A new method for measuring daytime sleepiness: the Epworth sleepiness scale

The development and use of a new scale, the Epworth sleepiness scale (ESS), is described. This is a simple, self-administered questionnaire which is shown to provide a measurement of the subject's general level of daytime sleepiness. One hundred and eighty adults answered the ESS, including 30 normal men and women as controls and 150 patients with a range of sleep disorders. They rated the chances that they would doze off or fall asleep when in eight different situations commonly encountered in daily life. Total ESS scores significantly distinguished normal subjects from patients in various diagnostic groups including obstructive sleep apnea syndrome, narcolepsy and idiopathic hypersomnia. ESS scores were significantly correlated with sleep latency measured during the multiple sleep latency test and during overnight polysomnography. In patients with obstructive sleep apnea syndrome ESS scores were significantly correlated with the respiratory disturbance index and the minimum SaO2 recorded overnight. ESS scores of patients who simply snored did not differ from controls.

Meta-analysis of quantitative sleep parameters from childhood to old age in healthy individuals: developing normative sleep values across the human lifespan

OBJECTIVES

The purposes of this study were to identify age-related changes in objectively recorded sleep patterns across the human life span in healthy individuals and to clarify whether sleep latency and percentages of stage 1, stage 2, and rapid eye movement (REM) sleep significantly change with age.

DESIGN

Review of literature of articles published between 1960 and 2003 in peer-reviewed journals and meta-analysis.

PARTICIPANTS

65 studies representing 3,577 subjects aged 5 years to 102 years.

MEASUREMENT

The research reports included in this meta-analysis met the following criteria: (1) included nonclinical participants aged 5 years or older; (2) included measures of sleep characteristics by "all night" polysomnography or actigraphy on sleep latency, sleep efficiency, total sleep time, stage 1 sleep, stage 2 sleep, slow-wave sleep, REM sleep, REM latency, or minutes awake after sleep onset; (3) included numeric presentation of the data; and (4) were published between 1960 and 2003 in peer-reviewed journals.

RESULTS

In children and adolescents, total sleep time decreased with age only in studies performed on school days. Percentage of slow-wave sleep was significantly negatively correlated with age. Percentages of stage 2 and REM sleep significantly changed with age. In adults, total sleep time, sleep efficiency, percentage of slow-wave sleep, percentage of REM sleep, and REM latency all significantly decreased with age, while sleep latency, percentage of stage 1 sleep, percentage of stage 2 sleep, and wake after sleep onset significantly increased with age. However, only sleep efficiency continued to significantly decrease after 60 years of age. The magnitudes of the effect sizes noted changed depending on whether or not studied participants were screened for mental disorders, organic diseases, use of drug or alcohol, obstructive sleep apnea syndrome, or other sleep disorders.

CONCLUSIONS

In adults, it appeared that sleep latency, percentages of stage 1 and stage 2 significantly increased with age while percentage of REM sleep decreased. However, effect sizes for the different sleep parameters were greatly modified by the quality of subject screening, diminishing or even masking age associations with different sleep parameters. The number of studies that examined the evolution of sleep parameters with age are scant among school-aged children, adolescents, and middle-aged adults. There are also very few studies that examined the effect of race on polysomnographic sleep parameters.

Non-motor symptoms of Parkinson's disease: diagnosis and management

The clinical diagnosis of Parkinson's disease rests on the identification of the characteristics related to dopamine deficiency that are a consequence of degeneration of the substantia nigra pars compacta. However, non-dopaminergic and non-motor symptoms are sometimes present before diagnosis and almost inevitably emerge with disease progression. Indeed, non-motor symptoms dominate the clinical picture of advanced Parkinson's disease and contribute to severe disability, impaired quality of life, and shortened life expectancy. By contrast with the dopaminergic symptoms of the disease, for which treatment is available, non-motor symptoms are often poorly recognised and inadequately treated. However, attention is now being focused on the recognition and quantitation of non-motor symptoms, which will form the basis of improved treatments. Some non-motor symptoms, including depression, constipation, pain, genitourinary problems, and sleep disorders, can be improved with available treatments. Other non-motor symptoms can be more refractory and need the introduction of novel non-dopaminergic drugs. Inevitably, the development of treatments that can slow or prevent the progression of Parkinson's disease and its multicentric neurodegeneration provides the best hope of curing non-motor symptoms.

