Characteristics of apneas and hypopneas during sleep and relation to excessive daytime sleepiness

STUDY OBJECTIVES: One of the most important symptoms in patients evaluated for possible obstructive sleep apnea syndrome is excessive daytime sleepiness, but the measures of apnea severity and of sleepiness used most commonly have not generally shown strong associations. We explored whether information recorded during standard polysomnography, other than the overall rate of apneas and hypopneas per hour of sleep (AHI), might help explain the measured severity of sleepiness. DESIGN: Observational SETTING: A clinical sleep laboratory in a university hospital PATIENTS: N = 1,146 patients evaluated for suspected sleep-disordered breathing with nocturnal polysomnograms and multiple sleep latency tests. RESULTS: The AHI during supine sleep (recorded in a subgroup of n = 169 subjects), the rate of apneas (n = 1,146), and the rate of obstructive apneas (n = 1,146) were particularly useful in explaining variation in measured levels sleepiness; rates of hypopneas and central apneas were less useful (n = 1,146). In addition, the minimum recorded oxygen saturation (n = 1,097) was as important as the AHI to the level of sleepiness. CONCLUSIONS: In an attempt to explain excessive daytime sleepiness among patients evaluated for sleep-disordered breathing, additional insight is provided by observation of supine sleep during polysomnography, by emphasis on apneas rather than hypopneas, by emphasis on obstructive rather than central events, and by consideration of the minimum oxygen saturation.     

The prevalence of Usher syndrome and other retinal dystrophy-hearing impairment associations

Fifty-two children without significant sleep disturbance seen at a primary care clinic for well-child care were compared on measures of temperament, parenting style, daytime behavior, and overall sleep disturbance to three diagnostic subgroups identified in a pediatric sleep clinic: children with obstructive sleep apnea (n = 33), parasomnias (night terrors, sleepwalking, etc.) (n = 16), and behavioral sleep disorders (limit-setting disorder, etc.) (n = 31). The mean age of the entire sample was 5.7 years. Temperamental emotionality in the behavioral sleep disorders group was associated with a higher level of sleep disturbance (p < .001); parenting laxness was associated with sleep disturbance in the general pediatric population (p < .01); and intense and negative temperament characteristics seemed to be associated with clinically significant behavioral sleep disturbances. Ineffective parenting styles and daytime disruptive behaviors were more likely to be associated with the milder sleep disturbances found in children in a primary care setting.     

A case of PTH related protein-producing large cell carcinoma of the lung]

The aim of this study was to determine the prevalence of symptoms suggestive of asthma in children aged 7-14 years in Ankara, Turkey. For this purpose, the recently developed ISAAC (International Study for Asthma and Allergies in Childhood) questionnaire supplemented with six additional questions was issued to parents of 3154 primary school children from 12 schools. A separate page with questions regarding risk factors was also added to the questionnaire. The response rate was 88.3%. The cumulative and 12-month prevalence of wheezing were 14.4 and 4.7% respectively. The prevalence of physician-diagnosed asthma was 8.1%. A family history of atopy was found to be the strongest risk factor for having ever had wheezing (odds ratio (OR) = 2.89, 95% confidence interval (CI) = 2.32-3.60), wheezing in the past 12 months (OR = 3.21, CI = 2.21-4.67), and severe attack (OR = 2.41, CI = 1.36-4.25). Passive smoking was a risk only for having ever had wheezing (OR = 1.33, CI = 1.03-1.76). Increasing age was associated with a lower risk of current wheezing (OR = 0.85, CI = 0.81-0.90) and severe attack (OR = 0.77, CI = 0.67-0.88). Gender, socio-economic level and pet ownership did not appear to be risk factors for asthma-related symptoms. This study, the first epidemiological survey in Ankara, Turkey, using the ISAAC protocol, clearly shows that symptoms suggestive of asthma, albeit lower than in most European countries, are quite common and constitute a major health problem in Turkey.     

Paradoxical response to valproic acid in a patient with a hypothalamic hamartoma

We investigated factors of daytime sleepiness in 22 middle-aged male patients with sleep apnea syndrome (SAS) using the Epworth sleepiness scale (ESS) and polysomnography. The subjects were classified into two groups according to ESS score as follows; low ESS group: ESS score < 10, and high ESS group; ESS score > or = 10. ESS score was significantly correlated with duration in which nocturnal oxygen saturation decreased below 90% (Time of SpO2 < 90%) (r = 0.54, p < 0.05). Time of SpO2 < 90% and percent of movement arousals at the termination of apnea/hypopnea (number of movement arousal/total number of apnea/hypopneas x 100) were significantly higher in high ESS group than in low ESS group. Our findings suggest that the severity of oxygen desaturation and sleep fragmentation caused by arousal response at the termination of apnea/hypopnea may be important factors of daytime sleepiness in patients with SAS.     

