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NAPS 2012-03-20

Posted by admin on March 20, 2012

  New Articles and Papers in Sleep for Mar 20 2012.

  Contents:
      Books / Reviews
      Physiology / Pharmacology
      Development / Aging / Evolution
      Dreaming / Behavior
      Biological Rhythms
      Sleep Deprivation
      Sleep Apnea / COPD / Snoring
      Other Disorders
      Methodology / Miscellaneous

Books / Reviews
Baumann CR (2012), "Traumatic Brain Injury and Disturbed Sleep and Wakefulness.", Neuromolecular Med., Mar, 2012.
Abstract: Traumatic brain injury is a frequent condition worldwide, and sleep-wake disturbances often complicate the course after the injuring event. Current evidence suggests that the most common sleep-wake disturbances following traumatic brain injury include excessive daytime sleepiness and posttraumatic hypersomnia, that is, increased sleep need per 24 h. The neuromolecular basis of posttraumatic sleep pressure enhancement is not entirely clear. First neuropathological and clinical studies suggest that impaired hypocretin (orexin) signalling might contribute to sleepiness, but direct or indirect traumatic injury also to other sleep-wake modulating systems in the brainstem and the mesencephalon is likely. Posttraumatic insomnia may be less common than posttraumatic sleepiness, but studies on its frequency revealed conflicting results. Furthermore, insomnia is often associated with psychiatric comorbidities, and some patients with posttraumatic disruption of their circadian rhythm may be misdiagnosed as insomnia patients. The pathophysiology of posttraumatic circadian sleep disorders remains elusive; however, there is some evidence that reduced evening melatonin production due to traumatic brain damage may cause disruption of circadian regulation of sleep and wakefulness.
Chen W, Xu Z-M, Wang G and Chen S-D (2012), "Non-motor symptoms of Parkinson's disease in China: A review of the literature.", Parkinsonism Relat Disord., Mar, 2012.
Abstract: Parkinson's disease (PD) is generally considered as a neurodegenerative disorder commonly characterized by bradykinesia, resting tremor, rigidity and postural instability. However, increasing evidence demonstrates that serial non-motor symptoms (NMSs), including sensory symptoms, dysautonomia, neurobehavioral disorders and sleep disturbances frequently occur prior to motor signs and invariably emerge with the disease progression. Compared with motor symptoms, the NMSs are frequently under-recognized and poorly managed in clinical practice. A growing number of clinical studies on NMSs of PD have been carried out in China over the past decade. They revealed that there were not only common features, but also some differences on NMSs between Chinese patients and those in the West. Meanwhile, pharmacological and non-pharmacological strategies are available for the treatment of some NMSs associated with PD in China contained in Chinese guidelines for the treatment of PD. Large cohort studies across the country are warranted in the future to explore the epidemiological and biological features of specific NMSs in Chinese PD patients.
Close J (2012), "Are stress responses to geomagnetic storms mediated by the cryptochrome compass system?", Proc Biol Sci., Mar, 2012.
Abstract: A controversial body of literature demonstrates associations of geomagnetic storms (GMS) with numerous cardiovascular, psychiatric and behavioural outcomes. Various melatonin hypotheses of GMS have suggested that temporal variation in the geomagnetic field (GMF) may be acting as an additional zeitgeber (a temporal synchronizer) for circadian rhythms, with GMS somehow interfering with the hypothesized system. The cryptochrome genes are known primarily as key components of the circadian pacemaker, ultimately involved in controlling the expression of the hormone melatonin. Cryptochrome is identified as a clear candidate for mediating the effect of GMS on humans, demonstrating the prior existence of several crucial pieces of evidence. A distinct scientific literature demonstrates the widespread use of geomagnetic information for navigation across a range of taxa. One mechanism of magnetoreception is thought to involve a light-dependent retinal molecular system mediated by cryptochrome, acting in a distinct functionality to its established role as a circadian oscillator. There is evidence suggesting that such a magnetosense-or at least the vestiges of it-may exist in humans. This paper argues that cryptochrome is not acting as secondary geomagnetic zeitgeber to influence melatonin synthesis. Instead, it is hypothesized that the cryptochrome compass system is mediating stress responses more broadly across the hypothalamic-pituitary-adrenal (HPA) axis (including alterations to circadian behaviour) in response to changes in the GMF. Two conceptual models are outlined for the existence of such responses-the first as a generalized migrational/dispersal strategy, the second as a stress response to unexpected signals to the magnetosense. It is therefore proposed that GMS lead to disorientation of hormonal systems in animals and humans, thus explaining the effects of GMS on human health and behaviour.
Del Felice A, Formaggio E, Storti SF, Fiaschi A and Manganotti P (2012), "The gating role of the thalamus to protect sleep: An f-MRI report.", Sleep Med., Mar, 2012.
Fedson AC, Pack AI and Gislason T (2012), "Frequently used sleep questionnaires in epidemiological and genetic research for obstructive sleep apnea: A review.", Sleep Med Rev., Mar, 2012.
