Psychometric evaluation of daytime sleepiness and nocturnal sleep onset scales in a representative community sample

Efficacy of a short-term psychoeducational intervention for persistent non-organic insomnia in severely mentally ill patients. A pilot study

Insomnia in psychiatric patients is frequently underestimated in clinical practice. Usually drugs are prescribed for the treatment of this disorder but non-pharmacological intervention can be successfully used. The present study aimed at evaluating the efficacy of a two-session psychoeducational intervention in improving persistent non-organic insomnia and reducing the administration of PRN therapy in severely mentally ill patients.

A pre-post study was performed on 36 psychiatric patients admitted to a residential psychiatric unit. The Nocturnal Sleep Onset Scale (NSOS) and Daytime Sleepiness Scale (DSS), the sleep onset latency, the time awake after sleep onset and the numbers of awakenings were gathered 2 weeks before the intervention (T0), immediately prior the intervention (T1), 2 weeks after the last session of the intervention (T2) and a 3-month follow-up (T3). The total number of administrations of PRN therapy from T0 toT1 and from T1 to T2 were also examined. A significant reduction was shown on the NSOS, the sleep onset latency and in the time awake after sleep onset from T1 to T2 and from T1 to T3, while no significant difference was found between T0 and T1. A significant decrease on the mean number of administrations of PRN therapy was also found between 15 days before the intervention (T0–T1) and 15 days after intervention (T1–T2). The initial results of this study seems to suggest the possible efficacy of a short-term psychoeducational intervention on improving persistent non-organic insomnia in severely mentally ill patients. Further control studies are necessary to confirm these findings.

Tracking the brain in myotonic dystrophies: A 5-year longitudinal follow-up study

Objectives

The aim of this study was to examine the natural history of brain involvement in adult-onset myotonic dystrophies type 1 and 2 (DM1, DM2).

Methods

We conducted a longitudinal observational study to examine functional and structural cerebral changes in myotonic dystrophies. We enrolled 16 adult-onset DM1 patients, 16 DM2 patients, and 17 controls. At baseline and after 5.5 ± 0.4 years participants underwent neurological, neuropsychological, and 3T-brain MRI examinations using identical study protocols that included voxel-based morphometry and diffusion tensor imaging. Data were analyzed by (i) group comparisons between patients and controls at baseline and follow-up, and (ii) group comparisons using difference maps (baseline–follow-up in each participant) to focus on disease-related effects over time.

Results

We found minor neuropsychological deficits with mild progression in DM1 more than DM2. Daytime sleepiness was restricted to DM1, whereas fatigue was present in both disease entities and stable over time. Comparing results of cross-sectional neuroimaging analyses at baseline and follow-up revealed an unchanged pattern of pronounced white matter alterations in DM1. There was mild additional gray matter reduction in DM1 at follow-up. In DM2, white matter reduction was of lesser extent, but there were some additional alterations at follow-up. Gray matter seemed unaffected in DM2. Intriguingly, longitudinal analyses using difference maps and comparing them between patients and controls did not reveal any significant differences of cerebral changes over time between patients and controls.

Conclusion

The lack of significant disease-related progression of gray and white matter involvement over a period of five years in our cohort of DM1 and DM2 patients suggests either a rather slowly progressive process or even a stable course of cerebral changes in middle-aged adult-onset patients. Being the first longitudinal neuroimaging trial in DM1 and DM2, this study provides useful additional information regarding the natural history of brain involvement.

Nocturnal rapid eye movement sleep latency for identifying patients with narcolepsy/hypocretin deficiency

IMPORTANCE

Narcolepsy, a disorder associated with HLA-DQB1*06:02 and caused by hypocretin (orexin) deficiency, is diagnosed using the Multiple Sleep Latency Test (MSLT) following nocturnal polysomnography (NPSG). In many patients, a short rapid eye movement sleep latency (REML) during the NPSG is also observed but not used diagnostically.

OBJECTIVE

To determine diagnostic accuracy and clinical utility of nocturnal REML measures in narcolepsy/hypocretin deficiency.

