Sleep in Autism Spectrum Disorders

Sleep and Autism: Current Research, Clinical Assessment, and Treatment Strategies

Autism spectrum disorder is associated with a high rate of sleep problems, affecting over 80% of autistic individuals. Sleep problems have pervasive negative effects on health, behavior, mood, and cognition but are underrecognized in autistic children. Problems initiating and maintaining sleep-hallmarks of insomnia-are common. Sleep-disordered breathing and restless legs syndrome have also been described in autism at a higher prevalence than in community populations. The authors describe current research on sleep in autistic children and potential pathophysiologic mechanisms. They describe practical approaches to sleep assessment and synthesize approaches to addressing sleep problems in autistic children.

Children with Autism Spectrum Disorder and Abnormalities of Clinical EEG: A Qualitative Review

Over the last decade, the comorbidity between Autism Spectrum Disorder (ASD) and epilepsy has been widely demonstrated, and many hypotheses regarding the common neurobiological bases of these disorders have been put forward. A variable, but significant, prevalence of abnormalities on electroencephalogram (EEG) has been documented in non-epileptic children with ASD; therefore, several scientific studies have recently tried to demonstrate the role of these abnormalities as a possible biomarker of altered neural connectivity in ASD individuals. This narrative review intends to summarize the main findings of the recent scientific literature regarding abnormalities detected with standard EEG in children/adolescents with idiopathic ASD. Research using three different databases (PubMed, Scopus and Google Scholar) was conducted, resulting in the selection of 10 original articles. Despite an important lack of studies on preschoolers and a deep heterogeneity in results, some authors speculated on a possible association between EEG abnormalities and ASD characteristics, in particular, the severity of symptoms. Although this correlation needs to be more strongly elucidated, these findings may encourage future studies aimed at demonstrating the role of electrical brain abnormalities as an early biomarker of neural circuit alterations in ASD, highlighting the potential diagnostic, prognostic and therapeutic value of EEG in this field.

A Global Transcriptional Atlas of the Effect of Sleep Deprivation in the Mouse Frontal Cortex

Sleep deprivation (SD) has negative effects on brain function. Sleep problems are prevalent in neurodevelopmental, neurodegenerative and psychiatric disorders. Thus, understanding the molecular consequences of SD is of fundamental importance in neuroscience. In this study, we present the first simultaneous bulk and single-nuclear (sn)RNA sequencing characterization of the effects of SD in the mouse frontal cortex. We show that SD predominantly affects glutamatergic neurons, specifically in layers 4 and 5, and produces isoform switching of thousands of transcripts. At both the global and cell-type specific level, SD has a large repressive effect on transcription, down-regulating thousands of genes and transcripts; underscoring the importance of accounting for the effects of sleep loss in transcriptome studies of brain function. As a resource we provide extensive characterizations of cell types, genes, transcripts and pathways affected by SD; as well as tutorials for data analysis.

Positive effects of physical activity in autism spectrum disorder: how influences behavior, metabolic disorder and gut microbiota

Autism spectrum disorder is a neurodevelopmental disorder characterized by social interactions and communication skills impairments that include intellectual disabilities, communication delays and self-injurious behaviors; often are present systemic comorbidities such as gastrointestinal disorders, obesity and cardiovascular disease. Moreover, in recent years has emerged a link between alterations in the intestinal microbiota and neurobehavioral symptoms in children with autism spectrum disorder. Recently, physical activity and exercise interventions are known to be beneficial for improving communication and social interaction and the composition of microbiota. In our review we intend to highlight how different types of sports can help to improve communication and social behaviors in children with autism and also show positive effects on gut microbiota composition.

Stem cell-specific ecdysone signaling regulates the development and function of a Drosophila sleep homeostat

Complex behaviors arise from neural circuits that are assembled from diverse cell types. Sleep is a conserved and essential behavior, yet little is known regarding how the nervous system generates neuron types of the sleep-wake circuit. Here, we focus on the specification of Drosophila sleep-promoting neurons-long-field tangential input neurons that project to the dorsal layers of the fan-shaped body neuropil in the central complex (CX). We use lineage analysis and genetic birth dating to identify two bilateral Type II neural stem cells that generate these dorsal fan-shaped body (dFB) neurons. We show that adult dFB neurons express Ecdysone-induced protein E93, and loss of Ecdysone signaling or E93 in Type II NSCs results in the misspecification of the adult dFB neurons. Finally, we show that E93 knockdown in Type II NSCs affects adult sleep behavior. Our results provide insight into how extrinsic hormonal signaling acts on NSCs to generate neuronal diversity required for adult sleep behavior. These findings suggest that some adult sleep disorders might derive from defects in stem cell-specific temporal neurodevelopmental programs.

Circadian Regulation of the Neuroimmune Environment Across the Lifespan: From Brain Development to Aging

Circadian clocks confer 24-h periodicity to biological systems, to ultimately maximize energy efficiency and promote survival in a world with regular environmental light cycles. In mammals, circadian rhythms regulate myriad physiological functions, including the immune, endocrine, and central nervous systems. Within the central nervous system, specialized glial cells such as astrocytes and microglia survey and maintain the neuroimmune environment. The contributions of these neuroimmune cells to both homeostatic and pathogenic demands vary greatly across the day. Moreover, the function of these cells changes across the lifespan. In this review, we discuss circadian regulation of the neuroimmune environment across the lifespan, with a focus on microglia and astrocytes. Circadian rhythms emerge in early life concurrent with neuroimmune sculpting of brain circuits and wane late in life alongside increasing immunosenescence and neurodegeneration. Importantly, circadian dysregulation can alter immune function, which may contribute to susceptibility to neurodevelopmental and neurodegenerative diseases. In this review, we highlight circadian neuroimmune interactions across the lifespan and share evidence that circadian dysregulation within the neuroimmune system may be a critical component in human neurodevelopmental and neurodegenerative diseases.

Subjective and objective sleep alterations in medication-naïve children and adolescents with autism spectrum disorder: a systematic review and meta-analysis

AIMS

This study aimed to summarize the evidence on sleep alterations in medication-naïve children and adolescents with autism spectrum disorder (ASD).

METHODS

We systematically searched PubMed/Medline, Embase and Web of Science databases from inception through March 22, 2021. This study was registered with PROSPERO (CRD42021243881). Any observational study was included that enrolled medication-naïve children and adolescents with ASD and compared objective (actigraphy and polysomnography) or subjective sleep parameters with typically developing (TD) counterparts. We extracted relevant data such as the study design and outcome measures. The methodological quality was assessed through the Newcastle-Ottawa Scale (NOS). A meta-analysis was carried out using the random-effects model by pooling effect sizes as Hedges' g. To assess publication bias, Egger's test and p-curve analysis were done. A priori planned meta-regression and subgroup analysis were also performed to identify potential moderators.

