Sarah N. Biggs

Sleep-disordered breathing in preschool children is associated with behavioral, but not cognitive, impairments

BACKGROUNDnSleep-disordered breathing (SDB) has been associated with impaired cognitive and behavioral function in school children; however, there have been limited studies in preschool children when the incidence of the disorder peaks. Thus, the aim of this study was to compare cognitive and behavioral functions of preschool children with SDB to those of non-snoring control children.nnnMETHODSnA clinical sample of 3-5 year-old children (primary snoring [PS], n=60; mild obstructive sleep apnea syndrome [OSAS], n=32; moderate/severe [MS] OSAS, n=24) and a community sample of non-snoring control children (n=37) were studied with overnight polysomnography. Cognitive performance and behavioral information were collected.nnnRESULTSnChildren with PS and mild OSAS had poorer behavior than controls on numerous measures (p<.05-p<.001), and on some measures they had poorer behavior than the MS OSAS group (p<.05). In contrast, all groups performed similarly on cognitive assessment. Outcomes related more to sleep than respiratory measures.nnnCONCLUSIONSnSDB of any severity was associated with poorer behavior but not cognitive performance. The lack of significant cognitive impairment in this age group may have identified a window of opportunity where early treatment may prevent deficits arising later in childhood.

Inconsistent sleep schedules and daytime behavioral difficulties in school-aged children

OBJECTIVESnCurrent recommendations for healthy sleep in school-aged children are predominantly focused on optimal sleep duration (9-11h). However, given the importance of routine for circadian health, the stability of sleep/wake schedules may also be important, especially for daytime behavioral functioning. We examined the relationship between short sleep duration, sleep schedule instability and behavioral difficulties in a community sample of Australian children.nnnMETHODSnChildren, aged 5-10 years (N=1622), without chronic health or psychological conditions, were recruited from primary schools in Adelaide, South Australia. A parent-report questionnaire was used to assess sleep/wake behavior. Behavioral functioning was assessed using the Strengths and Difficulties Questionnaire.nnnRESULTSnMost children met sleep duration recommendations with approximately 5% reporting <9h and 3% >12h. Weekly variability of bed and rise times >1h were reported in up to 50% of children. Multinomial regression analysis revealed sleep duration <10h, bedtime latency >60 min, and bed and rise time variability >60 min significantly increased the risk of scoring in the 95th percentile for behavioral sub-scales.nnnCONCLUSIONSnInconsistent sleep schedules were common and, similar to short sleep duration, were associated with behavioral difficulties. Considering the lack of study in this area, further research is needed for the development of new recommendations, education and sleep health messages.

Long-term changes in neurocognition and behavior following treatment of sleep disordered breathing in school-aged children.

STUDY OBJECTIVESnSleep disordered breathing (SDB) in children is associated with detrimental neurocognitive and behavioral consequences. The long term impact of treatment on these outcomes is unknown. This study examined the long-term effect of treatment of SDB on neurocognition, academic ability, and behavior in a cohort of school-aged children.nnnDESIGNnFour-year longitudinal study. Children originally diagnosed with SDB and healthy non-snoring controls underwent repeat polysomnography and age-standardized neurocognitive and behavioral assessment 4y following initial testing.nnnSETTINGnMelbourne Childrens Sleep Centre, Melbourne, Australia.nnnPARTICIPANTSnChildren 12-16 years of age, originally assessed at 7-12 years, were categorized into Treated (N = 12), Untreated (N = 26), and Control (N = 18) groups.nnnINTERVENTIONSnAdenotonsillectomy, Tonsillectomy, Nasal Steroids. Decision to treat was independent of this study.nnnMEASUREMENTS AND RESULTSnChanges in sleep and respiratory parameters over time were assessed. A decrease in obstructive apnea hypopnea index (OAHI) from Time 1 to Time 2 was seen in 63% and 100% of the Untreated and Treated groups, respectively. The predictive relationship between change in OAHI and standardized neurocognitive, academic, and behavioral scores over time was examined. Improvements in OAHI were predictive of improvements in Performance IQ, but not Verbal IQ or academic measures. Initial group differences in behavioral assessment on the Child Behavior Checklist did not change over time. Children with SDB at baseline continued to exhibit significantly poorer behavior than Controls at follow-up, irrespective of treatment.nnnCONCLUSIONSnAfter four years, improvements in SDB are concomitant with improvements in some areas of neurocognition, but not academic ability or behavior in school-aged children.

