Sleep Characteristics In Children Research Articles

Maternal depressive symptoms during and after pregnancy are associated with poorer sleep quantity and quality and sleep disorders in 3.5-year-old offspring

ObjectiveMaternal depressive symptoms during pregnancy have been associated with poor offspring sleep. Yet, it remains unknown whether depressive symptoms throughout pregnancy are more harmful to the child than depressive symptoms only during certain time periods in pregnancy, whether associations are specific to pregnancy stage, whether maternal symptomatology after pregnancy mediates or adds to the prenatal effects, and whether any effects are specific to some child sleep characteristics. MethodsA total of 2321 mothers from the Prediction and Prevention of Pre-eclampsia and Intrauterine Growth Restriction (PREDO) study completed the Center for Epidemiological Studies Depression Scale biweekly between gestational weeks + days 12 + 0/13 + 6 and 38 + 0/39 + 6. At child's mean age of 3.5 (standard deviation = 0.7) years, mothers completed the Beck Depression Inventory−II and answered questions on child sleep quantity and quality using the Brief Infant Sleep Questionnaire (BISQ) and sleep disorders using the Sleep Disturbance Scale for Children. ResultsMaternal depressive symptoms showed high stability throughout pregnancy. Children of mothers with clinically significant symptomatology throughout pregnancy had shorter mother-rated sleep duration, longer sleep latency, higher odds for waking up two or more times during the night and for total and several specific sleep disorders. These associations were robust to covariates. However, maternal depressive symptoms at the child follow-up fully mediated the associations with sleep duration and awakenings, partially mediated those with sleep latency and disorders, and added to the effects on sleep disorders. ConclusionMaternal depressive symptoms throughout pregnancy are associated with mother-rated child sleep quantity, quality, and disorders. Maternal depressive symptoms at child follow-up mediate and add to the prenatal adverse effects on child sleep characteristics.

Development of sleep patterns in children with obese and normal-weight parents.

AimTo study the sleep development and sleep characteristics in children at different obesity risks, based on parental weight, and also to explore their weekday–weekend sleep variations and associated family factors.MethodsA total of 145 children participating in a longitudinal obesity prevention project were included, of which 37 had normal‐weight parents (low obesity risk), and 108 had overweight/obese parents (high obesity risk). Sleep diaries at ages 1 and 2 years were used to study sleep development in children at different obesity risks. Objectively assessed sleep using an accelerometer at 2 years of age was used to analyse weekday–weekend sleep variations.ResultsThere was no difference in sleep development from age 1 to age 2 among children at different obesity risks, but more children in the high‐risk group had prolonged sleep onset latency and low sleep efficiency. At 2 years of age, children in the high‐risk group had more weekday–weekend variation in sleep offset (mean difference 18 min, 95% confidence interval (CI) 4–33 min), midpoint of sleep (mean difference 14 min, 95% CI 3–25 min) and nap onset (mean difference 42 min, 95% CI 10–74 min) than children in the low‐risk group, after adjusting for other family factors. However, no difference could be detected between groups in weekday–weekend variation in sleep duration.ConclusionsUnfavourable sleep characteristics, as well as more variation in sleep schedules, have been observed in children at high obesity risk. While the differences were relatively small, they may reflect the unfavourable sleep hygiene in families at high obesity risk.