RESULTS

Out of 4277 retrieved references, 16 studies were eligible with 981 ASD patients and 1220 TD individuals. The analysis of objective measures showed that medication-naïve ASD patients had significantly longer sleep latency (Hedges' g 0.59; 95% confidence interval [95% CI] 0.26 to 0.92), reduced sleep efficiency (Hedges' g -0.58; 95% CI -0.87 to -0.28), time in bed (Hedges' g -0.64; 95% CI -1.02 to -0.26) and total sleep time (Hedges' g -0.64; 95% CI -1.01 to -0.27). The analysis of subjective measures showed that they had more problems in daytime sleepiness (Hedges' g 0.48; 95% CI 0.26 to 0.71), sleep latency (Hedges' g 1.15; 95% CI 0.72 to 1.58), initiating and maintaining sleep (Hedges' g 0.86; 95% CI 0.39 to 1.33) and sleep hyperhidrosis (Hedges' g 0.48; 95% CI 0.29 to 0.66). Potential publication bias was detected for sleep latency, sleep period time and total sleep time measured by polysomnography. Some sleep alterations were moderated by age, sex and concurrent intellectual disability. The median NOS score was 8 (interquartile range 7.25-8.75).

CONCLUSION

We found that medication-naïve children and adolescents with ASD presented significantly more subjective and objective sleep alterations compared to TD and identified possible moderators of these differences. Future research requires an analysis of how these sleep alterations are linked to core symptom severity and comorbid behavioural problems, which would provide an integrated therapeutic intervention for ASD. However, our results should be interpreted in light of the potential publication bias.

Using pharmacotherapy to address sleep disturbances in autism spectrum disorders

INTRODUCTION

Sleep disorders are the second most common medical comorbidity in autism spectrum disorder (ASD), with effects on daytime behavior and functioning, mood and anxiety, and autism core features. In children with ASD, insomnia also has a negative impact on the whole family's quality of life. Therefore, treatment of sleep disturbances should be considered as a primary goal in the management of ASD patients, and it is important to clarify the scientific evidence to inappropriate treatments.

AREAS COVERED

The authors review the current literature concerning the pharmacological treatment options for the management of sleep-related disorders in patients with ASD (aged 0-18 years) using the PubMed and Cochrane Library databases with the search terms: autism, autistic, autism spectrum disorder, ASD, drug, drug therapy, drug intervention, drug treatment, pharmacotherapy, pharmacological treatment, pharmacological therapy, pharmacological intervention, sleep, sleep disturbance, and sleep disorder.

EXPERT OPINION

Currently, clinicians tend to select medications for the treatment of sleep disorders in ASD based on the first-hand experience of psychiatrists and pediatricians as well as expert opinion. Nevertheless, at the present time, the only compound for which there is sufficient evidence is melatonin, although antihistamines, trazodone, clonidine, ramelteon, gabapentin, or suvorexant can also be considered for selection.

Sleep disturbances in autism spectrum disorder: Animal models, neural mechanisms, and therapeutics

Sleep is crucial for brain development. Sleep disturbances are prevalent in children with autism spectrum disorder (ASD). Strikingly, these sleep problems are positively correlated with the severity of ASD core symptoms such as deficits in social skills and stereotypic behavior, indicating that sleep problems and the behavioral characteristics of ASD may be related. In this review, we will discuss sleep disturbances in children with ASD and highlight mouse models to study sleep disturbances and behavioral phenotypes in ASD. In addition, we will review neuromodulators controlling sleep and wakefulness and how these neuromodulatory systems are disrupted in animal models and patients with ASD. Lastly, we will address how the therapeutic interventions for patients with ASD improve various aspects of sleep. Together, gaining mechanistic insights into the neural mechanisms underlying sleep disturbances in children with ASD will help us to develop better therapeutic interventions.

Identification of atypical sleep microarchitecture biomarkers in children with autism spectrum disorder

Importance

Sleep disorders are one of the most frequent comorbidities in children with autism spectrum disorder (ASD). However, the link between neurodevelopmental effects in ASD children with their underlying sleep microarchitecture is not well understood. An improved understanding of etiology of sleep difficulties and identification of sleep-associated biomarkers for children with ASD can improve the accuracy of clinical diagnosis.

Objectives

To investigate whether machine learning models can identify biomarkers for children with ASD based on sleep EEG recordings.

Design setting and participants

Sleep polysomnogram data were obtained from the Nationwide Children' Health (NCH) Sleep DataBank. Children (ages: 8-16 yrs) with 149 autism and 197 age-matched controls without neurodevelopmental diagnosis were selected for analysis. An additional independent age-matched control group (n = 79) selected from the Childhood Adenotonsillectomy Trial (CHAT) was also used to validate the models. Furthermore, an independent smaller NCH cohort of younger infants and toddlers (age: 0.5-3 yr.; 38 autism and 75 controls) was used for additional validation.

Main outcomes and measures

We computed periodic and non-periodic characteristics from sleep EEG recordings: sleep stages, spectral power, sleep spindle characteristics, and aperiodic signals. Machine learning models including the Logistic Regression (LR) classifier, Support Vector Machine (SVM), and Random Forest (RF) model were trained using these features. We determined the autism class based on the prediction score of the classifier. The area under the receiver operating characteristics curve (AUC), accuracy, sensitivity, and specificity were used to evaluate the model performance.

Results

In the NCH study, RF outperformed two other models with a 10-fold cross-validated median AUC of 0.95 (interquartile range [IQR], [0.93, 0.98]). The LR and SVM models performed comparably across multiple metrics, with median AUC 0.80 [0.78, 0.85] and 0.83 [0.79, 0.87], respectively. In the CHAT study, three tested models have comparable AUC results: LR: 0.83 [0.76, 0.92], SVM: 0.87 [0.75, 1.00], and RF: 0.85 [0.75, 1.00]. Sleep spindle density, amplitude, spindle-slow oscillation (SSO) coupling, aperiodic signal's spectral slope and intercept, as well as the percentage of REM sleep were found to be key discriminative features in the predictive models.

Conclusion and relevance

Our results suggest that integration of EEG feature engineering and machine learning can identify sleep-based biomarkers for ASD children and produce good generalization in independent validation datasets. Microstructural EEG alterations may help reveal underlying pathophysiological mechanisms of autism that alter sleep quality and behaviors. Machine learning analysis may reveal new insight into the etiology and treatment of sleep difficulties in autism.

Sleep and Mental Health Problems in Children and Adolescents

Previous reviews have described the links between sleep and mental health extensively. In this narrative review, we focus on literature published during the last decade investigating the links between sleep and mental health difficulties in childhood and adolescence. More specifically, we focus on the mental health disorders listed in the most recent edition of the Diagnostic and Statistical Manual of Mental Disorders. We also discuss possible mechanisms underlying these associations. The review ends with a discussion of possible future lines of enquiry.