Long-Term Effects of Caffeine Therapy for Apnea of Prematurity on Sleep at School Age

RATIONALEnApnea of prematurity is a common condition that is usually treated with caffeine, an adenosine receptor blocker that has powerful influences on the central nervous system. However, little is known about the long-term effects of caffeine on sleep in the developing brain.nnnOBJECTIVESnWe hypothesized that neonatal caffeine use resulted in long-term abnormalities in sleep architecture and breathing during sleep.nnnMETHODSnA total of 201 ex-preterm children aged 5-12 years who participated as neonates in a double-blind, randomized, controlled clinical trial of caffeine versus placebo underwent actigraphy, polysomnography, and parental sleep questionnaires. Coprimary outcomes were total sleep time on actigraphy and apnea-hypopnea index on polysomnography.nnnMEASUREMENTS AND MAIN RESULTSnThere were no significant differences in primary outcomes between the caffeine group and the placebo (adjusted mean difference of -6.7 [95% confidence interval (CI) = -15.3 to 2.0 min]; P = 0.13 for actigraphic total sleep time; and adjusted rate ratio [caffeine/placebo] for apnea-hypopnea index of 0.89 [95% CI = 0.55-1.43]; P = 0.63). Polysomnographic total recording time and total sleep time were longer in the caffeine group, but there was no difference in sleep efficiency between groups. The percentage of children with obstructive sleep apnea (8.2% of caffeine group versus 11.0% of placebo; P = 0.22) or elevated periodic limb movements of sleep (17.5% in caffeine group versus 11% in placebo group) was high, but did not differ significantly between groups.nnnCONCLUSIONSnTherapeutic neonatal caffeine administration has no long-term effects on sleep duration or sleep apnea during childhood. Ex-preterm infants, regardless of caffeine status, are at risk for obstructive sleep apnea and periodic limb movements in later childhood.

The Children's Report of Sleep Patterns (CRSP): a self-report measure of sleep for school-aged children.

STUDY OBJECTIVESn(1) Present preliminary psychometrics for the Childrens Report of Sleep Patterns (CRSP), a three-module measure of Sleep Patterns, Sleep Hygiene, and Sleep Disturbance; and (2) explore whether the CRSP provides information about a childs sleep above and beyond parental report.nnnMETHODSnA multi-method, multi-reporter approach was used to validate the CRSP with 456 children aged 8-12 years (inclusive). Participants were recruited from pediatricians offices, sleep clinics/laboratories, childrens hospitals, schools, and the general population. Participants completed measures of sleep habits, sleep hygiene, anxiety, and sleepiness, with actigraphy and polysomnography used to provide objective measures of child sleep.nnnRESULTSnThe CRSP demonstrated good reliability and validity. Differences in sleep hygiene and sleep disturbances were found for children presenting to a sleep clinic/laboratory (vs. community population); for younger children (vs. older children); and for children who slept less than 8 hours or had a sleep onset later than 22:00 on actigraphy. Further, significant associations were found between the CRSP and child-reported anxiety or sleepiness. Notably, approximately 40% of parents were not aware of child reported difficulties with sleep onset latency, night wakings, or poor sleep quality.nnnCONCLUSIONSnThe three modules of the CRSP can be used together or independently, providing a reliable and valid self-report measure of sleep patterns, sleep hygiene, and sleep disturbances for children ages 8-12 years. Children not only provide valid information about their sleep, but may provide information that would not be otherwise captured in both clinical and research settings if relying solely on parental report.

