The experience-dependent increase in deep sleep activity is reduced in children with attention-deficit/hyperactivity disorder

Current research status and progress in neuropsychological development of children with congenital heart disease: A review

Children with congenital heart disease (CHD) are receiving widespread attention for their neuropsychological developmental issues, which include cognitive, adaptive, motor, speech, behavioral, and executive functioning deficits as well as autism spectrum disorders. Timely identification of risk factors influencing neuropsychological development and implementation of appropriate interventions are crucial for enhancing the neuropsychological outcomes of children with CHD, ultimately benefiting the children, their families, and society as a whole. This comprehensive review article aimed to explore the epidemiology, risk factors, assessment methods, and monitoring strategies of neuropsychological development in children with CHD. By providing a detailed examination of these factors, this review serves as a valuable resource for researchers and practitioners in the field, facilitating deeper understanding and more effective management of neuropsychological issues in this vulnerable population.

Wake EEG oscillation dynamics reflect both sleep need and brain maturation across childhood and adolescence

An objective measure of brain maturation is highly insightful for monitoring both typical and atypical development. Slow wave activity, recorded in the sleep electroencephalogram (EEG), reliably indexes changes in brain plasticity with age, as well as deficits related to developmental disorders such as attention-deficit hyperactivity disorder (ADHD). Unfortunately, measuring sleep EEG is resource-intensive and burdensome for participants. We therefore aimed to determine whether wake EEG could likewise index developmental changes in brain plasticity. We analyzed high-density wake EEG collected from 163 participants 3-25 years old, before and after a night of sleep. We compared two measures of oscillatory EEG activity, amplitudes and density, as well as two measures of aperiodic activity, intercepts and slopes. Furthermore, we compared these measures in patients with ADHD (8-17 y.o., N=58) to neurotypical controls. We found that wake oscillation amplitudes behaved the same as sleep slow wave activity: amplitudes decreased with age, decreased after sleep, and this overnight decrease decreased with age. Oscillation densities were also substantially age-dependent, decreasing overnight in children and increasing overnight in adolescents and adults. While both aperiodic intercepts and slopes decreased linearly with age, intercepts decreased overnight, and slopes increased overnight. Overall, our results indicate that wake oscillation amplitudes track both development and sleep need, and overnight changes in oscillation density reflect some yet-unknown shift in neural activity around puberty. No wake measure showed significant effects of ADHD, thus indicating that wake EEG measures, while easier to record, are not as sensitive as those during sleep.

Visuomotor adaptation, internal modelling, and compensatory movements in children with developmental coordination disorder

BACKGROUND

Developmental coordination disorder (DCD) is one of the most prevalent developmental disorders in school-aged children. The mechanisms and etiology underlying DCD remain somewhat unclear. Altered visuomotor adaptation and internal model deficits are discussed in the literature.

AIMS

The study aimed to investigate visuomotor adaptation and internal modelling to determine whether and to what extent visuomotor learning might be impaired in children with DCD compared to typically developing children (TD). Further, possible compensatory movements during visuomotor learning were explored.

METHODS AND PROCEDURES

Participants were 12 children with DCD (age 12.4 ± 1.8, four female) and 18 age-matched TD (12.3 ± 1.8, five female). Visuomotor learning was measured with the Motor task manager. Compensatory movements were parameterized by spatial and temporal variables.

OUTCOMES AND RESULTS

Despite no differences in visuomotor adaptation or internal modelling, significant main effects for group were found in parameters representing movement accuracy, motor speed, and movement variability between DCD and TD.

CONCLUSIONS AND IMPLICATIONS

Children with DCD showed comparable performances in visuomotor adaptation and internal modelling to TD. However, movement variability was increased, whereas movement accuracy and motor speed were reduced, suggesting decreased motor acuity in children with DCD.

What is sleep exactly? Global and local modulations of sleep oscillations all around the clock

Wakefulness, non-rapid eye-movement (NREM) and rapid eye-movement (REM) sleep differ from each other along three dimensions: behavioral, phenomenological, physiological. Although these dimensions often fluctuate in step, they can also dissociate. The current paradigm that views sleep as made of global NREM and REM states fail to account for these dissociations. This conundrum can be dissolved by stressing the existence and significance of the local regulation of sleep. We will review the evidence in animals and humans, healthy and pathological brains, showing different forms of local sleep and the consequences on behavior, cognition, and subjective experience. Altogether, we argue that the notion of local sleep provides a unified account for a host of phenomena: dreaming in REM and NREM sleep, NREM and REM parasomnias, intrasleep responsiveness, inattention and mind wandering in wakefulness. Yet, the physiological origins of local sleep or its putative functions remain unclear. Exploring further local sleep could provide a unique and novel perspective on how and why we sleep.

