Sleep problems and temperament in young children with Down syndrome and typically developing controls

An investigation of sleep problems, gastrointestinal symptoms, comorbid psychopathology and challenging behavior in children and adolescents with Down Syndrome

BACKGROUND

Down syndrome (DS) is one of the most common chromosomal abnormalities, and children with DS have increased risks of receiving diagnoses of specific comorbidities.

AIMS

This study aimed to assess the frequencies and relationships between sleep problems, gastrointestinal (GI) symptoms, comorbid psychopathology, and challenging behavior.

METHODS AND PROCEDURES

The Children's Sleep Habits Questionnaire, Gastrointestinal Symptom Inventory, Autism Spectrum Disorder-Comorbid for Children, and Behavior Problems Inventory-Short Form were completed by 123 parents of children and adolescents with DS.

OUTCOMES AND RESULTS

The frequency of GI symptoms was 74.8 %, with high frequencies also found for: sleep problems (100 %), challenging behavior (100 %), and moderate to severe levels of comorbid psychopathology (tantrum=80 %; repetitive behavior=63 %; avoidant behavior=82 %; worry/depressed=61 %; conduct behavior=100 %; over-eating=100 %; under-eating=100 %). A significant moderate correlation was found between total GI symptoms and self-injurious behavior frequency. Children who presented with abdominal pain engaged in self-injurious behavior more frequently than those with no abdominal pain.

CONCLUSIONS AND IMPLICATIONS

Findings indicated a high frequency of sleep problems, comorbid psychopathology, GI symptoms, and challenging behavior and demonstrated a relationship between GI symptoms and self-injurious behavior in children and adolescents with DS. This research illustrated the importance of investigating comorbid conditions in individuals with DS. WHAT THIS PAPER ADDS?: Down Syndrome (DS) is a genetic condition characterized by trisomy 21 and is a leading cause of intellectual disability worldwide. The prevalence of DS is commonly associated with advanced maternal age and is associated with multiple comorbid conditions. The current study aimed to investigate the frequency of and relationship between sleep problems, gastrointestinal symptoms, comorbid psychopathology, and challenging behavior in children and adolescents with DS. High-frequency levels were found for sleep problems (100 %), challenging behavior (100 %), gastrointestinal symptoms (74.8 %), and moderate to severe levels of the different comorbid psychopathologies (tantrum=80 %; repetitive behavior=63 %; avoidant behavior=82 %; worry/depressed=61 %; conduct behavior=100 %; over-eating=100 %; under-eating=100 %). Results indicated a significant difference in self-injurious behavior frequency between individuals who presented with abdominal pain and those who did not. This study is the first to investigate the relationship of multiple comorbid conditions in a sample of children with DS. This paper adds to the literature by demonstrating the frequency of a number of comorbid conditions in children and adolescents with DS. The paper also adds novel findings to the literature by investigating the relationships between comorbid conditions in this population. The findings of this paper highlighted the frequency and comorbidities that exist between gastrointestinal symptoms, sleep problems, comorbid psychopathology, and challenging behavior. Analyses indicated that those who presented with abdominal pain, engaged in self-injurious behavior more frequently. Sleep problems, gastrointestinal symptoms, comorbid psychopathology, and challenging behavior in children and adolescents with Down Syndrome.

Behavioural sleep problems in children and adults with intellectual disabilities: An integrative literature review

BACKGROUND

People with intellectual disabilities are more likely to experience sleep problems, which can affect quality of life, physical health, mental health and well-being.

METHODS

An integrative literature review was conducted to investigate what is known about behavioural sleep disturbances in people with an intellectual disability. The search used the following databases: Scopus, PsycInfo and Cinahl, to find papers published since 2015.

RESULTS

Within intellectual disability research, sleep appears as a common issue due to its high prevalence, negative relationships with an individual's physical and mental health, their quality of life, and impact of sleep problems on family or carers. The growing evidence base appears to support the use of behavioural, lifestyle and pharmacological interventions to improve sleep in people with an intellectual disability.

CONCLUSION

A wide array of literature provides evidence that people with intellectual disabilities are affected by and need support with their sleep.

Assessing sleep in children with Down syndrome: Comparison of parental sleep diaries, actigraphy and polysomnography

BACKGROUND

This study compared measurements of sleep and wake assessed with actigraphy, sleep diary and polysomnography in children with Down syndrome (DS) and also compared measures of actigraphic sleep recording in children with DS and typically developing (TD) children.