Automatic sleep/wake identification from wrist activity

The purpose of this study was to develop and validate automatic scoring methods to distinguish sleep from wakefulness based on wrist activity. Forty-one subjects (18 normals and 23 with sleep or psychiatric disorders) wore a wrist actigraph during overnight polysomnography. In a randomly selected subsample of 20 subjects, candidate sleep/wake prediction algorithms were iteratively optimized against standard sleep/wake scores. The optimal algorithms obtained for various data collection epoch lengths were then prospectively tested on the remaining 21 subjects. The final algorithms correctly distinguished sleep from wakefulness approximately 88% of the time. Actigraphic sleep percentage and sleep latency estimates correlated 0.82 and 0.90, respectively, with corresponding parameters scored from the polysomnogram (p < 0.0001). Automatic scoring of wrist activity provides valuable information about sleep and wakefulness that could be useful in both clinical and research applications.

Sleep disturbance and psychiatric disorders: a longitudinal epidemiological study of young adults

In a longitudinal epidemiological study of young adults, we estimated the association between sleep disturbance and psychiatric disorders, cross-sectionally and prospectively. A random sample of 1200 was drawn from all 21-30-year-old members of a large health maintenance organization (HMO) in Michigan; 1007 were interviewed in 1989 and 979 were reinterviewed in 1992. Lifetime prevalence of insomnia alone was 16.6%, of hypersomnia alone, 8.2%, and of insomnia plus hypersomnia, 8%. The gender-adjusted relative risk for new onset of major depression during the follow-up period in persons with history of insomnia at baseline was 4.0 (95% confidence interval [CI] 2.2-7.0) and in persons with baseline history of hypersomnia, 2.9 (95% CI 1.5-5.6). When history of other prior depressive symptoms (e.g., psychomotor retardation or agitation, suicidal ideation) was controlled for, prior insomnia remained a significant predictor of subsequent major depression. Complaints of 2 weeks or more of insomnia nearly every night might be a useful marker of subsequent onset of major depression.

Psychometric evaluation of the Pittsburgh Sleep Quality Index

The Pittsburgh Sleep Quality Index (PSQI) measures sleep quality and disturbance retrospectively over a 1-month period using self-reports. Although the PSQI has been used in a variety of populations, published psychometric data are limited. The goal of this study was to examine psychometric properties of the PSQI among four populations: bone marrow transplant patients (n=155); renal transplant patients (n=56); women with breast cancer (n=102); and women with benign breast problems (n=159). Results supported PSQI internal consistency reliability and construct validity. Cronbach's alphas were 0.80 across groups and correlations between global and component scores were moderate to high. PSQI scores were moderately to highly correlated with measures of sleep quality and sleep problems, and poorly correlated with unrelated constructs. Individuals with sleep problems, poor sleep quality, and sleep restlessness had significantly higher PSQI scores in comparison to individuals without such problems.

The Pittsburgh sleep quality index as a screening tool for sleep dysfunction in clinical and non-clinical samples: A systematic review and meta-analysis

This review appraises the process of development and the measurement properties of the Pittsburgh sleep quality index (PSQI), gauging its potential as a screening tool for sleep dysfunction in non-clinical and clinical samples; it also compares non-clinical and clinical populations in terms of PSQI scores. MEDLINE, Embase, PsycINFO, and HAPI databases were searched. Critical appraisal of studies of measurement properties was performed using COSMIN. Of 37 reviewed studies, 22 examined construct validity, 19 - known-group validity, 15 - internal consistency, and three - test-retest reliability. Study quality ranged from poor to excellent, with the majority designated fair. Internal consistency, based on Cronbach's alpha, was good. Discrepancies were observed in factor analytic studies. In non-clinical and clinical samples with known differences in sleep quality, the PSQI global scores and all subscale scores, with the exception of sleep disturbance, differed significantly. The best evidence synthesis for the PSQI showed strong reliability and validity, and moderate structural validity in a variety of samples, suggesting the tool fulfills its intended utility. A taxonometric analysis can contribute to better understanding of sleep dysfunction as either a dichotomous or continuous construct.

