Objective Sleep Measurement in Typically and Atypically Developing Preschool Children with ADHD-Like Profiles

Objective This study investigated the association between preschool children’s sleep patterns measured by actigraphy and parent-reported hyperactivity symptoms. Many previous studies have reported sleep problems in children with attention deficit hyperactivity disorder (ADHD)-like symptoms. Methods This study examined a cross-sectional sample of 186 preschoolers age 2–5 years in three groups: children with autism, children with developmental delay without autism, and typically developing children recruited from the general population. One week of actigraphic sleep data plus a parent report of the presence or absence of a current sleep problem were collected. Parents completed the child behavior checklist; a subset of children in preschool had teachers who completed the caregiver-teacher report form. Sleep behavior was compared for those children with and without clinical levels of attention-deficit/hyperactivity symptoms (T scores ≥65). Results The prevalence of a parent-defined sleep problem across the entire sample was 36.1%. Thirty-four percent of the sample had a parent-reported ADHD composite in the clinical range. Those children with a clinical ADHD profile were more likely to be described by parents as having a sleep problem. However, no significant differences in actigraphic sleep patterns or night-to-night sleep-wake variability were found for children with an ADHD profile in the clinical range. Conclusions In this non-clinical sample of preschool age children, parental reports of clinical ADHD profiles were significantly associated with parental reports of sleep problems but not with actigraphically recorded sleep-wake data.     

Handedness and circadian motor asymmetries in humans: Preliminary findings

Previous research studies indicate that a motor activity in the first half of nocturnal sleep is lateralized to the non-dominant hand. It was suggested that such phenomenon may be due to a more pronounced homeostatic deactivation of the dominant hemisphere (referring to the hypothesis of the use-dependent recovery function of sleep). If this were the case we should expect a reversed pattern of motor activity asymmetries between right- and left-handed subjects. We tested this hypothesis in an ecological study assessing the circadian motor activity in seventeen right- and seventeen left-handed subjects. All subjects wore actigraphs on both the left and right wrists for at least twelve consecutive days. In line with previous studies, right-handed subjects showed higher motor activity in the left vs. the right hand in late evening. We did not however find a reverse pattern of results in left-handed participants. On the whole the results do not seem to support the use-dependent recovery hypothesis, and are suggestive of a different circadian phase relationship between the two hemispheres regardless of handedness.     

Day Length Associates with Activity Level in Children Living at 60 Degrees North

The associations between day length and activity, rest-activity rhythm, and psychiatric symptoms were studied. Sixty-six healthy children participated in the study during one year. They were monitored for 72 consecutive hours with belt-worn activity monitors (actigraphs) to obtain objective data on their activity levels during the day and night. In addition, the parents filled out the Child Behavior Checklists. It was found, that the mean total and day and night time activity levels were increased and the relative circadian amplitude blunted with the longer day length. It was concluded that day length was associated with activity level and rest-activity rhythm and this association may reflect the seasonal changes in these parameters.     

No association of sleep with total daily physical activity in normal sleepers

The aim of two studies was to examine both between-subjects and within-subjects associations between daily amounts of physical activity and sleep in the home environment. Study 1 examined self-reported exercise durations and sleep diaries for 105 consecutive days in 31 college students who were normal sleepers. Between-subjects associations of mean exercise with mean sleep were assessed with Spearman rank-order correlations. Within-subjects correlations were determined across 105 days, and by comparing sleep on the 11 most active vs. the 11 least active days. Study 2 examined 71 physically active adults (n=38 ages 18-30 years, and n=33 ages 60-75 years), the majority of whom were normal sleepers. Over seven consecutive days, physical activity was assessed via actigraphy and a diary-derived estimate of energy expenditure, and sleep was assessed via actigraphy and sleep diaries. Between-subjects associations of mean physical activity with mean sleep were assessed with partial correlations, controlling for age. Within-subjects associations were assessed with ANCOVAs, with daily physical activity serving as the covariate, and by comparing sleep on the most active vs. the least active day. No significant within-subjects associations between physical activity and sleep were found in the main analyses of either study. Two small, but significant, between-subjects correlations between different physical activity measures and subjective sleep were found in Study 2. These results fail to support epidemiologic data on the value of exercise for sleep, but are consistent with experimental evidence showing only modest effects of exercise on sleep.     

TrkB-deficient mice show diminished phase shifts of the circadian activity rhythm in response to light

We studied the relationship between sleep quality and quantity and subsequently recorded automatically evoked event-related potential (ERP) responses. In previous studies decrement of attentional processing has been associated with changes in sleep. Sleep is shown to associate also with ERPs elicited by unattended sound stream, however, there is no consensus on these effects. A recent study suggested that the early anterior P3a to novel stimuli in attended stream is attenuated and the late parietal P3a is strengthened by total sleep deprivation. We carried out 72-h consecutive actigraphy measurements in a naturalistic setting to collect information about variation in sleep duration, sleep onset latency, sleep efficiency, and percentage of sleep. MMN and P3a deflections to infrequent changes in sound duration and pitch in unattended sound stream were obtained in a separate recording session from the same subjects when they were awake. No significant correlations were found between sleep and MMN parameters, indicating that MMN is resistant to normal variation in sleep. However, P3a to both pitch and duration changes correlated positively with sleep onset latency, and P3a to duration changes correlated negatively with sleep efficiency and percentage of sleep. The correlation was higher in the posterior scalp areas. Our results suggest that the involuntary attention switching system, reflected by the P3a is sensitized as a function of decreased sleep quality.     

