In summary, although actigraphy is not as accurate as PSG for determining some sleep measurements, studies are in general agreement that actigraphy, with its ability to record continuously for long time periods, is more reliable than sleep logs which rely on the patients' recall of how many times they woke up or how long they slept during the night and is more reliable than observations which only capture short time periods Actigraphy can provide information obtainable in no other practical way It can also have a role in the medical care of patients with sleep disorders However, it should not be held to the same expectations as polysomnography Actigraphy is one-dimensional, whereas polysomnography comprises at least 3 distinct types of data (EEG, EOG, EMG), which jointly determine whether a person is asleep or awake It is therefore doubtful whether actigraphic data will ever be informationally equivalent to the PSG, although progress on hardware and data processing software is continuously being made Although the 1995 practice parameters paper determined that actigraphy was not appropriate for the diagnosis of sleep disorders, more recent studies suggest that for some disorders, actigraphy may be more practical than PSG While actigraphy is still not appropriate for the diagnosis of sleep disordered breathing or of periodic limb movements in sleep, it is highly appropriate for examining the sleep variability (ie, night-to-night variability) in patients with insomnia Actigraphy is also appropriate for the assessment of and stability of treatment effects of anything from hypnotic drugs to light treatment to CPAP, particularly if assessments are done before and after the start of treatment A recent independent review of the actigraphy literature by Sadeh and Acebo reached many of these same conclusions Some of the research studies failed to find relationships between sleep measures and health-related symptoms The interpretation of these data is also not clear-cut Is it that the actigraph is not reliable enough to the access the relationship between sleep changes and quality of life measures, or, is it that, in fact, there is no relationship between sleep in that population and quality of life measures? Other studies of sleep disordered breathing, where actigraphy was not used and was not an outcome measure also failed to find any relationship with quality of life Is it then the actigraph that is not reliable or that the associations just do not exist? The one area where actigraphy can be used for clinical diagnosis is in the evaluation of circadian rhythm disorders Actigraphy has been shown to be very good for identifying rhythms Results of actigraphic recordings correlate well with measurements of melatonin and of core body temperature rhythms Activity records also show sleep disturbance when sleep is attempted at an unfavorable phase of the circadian cycle Actigraphy therefore would be particularly good for aiding in the diagnosis of delayed or advanced sleep phase syndrome, non-24-hour-sleep syndrome and in the evaluation of sleep disturbances in shift workers It must be remembered, however, that overt rest-activity rhythms are susceptible to various masking effects, so they may not always show the underlying rhythm of the endogenous circadian pacemaker In conclusion, the latest set of research articles suggest that in the clinical setting, actigraphy is reliable for evaluating sleep patterns in patients with insomnia, for studying the effect of treatments designed to improve sleep, in the diagnosis of circadian rhythm disorders (including shift work), and in evaluating sleep in individuals who are less likely to tolerate PSG, such as infants and demented elderly While actigraphy has been used in research studies for many years, up to now, methodological issues had not been systematically addressed in clinical research and practice Those issues have now been addressed and actigraphy may now be reaching the maturity needed for application in the clinical arena

The role of actigraphy in the study of sleep and circadian rhythms.

Over more than a century of research has established the fact that sleep benefits the retention of memory. In this review we aim to comprehensively cover the field of "sleep and memory" research by providing a historical perspective on concepts and a discussion of more recent key findings. Whereas initial theories posed a passive role for sleep enhancing memories by protecting them from interfering stimuli, current theories highlight an active role for sleep in which memories undergo a process of system consolidation during sleep. Whereas older research concentrated on the role of rapid-eye-movement (REM) sleep, recent work has revealed the importance of slow-wave sleep (SWS) for memory consolidation and also enlightened some of the underlying electrophysiological, neurochemical, and genetic mechanisms, as well as developmental aspects in these processes. Specifically, newer findings characterize sleep as a brain state optimizing memory consolidation, in opposition to the waking brain being optimized for encoding of memories. Consolidation originates from reactivation of recently encoded neuronal memory representations, which occur during SWS and transform respective representations for integration into long-term memory. Ensuing REM sleep may stabilize transformed memories. While elaborated with respect to hippocampus-dependent memories, the concept of an active redistribution of memory representations from networks serving as temporary store into long-term stores might hold also for non-hippocampus-dependent memory, and even for nonneuronal, i.e., immunological memories, giving rise to the idea that the offline consolidation of memory during sleep represents a principle of long-term memory formation established in quite different physiological systems.