Sleep problems in autism: Sex differences in the school-age population

Clinically significant sleep problems affect up to 86% of the autistic population in school-age. Sleep problems can have negative impacts on child cognition, behavior, and health. However, sex differences in the prevalence and types of sleep problems are not well understood in autism. To evaluate sex differences in sleep problems in the school-age autistic population, we obtained parent-report of sleep problems on the Children's Sleep Habits Questionnaire and conducted direct assessments to establish diagnosis and intellectual ability in 6-12-year-old children (autism n = 250; typical development [TD] n = 114). Almost 85% of autistic females demonstrated sleep problems compared to 65.8% of autistic males, 44.8% of TD females, and 42.4% of TD males; a statistically significant increase for autistic females. Autistic females demonstrated increased bedtime resistance, sleep anxiety, and sleepiness, and decreased sleep duration, but did not differ in sleep onset delay, night wakings, parasomnias, or disordered breathing compared with autistic males. Intellectual ability was not related to increased sleep problems. Higher anxiety scores were associated with more sleep problems for males but not females. In one of the first studies to evaluate sex differences in sleep in the school-age, autistic population, autistic females demonstrated increased sleep problems compared to autistic males, TD females, and TD males. Current autism assessment and intervention practices may benefit from increased attention to sleep problems in autistic school-age females and to anxiety in autistic males to enhance well-being and behavioral and health outcomes.

Sleep problems in children with autism spectrum disorder in Hong Kong: a cross-sectional study

Background

Autism spectrum disorder (ASD) is a neurodevelopmental disorder with a growing prevalence of sleep problems associated with significant behavioral problems and more severe autism clinical presentation. Little is known about the relationships between autism traits and sleep problems in Hong Kong. Therefore, this study aimed to examine whether children with autism have increased sleep problems than non-autistic children in Hong Kong. The secondary objective was to examine the factors associated with sleep problems in an autism clinical sample.

Methods

This cross-sectional study recruited 135 children with autism and 102 with the same age range of non-autistic children, aged between 6 and 12 years. Both groups were screened and compared on their sleep behaviors using the Children's Sleep Habits Questionnaire (CSHQ).

Results

Children with autism had significantly more sleep problems than non-autistic children [t _(226.73) = 6.20, p < 0.001]. Bed -sharing [beta = 0.25, t ₍₁₆₅₎ = 2.75, p = 0.07] and maternal age at birth [beta = 0.15, t ₍₁₆₅₎ = 2.05, p = 0.043] were significant factors associated with CSHQ score on the top of autism traits. Stepwise linear regression modeling identified that only separation anxiety disorder (beta = 4.83, t = 2.40, p = 0.019) best-predicted CSHQ.

Conclusion

In summary, autistic children suffered from significantly more sleep problems and co-occurring separation anxiety disorder brings greater sleep problems as compared to non-autistic children. Clinicians should be more aware of sleep problems to provide more effective treatments to children with autism.

Sleep mediates the relationship between having an autistic child and poor family functioning

Sleep is an important biological necessity, a lack of which can have many cognitive, psychological, social, and physical impacts. Children with autism are known to present with sleep difficulties more frequently than their typically developing peers but despite this, there is relatively little research looking at the impact of sleep on the family. To investigate the effect of sleep on families of autistic and typically developing (TD) children, we conducted a study of sleep disturbances among children, sleep quality of their parents in association with their family function. In our study, 239 parents of autistic children and 227 parents of TD children participated. These parents completed a survey about their child's sleep disturbances, their own sleep quality, and their family function, along with a series of demographic questions. Analyses indicated that autistic children experience more sleep difficulties than TD peers, that children's sleep disturbances are associated with parental sleep quality and that parents of autistic children report decreased sleep quality compared to parents of TD children. Parental sleep quality, and child sleep quality were both found to partially mediate the relationship between autism diagnosis and family function.

Calculating genetic risk for dysfunction in pleiotropic biological processes using whole exome sequencing data

BACKGROUND

Numerous genes are implicated in autism spectrum disorder (ASD). ASD encompasses a wide-range and severity of symptoms and co-occurring conditions; however, the details of how genetic variation contributes to phenotypic differences are unclear. This creates a challenge for translating genetic evidence into clinically useful knowledge. Sleep disturbances are particularly prevalent co-occurring conditions in ASD, and genetics may inform treatment. Identifying convergent mechanisms with evidence for dysfunction that connect ASD and sleep biology could help identify better treatments for sleep disturbances in these individuals.

METHODS

To identify mechanisms that influence risk for ASD and co-occurring sleep disturbances, we analyzed whole exome sequence data from individuals in the Simons Simplex Collection (n = 2380). We predicted protein damaging variants (PDVs) in genes currently implicated in either ASD or sleep duration in typically developing children. We predicted a network of ASD-related proteins with direct evidence for interaction with sleep duration-related proteins encoded by genes with PDVs. Overrepresentation analyses of Gene Ontology-defined biological processes were conducted on the resulting gene set. We calculated the likelihood of dysfunction in the top overrepresented biological process. We then tested if scores reflecting genetic dysfunction in the process were associated with parent-reported sleep duration.

RESULTS

There were 29 genes with PDVs in the ASD dataset where variation was reported in the literature to be associated with both ASD and sleep duration. A network of 108 proteins encoded by ASD and sleep duration candidate genes with PDVs was identified. The mechanism overrepresented in PDV-containing genes that encode proteins in the interaction network with the most evidence for dysfunction was cerebral cortex development (GO:0,021,987). Scores reflecting dysfunction in this process were associated with sleep durations; the largest effects were observed in adolescents (p = 4.65 × 10^-3).

CONCLUSIONS

Our bioinformatic-driven approach detected a biological process enriched for genes encoding a protein-protein interaction network linking ASD gene products with sleep duration gene products where accumulation of potentially damaging variants in individuals with ASD was associated with sleep duration as reported by the parents. Specifically, genetic dysfunction impacting development of the cerebral cortex may affect sleep by disrupting sleep homeostasis which is evidenced to be regulated by this brain region. Future functional assessments and objective measurements of sleep in adolescents with ASD could provide the basis for more informed treatment of sleep problems in these individuals.

Deficiency of autism-related Scn2a gene in mice disrupts sleep patterns and circadian rhythms

Autism spectrum disorder (ASD) affects ~2% of the population in the US, and monogenic forms of ASD often result in the most severe manifestation of the disorder. Recently, SCN2A has emerged as a leading gene associated with ASD, of which abnormal sleep pattern is a common comorbidity. SCN2A encodes the voltage-gated sodium channel NaV1.2. Predominantly expressed in the brain, NaV1.2 mediates the action potential firing of neurons. Clinical studies found that a large portion of children with SCN2A deficiency have sleep disorders, which severely impact the quality of life of affected individuals and their caregivers. The underlying mechanism of sleep disturbances related to NaV1.2 deficiency, however, is not known. Using a gene-trap Scn2a-deficient mouse model (Scn2atrap), we found that Scn2a deficiency results in increased wakefulness and reduced non-rapid-eye-movement (NREM) sleep. Brain region-specific Scn2a deficiency in the suprachiasmatic nucleus (SCN) containing region, which is involved in circadian rhythms, partially recapitulates the sleep disturbance phenotypes. At the cellular level, we found that Scn2a deficiency disrupted the firing pattern of spontaneously firing neurons in the SCN region. At the molecular level, RNA-sequencing analysis revealed differentially expressed genes in the circadian entrainment pathway including core clock genes Per1 and Per2. Performing a transcriptome-based compound discovery, we identified dexanabinol (HU-211), a putative glutamate receptor modulator, that can partially reverse the sleep disturbance in mice. Overall, our study reveals possible molecular and cellular mechanisms underlying Scn2a deficiency-related sleep disturbances, which may inform the development of potential pharmacogenetic interventions for the affected individuals.