Sleep and migraine: an actigraphic study

The aim of the study was to evaluate sleep of children with migraine during the interictal period and the modifications of sleep which precede, are concomitant with, or follow migraine attacks. Eighteen patients with migraine without aura were compared with a group of 17 healthy age-matched children. Sleep parameters were monitored for two full weeks by means of actigraphs and self-report diaries. Headache diaries were also filled out in order to evaluate the occurrence and the characteristics of migraine attacks. Fifty-seven attacks were recorded during the monitoring period. During the interictal period, sleep parameters of children suffering from migraine did not differ from those of controls; only sleep onset latency was slightly prolonged in the migraine group. Timing of the attack affected nocturnal motor activity which presented the lowest values on the night preceding the attack, indicating a decrease in cortical activation during sleep preceding migraine attacks. Further studies should clarify if the observed reduction in nocturnal motor activity close to the attack is related to neurotransmitter imbalance.     

Sleep-wake cycle and melatonin rhythms in adolescents and young adults with mood disorders: Comparison of unipolar and bipolar phenotypes

This study evaluated the potential of circadian measures as early markers of mood disorders subtypes. Patients with bipolar disorders had significantly lower levels and later onset of melatonin secretion than those with unipolar depression. Furthermore, abnormal phase angles between sleep, melatonin and temperature were found in several patients.     

Aiding the diagnosis of AD/HD in childhood: Using actigraphy and a continuous performance test to objectively quantify symptoms

The current gold standard for the diagnosis of AD/HD is based on subjective reports from teachers, parents, and clinicians. These measures can be problematic as they are open to rater biases and also fail to account for the developmental nature of symptoms. The current study examined the diagnostic accuracy of two objective measures, a computer-based Continuous Performance Task and actigraphy (e.g. motion tracking device) in differentiating children with AD/HD (N = 70) from healthy controls (N = 70). It was predicted that task-unrelated movement (measured via actigraphy) during a CPT and CPT performance would have high classification accuracy in differentiating children with AD/HD from healthy controls, and that the inclusion of age would increase this accuracy. Results indicated that total energy expenditure from the task-unrelated wrist and ankle movement during the CPT was higher in children with AD/HD than controls, and that CPT performance was poorer in AD/HD than controls. Discriminant function analyses revealed that the CPT Full-Scale Response Control Quotient and wrist and ankle energy expenditure provided optimal classification accuracy – correctly classifying 86% of cases, with sensitivity of 81.4% and specificity of 91.4%. The prediction that classification accuracy would increase with the inclusion of age was not supported by the data. When taken in conjunction with other clinical assessments, these findings suggest that actigraphy during a CPT and CPT performance may increase the probability of a correct AD/HD diagnosis.     

Actigraphy data in pediatric research: the role of sleep diaries

BackgroundWhen assessing children's sleep using actigraphy, researchers usually rely on a sleep diary completed by a parent as an aid in scoring actigraphic data. However, parental nonadherence in completing the sleep diary may significantly reduce the amount of available data. The current study examined the agreement between actigraphic data scored with and without a sleep diary to evaluate the impact of not using a sleep diary when studying children's sleep with actigraphy.MethodsSixty children (aged 6–10 years; 36 girls) wore an actigraph for three to seven consecutive nights, and mothers were asked to complete a diary of their child's sleep during the same period. Actigraphy data were scored under two conditions (with and without diary) rated independently for each child by two different research assistants, who each scored 50% of the files in each condition.ResultsGroup-level analyses and intraclass correlations revealed very strong convergence between the two scoring conditions: on all sleep variables (sleep duration, wake duration, and sleep efficiency), average mean differences were very small and intraclass correlations very high. Bland and Altman’s (1999) approach allowed for a child-by-child examination of agreement between the two conditions and revealed that, although they cannot be considered interchangeable, the two conditions produce quite minimal differences in the estimation of sleep variables.ConclusionsThe findings suggest that it is possible to use some actigraphy data for which no corresponding diary data are available, although this approach should be used sparingly.     

Total daily activity declines more rapidly with increasing age in older adults

Longitudinal studies of objectively measured physical activity are lacking in older adults. We tested whether objective measures of total daily activity decline more rapidly in older adults. This prospective, observational cohort study included 519 community-dwelling older persons from across metropolitan Chicago participating in the Rush Memory and Aging Project. Repeated total daily activity measures (leisure and non-leisure physical activity) were derived from actigraphic recordings for up to 10 days. Generalized estimating equation models which controlled for demographics measures were employed. At baseline, age was inversely related with the level of total daily activity (estimate, −0.014, S.E. 0.002, p < 0.001). During up to 6 years of follow-up, total daily activity declined by about 0.070 × 10⁵ activity counts/day/yr (estimate −0.065, S.E. 0.005, p < 0.001). Total daily activity declined 3% more rapidly for each additional year of age at baseline (estimate −0.002, S.E. 0.001, p = 0.027). Thus, total daily activity declined almost twice as fast in an individual 91 years old at baseline versus an individual 71 years old. A higher level of education was associated with a slower rate of decline (estimate 0.004, S.E. 0.002, p < 0.018). The associations of age and education with the rate of declining total daily activity were unchanged when controlling for baseline level of motor and cognitive function, other late-life activities and chronic health conditions. These data suggest that total daily activity in very old adults declines more rapidly with increasing age. Thus, physical inactivity is likely to become a larger problem in our aging population.