Practice Parameters for the Indications for Polysomnography and Related Procedures: An Update for 2005

These practice parameters are an update of the previously-published recommendations regarding the indications for polysomnography and related procedures in the diagnosis of sleep disorders. Diagnostic categories include the following: sleep related breathing disorders, other respiratory disorders, narcolepsy, parasomnias, sleep related seizure disorders, restless legs syndrome, periodic limb movement sleep disorder, depression with insomnia, and circadian rhythm sleep disorders. Polysomnography is routinely indicated for the diagnosis of sleep related breathing disorders; for continuous positive airway pressure (CPAP) titration in patients with sleep related breathing disorders; for the assessment of treatment results in some cases; with a multiple sleep latency test in the evaluation of suspected narcolepsy; in evaluating sleep related behaviors that are violent or otherwise potentially injurious to the patient or others; and in certain atypical or unusual parasomnias. Polysomnography may be indicated in patients with neuromuscular disorders and sleep related symptoms; to assist in the diagnosis of paroxysmal arousals or other sleep disruptions thought to be seizure related; in a presumed parasomnia or sleep related seizure disorder that does not respond to conventional therapy; or when there is a strong clinical suspicion of periodic limb movement sleep disorder. Polysomnography is not routinely indicated to diagnose chronic lung disease; in cases of typical, uncomplicated, and noninjurious parasomnias when the diagnosis is clearly delineated; for patients with seizures who have no specific complaints consistent with a sleep disorder; to diagnose or treat restless legs syndrome; for the diagnosis of circadian rhythm sleep disorders; or to establish a diagnosis of depression.

The association of sleep and pain: an update and a path forward

Ample evidence suggests that sleep and pain are related. However, many questions remain about the direction of causality in their association, as well as mechanisms that may account for their association. The prevailing view has generally been that they are reciprocally related. The present review critically examines the recent prospective and experimental literature (2005-present) in an attempt to update the field on emergent themes pertaining to the directionality and mechanisms of the association of sleep and pain. A key trend emerging from population-based longitudinal studies is that sleep impairments reliably predict new incidents and exacerbations of chronic pain. Microlongitudinal studies employing deep subjective and objective assessments of pain and sleep support the notion that sleep impairments are a stronger, more reliable predictor of pain than pain is of sleep impairments. Recent experimental studies suggest that sleep disturbance may impair key processes that contribute to the development and maintenance of chronic pain, including endogenous pain inhibition and joint pain. Several biopsychosocial targets for future mechanistic research on sleep and pain are discussed, including dopamine and opioid systems, positive and negative affect, and sociodemographic factors.

PERSPECTIVE

This critical review examines the recent prospective and experimental research (2005-present) on the association of sleep and pain in an attempt to identify trends suggestive of directionality and potential mechanisms. An update on this literature is needed to guide future clinical efforts to develop and augment treatments for chronic sleep disturbance and chronic pain.

Insufficient sleep in adolescents and young adults: an update on causes and consequences

Chronic sleep loss and associated sleepiness and daytime impairments in adolescence are a serious threat to the academic success, health, and safety of our nation's youth and an important public health issue. Understanding the extent and potential short- and long-term repercussions of sleep restriction, as well as the unhealthy sleep practices and environmental factors that contribute to sleep loss in adolescents, is key in setting public policies to mitigate these effects and in counseling patients and families in the clinical setting. This report reviews the current literature on sleep patterns in adolescents, factors contributing to chronic sleep loss (ie, electronic media use, caffeine consumption), and health-related consequences, such as depression, increased obesity risk, and higher rates of drowsy driving accidents. The report also discusses the potential role of later school start times as a means of reducing adolescent sleepiness.

Sleep and psychiatric disorders. A meta-analysis

We reviewed the literature on sleep in psychiatric disorders and evaluated the data by meta-analysis, a statistical method designed to combine data from different studies. A total of 177 studies with data from 7151 patients and controls were reviewed. Most psychiatric groups showed significantly reduced sleep efficiency and total sleep time, accounted for by decrements in non-rapid eye movement sleep. Rapid eye movement sleep time was relatively preserved in all groups, and percentage of rapid eye movement sleep was increased in affective disorders. Reduction in rapid eye movement sleep latency was seen in affective disorders but occurred in other categories as well. Although no single sleep variable appeared to have absolute specificity for any particular psychiatric disorder, patterns of sleep disturbances associated with categories of psychiatric illnesses were observed. Overall, findings for patients with affective disorders differed most frequently and significantly from those for normal controls.