Sleep disorders and endothelial dysfunction in children with sickle cell anemia

ObjectiveWe sought to assess sleep characteristics in children with sickle cell anemia (SCA) to investigate the possible association between sleep-related disorders and parameters of endothelial function. MethodsSleep Disturbance Scale for Children (SDSC) and endothelial function variables (flow-mediated dilatation using brachial artery ultrasound, cytokines) were compared in children with SCA and healthy children aged 6–18 years. ResultsFlow-mediated dilation (FMD) median (IQR) values were 10.1 (6.4; 14) vs 16.9 (12; 26.4), in the SCA and comparison groups (p = 0.001), respectively. Associations were found between difficulty initiating and maintaining sleep as well as IL-12p70 (rs = 0.3, p = 0.03) and IL-1b (rs = 0.4, p = 0.01); disorders of excessive sleepiness and TNF-a (rs = 0.3, p = 0.02), IL-6 (rs = 0.3, p = 0.03), e IL-17A (rs = 0.3, p = 0.04), and disorders of arousal with IL-6 (rs = 0.3, p = 0.04). Regarding SDSC subscales, the score for sleep breathing disorders was higher in the SCA group than in the comparison group [6.7 (3.4) vs. 5.2 (2.7), p = 0.04]. Sleep breathing disorders, disorders of excessive sleepiness and sleep hyperhidrosis scores were also higher among those SCA patients who were using hydroxyurea than those with SCA who were not using hydroxyurea [7.4 (3.9) vs. 5.9 (2.9); p = 0.026; 7.5 (3.5) vs. 6.9 (3); p = 0.028; 4.3 (3.1) vs. 3.9 (2.6); p = 0.044, respectively]. ConclusionThe SCA group presented higher sleep-disordered breathing scores and lower FMD values. Patients with SCA using hydroxyurea exhibited a higher frequency of scores on SDSC subscales. A positive correlation was found between SDSC subscales and cytokines.

Can working memory training improve children's sleep?

BackgroundImproving children's sleep could lead to significant benefits in several functional domains. Recent research in adults suggests that intensive, adaptive cognitive training may be beneficial in improving sleep, although there is limited understanding whether this approach yields similar results in children. ObjectiveTo determine whether a working memory training program improved sleep latency, sleep problems, and sleep duration on school and nonschool nights and whether there was a differential effect of the timing of training during the school day on sleep outcomes. Design/MethodsDesign: Population-based randomised controlled trial. Setting: Forty-four schools in Melbourne, Australia. Participants: All Grade 1 children (mean age = 6.9 years, SD 0.4) underwent WM screening using two subtests from the Automated Working Memory Assessment. Children with low verbal and/or visuo-spatial WM scores relative to their peers (‘low WM’, ∼25%) were randomised to intervention or control arms. Intervention: 20 to 25 computerised 25-min training sessions were conducted using the CogMed program, over 5–7 weeks at school. Outcomes: Parent-reported child sleep characteristics (time, latency, duration and problem) at 6 months post randomisation. ResultsA total of 452 (26.0%) of 1723 children screened (64.1% of approached) met trial eligibility criteria, with 226 in each study arm. Of intervention children, 91% completed the minimum 20 days of training. Retention was 90.5% at 6 months. Adjusted regressions showed that intervention children did not have better sleep latency, duration, bedtime consistency or less sleep problems. ConclusionIt does not appear that adaptive working memory training during the school day can be used as a novel approach to improve children's sleep attributes up to 6 months post-randomisation, regardless of the time of day training is delivered.

Sleep characteristics in children with specific language impairment: study in 72 patients

Sleep characteristics in children with specific language impairment: study in 72 patients

Impact of sleep on injury risk among rural children.

To examine sleep patterns in a large cohort of rural children and explore the association between sleep patterns and injury occurrence. Cross-sectional analyses of the baseline survey from a prospective cohort study (2012 to 2017) was conducted with 46 rural schools in Saskatchewan, Canada who distributed surveys to parents of 2275 rural dwelling farm and nonfarm children aged 0 to 17 years. Parents reported child sleep characteristics and farm or nonfarm injury in the previous calendar year. Multivariable log-binomial regression examined associations between sleep characteristics and injury risk. There was a significant trend of decreasing sleep duration with increasing age (P-trend < 0.001). Short sleep duration on weekdays (RR: 2.14; 95% CI: 1.25 to 3.66) and sleep debt (RR: 1.89; 95% CI: 1.21 to 2.95) increased injury risk in school-age children (7 to 12 years) but not in teens. A nearly fivefold increase in injury risk was identified among school-age children reporting all sleep problems (RR: 4.99; 95% CI: 1.99 to 12.50). Snoring in teens (13 to 17 years), often a symptom of obstructive sleep apnea, was associated with increased injury risk (RR: 1.98; 95% CI: 1.17 to 3.33). There were no statistically significant associations identified between sleep characteristics and injury risk in preschool children. Injuries to rural children are an important public health concern. This study highlights the impact of sleep problems on risk for injury among rural children. These findings are discussed in light of the recent American Academy of Pediatrics Technical Report on Insufficient Sleep in Adolescents and Young Adults.