Neural Hyperactivity Is a Core Pathophysiological Change Induced by Deletion of a High Autism Risk Gene Ash1L in the Mouse Brain

ASH1L is one of the highest risk genes associated with autism spectrum disorder (ASD) and intellectual disability (ID). Our recent studies demonstrate that loss of Ash1l in the mouse brain is sufficient to induce ASD/ID-like behavioral and cognitive deficits, suggesting that disruptive ASH1L mutations are likely to have a positive correlation with ASD/ID genesis. However, the core pathophysiological changes in the Ash1l-deficient brain remain largely unknown. Here we show that loss of Ash1l in the mouse brain causes locomotor hyperactivity, high metabolic activity, and hyperactivity-related disturbed sleep and lipid metabolic changes. In addition, the mutant mice display lower thresholds for the convulsant reagent-induced epilepsy and increased neuronal activities in multiple brain regions. Thus, our current study reveals that neural hyperactivity is a core pathophysiological change in the Ash1l-deficient mouse brain, which may function as a brain-level mechanism leading to the Ash1l-deletion-induced brain functional abnormalities and autistic-like behavioral deficits.

Characterizing sleep disorders in an autism-specific collection of electronic health records

OBJECTIVE/BACKGROUND

Sleep problems are common in people on the autism spectrum. This study reviews one detailed approach to querying the electronic health record (EHR) in a large tertiary care center.

PATIENTS/METHODS

We developed methods for identifying people on the autism spectrum and defined their sleep problems using the key words, "sleep" or "melatonin", or International Classification of Diseases (ICD) codes. We examined treatment responses of these individuals to melatonin supplementation.

RESULTS

Sleep problems were documented in 86% of patients with ages ranging from 6 to 30 years old. Our specific keyword search yielded more patients with sleep diagnoses than ICD codes alone. About two-thirds of patients who received melatonin supplementation reported benefit from its use.

CONCLUSIONS

Our study provides a framework for using deidentified medical records to characterize sleep, a common co-occurring condition, in people on the autism spectrum. Using specific keywords could be helpful in future work that queries the EHR.

Synaptic dysfunction connects autism spectrum disorder and sleep disturbances: A perspective from studies in model organisms

Sleep disturbances (SD) accompany many neurodevelopmental disorders, suggesting SD is a transdiagnostic process that can account for behavioral deficits and influence underlying neuropathogenesis. Autism Spectrum Disorder (ASD) comprises a complex set of neurodevelopmental conditions characterized by challenges in social interaction, communication, and restricted, repetitive behaviors. Diagnosis of ASD is based primarily on behavioral criteria, and there are no drugs that target core symptoms. Among the co-occurring conditions associated with ASD, SD are one of the most prevalent. SD often arises before the onset of other ASD symptoms. Sleep interventions improve not only sleep but also daytime behaviors in children with ASD. Here, we examine sleep phenotypes in multiple model systems relevant to ASD, e.g., mice, zebrafish, fruit flies and worms. Given the functions of sleep in promoting brain connectivity, neural plasticity, emotional regulation and social behavior, all of which are of critical importance in ASD pathogenesis, we propose that synaptic dysfunction is a major mechanism that connects ASD and SD. Common molecular targets in this interplay that are involved in synaptic function might be a novel avenue for therapy of individuals with ASD experiencing SD. Such therapy would be expected to improve not only sleep but also other ASD symptoms.

Practitioner's review: medication for children and adolescents with autism spectrum disorder (ASD) and comorbid conditions

Alleviating the multiple problems of children with autism spectrum disorder (ASD) and its comorbid conditions presents major challenges for the affected children, parents, and therapists. Because of a complex psychopathology, structured therapy and parent training are not always sufficient, especially for those patients with intellectual disability (ID) and multiple comorbidities. Moreover, structured therapy is not available for a large number of patients, and pharmacological support is often needed, especially in those children with additional attention deficit/hyperactivity and oppositional defiant, conduct, and sleep disorders.

Subjective and Electroencephalographic Sleep Parameters in Children and Adolescents with Autism Spectrum Disorder: A Systematic Review

Background: Sleep problems have commonly manifested in children and adolescents with autism spectrum disorder (ASD) with a complex and multifactorial interaction between clinical and etiological components. These disorders are associated with functional impairment, and provoke significant physical and mental affliction. The purpose of this study is to update the existing literature about objective and subjective sleep parameters in children and adolescents with ASD, extrapolating information from polysomnography or sleep electroencephalography, and sleep related questionnaires. Methods: We have conducted a systematic review of case-control studies on this topic, performing a web-based search on PubMed, Scopus and the Web of Science databases according to the Preferred Reporting items for Systematic Review and Meta-analyses (PRISMA) guidelines. Results: Data collected from 20 survey result reports showed that children and adolescents with ASD experienced a higher rate of sleep abnormalities than in typically developing children. The macrostructural sleep parameters that were consistent with subjective parent reported measures unveil a greater percentage of nighttime signs of insomnia. Sleep microstructure patterns, in addition, pointed towards the bidirectional relationship between brain dysfunctions and sleep problems in children with ASD. Conclusions: Today’s literature acknowledges that objective and subjective sleep difficulties are more often recognized in individuals with ASD, so clinicians should assess sleep quality in the ASD clinical population, taking into consideration the potential implications on treatment strategies. It would be worthwhile in future studies to examine how factors, such as age, cognitive level or ASD severity could be related to ASD sleep abnormalities. Future research should directly assess whether sleep alterations could represent a specific marker for atypical brain development in ASD.

Potential Risk Factors for Autism in Children Requiring Neonatal Intensive Care Unit

BACKGROUND

The etiology of autism spectrum disorder (ASD) is complex and involves the interplay of genetic and environmental factors.

AIM

We sought to identify potential prenatal, perinatal, and neonatal risk factors for ASD in a unique population of children who had perinatal complications and required care in a neonatal intensive care unit (NICU).

METHODS

This prospective cohort study included 73 patients discharged from a NICU who received long-term follow-up at the largest children's hospital in Brazil. Potential risk factors were compared between 44 children with a diagnosis of ASD and 29 children without using the Mann-Whitney U test. Proportions were analyzed using the chi-square test. Simple and multiple logistic regression tests were performed.

RESULTS

Of 38 factors analyzed, the following 7 were associated with ASD: family history of neuropsychiatric disorders (p = 0.049); maternal psychological distress during pregnancy (p = 0.007); ≥ 26 days in the NICU (p = 0.001); feeding tube for ≥ 15 days (p = 0.014); retinopathy of prematurity (p = 0.022); use of three or more antibiotics (p = 0.008); and co-sleeping until up to 2 years of age (p = 0.004).

CONCLUSION

This study found associations between specific risk factors during critical neurodevelopmental periods and a subsequent diagnosis of ASD. Knowledge of the etiologic factors that may influence the development for ASD is paramount for the development of intervention strategies and improvement of prognoses.