METHODS

Children with DS aged 3-19 years (N = 44) referred for assessment of sleep disordered breathing (SDB) underwent overnight polysomnography, together with 1 week of actigraphy with sleep diary. Actigraphy data from the children with DS were compared with data collected from TD children, matched for age and sex.

RESULTS

22 children (50%) with DS completed >3 consecutive nights of actigraphy with a matched sleep diary. There were no differences between bedtimes, wake times or time in bed on weeknights, weekends or over 7 nights between actigraphy and sleep diary. Total sleep time was over estimated by the sleep diary by almost 2 h and the number of night awakenings under-reported. Compared to matched TD children (N = 22), there was no difference in total sleep time, however children with DS fell asleep more quickly (p < 0.001), had more awakenings (p = 0.001) and more time awake after sleep onset (p = 0.007). Children with DS exhibited less variability in both bedtimes and wake times, and fewer had >1 h sleep schedule variability.

CONCLUSIONS

Parental sleep diaries over-estimate total sleep time but accurately report bed and wake times compared to actigraphy in children with DS. Children with DS have more regular sleep patterns than TD children of the same age, which is important for optimising daytime functioning. The reasons behind this warrant further investigation.

The Mediatory Role of Executive Functioning on the Association Between Sleep and Both Everyday Memory and ADHD Symptoms in Children and Youth With Down Syndrome

People with Down syndrome (DS) commonly experience challenges with sleep, executive functioning, everyday memory, and symptoms of attention deficit hyperactivity disorder (ADHD). A path analysis was conducted to determine if executive function mediated the relationship between sleep problems and both everyday memory and ADHD symptoms. Parents of 96 children and youth with DS completed questionnaires related to sleep, executive functioning, everyday memory, and ADHD symptoms. Results showed that executive functioning fully mediated the relation between sleep and both everyday memory and ADHD symptoms. Implications for education and intervention for children and youth with DS are discussed.

Sleep, Function, Behaviour and Cognition in a Cohort of Children with Down Syndrome

Objective: To describe the sleep problems experienced by children with Down syndrome attending a tertiary sleep clinic and relationship with behaviour, function and cognition. Methods: Data were collected from children with Down syndrome aged 3–18 years old. Carers completed the Abbreviated Child Sleep Habits Questionnaire, Child Behaviour Checklist and Life-Habits Questionnaire at enrolment. Cognitive assessment (Stanford-Binet 5) was undertaken by a trained psychologist. Children received management for their sleep problem as clinically indicated. Results: Forty-two subjects with a median age of 6.8 years (Interquartile Range-IQR 4.5, 9.8) were enrolled. A total of 92% were referred with snoring or symptoms of Obstructive Sleep Apnoea (OSA), with 79% of those referred having had previous ENT surgery. Thus, 85% of all participants underwent a sleep study and 61% were diagnosed with OSA (OAHI ≥ 1/h). Based on questionnaires, 86% of respondents indicated that their child had a significant sleep disorder and non-respiratory sleep problems were common. Non-respiratory problems included: trouble going to sleep independently (45%), restless sleep (76%), night-time waking (24%) and bedtime resistance (22%). No significant correlations were found between sleep measures (behavioural and medical sleep problems) and the behavioural, functional or cognitive parameters. Conclusion: Sleep disorders were very common, especially non-respiratory sleep problems. OSA was common despite previous surgery. No association was found between sleep-related problems (snoring, sleep-study-confirmed OSA or non-respiratory sleep problem) and parent-reported behavioural problems, functional impairments or intellectual performance. This may reflect limitations of the measures used in this study, that in this population ongoing problems with daytime function are not sleep related or that a cross-sectional assessment does not adequately take into account the impacts of past disease/treatments. Further research is required to further evaluate the tools used to evaluate sleep disorders, the impact of those disorder on children with Down syndrome and interventions which improve both sleep and daytime function.

Sleep Disorders in Adults with Down Syndrome

Sleep disorders, despite being very frequent in adults with Down syndrome (DS), are often overlooked due to a lack of awareness by families and physicians and the absence of specific clinical sleep guidelines. Untreated sleep disorders have a negative impact on physical and mental health, behavior, and cognitive performance. Growing evidence suggests that sleep disruption may also accelerate the progression to symptomatic Alzheimer's disease (AD) in this population. It is therefore imperative to have a better understanding of the sleep disorders associated with DS in order to treat them, and in doing so, improve cognition and quality of life, and prevent related comorbidities. This paper reviews the current knowledge of the main sleep disorders in adults with DS, including evaluation and management. It highlights the existing gaps in knowledge and discusses future directions to achieve earlier diagnosis and better treatment of sleep disorders most frequently found in this population.