Association between possible sleep bruxism and sleep characteristics in children

Aims: To evaluate the relationship between possible sleep bruxism and sleep characteristics in children.Methodology: A cross-sectional study was conducted through data collection of a pre-tested questionnaire answered by 111 parents on behalf of their children in the waiting room during their appointment at the Pediatric Dentistry Clinic of a public Brazilian university. The diagnosis of possible sleep bruxism was based on the international classification of sleep disorders (ICSD) criteria. The Chi-square test and logistic multinomial regression test were used in the statistical analysis.Results: The final model of logistic multinomial regression demonstrated that children with muscle pain in the mouth region (OR = 19.70 95% IC = 1.82–212.69), snoring (OR = 8.25 95% IC = 2, 56–26, 54), and those with parents with possible sleep bruxism have more of a probability of sleep bruxism.Conclusion: Potential sleep bruxism tends to be hereditary. Muscle pain, snoring, and mouth breathing were important signals associated with possible sleep bruxism among children.

Sleep Characteristics in Children with Attention Deficit Hyperactivity Disorder: Systematic Review and Meta-Analyses.

Sleep disturbances have been associated with attention deficit hyperactivity disorder (ADHD), but such relationship is still unclear. The results from the studies conducted do not provide enough evidence to support a sleep physiology inherent to ADHD. This study tries to determine if that sleep physiology really exists by comparing children with ADHD and control children in some sleep parameters. A search was conducted in several databases (Web of Science, Scopus, Pubmed and PsycINFO), and a manual search, to retrieve all the articles available from 1987 until March 2014. Of 8,678 non-duplicate studies retrieved, 11 studies met the inclusion and methodological quality criteria. Two meta-analyses were performed with eight of those studies, depending on data provided by them: polysomnographic or actigraphic. A fixed-effects model, and the standardized mean difference (SMD) as the index of effect size, were used in both meta-analyses. Significant differences were found only in the meta-analysis with polysomnography as outcome. Children with ADHD were found to spend more time in stage 1 sleep than controls (pooled SMD = 0.32, 95% CI = 0.08-0.55, p value = 0.009). Although few differences in sleep between children with ADHD and controls have been found in this review, further studies are required on this matter. Those studies should consider some variables discussed in this review, in order to obtain useful and reliable conclusions for research and clinical practice. Particularly, the influence of assessment criteria and ADHD subtypes in the sleep characteristics of children with ADHD should be addressed.

Short Sleep Duration Is Related to Emerging Cardiovascular Risk Factors in Obese Children.

The aim of the present study was to evaluate the influence of sleep duration on cardiovascular risk factors in obese children. Cross-sectional analysis of 90 obese children ages 7 to 16 years. Anthropometric and clinical evaluation with specification of dietary and lifestyle habits was carried out during an office visit. Sleep duration was evaluated by the BEARS (B = bedtime issues, E = excessive daytime sleepiness, A = night awakening, R = regularity and duration of sleep, S = snoring) questionnaire on children's sleep characteristics. Sleep time adequacy by age was assessed according to the criteria of the National Sleep Foundation. Biochemical blood variables indicative of metabolic risk (glucose, lipid profile, and insulin) were obtained. Emergent new factors of metabolic risk, including high-sensitive C-reactive protein, γ-glutamyltranspeptidase, homocysteine, retinol-binding protein 4 (RBP4), thyroid-stimulating hormone (TSH), inflammatory markers, and the adipokines leptin, adiponectin, and ghrelin were also evaluated. The relations between the duration of sleep and these variables were analyzed by general lineal model analysis. Significant variables were introduced in logistic regression analysis to determine the odds ratio (OR) and 95% confidence interval (CI) of cardiometabolic factors with respect to sleep. Children who slept for short duration were significantly more at risk of severe central obesity. In the regression model, the mean arterial pressure (odds ratio [OR] 1.10, 95% confidence interval [CI] 1.02-1.17, P = 0.008), homocysteine (OR 1.41, 95% CI 1.08-1.84, P = 0.013), RBP4 (OR 1.78, 95% CI 1.15-2.78, P = 0.010), and TSH (OR 2.01, 95% CI 1.21-3.34, P = 0.007) remain as significant independent predictors related to short sleep duration. We did not find any association between sleep duration and inflammatory markers or adipokines. Short sleep duration increases the severity of obesity and is related to cardiovascular risk factors in children.