Unfair treatment is associated with poor sleep in African American and Caucasian adults: Pittsburgh SleepSCORE project.

Objective: To test the association between self-reported unfair treatment and objective and self-reported sleep characteristics in African American and Caucasian adults. Design: Cross-sectional study of 97 African American and 113 Caucasian middle-aged adults. Main Outcome Measures: Participants completed: (a) two-night in-home, polysomnography (PSG) sleep study, (b) sleep diaries and actigraph assessments across 9 days and nights, and (c) self-report measures of sleep quality in the past month, and daytime sleepiness in the past 2 weeks. Results: Greater unfair treatment was associated with reports of poorer self-reported sleep quality and greater daytime sleepiness, shorter sleep duration, and lower sleep efficiency as measured by actigraphy and PSG, and a smaller proportion of rapid eye movement (REM) sleep. Racial/ethnic differences were few. Exploratory analyses showed that nightly worry partially mediated the associations of unfair treatment with sleep quality, daytime sleepiness, sleep efficiency (actigraphy), and proportion of REM sleep. Conclusion: Perceptions of unfair treatment are associated with sleep disturbances in both African American and Caucasian adults. Future studies are needed to identify the pathways that account for the association between unfair treatment and sleep. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

How sleep and mental disorders are related to complaints of daytime sleepiness

BACKGROUND: Daytime sleepiness is widespread and has negative impacts on the public sector. OBJECTIVE: To ascertain the incidence and prevalence of daytime sleepiness and associated risk factors in the general population. METHOD: In 1994, a representative sample of the non-institutionalized British population aged 15 years or older was interviewed via telephone using an expert computer-assisted program designed to facilitate surveys of this type (Sleep-Eval, M. M. Ohayon, Montreal, Quebec). Subjects were classified into 3 groups based on the severity of their daytime sleepiness. We completed 4972 interviews (acceptance rate, 79.6%). RESULTS: Severe daytime sleepiness was reported in 5.5% (95% confidence interval, 4.9%-6.1%) of the sample, and moderate daytime sleepiness in another 15.2% (95% confidence interval, 14.2%-16.2%). Associated factors with severe daytime sleepiness included female sex, middle age, napping, insomnia symptoms, high daily caffeine consumption, breathing pauses or leg pain in sleep, depressive disorder (based on the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria), falling asleep while reading or watching television, and motor vehicle crashes or accidents involving use of machinery. Moderate daytime sleepiness was associated with female sex, napping, insomnia symptoms, arthritis or heart disease, and gross motor movements during sleep. CONCLUSIONS: It is likely that daytime sleepiness deleteriously affects work activities, social and/or marital life, and exhibits a negative socioeconomic impact. In addition, the risk of a motor vehicle crash appears to be higher in this specific population: twice as many subjects operating a motor vehicle or using machine tools reported having a crash or accident, respectively, in the previous year in the groups with severe daytime sleepiness or moderate daytime sleepiness than did the general population with no daytime sleepiness. The high prevalence rates of daytime sleepiness and multiplicity of related factors mandate further scrutiny by public health officials.     

Relationship between child sleep disturbances and maternal sleep, mood, and parenting stress: A pilot study.

Although sleep disturbances in children are common, little is known about the relationship between children's sleep disruptions and maternal sleep and daytime functioning. Forty-seven mothers completed measures of sleep, depression, parenting stress, fatigue, and sleepiness. Significant differences in maternal mood and parenting stress were found between mothers of children with and without significant sleep disturbances. Regression analyses showed that the quality of the children's sleep significantly predicted the quality of maternal sleep. In addition, maternal sleep quality was a significant predictor of maternal mood, stress, and fatigue. Results from this pilot study support the need for future research examining the relationship between child sleep disturbances and maternal daytime functioning, and they highlight the importance of screening for and treating pediatric sleep disruptions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of long-term therapy of obstructive sleep apnea syndrome with CPAP for symptoms of daytime sleepiness