DESIGN, SETTING, AND PARTICIPANTS

Observational study using receiver operating characteristic curves for NPSG REML and MSLT findings (sleep studies performed between May 1976 and September 2011 at university medical centers in the United States, China, Korea, and Europe) to determine optimal diagnostic cutoffs for narcolepsy/hypocretin deficiency compared with different samples: controls, patients with other sleep disorders, patients with other hypersomnias, and patients with narcolepsy with normal hypocretin levels. Increasingly stringent comparisons were made. In a first comparison, 516 age- and sex-matched patients with narcolepsy/hypocretin deficiency were selected from 1749 patients and compared with 516 controls. In a second comparison, 749 successive patients undergoing sleep evaluation for any sleep disorders (low pretest probability for narcolepsy) were compared within groups by final diagnosis of narcolepsy/hypocretin deficiency. In the third comparison, 254 patients with a high pretest probability of having narcolepsy were compared within group by their final diagnosis. Finally, 118 patients with narcolepsy/hypocretin deficiency were compared with 118 age- and sex-matched patients with a diagnosis of narcolepsy but with normal hypocretin levels.

MAIN OUTCOME AND MEASURES

Sensitivity and specificity of NPSG REML and MSLT as diagnostic tests for narcolepsy/hypocretin deficiency. This diagnosis was defined as narcolepsy associated with cataplexy plus HLA-DQB1*06:02 positivity (no cerebrospinal fluid hypocretin-1 results available) or narcolepsy with documented low (≤ 110 pg/mL) cerebrospinal fluid hypocretin-1 level.

RESULTS

Short REML (≤15 minutes) during NPSG was highly specific (99.2% [95% CI, 98.5%-100.0%] of 516 and 99.6% [95% CI, 99.1%-100.0%] of 735) but not sensitive (50.6% [95% CI, 46.3%-54.9%] of 516 and 35.7% [95% CI, 10.6%-60.8%] of 14) for patients with narcolepsy/hypocretin deficiency vs population-based controls or all patients with sleep disorders undergoing a nocturnal sleep study (area under the curve, 0.799 [95% CI, 0.771-0.826] and 0.704 [95% CI, 0.524-0.907], respectively). In patients with central hypersomnia and thus a high pretest probability for narcolepsy, short REML remained highly specific (95.4% [95% CI, 90.4%-98.3%] of 132) and similarly sensitive (57.4% [95% CI, 48.1%-66.3%] of 122) for narcolepsy/hypocretin deficiency (area under the curve, 0.765 [95% CI, 0.707-0.831]). Positive predictive value in this high pretest probability sample was 92.1% (95% CI, 83.6%-97.0%).

CONCLUSIONS AND RELEVANCE

Among patients being evaluated for possible narcolepsy, short REML (≤15 minutes) at NPSG had high specificity and positive predictive value and may be considered diagnostic without the use of an MSLT; absence of short REML, however, requires a subsequent MSLT.

The brain in myotonic dystrophy 1 and 2: evidence for a predominant white matter disease