Effect of rapid maxillary expansion on sleep characteristics in children.

Introduction:Rapid maxillary expansion (RME) is an orthopedic treatment procedure routinely used to treat constricted maxillary arches and also a potential additional treatment in children presenting with sleep-disordered breathing (SDB).Aims and Objectives:The main objective of this study was to evaluate the effects of RME on sleep characteristics in children.Materials and Methods:Polysomnography was done on children of 8-13 years of age before expansion (T0), after expansion (T1) and after a period of 3 months after retention (T2). Bonded rapid maxillary expander was cemented in all children. Inter-molar distance was also measured at T0 and T2.Statistical Analysis:Nonparametric Friedman test was used for comparing the averages of sleep parameters at different time period (T0, T1, T2). Wilcoxon signed ranks test was used for comparing the averages of inter-molar width (T0-T2). P < 0.05 were considered as significant.Results:All children showed an improvement in sleep parameters with an increase in sleep efficiency, decreased in arousal and desaturation index after expansion. Total sleep time showed a statistically significant increase after expansion. A statistically significant increase in inter-molar distance was obtained after expansion.Conclusions:Rapid maxillary expansion is a useful treatment option for improving quality of sleep even in normal children without SDB. It also induces widening of the maxilla, corrects posterior crossbites and improves maxillary and mandibular dental arch coordination.

Sleep characteristics in children with specific language impairment: macrostructure and microstrucrure analysis

Introduction Sleep is important for learning, memory and underlying neural plasticity. Studies support that children utilize a dual memory system when acquiring and integrating new vocabulary, and sleep (especially sleep spindles, slow waves sleep and REM sleep) is important for this process. We aimed to describe sleep characteristics in children with diagnosis of Specific Language Impairment because sleep disruption, especially of the microstructure, could have an important role in the development and evolution in these patients. Materials and methods 30 children (24 boys and 6 girls) with 3–5 years old, diagnosed of specific language impairment (development quotient ⩾ 70 in Brunet-Lezine Scale), normal MRI, without epileptiform discharges in EEG, no hearing impairment, no other disorders and with parents in medium–high sociocultural level. Children participated in a polysomnographic (PSG) sleep recording. Sleep disorders like Obstructive Sleep Apnea Pediatric (OSAP), Periodic Limb Movement Disorder (PLMD) and parasomnias, and sleep characteristics like sleep stages percentage, spindles characteristics, presence of significant alpha rhythm during sleep (alpha-delta sleep), microarousal index, sleep efficiency and awakenings episodes were analyzed. Results In our sample, we found OSAP only in one patient, and parasomnias in 2 patients. However, data about PLMD was relevant, 93.3% present this disorder with an average index of 9.316 ± 6.11 . We found an average of 4.073 % ± 3.41 of stage 1, 40.76 ± 8.89 of stage 2, 25.381 ± 6.91 of stage 3, 25.587 ± 6.91 of stage REM, 112.76 ± 25.65 of body movements, 3.10 ± 1.6 awakening episodes ⩾ 5 min, 85.14 ± 9.07 of sleep efficiency, 37.556 ± 9.6 of microarousal index (83.4% with microarousal index ⩾ 30 ), 80% present significant percentage of alpha rhythm during sleep and 66.7% presented unsuitable spindles. Conclusion We observed that although the sleep architecture in terms of the macrostructure, like time spent in the different stage of sleep, appears to not be consistently altered in relation with normal values, it is very important the analysis of sleep microstructure because specific features would be altered in these patients and could be related to the problem of language skills. Treatment for specific sleep disorders and treatment to stabilize sleep structure, could improve the symptomatology in these patients.