https://www.zora.uzh.ch/id/eprint/77770/1/physiol_rev_93.pdf

About sleep's role in memory

1.0 BACKGROUND ACTIGRAPHY HAS BEEN USED TO STUDY SLEEP/WAKE PATTERNS FOR OVER 20 YEARS. The advantage of actigraphy over traditional polysomnography (PSG) is that actigraphy can conveniently record continuously for 24-hours a day for days, weeks or even longer. In 1995, Sadeh et al.,1 under the auspices of the American Sleep Disorders Association (now called the American Academy of Sleep Medicine, AASM), reviewed the current knowledge about the role of actigraphy in the evaluation of sleep disorders. They concluded that actigraphy does provide useful information and that it may be a “cost-effective method for assessing specific sleep disorders...[but that] methodological issues have not been systematically addressed in clinical research and practice.” Based on that task force’s report, the AASM Standards of Practice Committee concluded that actigraphy was not indicated for routine diagnosis or for assessment of severity or management of sleep disorders, but might be a useful adjunct for diagnosing insomnia, circadian rhythm disorders or excessive sleepiness.2 Since that time, actigraph technology has improved, and many more studies have been conducted. Several review papers have concluded that wrist actigraphy can usefully approximate sleep versus wake state during 24 hours and have noted that actigraphy has been used for monitoring insomnia, circadian sleep/wake disturbances, and periodic limb movement disorder.3,4 This paper begins where the 1995 paper left off. Under the auspices of the AASM, a new task force was established to review the current state of the art of this technology.

The Role of Actigraphy in the Study of Sleep and Circadian Rhythms AMERICAN ACADEMY OF SLEEP MEDICINE REVIEW PAPER

Study objectives To present psychometric data on a comprehensive, parent-report sleep screening instrument designed for school-aged children, the Children's Sleep Habits Questionnaire (CSHQ). The CSHQ yields both a total score and eight subscale scores, reflecting key sleep domains that encompass the major medical and behavioral sleep disorders in this age group. Design Cross-sectional survey. Setting Three elementary schools in New England, a pediatric sleep disorders clinic in a children's teaching hospital. Participants Parents of 469 school-aged children, aged 4 through 10 years (community sample), and parents of 154 patients diagnosed with sleep disorders in a pediatric sleep clinic completed the CSHQ. Interventions N/A. Measurements and results The CSHQ showed adequate internal consistency for both the community sample (p=0.68) and the clinical sample (p=0.78); alpha coefficients for the various subscales of the CSHQ ranged from 0.36 (Parasomnias) to 0.70 (Bedtime Resistance) for the community sample, and from 0.56 (Parasomnias) to 0.93 (Sleep-Disordered Breathing) for the sleep clinic group. Test-retest reliability was acceptable (range 0.62 to 0.79). CSHQ individual items, as well as the subscale and total scores were able to consistently differentiate the community group from the sleep-disordered group, demonstrating validity. A cut-off total CSHQ score of 41 generated by analysis of the Receiver Operator Characteristic Curve (ROC) correctly yielded a sensitivity of 0.80 and specificity of 0.72. Conclusions The CSHQ appears to be a useful sleep screening instrument to identify both behaviorally based and medically-based sleep problems in school-aged children.

https://nationaljewish.org/njh/media/pdf/meltzer references/owens-(2000)-cshq-school-aged-children.pdf

The Children's Sleep Habits Questionnaire (CSHQ): psychometric properties of a survey instrument for school-aged children.

Research on attention-deficit/hyperactivity disorder (ADHD), a highly prevalent and controversial condition, has, for the most part, been descriptive and atheoretical. The imperative to discover the genetic and environmental risk factors for ADHD is motivating the search for quantifiable intermediate constructs, termed endophenotypes. In this selective review, we conclude that such endophenotypes should be solidly grounded in the neurosciences. We propose that three such endophenotypes — a specific abnormality in reward-related circuitry that leads to shortened delay gradients, deficits in temporal processing that result in high intrasubject intertrial variability, and deficits in working memory — are most amenable to integrative collaborative approaches that aim to uncover the causes of ADHD.

Neuroscience of attention-deficit/hyperactivity disorder: the search for endophenotypes.

Objective To evaluate the relationship between sleep disturbances and attention-deficit/hyperactivity disorder (ADHD). Method Empirical research published since 1970 on sleep disturbances in children with ADHD was systematically reviewed. A “box-score” approach was used to examine consistency of findings across the studies, which used different outcome measures. Result Although subjective accounts of sleep disturbances in ADHD were prevalent, objective verification of these disturbances was less robust. The only consistent objective findings were that children with ADHD displayed more movements during sleep but did not differ from normal controls in total sleep time. An additional finding was that stimulant medication led to changes in the children's sleep (e.g., prolonged sleep latency, increased length of onset to first rapid eye movement cycle), but these changes were believed to be nonpathological. Conclusion The exact nature of the sleep problems in children with ADHD remains to be determined. Many of the relevant issues have not been adequately addressed. Factors such as poorly defined diagnostic groups, small sample sizes, few studies, and methodological and procedural limitations make it difficult to determine the relationship between ADHD and sleep problems.