Dimensional assessment of chronic fatigue syndrome

The absence of laboratory tests and clear criteria to identify homogeneous (sub)groups in patients presenting with unexplained fatigue, and to assess clinical status and disability in these patients, calls for further assessment methods. In the present study, a multi-dimensional approach to the assessment of chronic fatigue syndrome (CFS) is evaluated. Two-hundred and ninety-eight patients with CFS completed a set of postal questionnaires that assessed the behavioural, emotional, social, and cognitive aspects of CFS. By means of statistical analyses nine relatively independent dimensions of CFS were identified along which CFS-assessment and CFS-research can be directed. These dimensions were named: psychological well-being, functional impairment in daily life, sleep disturbances, avoidance of physical activity, neuropsychological impairment, causal attributions related to the complaints, social functioning, self-efficacy expectations, and subjective experience of the personal situation. A description of the study sample on these dimensions is presented.

The Sleep Disturbance Scale for Children (SDSC). Construction and validation of an instrument to evaluate sleep disturbances in childhood and adolescence

To attempt a categorization of sleep disorders in children, we developed a 27 item Likert-type rating scale (Sleep Disturbance Scale for Children: SDSC) and assessed the psychometric properties was developed. The scale was distributed to the mothers of 1304 children (1157 controls, mean age 9.8 y; 147 sleep disorder subjects, mean age 9.2y, composed of four clinical groups: Insomnia 39 subjects, Hypersomnia 12 subjects, Respiratory disturbances during sleep 25 subjects and Parasomnias 71 subjects). The internal consistency was high in controls (0.79) and remained at a satisfactory level in sleep disorder subjects (0.71); the test/retest reliability was adequate for the total (r = 0.71) and single item scores. The factor analysis (variance explained 44.21%) yielded six factors which represented the most common areas of sleep disorders in childhood and adolescence. Enuresis was the only item with a factor loading lower than 0.40 and with a low inter-item correlation and was therefore eliminated, resulting in a final scale of 26 items. The re-evaluation of the sample, using the factor scores, supported the validity and the discriminating capacity of the scales between controls and the four clinical groups. The correlation between factor scores corroborated the hypothesis that childhood sleep disturbances are not independent entities nor do they cluster into different groupings related to each other. The SDSC appears to be a useful tool in evaluating the sleep disturbances of school-age children in clinical and non-clinical populations.

Validity and reliability of a scale to assess fatigue

A visual analogue scale to evaluate fatigue severity (VAS-F) was developed and tested in a sample of 75 healthy individuals and a sample of 57 patients undergoing medical evaluation for sleep disorders. The scale consists of 18 items related to fatigue and energy, has simple instructions, and is completed with minimal time and effort. The VAS-F compares favorably with the Stanford Sleepiness Scale and the Profile of Mood States, and its internal consistency reliabilities are high. Healthy subjects demonstrated significant differences between their evening and morning scores on the VAS-F, while sleep-disordered patients did not.

A scale for the estimation of sleep problems in clinical research

Problems in sleeping are widely prevalent in modern society and are often one of the presenting complaints of patients consulting physicians. In addition, there is scattered epidemiologic evidence and considerable clinical support that disturbed or inadequate sleep may be a risk factor for clinical emergence of cardiovascular disease and for total mortality. The role of sleep problems both as a precursor and as a sequela of disease states could be better delineated in large groups by the availability of a brief, reliable and standardized scale for sleep disturbance. Such a scale could also be used to evaluate the impact of different therapies upon sleep problems. This paper presents data from two study populations responding to three and four item self-report scales. From 9 to 12% of air traffic controllers reported various sleep problems to have occurred on half or more of the days during the prior month, whereas 12-22% of patients 6 months after cardiac surgery reported such frequent sleep problems. Utilizing data from the 6 and 12 month follow-ups, test-retest reliability of the three-item scale in cardiac surgery patients was found to be 0.59. Internal consistency coefficients for the three and four-item scales were 0.63 and 0.79 respectively.