A longitudinal study of child sleep in high and low risk families: Relationship to early maternal settling strategies and child psychological functioning

To investigate whether sleep disturbances previously found to characterise high risk infants: (a) persist into childhood; (b) are influenced by early maternal settling strategies and (c) predict cognitive and emotional/behavioural functioning. Mothers experiencing high and low levels of psychosocial adversity (risk) were recruited antenatally and longitudinally assessed with their children. Mothers completed measures of settling strategies and infant sleep postnatally, and at 12 and 18 months, infant age. At five years, child sleep characteristics were measured via an actigraphy and maternal report; IQ and child adjustment were also assessed. Sleep disturbances observed in high-risk infants persisted at five years. Maternal involvement in infant settling was greater in high risk mothers, and predicted less optimal sleep at five years. Poorer five year sleep was associated with concurrent child anxiety/depression and aggression, but there was limited evidence for an influence of early sleep problems. Associations between infant/child sleep characteristics and IQ were also limited. Early maternal over-involvement in infant settling is associated with less optimal sleep in children, which in turn, is related to child adjustment. The findings highlight the importance of supporting parents in the early development of good settling practices, particularly in high-risk populations.

Sleep Behaviors and Parent Functioning in Young Children With Type 1 Diabetes

This study evaluates sleep characteristics among young children with type 1 diabetes and associations with parent sleep and emotional functioning and diabetes care. Study participants included 24 parents of young children with type 1 diabetes (ages 2–5) enrolled in a pilot study of a randomized-controlled trial. Child sleep characteristics were within normal limits. However, increased child bedtime resistance and behavioral insomnia were related to greater parent stress, anxiety, and depression and use of an intensive insulin regimen. Type 1 diabetes management may impact child and parent sleep as well as parent emotional functioning. Implications for practice are presented.

Periodic Limb Movements during Sleep in Children with Narcolepsy

In adults with narcolepsy, periodic limb movements of sleep (PLMS) occur more frequently than in control population, and presence of increased PLMS is associated with greater sleep disruption and shorter mean sleep latency. This study was performed to determine whether PLMS are common in children with narcolepsy, and whether the presence of PLMS is associated with greater sleep disruption. Demographic and polysomnographic information were collected from consecutive patients diagnosed with narcolepsy identified retrospectively by diagnosis-based search. Descriptive data were compiled, and sleep characteristics of children with and without PLMS were compared. Sleep disorders center in a children's hospital. 44 patients, 6-19 years old (mean 13 years, SD 3.57), were identified. Twenty-eight were African American. None. Four patients had a PLMS index (PLMI) ≥ 5/h (considered abnormal in literature). Sixteen (36%) had "any PLMS" (PLMI > 0/h). The mean PLMI was 1.3/h (SD 2.5). Sleep was significantly more disrupted, and the mean sleep latency was shorter in patients with "any PLMS" as compared to those with no PLMS. There was no correlation between the PLMI and other diagnostic criteria for narcolepsy. "Any PLMS" were present equally in children of African American and Caucasian heritage, 35.7% vs. 37.5%. As in adults, children with PLMS and narcolepsy have more sleep disruption and shorter mean sleep latencies than those with narcolepsy but without PLMS. Our findings also suggest that the use of adult criteria for diagnosis of "significant" PLMS in children may not be sufficiently sensitive.