The study was undertaken to investigate whether a long-term CPAP therapy improves the symptoms of daytime sleepiness in patients with the obstructive sleep apnoea syndrome. Seventy six patients (72 men and 4 women) with AHI = 53(+/- SE = 3), BMI 35 (+/- SE = 0.8), mean age 46.3 (+/- SE = 11.4) have undergone CPAP therapy for at least one year (mean: 2.48 +/- SE = 0.33). The aggravation of alterations of the daytime sleepiness was estimated using the questionnaire from Sleep Laboratory at the Marburg University and the Epworth Sleepiness Scale (ESS). After the CPAP therapy, we have observed the decrease of the symptoms of the excessive daytime sleepiness (p < 0.001). Negative correlation between CPAP compliance and ESS outcome was observed (r = 0.4; p < 0.001). There was not correlation between the term of using CPAP and the degree of the complaints decrease.     

Neuropsychological functioning and determinants of morning alertness in patients with obstructive sleep apnea syndrome

Neuropsychological functioning is reported to be impaired in patients suffering from obstructive sleep apnea syndrome (OSAS). This syndrome is characterized by nocturnal respiratory disturbances, blood oxygen desaturations, sleep fragmentation, and excessive daytime sleepiness. Opinions are divided concerning the exact relationship between the observed cognitive deficits, nocturnal hypoxia, sleep disruption, and impaired daytime alertness. In the present study, morning neuropsychological function of 26 moderate to severe middle-aged sleep apneics is compared to that of 22 primary insomniacs. There were no performance differences on a range of neuropsychological tests among the two patient groups. In addition, the data suggest that morning alertness impairment, which is closely associated with a lack of slow wave sleep (SWS) and rapid eye movement (REM) sleep, is of major importance in inducing poorer cognitive performance in patients with moderate to severe sleep apnea.     

Regional cerebral blood flow changes in chronic alcoholic patients induced by naltrexone challenge during detoxification

A follow-up study was performed with the aim to evaluate all individuals surgically treated by the uvulopalatopharyngoplasty (UPPP) or laser uvulopalatoplasty (LUPP) method from a whole county in Sweden, 1-8 years after surgery, by assessing snoring occurrence and daytime sleepiness, as experienced by the patients and their cohabitants. Questionnaires were mailed to all operated people (n = 457) and were returned by 91% (346 men, 69 women) preoperatively diagnosed as habitual snorers (n = 255), cases of obstructive sleep apnea syndrome (n = 110) and unspecified snorers (n = 48). In addition 345 bedpartners participated. For outcome of surgery, no significant differences in diagnoses or sex were found. Improvement in snoring occurrence was reported by 89.6% of the patients, confirmed by 92% of the cohabitants (r = 0.84, p < 0.01). The remaining snoring occurrence was significantly dependent on the surgical method and the time after operation. Excessive daytime sleepiness (EDS) was experienced by 73.3% of the patients compared to 67% reported by the cohabitants. Of 415 patients operated on, 18% were free from snoring and 25% were free from EDS. Individuals with a shorter time since surgery reported less snoring. The UPPP method gave a significantly better result than LUPP for the symptom 'snoring'.     

Continuous positive airway pressure requirement during the first month of treatment in patients with severe obstructive sleep apnea

OBJECTIVES: (1) To compare the continuous positive airway pressure (CPAP) requirement at the time of diagnosis (T0), after 2 weeks (T2), and after 4 weeks (T4) of CPAP treatment, in patients with severe obstructive sleep apnea (OSA); and (2) to assess whether any alteration in CPAP requirement over the first 4 weeks of CPAP treatment would influence daytime alertness, subjective sleepiness, or mood. DESIGN: A prospective, controlled, single-blind crossover study. SETTING: University teaching hospital. PATIENTS: Ten patients with newly diagnosed and previously untreated severe OSA (aged 52+/-9 years, apnea hypopnea index [AHI] of 99+/-31) and subsequently 10 control patients (aged 52+/-11 years, AHI 85+/-17). MEASUREMENTS: Overnight polysomnography with CPAP titration to determine the CPAP requirement, which was standardized for body position and sleep stage, on all three occasions (T0, T2, T4). Objective sleep quality, daytime alertness, subjective sleepiness (Epworth Sleepiness Scale), and mood (Hospital Anxiety and Depression Scale). RESULTS: CPAP requirement decreased from T0 to T2 (median difference, 1.5 cm H2O, 95% confidence interval [CI], 1.1 to 2.7 cm H2O, p=0.0004) and did not differ between T2 and T4. Use of the lower CPAP pressure during T2 to T4 was associated with a decrease in Epworth scale (mean difference, 2.6, 95% CI, 1.2 to 4; p=0.01) and anxiety (median change, 2; 95% CI, 0.5 to 2.9, p=0.03) scores, as compared with the first 2 weeks. Daytime alertness did not differ between T0 to T2 and T2 to T4. CONCLUSION: CPAP requirement falls within 2 weeks of starting CPAP treatment. A change to the lower required CPAP was not associated with any deterioration in daytime alertness but was associated with small subjective improvements in sleepiness and mood.     