Abstract: BACKGROUND & AIMS: Many sleep questionnaires are utilized by the epidemiological and genetic research communities. This paper reviewed sleep-related questions and answers commonly used in epidemiological studies (focused on sleep apnea and snoring), with an emphasis on the utility of the response options. METHODS: A literature search was conducted to identify relevant sleep questionnaires. Questionnaires were limited to the English language and had to include questions specific to snoring or stop breathing during sleep. Questionnaires had to demonstrate a citation count >10 through Web of Science. A comparison of questions and answers, and elements important in the design of good quality instruments was conducted. RESULTS: Fourteen questionnaires met the inclusion criteria for final review. Validation was conducted for many of these instruments, though the methods and validation populations were highly variable. Study sample sizes were also relatively small and differed in methods of data analysis. These questionnaires were very heterogeneous, with only some (n = 6) allowing a "don't know" alternative. Six specified the time period referred to as "past month", one referred to "last three months" and the remaining questionnaires had no specific timeframe. The response alternatives to specific questions were Yes/No (n = 5), wording only like "never", "seldom", "often" (n = 4), or a frequency scale indicating times per week (n = 8). CONCLUSIONS: There is a need for improved standardized instruments not only to capture relevant sleep information but also to allow greater comparability between studies.
Greenblatt DJ and Roth T (2012), "Zolpidem for insomnia.", Expert Opin Pharmacother., Apr, 2012. Vol. 13(6), pp. 879-893.
Abstract: Introduction : The imidazopyridine derivative zolpidem , which acts as a benzodiazepine (BZ) receptor agonist, is the most widely prescribed hypnotic drug in the US. Areas covered : This review addresses the neuroreceptor properties of zolpidem; clinical pharmacokinetics, pharmacodynamics and drug interactions; efficacy as a hypnotic; adverse effects; tolerance, dependence and withdrawal; relation to motor vehicle accidents and complex sleep behaviors; and new dosage forms. Expert opinion : Approved doses of zolpidem (10 mg for adults, 5 mg for the elderly) are consistently effective in reducing sleep latency and consequently increasing sleep duration in patients with insomnia. However, favorable effects on sleep maintenance are observed less consistently. Residual daytime effects are unlikely with recommended doses, and provided that at least 8 h elapse prior to arising. Hypnotic efficacy is maintained with repeated nightly use, and the risk of rebound insomnia is low. Dependence and abuse of zolpidem are no more likely to occur than with typical benzodiazepines. Newly available novel dosage forms of zolpidem have increased therapeutic options for patients with insomnia variants such as sleep maintenance insomnia and middle-of-the-night awakening.
Jaffe LM, Kjekshus J and Gottlieb SS (2012), "Importance and management of chronic sleep apnoea in cardiology.", Eur Heart J., Mar, 2012.
Abstract: Sleep apnoea is a common, yet underestimated, chronic disorder with a major impact on morbidity and mortality in the general population. It is quickly becoming recognized as an independent risk factor for cardiovascular impairment. Hypertension, coronary artery disease, diabetes, cardiovascular rhythm and conduction abnormalities, cerebrovascular disease, and heart failure have all been linked to this syndrome. This review will explore the critical connection between sleep apnoea and chronic cardiovascular diseases while highlighting established and emerging diagnostic and treatment strategies.
Klingenberg L, Sjödin A, Holmbäck U, Astrup A and Chaput J-P (2012), "Short sleep duration and its association with energy metabolism.", Obes Rev., Mar, 2012.
Abstract: A growing body of observational evidence suggests that short sleep duration is a risk factor for the development of obesity. Although increased energy intake is the most prevailing causal explanation for this association, we should also consider possible effects on energy metabolism to understand fully the potential impact of short sleep duration on the regulation of energy balance. We performed a search of the literature from 1970 to 2011, including original papers, investigating the relation between short sleep and energy metabolism in animals and humans. Although the limited number of experimental studies in humans precludes any definitive conclusions about causality, short sleep duration does not seem to substantially affect total daily energy expenditure, nor is there sufficient evidence in support of any meaningful effect of restricted sleep on the specific components of energy metabolism (i.e. resting metabolic rate, intentional as well as unintentional physical activity, diet-induced thermogenesis, and substrate utilization). As studies on rats suggest that other factors that can potentially influence energy metabolism could be affected (i.e. hormonal systems and thermoregulation), we included these factors in our literature search and found some indications in support of an up-regulation of thyroid hormones and glucocorticoids as well as increased heat dissipation following total or severe sleep deficit. Although we found some evidence also in humans that suggests a possible effect on energy metabolism, the limitations of the studies make it difficult to draw conclusions on the effect of short sleep on energy metabolism under relevant free living conditions. To explore this area further, more studies using suitable methodology under relevant conditions to mimic real-life situations are needed.
Lin CM, Huang YS and Guilleminault C (2012), "Pharmacotherapy of obstructive sleep apnea.", Expert Opin Pharmacother., Apr, 2012. Vol. 13(6), pp. 841-857.
Abstract: Introduction: Obstructive sleep apnea syndrome is a common public health problem in the general population. The important health-related consequences of obstructive sleep apnea include cardiovascular disorders, such as myocardial infarction and hypertension, stroke, sudden death and difficult blood sugar control related to diabetes mellitus. The current main treatment options include body weight loss, continuous positive airway pressure, oral appliances and surgical treatment. The effects of pharmacotherapy on sleep apnea continue to be controversial and supplemental only. Current medications for sleep apnea mainly act through reducing risk factors, treating predisposing endocrine disorders, improving residual sleepiness post management and controlling associated hypertension and metabolic disorders. Areas covered: This article discusses the pharmacotherapy of sleep apnea, including ventilatory stimulants, serotoninergic and REM sleep suppressant agents, acetylcholinesterase inhibitors, medications for predisposing endocrine disorders, stimulants, associated sleep apnea health problems and sleep apnea patient anesthetic precaution. Weight loss is not a direct pharmacological approach and is only briefly mentioned. Expert opinion: At present, there is no appropriate pharmacological treatment for obstructive sleep apnea. There are adjunct treatments such as anti-allergy treatment, and, if residual sleepiness is present, nonamphetaminic stimulants can help. Usage of these stimulants will, however, produce negative effects in an anticipated rate of about 10% of subjects taking these medications.