The impact of sleep problems on functional and cognitive outcomes in children with Down syndrome: a review of the literature

STUDY OBJECTIVES

The aim of this review was to summarize the existing literature on the association between sleep problems and cognition, function, and behavior in children with Down syndrome.

METHODS

Embase, PubMed, CINAHL, and PsychINFO databases were searched to retrieve all studies published between 1990 and 2018 that evaluated the relationship between sleep and cognition, function, or behavior in children with Down syndrome.

RESULTS

Fifteen articles were included, which were mostly of a cohort or case-controlled design. Five articles addressed sleep and cognition only, 6 reported on sleep and behavior, and only 1 reported on sleep and functional ability. Three papers evaluated sleep and both cognition and behavior. Findings varied across studies with methodological differences, making it difficult to directly compare results. The association between sleep and behavior or cognition in children with Down syndrome remains uncertain, but a large study in 110 children provides strong evidence of a negative impact of sleep disorders on the accomplishment of daily life habits.

CONCLUSIONS

The impact of coexisting sleep disorders in children with Down syndrome has not been widely studied, with only 15 relevant studies found through an extensive literature review. Large well-designed studies are required to fully understand this relationship further. This is important as sleep-disordered breathing and difficulties with sleep patterns and routines are highly prevalent in children with Down syndrome. Sleep may be one of the few treatable factors that can assist in improving long-term outcomes in this population.

Characterization of Sleep Disturbances in Children and Adolescents with Down Syndrome and Their Relation with Cognitive and Behavioral Features

Despite sleep disturbances are common among youths with Down syndrome (DS), the cognitive and behavioral features associated with sleep problems have not yet been studied extensively. The present study investigated the presence of sleep disturbances in a group of children and adolescents with DS and their cognitive and behavioral correlates. Seventy-one children and adolescents with DS underwent a neuropsychological evaluation, whereas parents completed questionnaires for the screening of the child's sleep, emotional and behavioral problems. We found no association between sleep disturbances and sex, nonverbal IQ, nor adaptive abilities. However, we found that age was positively associated with disorders in initiating and maintaining sleep (DIMS) and disorders of excessive somnolence (DOES), while body mass index was related with DOES. We also detected a relationship between visual-motor integrations and DIMS, as well as multiple associations between sleep disturbances and psychopathological and behavioral problems, mainly externalizing symptoms. The present study provided a detailed characterization of sleep problems in relation to several features of youths with DS. The proper identification of sleep disturbances profile in the DS population could support the process of clinical evaluation, in particular for psychopathological aspects.

A preliminary examination of brain morphometry in youth with Down syndrome with and without parent-reported sleep difficulties

BACKGROUND

Down syndrome is associated with poor sleep but little is known about its neural correlates.

AIMS

The current research compared brain morphometry in youth with Down syndrome with parent-reported sleep problems (DS-S) to peers with Down syndrome (DS) and typical development (TD) without parent-reported sleep problems matched on age (M = 15.15) and sex ratio (62 % female).

METHODS AND PROCEDURES

Magnetic resonance imaging was completed on a 3 T scanner. Participants were stratified into groups based on parent-report: DS-S (n = 17), DS (n = 9), TD (n = 22). Brain morphometry, processed with the FreeSurfer Image Analysis Suite, was compared across groups. In addition, the co-occurrence of medical conditions in the DS groups was examined.

OUTCOMES AND RESULTS

Youth with DS-S had reduced total, frontal, parietal, and temporal brain volumes relative to DS and TD peers. They also had higher rates of congenital heart defects than the DS-only group; however, this comorbidity did not appear to account for morphometry differences.

CONCLUSIONS AND IMPLICATIONS

Parent-reported sleep problems in DS appear to relate to global and localized volume reductions. These preliminary results have implications for understanding the neural correlates of poor sleep in DS; they also highlight the importance of examining relations between sleep and other medical comorbidities.

Sleep problems and recall memory in children with Down syndrome and typically developing controls

BACKGROUND

Research conducted with typically developing (TD) infants and children generally indicates that better habitual sleep and sleep after learning are related to enhanced memory. Less is known, however, about associations between sleep and recall memory in children with Down syndrome (DS).

