Children's ability to copy triangular figures is affected by their sleep-wakefulness rhythms

Problems in the Development of the Sleep-Wake Rhythm Influence Neurodevelopmental Disorders in Children

Development of the sleep-wake rhythm has a significant effect on the physical and mental development of children. The sleep-wake rhythm is controlled by aminergic neurons in the brainstem's ascending reticular activating system, which is associated with synaptogenesis and the promotion of brain development. The sleep-wake rhythm develops rapidly within the first year after birth. At 3-4 months of age, the framework of the circadian rhythm is established. The objective of the present review is to assess a hypothesis concerning problems in the development of the sleep-wake rhythm and their effect on neurodevelopmental disorders. Autism spectrum disorder is characterised by a delay in the development of sleep rhythms at 3-4 months of age and also insomnia and night-time awakenings, as supported by several reports. Melatonin may shorten the sleep latency in ASD. Rett syndrome sufferers kept awake during the daytime were analysed by the Sleep-wake Rhythm Investigation Support System (SWRISS) (IAC, Inc., (Tokyo, Japan)), and the cause was found to be the dysfunction of aminergic neurons. Children and adolescents with attention deficit hyperactivity disorder show sleep problems such as resistance to bedtime, difficulty falling asleep, sleep apnoea, and restless legs syndrome. Sleep deprivation syndrome in schoolchildren is deeply influenced by Internet use, games, and smartphones, and this syndrome affects emotion, learning, concentration, and executive functioning. Sleep disorders in adults are strongly considered to affect not only the physiological/autonomic nervous system but also neurocognitive/psychiatric symptoms. Even adults cannot avoid serious problems, much less children, and the impact of sleep problems is considerably greater in adults. Paediatricians and nurses should be aware of the significance, from birth, of sleep development and sleep hygiene education for carers and parents. This research was reviewed and approved by the ethical committee of the Segawa Memorial Neurological Clinic for Children (No. SMNCC23-02).

Sleep and the General Behavior of Infants and Parents during the Closure of Schools as a Result of the COVID-19 Pandemic: Comparison with 2019 Data

This study compared cross-sectional data from online surveys describing the sleep behavior of infants and caregivers in March 2020 (the school closure period during the early stages of the COVID-19 pandemic; n = 295, 23.8 ± 3.8 months old) and March 2019 (before the pandemic; n = 2017, 24.2 ± 3.8 months old). In comparing those two points in time, no significant differences were found in wake-up times (2019: 7:19 ± 0:46 am vs. 2020: 7:18 ± 0:47 am, p = 0.289), bedtimes (21:01 ± 0:48 pm vs. 21:04 ± 0:53 pm, p = 0.144), or nocturnal sleep times (593.7 ± 43.9 min vs. 588.1 ± 50.3 min, p = 0.613). Regarding the caregivers, in 2020, wake-up times (2019: 6:46 ± 0:50 am vs. 2020: 6:39 ± 0:50 am, p = 0.017) and bedtimes (22:53 ± 1:17 pm vs. 22:42 ± 1:04 pm, p = 0.016) became significantly earlier compared to 2019. Among infants staying at home, total sleep time and percentage of outdoor play decreased significantly, and media use increased significantly in 2020. Lower levels of exercise and more frequent media viewing may have caused prolonged sleep latency in these children. The percentage of caregivers responding with "negative childcare feelings" was significantly higher in the group with less than three nursery school attendance days. Caregivers and infants staying at home are a high-risk group during the pandemic.

Daytime physical activity and sleep in pre-schoolers with developmental disorders

AIM

This study aims to investigate the association between daytime physical activity (PA) and sleep in pre-schoolers with or without autism spectrum disorders (ASDs).

METHOD

Thirty-one pre-school children with ASD and 16 age-matched controls were recruited. Sleep and PA patterns were measured with an Actiwatch for 7 days. After average PA values were calculated for three periods (morning, afternoon and evening) of each day for each child, the days with maximum (active) and minimum (inactive) PA values for these three periods were determined. The Wilcoxon signed-rank test was used to compare sleep following active mornings, afternoons and evenings with that following inactive time periods.

RESULTS

In control children, sleep onset time following active mornings/afternoons did not differ from that following inactive mornings/afternoons. In contrast, sleep onset following the most inactive morning (median sleep onset time: 9:57 pm) and the most inactive afternoon (median sleep onset time: 10:24 pm) began significantly later than that following the most active mornings (median sleep onset time: 9:21 pm) and the most active afternoons (median sleep onset time: 9:39 pm) in children with ASD. The percentage of sleep for control children following active mornings was significantly higher (median: 93.2%) than that following inactive ones (median: 91.7%). Significant associations were not found between evening PA and sleep in either ASD or control children.