Musso G, Olivetti C, Cassader M and Gambino R (2012), "Obstructive sleep apnea-hypopnea syndrome and nonalcoholic Fatty liver disease: emerging evidence and mechanisms.", Semin Liver Dis., Feb, 2012. Vol. 32(1), pp. 49-64.
Abstract: Obstructive sleep apnea syndrome (OSAS) and nonalcoholic fatty liver disease (NAFLD) are common conditions, frequently encountered in patients with metabolic disorders. OSAS has been associated with an increased risk of cardiovascular and metabolic complications. It has been recently suggested that the chronic intermittent hypoxia of OSAS may also affect the presence and severity of NAFLD. We will critically review experimental and human evidence connecting OSAS to NAFLD pathogenesis, trying to dissect the effect of intermittent hypoxia from that of obesity and associated comorbidities, and examine molecular mechanisms connecting OSAS to liver and metabolic disease in NAFLD, including hypoxia inducible factor (HIF), nuclear factor-kappa B, unfolded protein response, hypoxic adipose tissue inflammation, and their therapeutic potential for NAFLD and its complications, including cirrhosis and hepatocellular carcinoma. Finally, we will provide suggestions for the management of NAFLD patients with suspected OSAS and recommendations for future research.
Penev PD (2012), "Update on Energy Homeostasis and Insufficient Sleep.", J Clin Endocrinol Metab., Mar, 2012.
Abstract: Driven by the demands and opportunities of modern life, many people habitually sleep less than 6 h a night. In the sleep clinic, chronic sleep restriction is recognized by the diagnosis of insufficient sleep syndrome (ICSD-9, 307.49-4), which is receiving increased scrutiny as a potential risk to metabolic health. Its relevance for the practicing endocrinologist is highlighted by a stream of epidemiological data that show an association of insufficient sleep with increased incidence of obesity and related morbidities. A central theme of this update is the notion that sleep loss incurs additional metabolic cost, which triggers a set of neuroendocrine, metabolic, and behavioral adaptations aimed at increasing food intake and conserving energy. Although this coordinated response may have evolved to offset the metabolic demands of extended wakefulness in natural habitats with limited food availability, it can be maladaptive in the context of a modern environment that allows many to overeat while maintaining a sedentary lifestyle without sufficient sleep. Importantly, such sleep loss-related metabolic adaptation may undermine the success of behavioral interventions based on reduced caloric intake and increased physical activity to lower metabolic risk in obesity-prone individuals. This emerging perspective is based on data from recently published human interventional studies and requires further experimental support. Nevertheless, it now seems prudent to recommend that overweight and obese individuals attempting to reduce their caloric intake and maintain increased physical activity should obtain adequate sleep and, if needed, seek effective treatment for any coexisting sleep disorders.
Schuman CC and Attarian HP (2012), "Integrating Sleep Management into Clinical Practice.", J Clin Psychol Med Settings., Mar, 2012.
Abstract: Although the basic function of sleep remains a mystery, insufficient sleep is associated with mood disturbance, fatigue and daytime lethargy, cognitive impairments, daytime behavior problems, academic problems, use of stimulants, work absenteeism, lost work production and an increase in healthcare utilization. The International Classification of Sleep Disorders distinguishes 90 different disorders, many of which can be effectively treated, but when left untreated can be costly in terms of quality of life, health and healthcare cost. Over the past 50 years we have become more effective in measuring sleep and have honed our treatments to better address the sleep disorders that most impact us. This article will focus on the three sleep disorders for which patients most frequently seek care, including insomnia, obstructive sleep apnea syndrome and restless leg syndrome.
Wilhelm I, Prehn-Kristensen A and Born J (2012), "Sleep-dependent memory consolidation - What can be learnt from children?", Neurosci Biobehav Rev., Mar, 2012.
Abstract: Extensive research has been accumulated demonstrating that sleep is essential for processes of memory consolidation in adults. In children and infants, a great capacity to learn and to memorize coincides with longer and more intense sleep. Here, we review the available data on the influence of sleep on memory consolidation in healthy children and infants, as well as in children with attention-deficit/hyperactivity disorder (ADHD) as a model of prefrontal impairment, and consider possible mechanisms underlying age-dependent differences. Findings indicate a major role of slow wave sleep (SWS) for processes of memory consolidation during early development. Importantly, longer and deeper SWS during childhood appears to produce a distinctly superior strengthening of hippocampus-dependent declarative memories, but concurrently prevents an immediate benefit from sleep for procedural memories, as typically observed in adults. Studies of ADHD children point toward an essential contribution of prefrontal cortex to the preferential consolidation of declarative memory during SWS. Developmental studies of sleep represent a particularly promising approach for characterizing the supra-ordinate control of memory consolidation during sleep by prefrontal-hippocampal circuitry underlying the encoding of declarative memory.