Sleep Disturbances in Children With Attention‐Deficit/Hyperactivity Disorder

Objective To determine the relationship of sleep problems to attention-deficit/hyperactivity disorder (ADHD), diagnostic subtype, comorbid disorders, and the effects of stimulant treatment. Method On the basis of clinical diagnostic interviews, children aged 6 to 12 years were assigned to 4 groups: unmedicated ADHD ( n = 79), medicated ADHD ( n = 22), clinical comparison ( n = 35), and healthy nonclinical comparison ( n = 36). These groups were compared on 2 sleep questionnaires completed by the parents that assessed current sleep problems and factors associated with sleep difficulties (i.e., sleep routines, sleep practices, child and family sleep history). Results Factor analysis revealed 3 sleep problem categories: dyssomnias, parasomnias, and sleep-related involuntary movements. Linear regression analyses showed that (1) dyssomnias were related to confounding factors (i.e., comorbid oppositional defiant disorder and stimulant medication) rather than ADHD; (2) parasomnias were similar in clinical and nonclinical children; and (3) the DSM-IV combined subtype of ADHD was associated with sleep-related involuntary movements. However, sleep-related involuntary movements were more highly associated with separation anxiety. Conclusions The results suggest that the relationship between sleep problems and ADHD is complex and depends on the type of sleep problem assessed as well as confounding factors such as comorbid clinical disorders and treatment with stimulant medication.

Sleep Problems in Children With Attention‐Deficit/Hyperactivity Disorder: Impact of Subtype, Comorbidity, and Stimulant Medication

The effect of 40 h of wakefulness on a variety of immunological parameters in the peripheral blood from 10 normal male subjects was studied Sleep deprivation led to enhanced nocturnal plasma interleukin 1-like and interleukin 2-like activities The rise in nocturnal response of lymphocytes to pokeweed mitogen stimulation during a normal 24 h sleep-wake cycle was delayed by sleep deprivation, but the response to the phytohemagglutinin mitogen was unaffected With resumed nocturnal sleep, there was a prolonged decline in natural killer cell activity (measured as spontaneous cytolytic activity for human tumor cells) and return of an increased response to pokeweed mitogen The altered patterns in immune functions occurred independently of the cortisol circadian rhythm, which remained unchanged

Effects of sleep deprivation on human immune functions.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/art.1780401103

The neuroscience and endocrinology of fibromyalgia

Study Objectives: To assess various sleep parameters in latency-aged children with ADHD and their normally developing peers through the use of multiple sleep measures. Design: Six sleep parameters were evaluated for two groups of children, ADHD and normal comparison. Each group consisted of 25 children (20 males, 5 females) who ranged in age from 7 to 11 years. All children underwent rigorous diagnostic procedures and the ADHD subjects were selected only if they displayed pervasiveness in their symptomatology and were medication naive. Parents completed a retrospective questionnaire which evaluated sleep problems over the past six months. Additionally, each child wore an actigraph for seven consecutive nights, and the child's parents completed a sleep diary during this time period. Setting: N/A Patients or Participants: N/A Interventions: N/A Results: Based on the findings from the questionnaire, parents of children with ADHD reported significantly more sleep problems than parents of normally developing children. However, the majority of these sleep differences were not verified through actigraphy or sleep diary data, with the exception of longer sleep duration for children with ADHD and parent reports that describe increased bedtime resistence. It was also found that child-parent interactions during bedtime routines were more challenging in the ADHD group. Conclusions: Despite the possibility of intrinsic sleep problems such as longer sleep duration, results indicate that many of the sleep problems of children with ADHD may be due to challenging behaviours during bedtime routines. The reason for discrepancies among sleep studies employing objective measures as well as between retrospective and prospective measures are discussed.

/pdf/actigraphy-and-parental-ratings-of-sleep-in-children-with-1m9jekwtof.pdf

Harvey Moldofsky

Papers

Sleep Disturbances in Children With Attention‐Deficit/Hyperactivity Disorder

Sleep Problems in Children With Attention‐Deficit/Hyperactivity Disorder: Impact of Subtype, Comorbidity, and Stimulant Medication

Effects of sleep deprivation on human immune functions.

The neuroscience and endocrinology of fibromyalgia

Actigraphy and parental ratings of sleep in children with attention-deficit/hyperactivity disorder (ADHD).