Myotonic dystrophy types 1 and 2 are progressive multisystemic disorders with potential brain involvement. We compared 22 myotonic dystrophy type 1 and 22 myotonic dystrophy type 2 clinically and neuropsychologically well-characterized patients and a corresponding healthy control group using structural brain magnetic resonance imaging at 3 T (T₁/T₂/diffusion-weighted). Voxel-based morphometry and diffusion tensor imaging with tract-based spatial statistics were applied for voxel-wise analysis of cerebral grey and white matter affection (P_corrected < 0.05). We further examined the association of structural brain changes with clinical and neuropsychological data. White matter lesions rated visually were more prevalent and severe in myotonic dystrophy type 1 compared with controls, with frontal white matter most prominently affected in both disorders, and temporal lesions restricted to myotonic dystrophy type 1. Voxel-based morphometry analyses demonstrated extensive white matter involvement in all cerebral lobes, brainstem and corpus callosum in myotonic dystrophy types 1 and 2, while grey matter decrease (cortical areas, thalamus, putamen) was restricted to myotonic dystrophy type 1. Accordingly, we found more prominent white matter affection in myotonic dystrophy type 1 than myotonic dystrophy type 2 by diffusion tensor imaging. Association fibres throughout the whole brain, limbic system fibre tracts, the callosal body and projection fibres (e.g. internal/external capsules) were affected in myotonic dystrophy types 1 and 2. Central motor pathways were exclusively impaired in myotonic dystrophy type 1. We found mild executive and attentional deficits in our patients when neuropsychological tests were corrected for manual motor dysfunctioning. Regression analyses revealed associations of white matter affection with several clinical parameters in both disease entities, but not with neuropsychological performance. We showed that depressed mood and fatigue were more prominent in patients with myotonic dystrophy type 1 with less white matter affection (early disease stages), contrary to patients with myotonic dystrophy type 2. Thus, depression in myotonic dystrophies might be a reactive adjustment disorder rather than a direct consequence of structural brain damage. Associations of white matter affection with age/disease duration as well as patterns of cerebral water diffusion parameters pointed towards an ongoing process of myelin destruction and/or axonal loss in our cross-sectional study design. Our data suggest that both myotonic dystrophy types 1 and 2 are serious white matter diseases with prominent callosal body and limbic system affection. White matter changes dominated the extent of grey matter changes, which might argue against Wallerian degeneration as the major cause of white matter affection in myotonic dystrophies.

Sleep loss and partner violence victimization

Intimate partner violence victimization has been associated with serious health problems among women, including many disorders that involve sleep disturbances. However, there has been only limited examination of sleep duration among women with victimization experiences. A total of 756 women with a domestic violence order (DVO) against a male intimate partner were interviewed about their health, mental health, substance use, and partner violence victimization. Face-to-face interviews were conducted from February 2001 to November 2003 for data collection in three rural and one urban county representing different jurisdictional settings. Because the current analyses focused on understanding intimate partner victimization in the past year and associations with sleep disturbance, 147 participants were excluded for reporting a relationship with the DVO partner for less than 6 months in the past year. The final sample for this article was 609. The women reported an average of a little above 5.5 hours of sleep per night. For women in the current study, significant predictors of sleep disturbance included race, number of children, number of other symptoms of depression in the past 2 weeks excluding sleep criteria, number of other symptoms of PTSD in the past 2 weeks excluding sleep criteria, number of chronic physical health problems, and severity of physical violence by the DVO partner in the past year. Addressing short sleep duration among partner victims in health care settings might enhance safety planning and prevent the development of health/mental health problems that can arise from victimization.

Sleep problems in the child with attention-deficit hyperactivity disorder: defining aetiology and appropriate treatments

An estimated 25-50% of children and adolescents with attention-deficit hyperactivity disorder (ADHD) experience problems with sleep. The most common sleep problems reported in children with ADHD include delayed sleep onset, sleep or bedtime resistance, prolonged tiredness upon waking and daytime sleepiness. Higher incidences of sleep disorders such as restless legs syndrome, periodic limb movement disorder and sleep-disordered breathing have been reported in paediatric ADHD populations compared with control populations. In some cases, medications for ADHD and/or co-morbid disorders may also contribute to sleep disturbances. Assessment tools, such as parent-child questionnaires and sleep diaries, can help clinicians evaluate sleep disturbances. Sleep problems may potentially exacerbate ADHD symptoms, and interventions targeted at ensuring adequate sleep (including behavioural, dietary, specific pharmacological agents for treatment-induced insomnia, and melatonin) could in turn potentially attenuate symptoms associated with ADHD, such as irritability. Whether metabolic or neurological pathways common to both sleep and ADHD may be disrupted, and whether targeting treatments to these pathways may simultaneously improve both ADHD and sleep symptoms, needs further elucidation.

The 10-year risk of verified motor vehicle crashes in relation to physiologic sleepiness

STUDY OBJECTIVES

The purpose of this study was to determine the risk of DMV documented crashes as a function of physiological sleepiness in a population-based sample.

DESIGN

24-hour laboratory assessment (nocturnal polysomnogram and daytime MSLT) and 10-year crash rate based on DMV obtained accident records.