Yeung W-F, Chung K-F, Man-Ki Poon M, Yan-Yee Ho F, Zhang S-P, Zhang Z-J, Tat-Chi Ziea E and Wong VT (2012), "Chinese herbal medicine for insomnia: A systematic review of randomized controlled trials.", Sleep Med Rev., Mar, 2012.
Abstract: Chinese herbal medicine (CHM), either in single herb or in herbal formula, has been used to treat insomnia for more than 2000 years. A systematic review including Chinese and English literature of randomized controlled trials was conducted to examine the efficacy, safety, and composition of CHM for insomnia. Among the 217 studies we have reviewed, only eight had a Jadad score ?3, and seven out of these eight studies had at least one domain with high risks of bias. Meta-analyses of the studies with Jadad score ?3 found that CHM was similar to Western medication (three studies) and placebo (three studies) in treating insomnia. Due to the poor methodological quality of the studies and the small number of trials included in meta-analyses, the current evidence is insufficient to support the efficacy of CHM for insomnia. The frequency of adverse events associated with CHM was similar to that of placebo, but lower than with Western medication. Gui Pi Tang was the most commonly used standardized formula, while Suan Zao Ren (Ziziphus jujuba) was the most frequently used single herb. Further studies with a double-blind placebo-controlled design are needed to accurately determine the benefits and risks of CHM for insomnia.
Physiology / Pharmacology
Bazil CW, Dave J, Cole J, Stalvey J and Drake E (2012), "Pregabalin increases slow-wave sleep and may improve attention in patients with partial epilepsy and insomnia.", Epilepsy Behav., Mar, 2012.
Abstract: Insomnia is a common phenomenon particularly in patients with epilepsy. This study was performed to look at the effects of pregabalin, an anticonvulsant known to increase sleep depth and decrease arousals, in patients with insomnia and well-controlled epilepsy. METHODS: This was a double-blind, placebo-controlled, crossover study of subjects with insomnia and epilepsy. Each subject was treated with pregabalin 150mg BID or placebo for two weeks, followed by a two-week washout period, then the other treatment for two weeks. Polysomnography and neuropsychological testing were performed at baseline and at the end of each treatment arm. RESULTS: There was a significant increase in percentage of slow-wave sleep and a decrease in stage 1 sleep when subjects were taking pregabalin. Sleep efficiency increased during pregabalin treatment, although this was not statistically significant (84.5+/-4.6% for placebo versus 90.4+/-2.6% for pregabalin). There were a significant improvement in attention in the pregabalin group based on trial one of the Rey-Auditory Verbal Learning Test and a trend toward improvement in the psychomotor vigilance task; other neuropsychological measures were not significantly changed. CONCLUSION: Concurrent treatment with pregabalin improves sleep depth in patients with insomnia and epilepsy and improves daytime attention.
Ensrud KE, Joffe H, Guthrie KA, Larson JC, Reed SD, Newton KM, Sternfeld B, Lacroix AZ, Landis CA, Woods NF and Freeman EW (2012), "Effect of escitalopram on insomnia symptoms and subjective sleep quality in healthy perimenopausal and postmenopausal women with hot flashes: a randomized controlled trial.", Menopause., Mar, 2012.
Abstract: OBJECTIVE: The aim of this study was to determine the effect of escitalopram on insomnia symptoms and subjective sleep quality in healthy perimenopausal and postmenopausal women with hot flashes. METHODS: A randomized, blinded, multicenter, placebo-controlled parallel-group 8-week trial with 205 women (95 African American, 102 white, 8 other) was conducted between July 2009 and June 2010. The participants received escitalopram (10-20 mg/d) or placebo. Insomnia symptoms (Insomnia Severity Index [ISI]) and subjective sleep quality (Pittsburgh Sleep Quality Index [PSQI]) at weeks 4 and 8 were the prespecified secondary outcomes. A total of 199 women (97 provided ISI data, and 194 (95 women provided PSQI data at follow-up. RESULTS: At baseline, mean hot flash frequency was 9.78 per day (SD, 5.60), mean ISI was 11.4 (SD, 6.3), and mean PSQI was 8.0 (SD, 3.7). Treatment with escitalopram reduced ISI at week 8 (mean difference, -2.00; 95% CI, -3.43 to -0.57; P < 0.001 overall treatment effect), with mean differences of -4.73 (95% CI, -5.72 to -3.75) in the escitalopram group and -2.73 (95% CI, -3.78 to -1.69) in the placebo group. The reduction in PSQI was greater in the escitalopram than in the placebo group at week 8 (mean difference, -1.31; 95% CI, -2.14 to -0.49; P < 0.001 overall treatment effect). Clinical improvement in insomnia symptoms and subjective sleep quality (?50% decreases in ISI and PSQI from baseline) was observed more frequently in the escitalopram group than in the placebo group (ISI, 50.0% vs 35.4 P = 0.04; PSQI, 29.6% vs 19.2 P = 0.09). CONCLUSIONS: Among healthy perimenopausal and postmenopausal women with hot flashes, escitalopram at 10 to 20 mg/day compared with placebo reduced insomnia symptoms and improved subjective sleep quality at 8 weeks of follow-up.
Houston CM, McGee TP, Mackenzie G, Troyano-Cuturi K, Rodriguez PM, Kutsarova E, Diamanti E, Hosie AM, Franks NP and Brickley SG (2012), "Are Extrasynaptic GABAA Receptors Important Targets for Sedative/Hypnotic Drugs?", J Neurosci., Mar, 2012. Vol. 32(11), pp. 3887-3897.