AIMS

The present study was conducted to determine whether parent-reported sleep problems were differentially associated with encoding, 1-month delayed recall memory, and forgetting over time in children with DS and those who were TD.

METHODS AND PROCEDURES

Ten children with DS (mean age = 33 months, 5 days) and 10 TD children (mean age = 21 months, 6 days) participated in a two-session study. At each session, recall memory was assessed using an elicited imitation paradigm. Immediate imitation was permitted at the first session as an index of encoding, and delayed recall was assessed 1 month later. In addition, parents provided demographic information and reported on child sleep problems.

OUTCOMES AND RESULTS

Although parents did not report more frequent sleep problems for children with DS relative to TD children, regression-based moderation analyses revealed that more frequent sleep problems were associated with increased forgetting of individual target actions and their order by children with DS. Evidence of moderation was not found when examining encoding or delayed recall.

CONCLUSIONS AND IMPLICATIONS

Although group differences were not found when considering parent-reported sleep problems, more frequent sleep problems were positively associated with increased forgetting by children with DS relative to those who were TD. Although future experimental work is needed to determine causality, these results suggest that improved sleep in children with DS might reduce forgetting, ultimately improving long-term recall memory.

Sleep problems in Korean children with Down syndrome and parental quality of life

BACKGROUND

Sleep problems are common among children with Down syndrome (DS), and they can have a serious impact on children with DS as well as their parents and other family members. Specific aims of this study were to evaluate parent-reported sleep problems in children with DS and to examine the relationship between the sleep behaviour of children with DS and their parents' quality of life (QOL).

METHOD

A cross-sectional survey was conducted in September and October of 2017. Parents of children with DS were recruited from an online self-support community for parents of children with DS in South Korea. The mean age of the parents and children with DS was 40.40 years (SD = 5.09) and 7.89 years (SD = 3.03), respectively. Children's sleep problems and parents' QOL were assessed using the Children's Sleep Habits Questionnaire and the abbreviated version of the World Health Organization Quality of Life scale, respectively.

RESULTS

Results revealed that 83% of the parents reported that their child with DS experienced sleep problems. Children with DS had significantly more bedtime resistance, night waking, parasomnias and sleep-disordered breathing than did typically developing children. In addition, their Children's Sleep Habits Questionnaire scores were higher than those of typically developing children. Moreover, being older, being male and having more severe developmental delays were significant risk factors for sleep problems among children with DS. Furthermore, sleep problems in children with DS negatively affected parents' QOL.

CONCLUSIONS

Sleep problems negatively affect children with DS as well as their parents; therefore, health care providers should be aware of these issues and help parents manage sleep problems proactively.

Participation in Social Skills Therapy is Associated With Enhanced Recall Memory by Children With Down Syndrome: An Exploratory Study

Participation in social skills therapy (SST) facilitates cognitive functioning in children with developmental disabilities. The present pilot study examined whether participation in SST was associated with enhanced encoding and 1-month delayed recall in children with Down syndrome (DS). Children were presented with novel three-step event sequences in an elicited imitation procedure. Immediate imitation was permitted as an index of encoding; long-term memory was assessed 1 month later. Parents completed questionnaires inquiring about children's participation in SST. Participation in SST was associated with enhanced encoding of temporal order information and 1-month delayed recall of individual target actions. In addition, encoding mediated the relation between group and 1-month delayed recall. The conducted research indicates that involvement in SST may be beneficial for children with DS despite their noted strengths in imitation and social learning. As such, additional experimental work is warranted to determine causality.

Sleep and sleep disordered breathing in children with down syndrome: Effects on behaviour, neurocognition and the cardiovascular system

Down syndrome (DS), the most common human chromosomal malformation, has an estimated annual incidence of one in 1000 live births worldwide. Sleep problems are common in children with DS, reported by parents in up to 65% of school-aged children, significantly higher rates than in typically developing (TD) children. Problems include difficulty in sleep initiation and maintenance together with obstructive sleep apnoea (OSA) which affects up to over 90%, of DS children compared with 1-5% in the general paediatric population. Any sleep problem has the potential to exert significant negative effects on daytime behaviour, learning and quality of life in TD children and there is now a growing body of evidence that children with DS are similarly affected. In addition to adverse effects on daytime functioning, OSA has adverse effects on the cardiovascular system and this is a particularly significant issue given the high rates of hypertension and premature cardiac disease in people with DS. This review discusses the effects of sleep problems and OSA on daytime functioning and cardiovascular function in children with DS and evidence of the effectiveness of treatment in improving outcomes and quality of life for these children.