PARTICIPANTS

618 individuals (mean age = 41.6 +/- 12.8; 48.5% male) were recruited from the general population of southeastern Michigan using random-digit dialing techniques.

RESULTS

Subjects were divided into 3 groups based on their average MSLT latency (in minutes) as follows: excessively sleepy, 0.0 to < or = 5.0 (n = 69); moderately sleepy, 5.0 to < or = 10.0 (n = 204); and alert, > 10 (n = 345). Main outcome measures were DMV data on accidents from 1995-2005. Rates for all accidents in the 3 MSLT groups were: excessively sleepy = 59.4%, moderately sleepy = 52.5%, alert = 47.3%. Excessively sleepy subjects were at significantly greater risk of an accident over the 10-year period compared to alert subjects. A similar relation was observed when we limited the database to those accident victims with severe injury (excessively sleepy = 4.3%, moderately sleepy = 0.5%, alert = 0.6%; P = 0.028). When the victim was the only occupant of the car, subjects in the lowest MSLT group (highest sleepiness) had the greatest crash rate compared with alert individuals (excessively sleepy = 52.2%, moderately sleepy = 42.2%, alert = 37.4%; P = 0.022).

INTERVENTIONS

N/A.

CONCLUSIONS

These data demonstrate that the MSLT, a physiological measure of sleepiness, is predictive of an increased risk of DMV documented automotive crashes in the general population.

Measurements of sleepiness and fatigue

Sleepiness and fatigue are terms commonly used in clinical practice and research. At times sleepiness and fatigue are used interchangeably; however, each of them has distinct implications for diagnosis and treatment. The objective of this article is to review the psychometric properties of the measurements of sleepiness and fatigue. Although there are objective and subject measures to evaluate sleepiness, only rating scales are available to assess fatigue. Further research should be directed toward exploring the potential mechanisms underlying the measurements of sleepiness and fatigue. Establishing objective assessing instruments to evaluate fatigue and clarifying the relationship between objective and subjective assessments of sleepiness are crucially needed.

Antidepressant drugs for narcolepsy

BACKGROUND

Narcolepsy is a disorder of the central nervous system, the main symptoms of which are excessive daytime sleepiness (EDS) and cataplexy (an abrupt and reversible decrease in or loss of muscle tone, affecting the limbs or trunk or both, elicited by emotional stimuli). Narcolepsy has an adverse impact on people's quality of life. Together with stimulant drugs (used to control EDS), antidepressants are usually recommended to counteract cataplexy. In addition, some antidepressants are also reported to improve EDS.

OBJECTIVES

To evaluate the effects of antidepressant drugs on EDS, cataplexy, quality of life, and their side effects in people with narcolepsy.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 2, 2007), MEDLINE (1966 to 2007), EMBASE (1980 to 2007), PsycINFO (1872 to 2007), and CINAHL (1981 to 2007). Bibliographies of identified articles were reviewed to find additional references. Unpublished randomised trials were searched for by consulting governmental and non-governmental clinical trial registers, disease-specific websites, investigators and experts in the field, pharmaceutical companies/manufacturers.

SELECTION CRITERIA

Parallel or cross-over randomised or quasi-randomised controlled trials testing the treatment of narcolepsy with any type of antidepressant drug versus no treatment, placebo, or another antidepressant drug.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data.

MAIN RESULTS

Three cross-over and two parallel trials were included with a total of 246 participants. The methodological quality of all studies was unclear. As the trials tested different comparisons, or had a different design or dealt with different outcome measures, meta-analysis was not performed. In one cross-over trial (10 participants) femoxetine had no significant effect in eliminating or reducing EDS but significantly reduced cataplexy. Mild and transient side effects were reported in the femoxetine treatment period by two participants. In a second cross-over trial (56 participants) viloxazine significantly reduced EDS and cataplexy. In a third cross-over trial the authors inappropriately treated the trial design as a parallel study and no conclusions can be reached in favour of either drug. Two more trials with parallel design tested ritanserin versus placebo without finding differences of effectiveness in reducing EDS or cataplexy.