Abstract: High-affinity extrasynaptic GABA(A) receptors are persistently activated by the low ambient GABA levels that are known to be present in extracellular space. The resulting tonic conductance generates a form of shunting inhibition that is capable of altering cellular and network behavior. It has been suggested that this tonic inhibition will be enhanced by neurosteroids, antiepileptics, and sedative/hypnotic drugs. However, we show that the ability of sedative/hypnotic drugs to enhance tonic inhibition in the mouse cerebellum will critically depend on ambient GABA levels. For example, we show that the intravenous anesthetic propofol enhances tonic inhibition only when ambient GABA levels are <100 nm. More surprisingly, the actions of the sleep-promoting drug 4,5,6,7-tetrahydroisothiazolo-[5,4-c]pyridin-3-ol (THIP) are attenuated at ambient GABA levels of just 20 nm. In contrast, our data suggest that neurosteroid enhancement of tonic inhibition will be greater at high ambient GABA concentrations. We present a model that takes into account realistic estimates of ambient GABA levels and predicted extrasynaptic GABA(A) receptor numbers when considering the ability of sedative/hypnotic drugs to enhance tonic inhibition. These issues will be important when considering drug strategies designed to target extrasynaptic GABA(A) receptors in the treatment of sleep disorders and other neurological conditions.
Kounalakis SN, Eiken O and Mekjavic IB (2012), "Exercise thermoregulatory responses following a 28-day sleep-high train-low regimen.", Eur J Appl Physiol., Mar, 2012.
Abstract: The potentiated exercise-sweating rate observed during acute hypoxia is diminished after a sleep-high train-low (SH-TL) regimen. We tested the hypothesis that this attenuation of the sweating response after SH-TL is compensated for by an increase in heat loss via vasodilatation. Nine male subjects participated in a 28-day SH-TL regimen. Before (pre-), and after (post-) the SH-TL protocol, they performed an [Formula: see text] test under normoxia and hypoxia. Additionally, pre- and post-SH-TL they completed three 30-min constant-work rate trials on a cycle ergometer. In one trial, the subjects inspired room air while exercising at 50 % of normoxic [Formula: see text] (CT). In the remaining trials, subjects exercised in hypoxia (F(I)O(2) 12.5 , either at the same absolute (HAT) or relative (50 % of hypoxic [Formula: see text]) work rate (HRT) as in CT. Despite similar exercise core temperature responses between pre- and post-SH-TL trials, sweating rate was potentiated in HAT pre-SH-TL [CT: 1.97 (0.42); HRT: 1.86 (0.31); HAT: 2.55 (0.53) mg cm(-2) min(-1); p < 0.05]. Post-SH-TL exercise sweating rate was increased for CT, and remained unchanged in HRT and HAT [CT: 2.42 (0.76); HRT: 2.01 (0.33); HAT: 2.59 (0.30) mg cm(-2) min(-1)]. Pre-SH-TL, the forearm-fingertip skin temperature difference (Tsk(f-f)) was higher in HAT than in CT and HRT by ~3.5°C (p < 0.05). The inter-condition differences in Tsk(f-f) were diminished post-SH-TL. In conclusion, the decrease in sweating rate during hypoxic exercise, following a SH-TL regimen, was countered by an increase in vasodilatation (reduced Tsk(f-f)), whereas SH-TL enhanced the sweating response during normoxic exercise. The mechanisms underlying these SH-TL-induced alterations in thermoregulatory responses remain to be settled.
Mari F, Zelmann R, Andrade-Valenca L, Dubeau F and Gotman J (2012), "Continuous high-frequency activity in mesial temporal lobe structures.", Epilepsia., Mar, 2012.
Abstract: Purpose:? Many recent studies have reported the importance of high-frequency oscillations (HFOs) in the intracerebral electroencephalography (EEG) of patients with epilepsy. These HFOs have been defined as events that stand out from the background. We have noticed that this background often consists itself of high-frequency rhythmic activity. The purpose of this study is to perform a first evaluation of the characteristics of high-frequency continuous or semicontinuous background activity. Methods:? Because the continuous high-frequency pattern was noted mainly in mesial temporal structures, we reviewed the EEG studies from these structures in 24 unselected patients with electrodes implanted in these regions. Sections of background away from interictal spikes were marked visually during periods of slow-wave sleep and wakefulness. They were then high-passed filtered at 80?Hz and categorized as having high-frequency rhythmic activity in one of three patterns: continuous/semicontinuous, irregular, sporadic. Wavelet entropy, which measures the degree of rhythmicity of a signal, was calculated for the marked background sections. Key Findings:? Ninety-six bipolar channels were analyzed. The continuous/semicontinuous pattern was found frequently (29/96 channels during wake and 34/96 during sleep). The different patterns were consistent between sleep and wakefulness. The continuous/semicontinuous pattern was found significantly more often in the hippocampus than in the parahippocampal gyrus and was rarely found in the amygdala. The types of pattern were not influenced by whether a channel was within the seizure-onset zone, or whether it was a lesional channel. The continuous/semicontinuous pattern was associated with a higher frequency of spikes and with high rates of ripples and fast ripples. Significance:? It appears that high-frequency activity (above 80?Hz) does not appear only in the form of brief paroxysmal events but also in the form of continuous rhythmic activity or very long bursts. In this study limited to mesial temporal structures, we found a clear anatomic preference for the hippocampus. Although associated with spikes and with distinct HFOs, this pattern was not clearly associated with the seizure-onset zone. Future studies will need to evaluate systematically the presence of this pattern, as it may have a pathophysiologic significance and it will also have an important influence on the very definition of HFOs.