Sleep and depression

BACKGROUND

Of all the psychiatric disorders associated with insomnia, depression is the most common. It has been estimated that 90% of patients with depression complain about sleep quality. Since the first reports of short rapid eye movement (REM) latency in depressed patients and of the effect of sleep deprivation on depression in the 1970s, numerous sleep studies have provided extensive observations and theoretical hypotheses concerning the etiology and pathophysiology of depression. The aim of this review is to summarize knowledge regarding the relationships between sleep and depression.

DATA SOURCES AND SELECTION

MEDLINE and PsycINFO searches of the literature published in English or French between 1964 and 2005 that examined the relationships between sleep disturbance and depression were conducted. Search terms used were depression, depressive disorder, affective disorder, mood disorders, seasonal affective disorder, sleep, sleep disorders, insomnia, REM, polysomnography, sleep deprivation, electroencephalography, PET, SPECT, and fMRI.

DATA SYNTHESIS

Two hundred five papers were identified and selected and then integrated into the following categories: sleep architecture, antidepressive therapies, age- and gender-associated differences, functional imaging results, and sleep-related hypotheses explaining the pathophysiology of depression.

CONCLUSION

Numerous studies provide findings indicating the remarkable relationship between sleep alterations and depression. Although the existing hypotheses are not likely to explain all aspects of the sleep alterations in depression, each may be worth being maintained for refinements of pathophysiologic models of depression as new data accumulate. Further research taking into account the heterogeneity of depressive disorder and linking the different areas of research is needed to develop more comprehensive theoretical models and new therapies for depression.

Assessment and management of behavioral and psychological symptoms of dementia

Behavioral and psychological symptoms of dementia include agitation, depression, apathy, repetitive questioning, psychosis, aggression, sleep problems, wandering, and a variety of inappropriate behaviors. One or more of these symptoms will affect nearly all people with dementia over the course of their illness. These symptoms are among the most complex, stressful, and costly aspects of care, and they lead to a myriad of poor patient health outcomes, healthcare problems, and income loss for family care givers. The causes include neurobiologically related disease factors; unmet needs; care giver factors; environmental triggers; and interactions of individual, care giver, and environmental factors. The complexity of these symptoms means that there is no "one size fits all solution," and approaches tailored to the patient and the care giver are needed. Non-pharmacologic approaches should be used first line, although several exceptions are discussed. Non-pharmacologic approaches with the strongest evidence base involve family care giver interventions. Regarding pharmacologic treatments, antipsychotics have the strongest evidence base, although the risk to benefit ratio is a concern. An approach to integrating non-pharmacologic and pharmacologic treatments is described. Finally, the paradigm shift needed to fully institute tailored treatments for people and families dealing with these symptoms in the community is discussed.

Chronic behavioral disorders of human REM sleep: a new category of parasomnia

Four men, aged 67-72 years, had 4-month to 6-year histories of injuring themselves or their spouses with aggressive behaviors during sleep, often during attempted dream enactment. A 60-year-old woman had disruptive though nonviolent sleep and dream behaviors. Polysomnography did not detect seizures but did document REM sleep pathology with variable loss of chin atonia, extraordinarily increased limb-twitch activity, and increased REM ocular activity and density. A broad range of REM sleep behaviors was recorded on videotape, including stereotypical hand motions, reaching and searching gestures, punches, kicks, and verified dream movements. Stage 3-4 slow wave sleep was elevated for age in all patients. NREM sleep was devoid of harmful behaviors, although three men had periodic myoclonus. There was no associated psychiatric disorder, whereas serious neurologic disorder was closely associated in four cases: olivo-ponto-cerebellar degeneration, Guillain-Barré syndrome, subarachnoid hemorrhage, and an atypical dementia. Two patients had immediate and lasting sleep behavioral suppression induced by clonazepam, and another patient had the same response with desipramine. All instances of drug discontinuation prompted immediate relapse. In four cases there was associated dream hyperactivity, which resolved with behavioral control. These REM sleep neurobehavioral disorders constitute another category of parasomnia, replicate findings from 21 years ago in cats receiving pontine tegmental lesions, and offer additional perspectives on human behavior, neurophysiology, pharmacology, and dream phenomenology.