Melatonin Treatment and Adequate Sleep Hygiene Interventions in Children with Autism Spectrum Disorder: A Randomized Controlled Trial

Robust clinical evidence has not been available for melatonin, a drug commonly administered for treating sleep problems of children with autism spectrum disorder (ASD). In a phase 3 randomized, placebo-controlled clinical trial, we administered 1-mg melatonin (n = 65), 4-mg melatonin (n = 65), or placebo (n = 66) to196 children with ASD once daily before bedtime under adequate sleep hygiene interventions. The primary outcome was sleep onset latency (SOL) assessed with the electronic sleep diary. SOL shortened significantly in the 1- and 4-mg melatonin groups compared to the placebo group (- 22.0, - 28.0, and - 5.0 min, respectively; p < 0.0001 each). This therapeutic regimen of melatonin is a reasonable clinical approach to cope with ASD-emergent difficulties in children with ASD.

Sleep problems in children with autism spectrum disorder and typical development

BACKGROUND

Although higher sleep problems have been mostly reported in children with autism spectrum disorder (ASD) compared with typically developing (TD) children, particularly in Western countries, such evidence is relatively scarce in developing countries. We therefore investigated sleep difficulties in Thai children aged 3-16 years with ASD compared with age- and gender-matched TD children by using the Children's Sleep Habits Questionnaire (CSHQ)-Thai version.

METHODS

Sixty-five children with ASD (mean age 97.7, SD 44.5 months; boys 70.8%) and 65 TD individuals (mean age 98.5, SD 43.5 months) were enrolled at a university-based hospital in Bangkok. Background characteristics, sleep duration variables, and the CSHQ were completed by the participants' parents. The CSHQ subscales and total score between children with ASD and TD controls were then compared.

RESULTS

Children with ASD were more likely to have longer sleep latency than TD individuals for both weekdays and the weekend. Those with ASD had higher CSHQ subscales including bedtime resistance, sleep onset delay, sleep anxiety, and night waking in addition to the CSHQ total scores than TD controls. In the ASD group, those who took psychostimulants for treatment of ADHD had lower scores on the sleep duration subscale compared with unmedicated individuals.

CONCLUSIONS

Sleep difficulties were more prevalent in children with ASD compared with TD individuals. Parents should be advised to be aware of sleep problems in individuals with ASD. As such, sleep disturbances will be identified early, resulting in appropriate management and improved quality of life, not only for those with ASD but also their families.

Sleep Problems in Children with ASD and Gene Disrupting Mutations

Sleep difficulties are pervasive in autism spectrum disorder (ASD), yet how sleep problems relate to underlying biological mechanisms such as genetic etiology is unclear, despite recent reports of profound sleep problems in children with ASD-associated de novo likely gene disrupting (dnLGD) mutations, CHD8, DYRK1A, and ADNP. We aimed to inform etiological contributions to ASD and sleep by characterizing sleep problems in individuals with dnLGD mutations. Participants (N = 2886) were families who completed dichotomous questions about sleep problems within a medical history interview for their child with ASD (age 3-28 years). Confirmatory factor analyses compared between those with ASD and a dnLGD mutation and those with idiopathic ASD (i.e., no known genetic event, NON) highlighted four domains (sleep onset, breathing issues, nighttime awakenings, and daytime tiredness) with sleep onset as a strong factor for both groups. Overall, participant predictors indicated that internalizing behavioral problems and lower cognitive scores were related to increased sleep problems. Internalizing problems were also related to increase nighttime awakenings in the dnLGD group. As an exploratory aim, patterns of sleep issues are described for genetic subgroups with unique patterns including more overall sleep issues in ADNP (n = 19), problems falling asleep in CHD8 (n = 22), and increased daytime naps in DYRK1A (n = 23). Implications for considering genetically defined subgroups when approaching sleep problems in children with ASD are discussed.

Sleep phenotype of individuals with autism spectrum disorder bearing mutations in the PER2 circadian rhythm gene

The Per family of genes functions as a primary circadian rhythm maintenance in the brain. Mutations in PER2 are associated with familial advanced sleep-phase syndrome 1 (FASPS1), and recently suggested in delayed sleep phase syndrome and idiopathic hypersomnia. The detection of PER2 variants in individuals with autism spectrum disorder (ASD) and without reported sleep disorders, has suggested a role of circadian-relevant genes in the pathophysiology of ASD. It remains unclear whether these individuals may have, in addition to ASD, an undiagnosed circadian rhythm sleep disorder. The MSSNG database was used to screen whole genome sequencing data of 5,102 individuals with ASD for putative mutations in PER2. Families identified were invited to complete sleep phenotyping consisting of a structured interview and two standardized sleep questionnaires: the Pittsburgh Sleep Quality Index and the Morningness-Eveningness Questionnaire. From 5,102 individuals with ASD, two nonsense, one frameshift, and one de novo missense PER2 variants were identified (0.08%). Of these four, none had a diagnosed sleep disorder. Three reported either a history of, or ongoing sleep disturbances, and one had symptoms highly suggestive of FASPS1 (as did a mutation carrier father without ASD). The individual with the missense variant did not report sleep concerns. The ASD and cognitive profiles of these individuals varied in severity and symptoms. The results support a possible role of PER2-related circadian rhythm disturbances in the dysregulation of sleep overall and sometimes FASPS1. The relationship between dysregulated sleep and the pathophysiology of ASD require further exploration.

Iron and Insomnia in Autism Spectrum Disorder

Investigators from four major Universities studied the impact of iron supplementation on insomnia symptoms in children with Autism Spectrum Disorder (ASD) and ferritin levels not indicative of iron deficiency anemia.

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.

Sleep-Wake Disorders in Childhood

PURPOSE OF REVIEW

The presentation of sleep issues in childhood differs from the presentation in adulthood and may be more subtle. Sleep issues may affect children differently than adults, and distinct treatment approaches are often used in children.

RECENT FINDINGS

Sodium oxybate was approved by the US Food and Drug Administration (FDA) in October 2018 for an expanded indication of treatment of sleepiness or cataplexy in patients with narcolepsy type 1 or narcolepsy type 2 aged 7 years or older, with side effect and safety profiles similar to those seen in adults. Restless sleep disorder is a recently proposed entity in which restless sleep, daytime sleepiness, and often iron deficiency are observed, but children do not meet the criteria for restless legs syndrome or periodic limb movement disorder.

SUMMARY

Children's sleep is discussed in this article, including normal sleep patterns and effects of insufficient sleep. Sleep disorders of childhood are reviewed, including insomnia, obstructive sleep apnea, restless legs syndrome, parasomnias, narcolepsy, and Kleine-Levin syndrome. Children with neurologic issues or neurodevelopmental disorders frequently have sleep disorders arising from an interaction of heterogeneous factors. Further attention to sleep may often be warranted through a polysomnogram or referral to a pediatric sleep specialist. Sleep disorders may cause indelible effects on children's cognitive functioning, general health, and well-being, and awareness of sleep disorders is imperative for neurologists who treat children.

An Exploration of Health Behaviors in a Mind-Body Resilience Intervention for Parents of Children with Developmental Disabilities

OBJECTIVE

Parents of children with special needs such as learning and attentional disabilities (LADs) and autism spectrum disorder (ASD) are at high risk for stress-related disorders. The demands of parenting may compete with time for self-care behaviors such as physical activity, healthy eating, and adequate sleep. The objective was to describe health behaviors among this understudied population and assess the changes after a resilience intervention.