AUTHORS' CONCLUSIONS

There was no good quality evidence that antidepressants are effective for narcolepsy or improve quality of life. Despite the clinical consensus recommending antidepressants for cataplexy there is scarce evidence that antidepressants have a positive effect on this symptom. There is a clear need for well-designed randomised controlled trials to assess the effect of antidepressants on narcolepsy.

Sonolência excessiva diurna na população geral de um município brasileiro

OBJETIVO: Buscou-se avaliar a prevalência da sonolência excessiva diurna (SED) na população geral de um município brasileiro. MÉTODO: Foram feitas 198 entrevistas domiciliares entre os adultos, em amostra representativa da população geral de Ribeirão do Largo, BA. A amostragem foi aleatória simples. Tinham SED as pessoas com 11 ou mais pontos na Escala de Sonolência de Epworth (ESE). Usaram-se os testes de qui-quadrado, Fisher e ANOVA; nível de significância 5%. RESULTADOS: Tinham SED 21,5% da população (DP = 2,9%; IC 15,8% a 27,2%); não houve associação significativa entre SED e idade (p = 0,924), nem IMC (p = 0,197), sexo (p = 0,095), instrução (p = 0,700), estado civil (p = 0,414) e uso de hipnóticos (p = 0,176). Houve associação com o despertar precoce (p = 0,046). CONCLUSÃO: Foi alta a prevalência de SED na população estudada.

Antidepressant drugs for narcolepsy

BACKGROUND

Narcolepsy is a disorder of the central nervous system, the main symptoms of which are excessive daytime sleepiness (EDS) and cataplexy (an abrupt and reversible decrease in or loss of muscle tone, affecting the limbs and/or trunk, elicited by emotional stimuli). Narcolepsy has an adverse impact on people's quality of life. Together with stimulant drugs (used to control EDS), antidepressants are usually recommended to counteract cataplexy. In addition, some antidepressants are also reported to improve EDS.

OBJECTIVES

To evaluate the effects of antidepressant drugs on EDS, cataplexy, quality of life, and their side effects in people with narcolepsy.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 3, 2003), MEDLINE (1966 to 2003), EMBASE (1980 to 2003), PsycINFO (1872 to 2003), and CINAHL (1981 to 2003). Bibliographies of identified articles were reviewed to find additional references. Unpublished randomised trials were searched for by consulting governmental and non-governmental clinical trial registers, disease-specific websites, investigators and experts in the field, pharmaceutical companies/manufacturers.

SELECTION CRITERIA

Parallel or cross-over randomised or quasi-randomised controlled trials testing the treatment of narcolepsy with any type of antidepressant drug versus no treatment, placebo, or another antidepressant drug.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected trials for inclusion and extracted data. Outcomes were: (a) elimination of EDS; (b) mean reduction of EDS; (c) elimination of cataplexy; (d) 50% or greater reduction in cataplexy frequency; (e) mean reduction of cataplexy; (f) mean improvement in quality of life; (g) adverse events; (h) withdrawal from treatment.

MAIN RESULTS

Two cross-over trials were included. The methodological quality of both studies was unclear and so the influence of common biases was impossible to define. As the trials tested two different comparisons (one femoxetine versus placebo, the other fluvoxamine versus clomipramine) meta-analysis was not performed. In the first trial (10 participants) femoxetine had no significant effect in eliminating or reducing EDS; a significant reduction of cataplexy was in favour of femoxetine. Mild and transient side effects were reported in the femoxetine treatment period by two participants. In the second trial the authors inappropriately treated the trial design as a parallel study and no conclusions can be reached in favour of either drug.

AUTHORS' CONCLUSIONS

There was no good quality evidence that antidepressants are effective for narcolepsy or improve quality of life. Despite the clinical consensus recommending antidepressants for cataplexy there is scarce evidence that antidepressants have a positive effect on this symptom. There is a clear need for well-designed randomised controlled trials to assess the effect of antidepressants on narcolepsy.