Developmental trajectories of children with Down syndrome by socio-economic status: the case of Latin America

BACKGROUND

Several studies show that socio-economic status (SES) is related to the developmental trajectories of children with typical development (TD). However, few studies have analysed this relationship regarding children with neurodevelopmental disorders such as Down syndrome (DS). In this paper, we analyse the impact of SES in the neurodevelopmental trajectories of children with DS in comparison with children with TD.

METHOD

Cognitive, language, motor and socio-emotional development were assessed in 31 children with DS between the ages of 15 and 80 months from high to low SES backgrounds. Data from this group were compared with data from a sample of 72 children with TD randomly selected from the Longitudinal Survey of Early Childhood. We analyse and compare these two groups using the developmental trajectories method RESULTS: The results show delayed onsets for the four abilities measured in children with DS compared with children with TD from high to low SES. In the comparison of the developmental trajectories, we found that the differences between the neurodevelopmental trajectories in DS and TD vary according to SES. High SES show differences only in language development, while low SES show significant differences in cognitive, language and socio-emotional development.

CONCLUSIONS

The results indicate that SES is a factor that could impact the developmental trajectories of children with DS. Although the differences between children with DS and with TD are similar at the beginning regardless of SES, the developmental trajectories are slower in children with DS of low SES than in children of high SES. We argue that the differences are related to the complex interaction of several biological and cultural factors associated with SES. Some specific hypotheses about nutrition, health care access, quality of education and parenting practices are presented, but more research in this area is needed to fully understand these results.

Impact of sleep on executive functioning in school-age children with Down syndrome

BACKGROUND

Sleep problems have an impact on executive functioning in the general population. While children with Down syndrome (DS) are at high risk for sleep problems, the impact of these sleep problems on executive functioning in school-age children with DS is less well documented. Our study examined the relationship between parent-reported and actigraphy-measured sleep duration and sleep quality with parent and teacher reports and neuropsychology assessments of executive functioning among school-age children with DS.

METHOD

Thirty school-age children with DS wore an actigraph watch for a week at home at night. Their parent completed ratings of the child's sleep during that same week. Children completed a neuropsychology assessment of their inhibitory control, ability to shift and working memory. Their parents and teachers completed rating scales to assess these same constructs of executive functioning.

RESULTS

Parent reports of restless sleep behaviours on the Children's Sleep Habits Questionnaire (CSHQ), but not actigraph-measured sleep period or efficiency, were predictive of parent reports of concerns with inhibitory control, shifting and working memory, and of teacher reports of inhibitory control. No measure of sleep was predictive of executive functioning as measured by the neuropsychology assessment.

CONCLUSION

The study findings corroborate the preliminary literature that parent-reported sleep problems are related to executive functioning in school-age children with DS, particularly in the area of inhibitory control across home and school. These findings have implications for understanding contributing factors to academic performance and school behaviour in school-age children with DS.

Sleep-disordered breathing and cognitive functioning in preschool children with and without Down syndrome

BACKGROUND

Sleep affects children's cognitive development, preparedness for school and future academic outcomes. People with Down syndrome (DS) are particularly at risk for sleep-disordered breathing (SDB). To our knowledge, the association between SDB and cognition in preschoolers with DS is unknown.

METHODS

We assessed sleep by using cardiorespiratory polygraphy in 22 typically developing (TD) preschoolers and 22 with DS. Cognition was assessed by using the Mullen Scales of Early Learning and behaviour by using the Strengths and Difficulties Questionnaire (SDQ). The MacArthur Communicative Development Inventory (MCDI) measured language level. We predicted that sleep problems would be associated with lower cognitive and behavioural functioning.

RESULTS

In TD children, longer sleep duration was associated with higher scores on MCDI expressive language and fewer emotional symptoms such as fear and unhappiness on the SDQ, whilst SDB was associated with increased conduct problems and less prosocial behaviour on the SDQ. Conversely, for children with DS, SDB was associated with increased language understanding and use of actions and gestures on the MCDI.

CONCLUSIONS

The findings in the TD group support our hypotheses. We recommend that sleep problems are screened for and treated as even mild SDB may prompt poorer cognition and behaviour. For children with DS, we expect that multiple factors in this complex syndrome mask or mediate the association between sleep and cognitive development and tighter controls are necessary to uncover effects of sleep. We propose longitudinal studies as a necessary tool to assess the precise impact of sleep on cognitive development in accounting for individual differences in DS.