METHODS

This was a secondary data analysis of a randomized controlled pilot virtual mind-body resilience intervention (Stress Management and Resiliency Training: A Relaxation Response Resiliency Program) trial for parents of children with LADs (n = 52) and ASD (n = 47). Parents completed self-report questionnaires about their weekly physical activity, eating behaviors, sleep duration, and fatigue before and after the 8-week intervention. Descriptive statistics and pre-post intervention effect sizes (Cohen's d) were calculated.

RESULTS

Both parent groups reported suboptimal levels of health behaviors at baseline, but ASD parents reported lower health behaviors than LAD parents. LAD parents improved more on physical activity, with a higher percentage meeting recommendations at postintervention follow-up (d = 0.71) than ASD parents (d = 0.01). Eating behaviors showed small effect size improvements for both groups. Although sleep duration improved only with small or medium effect sizes for both groups, ASD parents rated their fatigue lower after the intervention (d = 0.81).

CONCLUSION

Parents of children with special needs who participated in a virtual resilience intervention demonstrated suboptimal health behaviors. There is a need for targeted interventions for health behaviors that can promote resilience in these high-stress populations.

Mirtazapine for sleep disturbances in Angelman syndrome: a retrospective chart review of 8 pediatric cases

STUDY OBJECTIVES

Angelman syndrome (AS) is a rare neurodevelopmental disorder that is characterized by developmental delay, intellectual disability, seizures, a characteristic happy personality, gait ataxia, tremulousness of the limbs, microcephaly, and anxiety. Severe sleep disturbances with the diminished need for sleep and abnormal sleep-wake cycles are seen in up to 90% of patients with AS. AS is caused by absent maternal expression of the gene UBE3A located in the 15q11.2-q13 locus. We hypothesized that selective antagonism of 5-HT₂ and 5-HT₃ serotonin receptors with mirtazapine would benefit sleep disturbances in patients with AS.

METHODS

Institutional Review Board approval was obtained at Vanderbilt University Medical Center. Medical records of individuals seen in the Comprehensive Angelman Syndrome clinic were retrospectively reviewed to determine the use of mirtazapine for disordered sleep. Parents were asked to respond to a survey to assess the phenotypic features of sleep and behavioral disturbances in AS. They were asked about the use of medications for sleep, focusing on the benefits and risks of mirtazapine.

RESULTS

A cohort of 8 individuals with AS, ranging in age from 3 to 16 years old with histories of sleep challenges, were treated with 3.75 to 30 mg of mirtazapine at bedtime for 0 to 36 weeks. Nocturnal awakenings were the most common sleep challenge reported. Seven of eight patients reported benefits from mirtazapine, including increased total sleep time, decreased nocturnal awakenings, and decreased time to fall asleep. The most significant side effects of mirtazapine were hyperphagia and weight gain.

CONCLUSIONS

Individuals with AS have abnormal sleep-wake cycles and a high unmet medical need. Mirtazapine helped with sleep onset and nighttime awakenings in 7 of 8 patients, with 2 patients reporting a positive benefit with respect to behavior. These data suggest that mirtazapine may be considered for the treatment of sleep difficulties in patients with AS who remain refractory to more conventional therapies. Weight gain was a common side-effect and led to discontinuation of treatment in 1 patient.

Weight Management in Primary Care for Children With Autism: Expert Recommendations

Research suggests that the prevalence of obesity in children with autism spectrum disorder (ASD) is higher than in typically developing children. The US Preventive Services Task Force and the American Academy of Pediatrics (AAP) have endorsed screening children for overweight and obesity as part of the standard of care for physicians. However, the pediatric provider community has been inadequately prepared to address this issue in children with ASD. The Healthy Weight Research Network, a national research network of pediatric obesity and autism experts funded by the US Health Resources and Service Administration Maternal and Child Health Bureau, developed recommendations for managing overweight and obesity in children with ASD, which include adaptations to the AAP's 2007 guidance. These recommendations were developed from extant scientific evidence in children with ASD, and when evidence was unavailable, consensus was established on the basis of clinical experience. It should be noted that these recommendations do not reflect official AAP policy. Many of the AAP recommendations remain appropriate for primary care practitioners to implement with their patients with ASD; however, the significant challenges experienced by this population in both dietary and physical activity domains, as well as the stress experienced by their families, require adaptations and modifications for both preventive and intervention efforts. These recommendations can assist pediatric providers in providing tailored guidance on weight management to children with ASD and their families.

Practice guideline: Treatment for insomnia and disrupted sleep behavior in children and adolescents with autism spectrum disorder: Report of the Guideline Development, Dissemination, and Implementation Subcommittee of the American Academy of Neurology

OBJECTIVE

To review pharmacologic and nonpharmacologic strategies for treating sleep disturbances in children and adolescents with autism spectrum disorder (ASD) and to develop recommendations for addressing sleep disturbance in this population.

METHODS

The guideline panel followed the American Academy of Neurology 2011 guideline development process, as amended. The systematic review included studies through December 2017. Recommendations were based on evidence, related evidence, principles of care, and inferences.

MAJOR RECOMMENDATIONS LEVEL B

For children and adolescents with ASD and sleep disturbance, clinicians should assess for medications and coexisting conditions that could contribute to the sleep disturbance and should address identified issues. Clinicians should counsel parents regarding strategies for improved sleep habits with behavioral strategies as a first-line treatment approach for sleep disturbance either alone or in combination with pharmacologic or nutraceutical approaches. Clinicians should offer melatonin if behavioral strategies have not been helpful and contributing coexisting conditions and use of concomitant medications have been addressed, starting with a low dose. Clinicians should recommend using pharmaceutical-grade melatonin if available. Clinicians should counsel children, adolescents, and parents regarding potential adverse effects of melatonin use and the lack of long-term safety data. Clinicians should counsel that there is currently no evidence to support the routine use of weighted blankets or specialized mattress technology for improving disrupted sleep. If asked about weighted blankets, clinicians should counsel that the trial reported no serious adverse events with blanket use and that blankets could be a reasonable nonpharmacologic approach for some individuals.

Understanding the role of sleep and its disturbances in Autism spectrum disorder

BACKGROUND

Several studies have established a positive relationship between sleep difficulties and symptomatology in ASD children. The rationale for this review is to describe and discuss the sleep difficulties, which are one of the significant complications associated with autism spectrum disorder (ASD).

PURPOSE

Many types of sleep disorders have been reported in ASD individuals, but still lack a comprehensive study and in-depth analysis. Despite the contribution of sleep problems to the overall symptoms of ASD, the symptoms of disturbed sleep experienced by many affected patients have only recently started to receive attention from clinicians and family members.

MATERIALS AND METHODS

This narrative overview has been prepared based on searching standard research databases with specific keywords; b. Additional search was made using the bibliographies of the retrieved articles; and c. author's collection of relevant peer-reviewed articles. Once selected, manuscripts are then compared and summarized based on the author's perspective. Results are based on a qualitative rather than a quantitative level.

RESULTS

This article highlights the role of sleep in the brain and neural development of children and emphasizes that the intensity of sleep problems is associated with an increased occurrence of ASD symptoms. It also suggests the significance of treating sleep problems in ASD individuals.