CONCLUSIONS

A high level of morning and afternoon PA can advance the sleep phase in children with ASD.

A newly proposed disease condition produced by light exposure during night: asynchronization

The bedtime of preschoolers/pupils/students in Japan has become progressively later with the result sleep duration has become progressively shorter. With these changes, more than half of the preschoolers/pupils/students in Japan recently have complained of daytime sleepiness, while approximately one quarter of junior and senior high school students in Japan reportedly suffer from insomnia. These preschoolers/pupils/students may be suffering from behaviorally induced insufficient sleep syndrome due to inadequate sleep hygiene. If this diagnosis is correct, they should be free from these complaints after obtaining sufficient sleep by avoiding inadequate sleep hygiene. However, such a therapeutic approach often fails. Although social factors are often involved in these sleep disturbances, a novel clinical notion--asynchronization--can further a deeper understanding of the pathophysiology of these disturbances. The essence of asynchronization is a disturbance in various aspects (e.g., cycle, amplitude, phase and interrelationship) of the biological rhythms that normally exhibit circadian oscillation, presumably involving decreased activity of the serotonergic system. The major trigger of asynchronization is hypothesized to be a combination of light exposure during the night and a lack of light exposure in the morning. In addition to basic principles of morning light and an avoidance of nocturnal light exposure, presumable potential therapeutic approaches for asynchronization involve both conventional ones (light therapy, medications (hypnotics, antidepressants, melatonin, vitamin B12), physical activation, chronotherapy) and alternative ones (kampo, pulse therapy, direct contact, control of the autonomic nervous system, respiration (qigong, tanden breathing), chewing, crawling). A morning-type behavioral preference is described in several of the traditional textbooks for good health. The author recommends a morning-type behavioral lifestyle as a way to reduce behavioral/emotional problems, and to lessen the likelihood of falling into asynchronization.

A study of the association between sleep habits and problematic behaviors in preschool children

This preliminary study examined the association between sleep habits and problematic behaviors in healthy preschool children using an internationally standardized method. Two groups of 4-6-yr-old healthy Japanese children were recruited. Children in Group A (n=68) met one or more of the following three conditions: they went out from their home with adults after 21:00 h two or more times a week, they went to bed after 23:00 h four or more times a week, and they returned home after 21:00 h three or more times a week, while those in Group B (n=67) met none of these conditions. Sleep-wake logs and the Child Behavior Checklist (CBCL)/4-18 were completed daily for two weeks. The CBCL consists of questions with 113 items categorized into eight subscale items: (I) Withdrawn, (II) Somatic complaints, (III) Anxious/depressed, (IV) Social problems, (V) Thought problems, (VI) Attention problems, (VII) Delinquent behavior, and (VIII) Aggressive behavior. Internalizing (I+II+III), externalizing (VII+VIII), and total scale scores were also derived. Generally, the higher the score, the greater the likelihood of problematic behaviors in that scale. We compared both the CBCL scores and distribution of the CBCL score-determined clinical classification of behavior (normal, borderline, and abnormal) between the groups. Correlation coefficients between CBCL scores and each of the seven indices of the studied sleep habits (wake-up times, bedtimes, nocturnal sleep duration, nap duration, total sleep duration, and range of variation in wake-up and bedtime) were also assessed. Group A children showed significantly shorter average nocturnal sleep, nap, and total sleep duration, significantly later average bedtimes and wake-up times, and a significantly greater range of variation in bedtimes and wake-up times than Group B children. The CBCL score of the total scale was significantly higher in Group A than Group B children. The distribution of the clinical classifications of behavior between the two groups showed no significant differences. Although nocturnal sleep, nap, and total sleep duration did not correlate with total CBCL score, it showed a high positive correlation with wake-up times, bedtimes, and ranges of variation in both wake-up and bed times. The distribution of the clinical classification for the total scale showed significant differences between early and late risers, and also between regular and irregular sleepers. The number of children classified as normal for the total scale score was higher in early risers and regular sleepers than in late risers and irregular sleepers. Preschool children of Group A, late risers, late sleepers, irregular risers, and irregular sleepers were likely to show problematic behaviors.