Sleep Characteristics in Children with Growth Hormone Deficiency

Background/Aims: Growth hormone (GH) is preferentially secreted during slow wave sleep and the interactions between human sleep and the somatotropic system are well documented, although only few studies have investigated the sleep EEG in children with GH deficiency (GHD). The aim of this study was to evaluate the sleep structure of children with dysregulation of the GH/insulin-like growth factor axis. Methods: Laboratory polysomnographic sleep recordings were obtained from 10 GHD children and 20 normal healthy age-matched children. The classical sleep parameters were evaluated together with sleep microstructure, by means of the cyclic alternating pattern (CAP), in GHD patients and compared to the control group. Results: GHD children showed a significant decrease in total sleep time, sleep efficiency, movement time and in non-rapid eye movement sleep stage 2. Although some indicators of sleep fragmentation were increased in GHD children, we found a general decrease in EEG arousability represented by a significant global decrease in the CAP rate, involving all CAP A phase subtypes. Conclusions: The analysis of sleep microstructure by means of CAP, in children with GHD, showed a reduction of transient EEG amplitude oscillations. Further studies are needed in order to better clarify whether GH therapy is able to modify sleep microstructure in GHD children, and the relationships between sleep microstructure, hormonal secretion and neurocognitive function in these patients.

P01-419 - Two faces of rem sleep in normal and psychopathological development

IntroductionWe have previously found an increased rapid eye movement (REM) sleep in children with attention-deficit/hyperactivity disorder (ADHD).ObjectivesTo further investigate sleep characteristics in children with ADHD and their association with cognitive and neurobehavioral functions.AimsWe asked whether and how REM sleep might have been associated with cognitive ability and neurobehavioral functions in children with ADHD compared with healthy children.MethodsTwenty-three children with ADHD and 21 healthy controls underwent a two-night polysomnography and completed a number of standardized tests for cognitive and neurobehavioral functioning.ResultsCompared with controls, ADHD children exhibited a greater amount of REM sleep. In the ADHD group, the increased amount of REM sleep correlated positively with psychopathological scores (inattention) and negatively with performance intelligence quotient (IQ) (Fig. 1).Fig. 1[Kirov et al_Figure 1]In contrast, in the healthy controls, the REM sleep amount correlated positively with performance IQ and negatively with psychopathological scores (inattention) (Fig. 2).Fig. 2[Kirov et al_Figure 2]ConclusionsWe conclude that REM sleep may have a bi-directional role in cognition and neurobehavioral functioning during childhood depending on the presence or absence of psychopathology.

Children receiving treatment for cancer and their caregivers: A mixed methods study of their sleep characteristics

Sleep has a significant impact on the daily functioning of children and their parents. The purpose of this study was to describe and gain an understanding of the sleep characteristics of children receiving treatment for cancer and their caregivers using a mixed methods concurrent triangulation design. Data were collected from questionnaires completed by 35 caregivers of children receiving treatment for cancer and compared to similar data from 64 caregivers of healthy children. There was considerable variability in the sleep characteristics of the children receiving treatment for cancer as reported by their caregivers. However, as a group, the magnitude of their sleep problems, particularly among the adolescents, was significantly greater than that of the comparison group and had the potential to impact negatively on their participation in everyday life. They had poorer sleep efficiency. Many impairments, particularly pain, nightmares, and symptoms associated with steroid administration, impacted their sleep. Their caregivers also experienced an increased prevalence of sleep issues, which impacted their daytime functioning. Suggestions to prevent and treat the sleep issues of children receiving treatment for cancer focused on practicing good sleep habits, ensuring a safe, secure, and comfortable sleep environment, and using non-pharmaceutical and pharmaceutical interventions to address impairments interfering with sleep. Caregivers noted that it was important to take care of themselves by getting sufficient sleep and accepting help from others. Sleep issues are prevalent in families of children receiving treatment for cancer and should be assessed routinely and addressed.

Differences between Objective and Subjective Sleep Measures in Children with Attention Deficit Hyperactivity Disorder

To assess sleep characteristics in children with ADHD through polysomnographic recordings and parental reports of sleep problems. Standard overnight polysomnography evaluation was performed to record sleep in 27 children with ADHD and 26 healthy controls, aged 7 to 12 years. The diagnosis of ADHD was determined by the Korean version of the Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version (K-SADS-PL-K). Children taking any medications or in poor health were excluded. All the subjects were assessed with the Children's Sleep Habits Questionnaire which was completed by parents. Overall neurobehavioral functioning was examined using various questionnaires, including the Child Behavioral Checklist (CBCL). Based on the findings from the questionnaire, the ADHD group had significantly higher scores on the sleep onset delay (p = 0.027), sleep duration (p = 0.032), night waking (p = 0.006), parasomnias (p = 0.016), daytime sleepiness (p = 0.007), and total sleep disturbance factors (p < 0.001) than children in the control group. However, there were no differences between ADHD and healthy groups on any polysomnographic variables, including sleep structure, arousals, and respiratory disturbances. Reported sleep problems were significantly associated with almost all subscales of CBCL as well as CBCL total score. The majority of sleep problems reported by the parents of ADHD children were not verified through the use of polysomnography. These findings raise the possibility that some of the reported sleep problems in ADHD may be related to disturbing behaviors which often characterize children with ADHD.