CONCLUSIONS

The review provides broader perspectives and a better understanding of sleep problems in pathophysiology, mechanism, and management with respect to ASD individuals. Finally, the implications for clinical practice and future agendas have also been discussed.

Identification, Evaluation, and Management of Children With Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a common neurodevelopmental disorder with reported prevalence in the United States of 1 in 59 children (approximately 1.7%). Core deficits are identified in 2 domains: social communication/interaction and restrictive, repetitive patterns of behavior. Children and youth with ASD have service needs in behavioral, educational, health, leisure, family support, and other areas. Standardized screening for ASD at 18 and 24 months of age with ongoing developmental surveillance continues to be recommended in primary care (although it may be performed in other settings), because ASD is common, can be diagnosed as young as 18 months of age, and has evidenced-based interventions that may improve function. More accurate and culturally sensitive screening approaches are needed. Primary care providers should be familiar with the diagnostic criteria for ASD, appropriate etiologic evaluation, and co-occurring medical and behavioral conditions (such as disorders of sleep and feeding, gastrointestinal tract symptoms, obesity, seizures, attention-deficit/hyperactivity disorder, anxiety, and wandering) that affect the child's function and quality of life. There is an increasing evidence base to support behavioral and other interventions to address specific skills and symptoms. Shared decision making calls for collaboration with families in evaluation and choice of interventions.  This single clinical report updates the 2007 American Academy of Pediatrics clinical reports on the evaluation and treatment of ASD in one publication with an online table of contents and section view available through the American Academy of Pediatrics Gateway to help the reader identify topic areas within the report.

Sleep disturbances and associated factors among 2-6-year-old male children with autism in Bhubaneswar, India

BACKGROUND

Sleep disturbances are considered one of the significant comorbidities of autism; they negatively impact the quality of life of children with autism as well as their parents or caregivers. This study aimed to determine the prevalence of sleep disturbances in Indian male children diagnosed with autism and examine the association of lifestyle behaviors and socio-demographic characteristics with sleep problems.

METHODS

The present cross-sectional study was conducted in Bhubaneswar city in the year 2018, involving mothers of 100 male children with autism aged 2-6 years. We used a children's sleep habits questionnaire (CSHQ) to evaluate the sleep problems in children with autism and a semi-structured schedule for gathering information regarding lifestyle behaviors and socio-demographic characteristics.

RESULTS

The overall prevalence of parent-reported sleep problems was 93%; the most prevalent CSHQ subscales were: bedtime resistance (95%), sleep anxiety (85%), and sleep duration (81%). The mean ISAA score of the study sample was 133.89 ± 19.59, where 12%, 71%, and 17% of the children had mild, moderate, and severe autism, respectively. Multiple linear regression analysis revealed that variables such as autism severity, screen time, caffeine intake, physical activity, maternal age, child's age, and birth weight were significantly associated with the CSHQ subscales.

CONCLUSION

The prevalence of parent-reported sleep problems is very high among the male children with autism in Bhubaneswar, India, and there is an urgent need for interventional measures for appropriate management of this problem among these children.

Associations between parenting stress, parent mental health and child sleep problems for children with ADHD and ASD: Systematic review

BACKGROUND

Children with attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) experience high rates of sleep problems. Their parents experience higher parenting stress and more mental health difficulties than parents of typically developing children.

AIM

To examine the association between child sleep problems, parenting stress and parent mental health for children with ADHD or ASD.

METHODS

MEDLINE Complete, EMBASE, PsycINFO and CINAHL Complete databases were searched. Studies needed to include: children aged 5-18 with ADHD or ASD, a child sleep measure, and a parenting stress or adult mental health measure.

RESULTS

Eleven studies were identified (four ADHD, seven ASD). Six studies examined parenting stress (five cross-sectional, one longitudinal) and five found associations, of varying strengths, with child sleep problems. Six studies examined parent mental health (four cross-sectional, two longitudinal) and five found associations, of differing magnitudes, with child sleep problems.

CONCLUSIONS

These studies demonstrate child sleep problems are associated with poorer parent mental health and higher parenting stress.

IMPLICATIONS

Future longitudinal research including multiple measurements of child sleep problems and family functioning is required to clarify the directionality of associations. Such knowledge is key in adapting sleep interventions to better meet the needs of children with ADHD or ASD and their families.

Sleep Problems and Their Relationship to Maladaptive Behavior Severity in Psychiatrically Hospitalized Children with Autism Spectrum Disorder (ASD)

We examined the relationship between sleep duration and awakenings to Aberrant Behavior Checklist-Community (ABC-C) and Autism Diagnostic Observation Schedule (ADOS-2) scores in hospitalized youth with ASD and behavioral disturbance. Participants included 106 patients with a stay of at least 10 nights. Sleep in the hospital was recorded by staff observation. Higher scores on the ABC-C (irritability, stereotypy, and hyperactivity subscales) at admission were significantly associated with fewer minutes slept during the last five nights of hospitalization. There was no association between total awakenings and ABC-C scores or ADOS-2 comparison scores. Improved understanding of the relationship between sleep quality and maladaptive behavior in this challenging cohort of patients with ASD is vital to the definition and design of future effective interventions.

Efficacy of parent training incorporated in behavioral sleep interventions for children with autism spectrum disorder and/or intellectual disabilities: a systematic review

OBJECTIVE

Behavioral sleep interventions are regularly used to improve sleep problems experienced by children with autism spectrum disorder (ASD) and/or intellectual disability (ID). Recent developments have seen the introduction of parent sleep education and healthy sleep practice training to sleep interventions. This article aims to systematically review the evidence on the efficacy of parent training that is incorporated within recent sleep interventions for children with ASD and/or ID.

METHOD

Electronic databases and manual searches of reference lists identified 11 studies (n = 416 children) that met the inclusion criteria.

RESULTS

The evidence presented in this systematic review would suggest that the inclusion of parent training within behavioral sleep interventions for children with ASD and/or ID is generally effective and valued by parents. Nine of the 11 studies reviewed reported a reduction in sleep problems.

CONCLUSION

The literature conveys an emerging evidence-based practice that could contribute to future behavioral sleep research and guide best-practice decisions to support effective parent training to improve sleep outcomes for children with ASD and/or ID.

The Relationship between Sleep Problems, Neurobiological Alterations, Core Symptoms of Autism Spectrum Disorder, and Psychiatric Comorbidities

Children with Autism Spectrum Disorder (ASD) are at an increased risk for sleep disturbances, and studies indicate that between 50 and 80% of children with ASD experience sleep problems. These problems increase parental stress and adversely affect family quality of life. Studies have also suggested that sleep disturbances may increase behavioral problems in this clinical population. Although understanding the causes of sleep disorders in ASD is a clinical priority, the causal relationship between these two conditions remains unclear. Given the complex nature of ASD, the etiology of sleep problems in this clinical population is probably multi-factorial. In this overview, we discuss in detail three possible etiological explanations of sleep problems in ASD that can all contribute to the high rate of these symptoms in ASD. Specifically, we examine how neurobiological alterations, genetic mutations, and disrupted sleep architecture can cause sleep problems in individuals with ASD. We also discuss how sleep problems may be a direct result of core symptoms of ASD. Finally, a detailed examination of the relationship between sleep problems and associated clinical features and psychiatric comorbidities in individuals with ASD is described.