Cell adhesion molecules in vasculitis

Daytime sleepiness is a common complaint in blind subjects. Abnormally timed melatonin has been invoked as a possible cause of both daytime sleepiness and nighttime awakening. In free-running blind individuals, there is an opportunity to assess the relationship between endogenous melatonin rhythms and subjective sleepiness and naps. The aim of this study was to characterize melatonin rhythms and simultaneously to evaluate subjective napping. A total of 15 subjects with no conscious light perception (NPL) were studied for 1 month. Prior to the study, sleep disorders were assessed using the Pittsburgh Sleep Quality Index. Cosinor and regression analysis revealed that 9 of the 15 NPL subjects had free-running 6-sulphatoxymelatonin (aMT6s) rhythms (period [tau] range = 24.34 to 24.79 h), 3 were entrained with an abnormal phase, and 3 were normally entrained. Most of the subjects (13 of 15) had daytime naps; the 2 individuals who did not made conscious efforts not to do so. Subjects with abnormal aMT6s rhythms had more naps of a longer duration than did those with normal rhythms. Free-running nap rhythms occurred only in subjects with free-running aMT6s rhythms. The 2 abnormally entrained subjects who napped did so at times that coincided with high levels of aMT6s (mean aMT6s acrophase [phi] +/- SD = 14.30 +/- 1.08 h, 20.30 +/- 0.62 h; mean nap time +/- SD = 14.01 +/- 3.60 h, 18.23 +/- 3.20 h, respectively). Regardless of aMT6s rhythm abnormality, significantly more naps occurred with a 4-h period before and after the estimated aMT6s acrophase. In 4 free-running subjects, aMT6s acrophase (phi) passed through an entire 24-h period. When aMT6s was in a normal phase position (24:00 to 06:00 h), night-sleep duration tended to increase with a significant reduction in the number and duration of naps. Sleep onset and offset times tended to advance and delay as the aMT6s rhythms advanced and delayed. Our results show a striking relationship between the timing of daytime production of melatonin and the timing of daytime naps. This suggests that abnormally timed endogenous melatonin may induce sleepiness in blind subjects.     

Child sleep disorders: Associations with parental sleep duration and daytime sleepiness.

This study examined the associations between childhood sleep disorders and mothers' and fathers' sleep duration and daytime sleepiness. One hundred seven families of children (ages 2-12 years) presenting to a pediatric sleep disorders clinic completed questionnaires assessing the sleep symptoms of the mother, father, and child. Parents of children with more than 1 type of sleep disorder experienced more daytime sleepiness than parents of children with a single sleep disorder. The pattern of results suggested more associations between maternal and child sleep than between paternal and child sleep. Within families, mothers reported significantly more daytime sleepiness than fathers, although there were no parental differences in sleep duration. Results provide preliminary evidence for an association between child sleep problems and parental daytime sleepiness, which may, in turn, extend previous research linking young children's sleep problems and parental functioning. Implications for treatment of both children and adults with sleep problems are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The detection of the sleep apnea syndrome in a population of professional drivers