Neunuebel JP and Knierim JJ (2012), "Spatial firing correlates of physiologically distinct cell types of the rat dentate gyrus.", J Neurosci., Mar, 2012. Vol. 32(11), pp. 3848-3858.
Abstract: The dentate gyrus (DG) occupies a key position in information flow through the hippocampus. Its principal cell, the granule cell, has spatially selective place fields. However, the behavioral correlates of cells located in the hilus of the rat dentate gyrus are unknown. We report here that cells below the granule layer show spatially selective firing that consists of multiple subfields. Other cells recorded from the DG had single place fields. Compared with cells with multiple fields, cells with single fields fired at lower rates during sleep were less bursty, and were more likely to be recorded simultaneously with large populations of neurons that were active during sleep and silent during behavior. We propose that cells with single fields are likely to be mature granule cells that use sparse encoding to potentially disambiguate input patterns. Furthermore, we hypothesize that cells with multiple fields might be cells of the hilus or newborn granule cells. These data are the first demonstration, based on physiological criteria, that single- and multiple-field cells constitute at least two distinct cell classes in the DG. Because of the heterogeneity of firing correlates and cell types in the DG, understanding which cell types correspond to which firing patterns, and how these correlates change with behavioral state and between different environments, are critical questions for testing long-standing computational theories that the DG performs a pattern separation function using a very sparse coding strategy.
Rytlewski JA, Lee JT and Raj SR (2012), "Sleep Syncope: Treatment with a Permanent Pacemaker.", Pacing Clin Electrophysiol., Mar, 2012.
Abstract: Vasovagal syncope usually occurs during upright posture, but Jardine et al. have described a variant that occurs at night. During "sleep syncope" patients are awakened from sleep with nausea, abdominal cramping, or a sense of impending diarrhea; get up; and faint in the bathroom. We report on a patient with recurrent sleep syncope (with physical injury) in whom an asystolic pause was documented during one of her "sleep syncope" spells. Implantation of a dual chamber pacemaker (5-year follow-up) "cured" her of further syncope. This is a report of pacemaker use for this unusual form of reflex syncope. (PACE 2012;xx; e1-e4).
Tsai S-Y and Thomas KA (2012), "Sleep disturbances and depressive symptoms in healthy postpartum women: A pilot study.", Res Nurs Health., Mar, 2012.
Abstract: In this pilot study we examined the relationship between objective and subjective sleep disturbances and depressive symptoms in 22 healthy primiparous postpartum women within 3 months after delivery. We found that none of the women in our study had clinically significant depression scores on the Edinburgh Postnatal Depression Scale; nonetheless, a variable duration of night-time sleep from night to night during the 7-day monitoring period and reported awakening too early were significantly correlated with increased depressive symptoms. Results suggest that first-time mothers who complain of irregular night-time sleep duration and waking up too early should be screened and evaluated for potential postpartum depressive symptoms. © 2012 Wiley Periodicals, Inc. Res Nurs Health.
Development / Aging / Evolution
Wang M and Saudino KJ (2012), "Genetic and Environmental Contributions to Stability and Change of Sleep Problems in Toddlerhood.", J Pediatr Psychol., Mar, 2012.
Abstract: OBJECTIVE: To examine genetic and environmental contributions to stability and change in sleep problems (SP) in early childhood. METHODS: The sample comprised over 300 twin pairs assessed at ages 2 and 3 years. Parents rated SP on the Sleep Problems subscale of the Child Behavior Checklist for ages 1.5-5 years. RESULTS: Longitudinal quantitative genetic analyses indicated that SP were genetically influenced at both ages. The stability of SP from ages 2 to 3 years was largely due to genetic factors common to both ages. Nonshared environmental influences displayed modest continuity across age. New genetic and nonshared environmental factors emerged at age 3 years. CONCLUSIONS: Genetic factors contribute to the stability in SP, whereas change is due to both genetic and nonshared environmental influences. Early interventions on SP and individualized treatments based on children's unique environmental experiences may be fruitful.
Biological Rhythms
Del Pozo A, Montoya A, Vera LM and Sánchez-Vázquez FJ (2012), "Daily rhythms of clock gene expression, glycaemia and digestive physiology in diurnal/nocturnal European seabass.", Physiol Behav., Mar, 2012.