Abnormal Sleep Architecture and Refractory Nocturnal Enuresis

The relation between sleep and nocturnal enuresis has been an area of discussion for many years. Children with enuresis are generally believed to have sleep that is too deep with decreased arousability. We investigated sleep characteristics in children with refractory nocturnal enuresis. Nine girls and 20 boys between 5 and 19 years old (mean +/- SD age 12.1 +/- 2.7) diagnosed with desmopressin dependent (14) and/or resistant (15) nocturnal enuresis and nocturnal polyuria underwent a standardized investigation protocol, including 1 night of polysomnography. Two age groups of 4 boys and 2 girls 5 to 9 years old, and 16 boys and 7 girls 10 to 19 years old were compared to previously defined controls, including 5 boys and 2 girls 5 to 9 years old and 7 boys and 2 girls 10 to 19 years old. Five to 9 and 10 to 19-year-old controls had a mean of 4.2 +/- 1.5 and 3.3 +/- 0.6 periodic limb movements per hour of sleep, respectively. The total number of arousal-awakenings during sleep was 21.6 +/- 8.1 at ages 5 to 9 years and 21.7 +/- 12.8 at ages 10 to 19. All except 1 patient had greater than 5 periodic limb movements per sleep hour. The younger and older age groups had a mean of 18.6 +/- 5.7 and 18 +/- 7.8 periodic limb movements per sleep hour, respectively. Total arousal-awakenings were also increased at 86.7 +/- 58.1 and 73.8 +/- 34.8, respectively. Statistical differences were calculated with the Mann-Whitney U test in controls vs the study population for periodic limb movements and in the 2 age groups for arousal-awakening (p = 0.003 and <0.001, respectively). Preliminary data indicate a high incidence of periodic limb movements in sleep at night in children with refractory nocturnal enuresis and increased cortical arousability, leading to awakening.

Longitudinal Study of Bad Dreams in Preschool-Aged Children: Prevalence, Demographic Correlates, Risk and Protective Factors

To (1) clarify the epidemiology of bad dreams in children and investigate risk and protective factors related to (2) the child's sleep, (3) parental sleep-enabling practices, and (4) the child's temperament. Longitudinal with 6 time points from 5 months to 6 years. Subjects' homes. Representative sample of 987 children in the Province of Quebec. None. Longitudinal logistic regression analysis models with primary endpoints of presence or absence of parent-rated bad dreams at 29 months, 41 months, 50 months, 5 years, and 6 years and predictor variables of demographic characteristics, parent ratings of child's sleep characteristics, parental sleep-enabling practices (e.g., cosleeping), and child's psychological characteristics at 5 and 17 months (anxiousness, temperament). Mothers' ratings indicated lower than expected prevalence of frequent bad dreams (1.3% to 3.9%). Demographic correlates of bad dreams were high family income, absence of siblings at 29 months, and a non-immigrant mother. The best predictor at 41 and 50 months was the presence of bad dreams the preceding year, whereas at 5 and 6 years, it was their earlier presence at 29 months. Early protective factors were parental practices favoring emotional nurturance after night awakenings (29 and 41 months); early risk factors were sleep-onset emotional nurturance (29 months), difficult temperament (5 months), and anxiousness (17 months). Bad dreams in preschoolers are less prevalent than thought but, when present, are trait-like in nature and associated with personality characteristics measured as early as 5 months. A stress-diathesis model may best account for the observed pattern of predictive factors.