The aim of this study was to reduce the risk of traffic accidents related to obstructive sleep apnea syndrome (OSAS) by means its detection and treatment in a group of 100 commercial drivers from Seville. Besides, to analyze which clinical findings could suggest OSAS. By means a questionnaire we selected subjects without (questionnaire score < 10 points) and with (questionnaire score > or = 10) clinical history of OSAS. In cases with score > or = 10, an overnight home polygraphy was carried out (Apnoescreen II, Jaeger), with measurement of oronasal airflow, chest and abdominal movements, oxygen saturation, electrocardiogram, body position and actimetry. We performed a manual analysis of recordings, and polygraphy was considered to be positive for OSAS if both AHI (respiratory events Index) or DI (desaturation Index) were > or = 10. In these positive cases, overnight conventional polysomnography was carried out (SleepLab, Jaeger), with therapeutic tests with CPAP if OSAS was diagnosed (AHI > or = 10). Average age and BMI (Body Mass Index) were 41.5 +/- 0.9 years and 28.2 +/- 0.4 kg/m2. Questionnaire was positive in 59 subjects, in 35 of whom home polysomnography was done. We did not find differences in age, BMI, neck circumference or symptomatology among these 35 drivers and the 24 remaining subjects in whom home polygraphy was not performed. Home polygraphy was positive in 10 subjects and negative In 25. Drivers in first group were older, heavier and complaint more frequently about snoring, sleep apnea and daytime sleepiness. We did not find differences in neck circumference, waist/hip ratio nor alcohol consumption between both groups. From the group with positive polygraphy, we performed conventional polysomnography in 8 cases and OSAS was diagnosed in 5 (in all cases, treatment with CPAP was started). This study does not provide data about prevalence, but it seems that the percentage of our drivers with OSAS could be lightly higher than the prevalence in general population. These subjects seem to be older, heavier and complaint more frequently about snoring, sleep apnea and daytime sleepiness.     

Right atrial thrombi: percutaneous mechanical thrombectomy

Daytime sleepiness is an important symptom of obstructive sleep apnoea syndrome (OSAS). The standard tests for its objective quantification use EEG recordings, and are time consuming and expensive, which makes them difficult to use for large studies. This study assesses the ability of a simple test of sustained 'wakefulness' to discriminate the excessive somnolence of severe symptomatic obstructive sleep apnoea from normality, and compares its results to the traditional EEG based Maintenance of Wakefulness Test (MWT). Ten subjects (7M 3F) with severe sleep apnoea (> 4% SaO2 dip rate median 32.7 (90% central range 9.7-65.6)) and symptoms of daytime sleepiness, (Epworth Sleepiness Score (ESS)17(10-24)) and 10 normal subjects (4M 6F, ESS 3.5(1-8)) were studied. The MWT and the behavioural test (Oxford SLEep Resistance test - OSLER test) were performed on each subject in random order on 2 separate days. The protocol for both tests was the same with 4 X 40 min sleep resistance challenges throughout the day while sound isolated in a darkened room. During the OSLER test subjects were asked to press a switch in response to a light emitting diode (LED), which was lit for 1 s in every three. Both the switch and the light were connected to a computer that stored both the number of times the light was illuminated and whether a correct response was made. The OSLER test discriminated the normal subjects from the sleep apnoea group (mean sleep latency (min) normal group 39.8, OSA group 10.5) as well as the traditional MWT (normal group 38.1 OSA group 7.3) and was much simpler to administer. This test has the advantage that sleep onset is defined objectively and automatically as a failure to respond to the light, rather than from EEG interpretation, which is inevitable partly subjective. This technique may provide a simple and robust method of objectively quantifying daytime sleepiness for large studies.     

Asthma and other atopic diseases in Australian children. Australian arm of the International Study of Asthma and Allergy in Childhood

OBJECTIVE: To determine the prevalence of asthma, eczema and allergic rhinitis in Australian schoolchildren using the protocol of the International Study of Asthma and Allergy in Childhood (ISAAC). DESIGN: Questionnaire-based survey. SETTING: Melbourne, Sydney, Adelaide (in winter-spring, 1993) and Perth (in winter-spring, 1994). SUBJECTS: All children in school years 1 and 2 (ages 6-7 years) or in year 8 (ages 13-14 years), attending a random sample of 272 schools, stratified by age and city. MAIN OUTCOME MEASURES: Parent-reported (for 6-7 year olds) or self-reported (for 13-14 year olds) symptoms of atopic disease in the previous 12 months, or ever; treatment of asthma; and country of birth. RESULTS: 10,914 questionnaires were completed for 6-7 year olds and 12,280 for 13-14 year olds (84% and 94% response rates, respectively). Prevalence of wheeze in the past 12 months was 24.6% for the 6-7 year olds and 29.4% for the 13-14 year olds, and, among 6-7 year olds, was significantly higher in boys (27.4%) than girls (21.7%). Children born in Australia were more likely to report current wheeze than those born elsewhere (6-7 year olds: odds ratio [OR], 1.82; 95% confidence interval [CI] 1.55-2.15; and 13-14 year olds: OR, 1.88; 95% CI, 1.68-2.11). Prevalences of current eczema and allergic rhinitis were 10.9% and 12.0%, respectively, for the 6-7 year olds, and 9.7% and 19.6%, respectively, for the 13-14 year olds. Asthma, eczema and rhinitis coexisted in 1.8% of 6-7 year olds and 2.8% of 13-14 year olds. CONCLUSION: This study provides evidence that asthma prevalence in Australian schoolchildren is continuing to increase and is higher among Australian-born children than among those born elsewhere. Asthma, eczema and allergic rhinitis coexist to a lesser extent than expected. These results form the basis for future Australian and international comparisons.     