Functional networks of working memory abilities in children with complex congenital heart disease: a sleep EEG study

Working memory is frequently impaired in children with complex congenital heart disease (CHD), but little is known about the functional neuronal correlates. Sleep slow wave activity (SWA; 1-4.5 Hz EEG power) has previously been shown to reliably map neurofunctional networks of cognitive abilities in children with and without neurodevelopmental impairments. This study investigated whether functional networks of working memory abilities are altered in children with complex CHD using EEG recordings during sleep. Twenty-one children with complex CHD (aged 10.9 [SD: 0.3] years) and 17 typically-developing peers (10.5 [0.7] years) completed different working memory tasks and an overnight high-density sleep EEG recording (128 electrodes). The combined working memory score tended to be lower in children with complex CHD (CHD group: -0.44 [1.12], typically-developing group: 0.55 [1.24], d = 0.59, p = .06). The working memory score and sleep SWA of the first hour of deep sleep were correlated over similar brain regions in both groups: Strong positive associations were found over prefrontal and fronto-parietal brain regions - known to be part of the working memory network - and strong negative associations were found over central brain regions. Within these working memory networks, the associations between working memory abilities and sleep SWA (r between -.36 and .58, all p < .03) were not different between the two groups (no interactions, all p > .05). The current findings suggest that sleep SWA reliably maps working memory networks in children with complex CHD and that these functional networks are generally preserved in these patients.

Objectively measured sleep continuity in children and adolescents with ADHD: A systematic review and meta-analysis

Sleep disturbances are often linked to attention-deficit/hyperactivity disorder (ADHD). Consistent findings document that children and adolescents with ADHD report more sleep problems than their typically developing (TD) peers across subjective sleep domains. However, few differences between these groups were observed in objectively measured sleep parameters, such as polysomnography (PSG) and actigraphy. This study synthesized empirical studies to identify objectively measured sleep continuity differences between children and adolescents with ADHD and TD. We included observational research and baseline data from intervention studies between 5- to 18-year-old individuals with ADHD and their TD peers at five databases from inception and September 2022. This systematic review and meta-analysis of 45 articles, including 1622 children and adolescents with ADHD and 2013 TD, found that compared with TD, children and adolescents with ADHD have higher sleep latency and moderately decreased sleep efficiency measured by actigraphy. Polysomnography-measured differences between ADHD and TD were not significant. Medication status and comorbid psychiatric status significantly moderated the group differences in sleep efficiency between ADHD and TD. Also, the group differences in sleep latency between ADHD and TD were moderated by actigraphy recorded nights. These findings highlight the importance of reducing disparities in sleep parameters among children and adolescents with and without ADHD.

The Associations between the Homeostatic and Circadian Sleep Processes and the Neurobehavioral Functioning (NBF) of Individuals with ADHD-A Systematic Review

The objective of the present review was to systematically examine associations between perturbations of the homeostatic or circadian sleep processes and the neurobehavioral functioning (NBF) of individuals with ADHD. Electronic databases were searched for articles published between December 2013 and March 2023. Studies were included if they used objective measures of NBF, used objective or subjective measures of sleep, and focused on individuals with ADHD. Ten studies met these inclusion criteria. Of these, eight studies found perturbations in the interplay between NBF and Process S or Process C, and three studies did not. The quality of the studies was degraded because they failed to address key factors that affect the sleep processes and by the presence of methodological weaknesses. Our review suggests that homeostatic and circadian sleep processes are associated with NBF in individuals with ADHD. However, to confirm the validity of this conclusion, future studies should examine or control for confounders and utilize experimental designs that allow causality to be inferred.

Local sleep: A new concept in brain plasticity

Traditionally, sleep and wakefulness have been considered as two global, mutually exclusive states. However, this view has been challenged by the discovery that sleep and wakefulness are actually locally regulated and that islands of these two states may often coexist in the same individual. Importantly, such a local regulation seems to be the key for many essential functions of sleep, including the maintenance of cognitive efficiency and the consolidation of new skills and memories. Indeed, local changes in sleep-related oscillations occur in brain areas that are used and involved in learning during wakefulness. In turn, these changes directly modulate experience-dependent brain adaptations and the consolidation of newly acquired memories. In line with these observations, alterations in the regional balance between wake- and sleep-like activity have been shown to accompany many pathologic conditions, including psychiatric and neurologic disorders. In the last decade, experimental research has started to shed light on the mechanisms involved in the local regulation of sleep and wakefulness. The results of this research have opened new avenues of investigation regarding the function of sleep and have revealed novel potential targets for the treatment of several pathologic conditions.