Abstract: Seabass is a fish species with dual (diurnal/nocturnal) feeding behavior, although little is known about changes in its molecular clock, physiology and metabolism linked to this dual behavior. In the research described here possible differences in clock gene expression in central (brain) and peripheral (liver) oscillators, and in physiology (blood glucose and amylase activity in mid-intestine) were studied in seabass with diurnal or nocturnal self-feeding patterns under LD 12:12h (light:dark) (lights on=Zeitgeber Time (ZT) 00:00h). The results revealed that per1 expression in brain shows daily rhythmicity with the acrophase (?) around the lights offset (ZT 12:00h, Cosinor, p<0.01) in both diurnal and nocturnal seabass. In liver, per 1 daily levels of expression were higher in diurnal fish (univariate GML, p<0.02). Daily blood glucose variations were observed in both groups (ANOVA I, p<0.01), with higher glucose levels occurring at night in nocturnal as well as in diurnal fish, although only diurnal seabass displayed a significant daily rhythm (?=ZT 16:52h, Cosinor, p<0.02). The highest values of amylase activity coincided with the feeding-phase of fish; that is, in nocturnal seabass the maximum was reached at ZT 18:00h (ANOVA I, p<0.01), whereas in diurnal seabass the ? was ZT 03:39h (Cosinor, p<0.02). In short, our findings indicated that the feeding rhythm (diurnal vs. nocturnal) strongly influenced the daily patterns of digestive function and clock gene expression in the liver (feeding-entrained clock), but not in the brain (light-entrained clock).
Madsen HØ, Dam H and Hageman I (2012), "Study protocol: a cross-sectional survey of seasonal affective disorder in Danish populations with and without severe visual impairments.", BMJ Open. Vol. 2(2), pp. e001020.
Abstract: INTRODUCTION: People with seasonal affective disorder (SAD) experience recurrent seasonal fluctuations in energy, mood and appetite. Retinal light exposure is suggested to play an important role in the pathogenesis and treatment of SAD. The aim of the study is to determine the prevalence of SAD in persons with severe visual impairments or blindness and to compare the results to a control group without visual impairments. Moreover, the authors wish to investigate whether SAD is correlated to the degree of impairment or to the diagnosis. METHODS AND ANALYSIS: 2781 persons with visual impairments ranging from total blindness to Snellen visual acuity 6/60 receive information letter and questionnaire by post. Completed questionnaires can be returned by post, email or telephone. For each respondent, all eye-related diagnoses will be obtained from national registries. Normally sighted and demographically matched control respondents will be contacted in a similar manner the subsequent winter season. The Seasonal Pattern Assessment Questionnaire rates seasonal variation within the six items: sleep, appetite, social activity, mood, energy and body weight. The Seasonal Pattern Assessment Questionnaire yields a Global Seasonal Score and a prevalence of SAD. Outcomes from the two groups will be compared. Moreover, outcomes from subgroups of the visually impaired population will be compared. ETHICS AND DISSEMINATION: The study is approved by the Danish Data Protection Agency. Results will be published in a relevant scientific journal and be communicated to respondents and relevant institutions through cooperation with the Danish Association of the Blind.
Sleep Deprivation
Carlsson ME (2012), "Sleep disturbance in relatives of palliative patients cared for at home.", Palliat Support Care., Mar, 2012. , pp. 1-6.
Abstract: Objective:The aim of the present pilot study was to investigate insomnia, sleep quality, and daytime sleepiness in relatives of dying patients cared for at home.Method:The study has a descriptive, comparative, and cross-sectional design. The sample consisted of relatives of patients cared for through palliative home care in Uppsala County on 3 specific days. Relatives completed a questionnaire consisting of demographic questions, and items from the Insomnia Severity Index (ISI), the Epworth Sleepiness Scale (ESS), and the Richard Campell Sleep Questionnaire (RCSQ).Results:Seventy-five relatives answered the questionnaire. The average total ISI score was 9.6, with 23% reporting moderate or severe clinical insomnia. The mean sleep duration was 6.5 hours, the mean assessed need of sleep was 8 hours, and the mean discrepancy was 1 hour. The total mean ESS score was 5.6 and only 15% of respondents reported excessive daytime sleepiness. Four percent scored very poor sleep quality, whereas 39% scored very good sleep quality (RCSQ). Two general age- and gender-related patterns were observed. Negative correlations were found between age and sleep problems, with younger relatives reporting more insomnia problems and more daytime sleepiness than did older relatives. The other general pattern was that womens' sleep quality was significantly inferior to that of men. A significant positive correlation was found between ISI and ESS, but not between RCSQ and ESS.Significance of results:The picture of the relatives' sleep condition is fairly complex. A minority reported clinical insomnia problems or excessive daytime sleepiness, and 73% reported getting less sleep than they wanted.
Lee DR, McKeith I, Mosimann U, Ghosh-Nodyal A and Thomas AJ (2012), "Examining carer stress in dementia: the role of subtype diagnosis and neuropsychiatric symptoms.", Int J Geriatr Psychiatry., Mar, 2012.
Abstract: INTRODUCTION: Caring for people with dementia incurs significant stress for carers. Stress has been related to the duration of caring role, the number of weekly hours provided and severity of cognitive impairment. What remains less clear is the impact of neuropsychiatric symptoms and subtype of dementia on carer stress and this study aimed to examine these. METHODS: Dementia carers were recruited for people with a range of dementia subtypes. Carers were interviewed using the Neuropsychiatric Inventory with the Carer Distress Scale. Cognitive fluctuations were assessed using the Dementia Cognitive Fluctuations Scale. All patients were also examined with The Cambridge Assessment for mental disorders in the elderly. RESULTS: Dementia diagnostic subtype, the presence of cognitive fluctuations and some neuropsychiatric symptoms (psychosis and mood disturbance) did predict carer stress (all at p??0.33). Carers of people with dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD) experienced more stress than those caring for patients with Alzheimer's disease and vascular dementia. Carer stress was associated with higher levels of psychosis, mood disturbances, daytime sleep and cognitive fluctuations in the person with dementia. CONCLUSIONS: This study identified the significant impact on carers of providing care for people with DLB and PDD dementia subtypes and also highlighted the significant impact of providing care for patients with high levels of psychosis, mood disturbances and cognitive fluctuations. Copyright © 2012 John Wiley & Sons, Ltd.