Chasing the silver bullet: Measuring driver fatigue using simple and complex tasks

Driver fatigue remains a significant cause of motor-vehicle accidents worldwide. New technologies are increasingly utilised to improve road safety, but there are no effective on-road measures for fatigue. While simulated driving tasks are sensitive, and simple performance tasks have been used in industrial fatigue management systems (FMS) to quantify risk, little is known about the relationship between such measures. Establishing a simple, on-road measure of fatigue, as a fitness-to-drive tool, is an important issue for road safety and accident prevention, particularly as many fatigue related accidents are preventable. This study aimed to measure fatigue-related performance decrements using a simple task (reaction time - RT) and a complex task (driving simulation), and to determine the potential for a link between such measures, thus improving FMS success. Fifteen volunteer participants (7 m, 8 f) aged 22-56 years (mean 33.6 years), underwent 26 h of supervised wakefulness before an 8h recovery sleep opportunity. Participants were tested using a 30-min interactive driving simulation test, bracketed by a 10-min psychomotor vigilance task (PVT) at 4, 8, 18 and 24h of wakefulness, and following recovery sleep. Extended wakefulness caused significant decrements in PVT and driving performance. Although these measures are clearly linked, our analyses suggest that driving simulation cannot be replaced by a simple PVT. Further research is needed to closely examine links between performance measures, and to facilitate accurate management of fitness to drive, which requires more complex assessments of performance than RT alone.

Preschool Children with Obstructive Sleep Apnea: The Beginnings of Elevated Blood Pressure?

STUDY OBJECTIVESnIn adults and older children, snoring and obstructive sleep apnea (OSA) are associated with elevated blood pressure (BP). However, BP has not been assessed in preschool children, the age of highest OSA prevalence. We aimed to assess overnight BP in preschool children with snoring and OSA using pulse transit time (PTT), an inverse continuous indicator of BP changes.nnnDESIGNnOvernight polysomnography including PTT. Children were grouped according to their obstructive apnea-hypopnea index (OAHI); control (no snoring, with OAHI of one event or less per hour), primary snoring (OAHI one event or less per hour), mild OSA (OAHI greater than one event to five events per hour) and moderate-severe OSA (OAHI more than five events per hour).nnnSETTINGnPediatric sleep laboratory.nnnPATIENTSnThere were 128 clinically referred children (aged 3-5 years) and 35 nonsnoring community control children.nnnMEASUREMENT AND RESULTSnPTT was averaged for each 30-sec epoch of rapid eye movement (REM) or nonrapid eye movement (NREM) sleep and normalized to each childs mean wake PTT. PTT during NREM was significantly higher than during REM sleep in all groups (P < 0.001 for all). During REM sleep, the moderate-severe OSA group had significantly lower PTT than the mild and primary snoring groups (P < 0.05 for both). This difference persisted after removal of event-related PTT changes.nnnCONCLUSIONSnModerate-severe OSA in preschool children has a significant effect on pulse transit time during REM sleep, indicating that these young children have a higher baseline BP during this state. We propose that the REM-related elevation in BP may be the first step toward development of daytime BP abnormalities. Given that increased BP during childhood predicts hypertension in adulthood, longitudinal studies are needed to determine the effect of resolution of snoring and/or OSA at this age.

The conundrum of primary snoring in children: What are we missing in regards to cognitive and behavioural morbidity?