A systematic review of patient-reported outcome instruments measuring sleep dysfunction in adults

Sleep dysfunction can manifest in several ways, ranging from insomnia to somnolence, and from disrupted sleep to lack of restful sleep. Measuring sleep dysfunction is an area of active research and there exist a number of patient-reported outcome instruments that measure various aspects of sleep dysfunction. However, these instruments have not been evaluated systematically. We used a conceptual model of sleep that included four physical domains of general interest to patients and investigators, and cover the breadth of this disorder: sleep initiation; sleep maintenance; sleep adequacy; and somnolence. We next considered the additional health-related quality-of-life (HR-QOL) domains of psychological and social functioning, progressing along the continuum to include health perceptions and opportunity. We then conducted a literature review to identify instruments and, using criteria developed by the Medical Outcomes Trust Scientific Advisory Committee, evaluated these instruments for their potential use in measuring sleep dysfunction. Twenty-two instruments were identified. Six instruments were found to include the four physical domains defined a priori (Basic Nordic Sleep Questionnaire, Leeds Sleep Evaluation Questionnaire, Medical Outcomes Study - Sleep Problems Measures, Pittsburgh Sleep Diary, Pittsburgh Sleep Quality Index, Self-Rated Sleep Questionnaire and the Sleep Dissatisfaction Questionnaire). Several additional instruments addressed at least some of the domains and thus may be useful for specific purposes. A few instruments addressed overall HR-QOL, but did not include all four domains of interest (Functional Outcomes of Sleep Questionnaire, Quality of Life in Insomniacs and the Sleep-Wake Activity Inventory). Two instruments had undergone extensive psychometric evaluation (Medical Outcomes Study - Sleep Problems Measures and Pittsburgh Sleep Quality Index), with only the latter reporting information about interpretability. Our review indicates that measuring sleep dysfunction in adults is an area of active research and that much work still needs to be completed, specifically the study of interpretability and the application of patient preferences or item response theory. The specific research focus should dictate instrument selection.

Association of daytime sleepiness and the morningness/eveningness dimension in young adult subjects in Brazil

Sleepiness is a major public health problem associated with motor vehicle crashes, occupational accidents, decreased productivity, and interpersonal problems. It can be influenced by many factors, including the individual's circadian rhythm. The objective of this study is to assess the correlation between the morningness/eveningness dimension and daytime sleepiness in medical school students. This is a cross-sectional study; 310 subjects (123 women and 187 men, M age 20.5 +/- 1.9 yr.) completed a questionnaire on use of drugs, diagnostic diseases, sleeping habits, the Morningness/Eveningness Questionnaire and the Epworth Sleepiness Scale. The only variable related to daytime sleepiness was the morningness/eveningness dimension (r = -.18, p=.002). Questions with higher coefficients of discrimination between the morning and the evening chronotype were "Lying down to rest in the afternoon when circumstances permit" (.61), "Sitting and reading" (.53), and "As a passenger in a car for an hour without a break" (.53). The implications of the findings are discussed.

Excessive daytime sleepiness in Campo Grande general population, Brazil

The prevalence of excessive daytime sleepiness (EDS) in general population was determined by means of 408 home interviews of adults, in a representative sample of Campo Grande city, Brazil. The random sample was stratified by sex, age and economic social status. EDS was considered in those with indexes 11 or more in the Epworth Sleepiness Scale. Statistics used chi-square, Fisher and Pearson tests; and inferences based on binomial distribution parameters; the significance level was 5% and confidence interval (CI) was 95%. The prevalence of EDS was 18.9% of the general population ( SD=1.9%; CI 15.1% to 22.7%). No significant association was found between EDS and the use of hypnotics, nor with insomnia, body mass index, sex, age, years of schooling, economic social status, marital status, occupation and the use of alternative means to improve sleep. When the sample was separated according to sex, only the male group showed significant association between EDS and actual insomnia (p=0.005).