Development of guidelines to designate alleles using an STR multiplex system

A random sample of 876 subjects aged 65-79 years were investigated by means of a questionnaire concerning sleep and related factors. Sleep problems were reported by 23.8% of females and 13.3% of males. Moderate or major complaints of maintaining sleep were reported by 43.5% of subjects, early morning awakening 33.4% and difficulties falling asleep 31.4%. Daytime sleepiness was more common among males, and a relationship between daytime sleepiness and perceived poor sleep was found. Daytime napping was common, but not related to poor sleep. The prevalence of regular sleeping pill users was 7.6% for females and 3.0% for males and a relationship between sleep problems, sleeping pill usage and psychiatric symptoms was established. Among the regular sleeping pill users 39.1% had possible depression (PD) and 63.0% had possible anxiety disorder (PA). Among respondents with sleep complaints 29.8% had PD and 48.7% had PA. Sleep problems were also related to impaired physical health. Various medical illnesses contributed to sleep complaints among males, and depression affected sleep the most among females.     

Association between sleep duration and intelligence scores in healthy children.

We examined the association between sleep behavior and cognitive functioning in 60 healthy children between 7 and 11 years of age under nonexperimental conditions. Intellectual abilities were assessed by the Wechsler Intelligence Scale for Children (4th edition) and sleep variables by questionnaires, actigraphy, and sleep diaries. Correlation analysis revealed a negative association between sleep duration on weekends and measures of intelligence (full-scale IQ, r = ?.29; fluid IQ, r = ?.36). The regression coefficient for sleep duration on weekends was ?6.11 (SE = 2.09), indicating an increase of 6.11 points on fluid IQ scores for each hour of shorter sleep duration. Attention measures did not correlate with cognitive or sleep variables. Daytime sleepiness as a potential moderator of the relationship between sleep duration and cognitive performance was not related to cognitive or sleep variables. We conclude that children with higher daytime cognitive efficiency (reflected by higher intelligence scores) show increased nighttime efficiency (reflected by shorter sleep duration). In the light of the neural efficiency hypothesis, the current results argue for an extension of the original theory—referring not only to daytime but also to nighttime behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of cocaine on mood and sleep in cocaine-dependent males.

The effects of cocaine use and withdrawal on mood and sleep were examined. Three cocaine-dependent men lived in an inpatient facility for approximately 4 weeks, which included an initial abstinence phase (8–10 days), a cocaine administration phase (5 days), and a 2nd abstinence phase (14–16 days). During the 2nd phase, cocaine was administered intranasally a few hours before bedtime. During the day, mood and daytime sleepiness were measured, and sleep was monitored each night. Cocaine produced typical changes in mood and blood pressure, and sleep was severely disrupted. Following Phase 2, there were no changes in mood that was indicative of an abstinence syndrome, although, initially, daytime sleepiness increased. After 2 weeks, sleep architecture remained different from age-matched controls. This study is the first to measure changes in sleep architecture polysomnographically following a period of controlled cocaine use. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sleep patterns and sleep disruptions in school-age children.

This study assessed the sleep patterns, sleep disruptions, and sleepiness of school-age children. Sleep patterns of 140 children (72 boys and 68 girls; 2nd-, 4th-, and 6th-grade students) were evaluated with activity monitors (actigraphs). In addition, the children and their parents completed complementary sleep questionnaires and daily reports. The findings reflected significant age differences, indicating that older children have more delayed sleep onset times and increased reported daytime sleepiness. Girls were found to spend more time in sleep and to have an increased percentage of motionless sleep. Fragmented sleep was found in 18% of the children. No age differences were found in any of the sleep quality measures. Scores on objective sleep measures were associated with subjective reports of sleepiness. Family stress, parental age, and parental education were related to the child's sleep–wake measures. (PsycINFO Database Record (c) 2010 APA, all rights reserved)