Delayed emergence of a parkinsonian disorder in 38% of 29 older men initially diagnosed with idiopathic rapid eye movement sleep behaviour disorder

We report longitudinal data on a group of 29 male patients 50 years of age or older who were initially diagnosed as having idiopathic REM sleep behavior disorder (RBD) after extensive polysomnographic and neurologic evaluations. Thirty-eight percent (11/29) were eventually diagnosed as having a parkinsonian disorder (presumably Parkinson's disease) at a mean interval of 3.7 +/- 1.4 (SD) years after the diagnosis of RBD+, and at a mean interval of 12.7 +/- 7.3 years after the onset of RBD. To date, only 7% (2/29) of patients have developed any other neurologic disorder. At the time of RBD diagnosis, data from the RBD group with eventual Parkinson's disease (n = 11) and the current idiopathic RBD group (n = 16) were indistinguishable, with two exceptions: the RBD-Parkinson's disease group had a significantly elevated hourly index of periodic limb movements of non-REM sleep and an elevated REM sleep percentage. RBD was fully or substantially controlled with nightly clonazepam treatment in 89% (24/27) of patients in both groups. Thus, RBD can be the heralding manifestation of Parkinson's disease in a substantial subgroup of older male RBD patients. However, a number of presumed Parkinson's disease patients may eventually be diagnosed with multiple system atrophy (striatonigral degeneration subtype). Our findings indicate the importance of serial neurologic evaluations after RBD is diagnosed and implicate the pedunculopontine nucleus as a likely site of pathology in combined RBD-Parkinson's disease, based on experimental and theoretical considerations rather than on autopsy data.

Psychometric assessment of subjective sleep quality using the Japanese version of the Pittsburgh Sleep Quality Index (PSQI-J) in psychiatric disordered and control subjects

Subjective sleep quality has been identified as an important clinical construct in psychiatric disordered patients. The Pittsburgh Sleep Quality Index (PSQI), one of the most widely used standardized measures to assess subjective sleep quality, generates a global score and scores seven components. The present study psychometrically assessed clinical profiles of subjective sleep quality in 82 control and 92 psychiatric disordered subjects (primary insomnia, n=14; major depression, n=30; generalized anxiety disorder, n=24; and schizophrenia, n=24), using the Japanese version of the Pittsburgh Sleep Quality Index (PSQI-J). The overall reliability coefficient of the PSQI-J was high (Cronbach's alpha=0.77). Correlation coefficients between the PSQI-J global and component scores were statistically significant. The PSQI-J global and component mean scores were significantly higher in psychiatric disordered subjects than control subjects, except for the component of sleep duration. Using a cut-off point of 5.5 in the PSQI-J global score, estimations of sensitivity and specificity provided 85.7 and 86.6% for primary insomnia, 80.0 and 86.6% for major depression, 83.3 and 86.6% for generalized anxiety disorder, and 83.3 and 86.6% for schizophrenia, respectively. The present study supports the utility of the PSQI-J as a reliable and valid measure for subjective sleep quality in clinical practice and research.

A brief screening questionnaire for infant sleep problems: validation and findings for an Internet sample

OBJECTIVE

To develop and validate (using subjective and objective methods) a brief infant sleep questionnaire (BISQ) that would be appropriate for screening in pediatric settings.

DESIGN

Two studies were performed to assess the properties of the BISQ. Study I compared BISQ measures with sleep diary measures and objective actigraphic sleep measures for clinical (N = 43) and control (N = 57) groups of infants (5-29 months of age). The second study was based on an Internet survey of 1028 respondents who completed the BISQ posted on an infant sleep web site.

RESULTS

In study I, BISQ measures were found to be correlated significantly with sleep measures derived from actigraphy and sleep diaries. BISQ measures (number of night wakings and nocturnal sleep duration) were the best predictors for distinguishing between clinical and control samples. High test-retest correlations (r >.82) were demonstrated for BISQ measures for a subsample of 26 infants. Study II provided a developmental perspective on BISQ measures. The study demonstrated that BISQ measures derived from a large Internet survey provided developmental and sleep ecology-related findings that corresponded to the existing literature findings on sleep patterns in early childhood.

CONCLUSIONS

The findings provide psychometric, clinical, and ecologic support for the use of the BISQ as a brief infant sleep screening tool for clinical and research purposes. Potential clinical cutoff scores are provided.