Daytime sleepiness and its evaluation

Basic models of sleepiness, focusing on the homeostatic and circadian components of sleepiness, are able to predict important fluctuations of sleepiness. However, they fail in explaining certain sleepiness phenomena, as for instance in insomnia patients. To meet this shortcoming, modern models incorporate the arousal component of sleepiness, in addition to the sleep drive. While these models mainly concentrate on short-term changes in sleepiness, "state" sleepiness, there are indications that a stable characteristic level of sleepiness, "trait" sleepiness, is also an important determinant of a person's level of sleepiness. This leads to a conceptualization of sleepiness in which situational factors modify a basal level of sleep drive and arousal. It implies that sleepiness is not a unitary concept and can reflect essentially different states. Multiple sleepiness assessment tools have been proposed in the past. The majority of them offer valuable information, but they do not grasp all aspects of sleepiness. We should bear in mind that tools for assessing sleepiness are always operationalizations reflecting the theoretical framework the investigator has on sleepiness. Hence, rather than searching for a gold standard for the measurement of sleepiness, future research effort should be aimed at linking the various measurement techniques with the hypothesized underlying components of sleepiness on a sound empirical basis.

Sleepiness: evaluating and quantifying methods

The aim of this literature review is to analyze the methods mainly used for evaluating and quantifying the complex phenomenon of sleepiness. The most common distinction is between subjective measures or self-evaluations, performance decrement measures, measures for evaluating sleep propensity and measures of arousal decrease. Techniques mainly used in specialized literature will be briefly presented and commented upon, evaluating their sensitivity, advantages and limitations. We conclude that: (a) different measures inevitably are differently sensitive to sleepiness fluctuations; (b) the amount of prior sleep is strongly relevant in quantifying sleepiness levels; (c) subjective and behavioral measures show a higher level of vulnerability to external and motivational factors.

Sleepiness/alertness among healthy evening and morning type individuals

Objective: The aim of this study was to determine the level of sleepiness/alertness among different chronotypes.Background: The Horne-Ostberg Morningness-Eveningness Questionnaire (MEQ) has allowed the characterization of chronotypes that are associated with a number of biological factors including: body temperature, cortisol rhythm, sleep patterns, and architecture.Methods: Fifty-six consecutive normal volunteers underwent an 8-h polysomnogram followed by a multiple sleep latency test (MSLT). Each subject also completed the MEQ and the Sleep/Wake Activity Inventory.Results: Evening types (ET) reported significantly later bedtimes and risetimes than both morning types (MT) and neither types (NT, P<0.05). On nocturnal polysomnography, the ET documented significantly longer latencies to stage 1 and persistent sleep when compared to both the NT and MT (P<0.01). There were no significant differences in the level of sleepiness on the MSLT across the different chronotypes. However, the pattern of sleepiness differed among them. While ET and NT showed differential sleep latencies across nap opportunities, MT showed no evidence of circadian variation on their level of sleepiness.Conclusions: There were no overall differences in daytime sleepiness/alertness across chronotypes. However, a differential pattern of sleep latencies was noted on the MSLT.

Self-reported levels of sleepiness among subjects with insomnia

Objectives: To determine the prevalence of sleepiness in a cohort of insomnia subjects. We evaluated if differential levels of subjective sleepiness predict systematic differences in the polysomnographic characteristics of these subjects.Background: Insomnia is prevalent among the adult population. While it has been speculated that sleepiness may be an important daytime consequence of insomnia, this has not been demonstrated.Methods: Sixty-two subjects with complaints of insomnia for at least 6 months were polysomnographically evaluated. Subjects were asked to self-report their level of sleepiness based on their experiences for the previous 7 days. Subjects were divided into three groups based on their level of sleepiness. Sleepiness was determined using the excessive daytime sleepiness scale of the Sleep/Wake Activity Inventory (SWAI-EDS).Results: Twenty-two percent of insomnia subjects were found to be sleepy on the EDS scale of the SWAI. The level of sleepiness was also found to predict difficulty initiating sleep both on the nocturnal scale of the SWAI, and on nocturnal polysomnography.Conclusions: This study established a base rate of sleepiness among a cohort of insomnia subjects. It also demonstrated a wide spectrum of sleepiness/alertness among subjects with insomnia. Differential levels of sleepiness were found to predict nocturnal sleep latencies.