a severe neurodevelopmental disorder caused by a loss of the maternally-inherited UBE3A; the paternal UBE3A is silenced in neurons by a mechanism involving an antisense transcript (UBE3A-AS) at the unmethylated paternal locus. We reviewed all published information on the clinical trials that have been completed as well as the publicly available information on ongoing trials of therapies in AS. To date, all clinical trials that strove to improve neurodevelopment in AS have been unsuccessful. Attempts at hypermethylating the maternal locus through dietary compounds were ineffective. The results of an 8-week open-label trial using minocycline as a matrix metalloproteinase-9 inhibitor were inconclusive, while a subsequent randomized placebo-controlled trial suggested that treatment with minocycline for 8 weeks did not result in any neurodevelopmental gains. A 1-year randomized placebo-controlled trial using levodopa to alter the phosphorylation of calcium/calmodulin-dependent kinase II did not lead to any improvement in neurodevelopment. Topoisomerase inhibitors and antisense oligonucleotides are being developed to directly inhibit UBE3A-AS. Artificial transcription factors are being developed to "super activate" UBE3A or inhibit UBE3A-AS. Other strategies targeting specific pathways are briefly discussed. We also reviewed the medications that are currently used to treat seizures and sleep disturbances, which are two of the more common complications of AS. © 2016 Wiley Periodicals, Inc.

Unraveling the Neurobiology of Sleep and Sleep Disorders Using Drosophila

Sleep disorders in humans are increasingly appreciated to be not only widespread but also detrimental to multiple facets of physical and mental health. Recent work has begun to shed light on the mechanistic basis of sleep disorders like insomnia, restless legs syndrome, narcolepsy, and a host of others, but a more detailed genetic and molecular understanding of how sleep goes awry is lacking. Over the past 15 years, studies in Drosophila have yielded new insights into basic questions regarding sleep function and regulation. More recently, powerful genetic approaches in the fly have been applied toward studying primary human sleep disorders and other disease states associated with dysregulated sleep. In this review, we discuss the contribution of Drosophila to the landscape of sleep biology, examining not only fundamental advances in sleep neurobiology but also how flies have begun to inform pathological sleep states in humans.