Sleep disordered breathing (SDB) is common in children and describes a continuum of nocturnal respiratory disturbance from primary snoring (PS) to obstructive sleep apnoea (OSA). Historically, PS has been considered benign, however there is growing evidence that children with PS exhibit cognitive and behavioural deficits equivalent to children with OSA. There are two popular mechanistic theories linking SDB with daytime morbidity: hypoxic insult to the developing brain; and sleep disruption due to repeated arousals. These theories apply well to OSA, but children with PS experience neither hypoxia nor increased arousals when compared to non snoring controls. So what are we missing? This review summarises the literature examining daytime morbidity in children with PS and discusses the current debates surrounding this relationship. Specifically, questions exist as to the sensitivity of our standard assessment techniques to measure subtle hypoxia and arousal. There is also a suggestion that the association between PS and daytime morbidity may not be mediated by nocturnal respiratory disturbance at all, but by a number of other comorbid, but perhaps unrelated factors. As approximately 70% of children with SDB are diagnosed with PS, but are rarely treated, a paradigm shift in the investigation of PS may be required.

Gender, socioeconomic, and ethnic differences in sleep patterns in school-aged children

OBJECTIVESnAge-related changes in sleep behavior are well described in children, yet the effect of gender, socioeconomic status (SES), and ethnicity is less clear. These factors are important when developing culturally and socially appropriate guidelines for healthy sleep. The objective of our study was to examine the effects of age, gender, SES, and ethnicity on sleep patterns in school-aged children.nnnMETHODSnA cross-sectional survey was conducted through primary schools in Adelaide, South Australia. Parents reported demographic information and sleep patterns for school and non-school days for 1845 children aged 5 to 10years.nnnRESULTSn48% of the cohort were boys (mean age, 7.7±1.7y), 85% were Caucasian, and there was an equal distribution across defined SES bands. Sleep duration reduced with age and was shorter on non-school than school nights as a result of later bedtimes. Boys, children from low SES areas, and non-Caucasian children reported shorter sleep times than girls, children from high SES areas, and Caucasian children, respectively. Non-Caucasian children from low SES areas reported the shortest sleep opportunity.nnnCONCLUSIONSnThe results from our study suggest that in addition to biological mechanisms, sleep behaviors are culturally and socially driven and should be considered when developing recommendations for healthy sleep in children.

Comparison of Commercial Wrist-Based and Smartphone Accelerometers, Actigraphy, and PSG in a Clinical Cohort of Children and Adolescents

STUDY OBJECTIVESnTo compare two commercial sleep devices, an accelerometer worn as a wristband (UP by Jawbone) and a smartphone application (MotionX 24/7), against polysomnography (PSG) and actigraphy (Actiwatch2) in a clinical pediatric sample.nnnMETHODSnChildren and adolescents (n = 78, 65% male, mean age 8.4 ± 4.0 y) with suspected sleep disordered breathing (SDB), simultaneously wore an actiwatch, a commercial wrist-based device and had a smartphone with a sleep application activated placed near their right shoulder, during their diagnostic PSG. Outcome variables were sleep onset latency (SOL), total sleep time (TST), wake after sleep onset (WASO), and sleep efficiency (SE). Paired comparisons were made between PSG, actigraphy, UP, and MotionX 24/7. Epoch-by-epoch comparisons determined sensitivity, specificity, and accuracy between PSG, actigraphy, and UP. Bland-Altman plots determined level of agreement. Differences in bias between SDB severity and developmental age were assessed.nnnRESULTSnNo differences in mean TST, WASO, or SE between PSG and actigraphy or PSG and UP were found. Actigraphy overestimated SOL (21 min). MotionX 24/7 underestimated SOL (12 min) and WASO (63 min), and overestimated TST (106 min) and SE (17%). UP showed good sensitivity (0.92) and accuracy (0.86) but poor specificity (0.66) when compared to PSG. Bland-Altman plots showed similar levels of bias in both actigraphy and UP. Bias did not differ by SDB severity, however was affected by age.nnnCONCLUSIONSnWhen compared to PSG, UP was analogous to Actiwatch2 and may have some clinical utility in children with sleep disordered breathing. MotionX 24/7 did not accurately reflect sleep or wake and should be used with caution.