Sleep Outcomes for Parents of Children With Neurodevelopmental Disabilities: A Systematic Review

Parents of children with Neurodevelopmental Disabilities (NDDs) are at risk of sleep loss. No comprehensive systematic reviews examining parental sleep outcomes in caregivers of children with NDDs exist. A systematic search was conducted between June and August 2016 examining sleep quantity, quality, sleepiness, and fatigue outcomes of caregivers of children with NDDs. Of 7,534 citations retrieved, 33 met eligibility criteria. Most studies ( n = 27) were cross-sectional, included a range of NDDs and were of "poor" ( n = 14) or "fair" ( n = 17) quality. Few good quality studies compared objectively measured sleep in parents of children with NDDs with parents with typically developing children. Parents of children with NDDs consistently reported significantly poorer subjective sleep quality. There is a paucity of good quality comparative studies, using well-validated measures, examining parental sleep outcomes. Future research should aim to fill this gap, providing greater insight to parents' experiences, and identifying targets for intervention design and evaluation.

Cytokine levels and associations with symptom severity in male and female children with autism spectrum disorder

Background

Autism spectrum disorders (ASDs) are complex, pervasive, and heterogeneous neurodevelopmental conditions with varying trajectories, significant male bias and largely unknown etiology. However, an understanding of the biological mechanisms driving pathophysiology is evolving. Immune system aberrations, as identified through cytokine profiles, are believed to have a role in ASD. Altered cytokine levels may facilitate identification of ASD subtypes as well as provide biological markers of response to effective treatments. Research exploring the relationship between cytokine profiles and ASD symptoms is, however, in its infancy. The objective of this study was to explore relationships between cytokine levels and the severity of ASD and other clinical traits.

Methods

Multiplex assay techniques were used to measure levels of 27 cytokines in plasma samples from a cohort of 144 children diagnosed with ASD.

Results

Overall, results showed a significant negative association between platelet-derived growth factor (PDGF)-BB, and the severity of ASD symptoms. Furthermore, a significant interaction with sex suggested a different immune profile for females compared to males. ASD symptom severity was negatively associated with levels of 4 cytokines, IL-1β, IL-8, MIP-1β, and VEGF, in females, but not in males.

Conclusions

Results of the present study suggest that an altered cytokine response or profile is associated with the severity of ASD-related symptoms, with sex a potential modifier of this relationship. Further research in larger populations which recognizes the importance of sex comparisons and longitudinal assessments are now required to extend and further describe the role of the immune system in ASD.

Electronic supplementary material

The online version of this article (10.1186/s13229-017-0176-2) contains supplementary material, which is available to authorized users.

Assessment of Sleep in Children with Autism Spectrum Disorder

Sleep disturbances in children with autism spectrum disorder (ASD) are significantly more prevalent than found in typically developing (TD) children. Given the detrimental impact of poor sleep on cognitive, emotional, and behavioral functioning, it is imperative to screen and assess for sleep disturbances in this population. In this paper, we describe the screening and assessment process, as well as specific measures commonly used for assessing sleep in children with ASD. Advantages and limitations for use in children with ASD are discussed. While subjective measures, such as parent-report questionnaires and sleep diaries, are the most widely used, more objective measures such as actigraphy, polysomnography, and videosomnography provide additional valuable information for both diagnostic purposes and treatment planning. These objective measures, nonetheless, are limited by cost, availability, and feasibility of use with children with ASD. The current review provides an argument for the complementary uses of both subjective and objective measures of sleep specifically for use in children with ASD.

Sleep Is for Forgetting

It is possible that one of the essential functions of sleep is to take out the garbage, as it were, erasing and "forgetting" information built up throughout the day that would clutter the synaptic network that defines us. It may also be that this cleanup function of sleep is a general principle of neuroscience, applicable to every creature with a nervous system.

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

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

Pleiotropic genetic effects influencing sleep and neurological disorders

Research evidence increasingly points to the large impact of sleep disturbances on public health. Many aspects of sleep are heritable and genes influencing traits such as timing, EEG characteristics, sleep duration, and response to sleep loss have been identified. Notably, large-scale genome-wide analyses have implicated numerous genes with small effects on sleep timing. Additionally, there has been considerable progress in the identification of genes influencing risk for some neurological sleep disorders. For restless legs syndrome, implicated variants are typically in genes associated with neuronal development. By contrast, genes conferring risk for narcolepsy function in the immune system. Many genetic variants associated with sleep disorders are also implicated in neurological disorders in which sleep abnormalities are common; for example, variation in genes involved in synaptic homoeostasis are implicated in autism spectrum disorder and sleep-wake control. Further investigation into pleiotropic roles of genes influencing both sleep and neurological disorders could lead to new treatment strategies for a variety of sleep disturbances.

Human genetics and sleep behavior

Why we sleep remains one of the greatest mysteries in science. In the past few years, great advances have been made to better understand this phenomenon. Human genetics has contributed significantly to this movement, as many features of sleep have been found to be heritable. Discoveries about these genetic variations that affect human sleep will aid us in understanding the underlying mechanism of sleep. Here we summarize recent discoveries about the genetic variations affecting the timing of sleep, duration of sleep and EEG patterns. To conclude, we also discuss some of the sleep-related neurological disorders such as Autism Spectrum Disorder (ASD) and Alzheimer's Disease (AD) and the potential challenges and future directions of human genetics in sleep research.

Shorter sleep duration is associated with social impairment and comorbidities in ASD

Sleep disturbance, particularly insomnia, is common in children with autism spectrum disorders (ASD). Furthermore, disturbed sleep affects core symptoms and other related comorbidities. Understanding the causes and consequences of sleep disturbances in children with ASD is an important step toward mitigating these symptoms. To better understand the connection between sleep duration and ASD severity, we analyzed ASD-related symptoms using the Autism Diagnostic Interview-Revised (ADI-R), Autism Diagnostic Observation Schedule (ADOS), IQ scores, and parent reports of the average amount of time slept per night that were available in the medical histories of 2,714 children with ASD in the Simons Simplex Collection (SSC). The mean (SD) sleep duration was 555 minutes. Sleep duration and severity of core ASD symptoms were negatively correlated, and sleep duration and IQ scores were positively correlated. Regression results indicated that more severe social impairment, primarily a failure to develop peer relationships, is the core symptom most strongly associated with short sleep duration. Furthermore, increased severity for numerous maladaptive behaviors assessed on the Child Behavior Checklist, as well as reports of attention deficit disorder, depressive disorder, and obsessive compulsive disorder were associated with short sleep duration. Severity scores for social/communication impairment and restricted and repetitive behaviors (RRB) were increased, and IQ scores were decreased, for children reported to sleep ≤420 minutes per night (lower 5th percentile) compared to children sleeping ≥660 minutes (upper 95th percentile). Our results indicate that reduced amounts of sleep are related to more severe symptoms in children with ASD. Autism Res 2017. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. Autism Res 2017, 10: 1221-1238. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.