Sleep Apnea / COPD / Snoring
van Maanen JP, Ravesloot MJL, Witte BI, Grijseels M and de Vries N (2012), "Exploration of the relationship between sleep position and isolated tongue base or multilevel surgery in obstructive sleep apnea.", Eur Arch Otorhinolaryngol., Mar, 2012.
Abstract: This study aimed to elucidate the role of sleep position as a confounding factor on apnea hypopnea index (AHI) and surgical success in isolated tongue base or multilevel surgery. This study was conducted using retrospective analysis of patients who underwent hyoid suspension because of obstructive sleep apnea (OSA), in the St. Lucas Andreas Hospital, Amsterdam, The Netherlands, from 2004 to 2011. Concurrent surgical treatment was documented. Sleep positions and corresponding AHIs before and after surgery were compared. A total of 130 patients were included. 94 patients underwent surgery of base of tongue and palate (either uvulopalatopharyngoplasty or Z-palatoplasty), of whom 72 underwent concurrent radiofrequent thermotherapy of the base of tongue. 36 patients underwent base of tongue surgery alone, of whom 22 underwent concurrent radiofrequent thermotherapy of the base of tongue. 65 patients either had a successful reduction in AHI or in AI. Isolated tongue base or multilevel surgery was as successful on the supine AHI as it was on the AHI in other sleeping positions. Surgery was not more successful in the group with position-dependent patients as compared with the non-position-dependent patients (P = 0.615). Successful and non-successful surgical results could not be explained by variations in percentages of supine sleep position. Sleep position is not a confounding factor on surgical outcomes in tongue base surgery. The results of isolated base of tongue or multilevel surgery in position-dependent OSA patients leave room for improvement, possibly through positional therapy.
Ak M, Balikci A, Haciomeroglu B, Zincir S, Cinar A, Congologlu E, Bozkurt A, Ozgen F and Ozsahin A (2012), "Quality of sexual life in men with obstructive sleep apnoea.", J Health Psychol., Mar, 2012.
Abstract: The study investigated the quality of sexual life of male obstructive sleep apnoea patients. Apnoea and non-apnoea participants were assessed with Golombok Rust Inventory of Sexual Satisfaction (GRISS) and Structured Clinical Interview for DSM-IV (SCID) before the sleep test. Folicule Stimulating Hormone (FSH), Luteinising Hormone (LH), prolactin, testosterone and oestrogen levels were also evaluated. The apnoea group had a higher BMI and lower LH and testosterone levels than the non-apnoea group. There were no differences between the apnoea, non-apnoea groups and within the apnoea groups (mild, moderate and high apnoea) in terms of sexual satisfaction. Although there was a change in the hormonal levels of obstructive sleep apnoea patients, the sexual life of apnoea patients was not affected at the clinical level.
Andrews G, Ainslie PN, Shepherd K, Dawson A, Swart M and Lucas S (2012), "The effect of partial acclimatisation to high altitude on loop gain and central sleep apnoea severity.", Respirology., Mar, 2012.
Abstract: SUMMARY AT A GLANCE: Twelve normal subjects were studied at an altitude of 5,050 metres over a 2 week period of partial acclimatisation. Polysomnography and arterial blood gas measurements were made. Loop gain was measured by the "duty cycle" technique. Partial acclimatisation was associated with an increase in loop gain and severity of central sleep apnoea with a further fall in PaCO(2) . ABSTRACT: Background and objective:? Loop gain is an engineering term that predicts the stability of a feedback control system, such as the control of breathing. Based on earlier studies at lower altitudes, it was hypothesised that acclimatisation to high altitude would lead to a reduction in loop gain and thus central sleep apnea (CSA) severity. Methods:? This study used exposure to very high altitude to induce CSA in healthy subjects to investigate the effect of partial acclimatisation on loop gain and CSA severity. Measurements were made on 12 subjects (age 30±10yrs, BMI 22.8±1.9, 8 males, 4 females) at an altitude of 5,050m over a two-week period; upon initial arrival (days 2-4) and following partial acclimatisation (days 12-14). Sleep was studied by full polysomnography and resting arterial blood gases were measured. Loop gain was measured by the "duty cycle" method (duration of hyperpnea/cycle length). Results:? Partial acclimatisation to high altitude exposure was associated with both an increase in loop gain [duty cycle fell from 0.60±0.05 to 0.55±0.06, (p=0.03)] and severity of CSA [AHI increased from 76.8±48.8 to 115.9±20.2 (p=0.01)] whilst PaCO(2 ) fell from 29±3 to 26±2 (p=0.01). Conclusions:? Contrary to the results at lower altitudes, at high altitude loop gain and severity of CSA increased. © 2012 The Authors. Respirology © 2012 Asian Pacific Society of Respirology.
Butt M, Dwivedi G, Shantsila A, Khair OA and Lip GYH (2012), "Left ventricular systolic and diastolic function in obstructive sleep apnea: impact of continuous positive airway pressure therapy.", Circ Heart Fail., Mar, 2012. Vol. 5(2), pp. 226-233.
Abstract: Background- Previous studies in obstructive sleep apnea (OSA) were limited by study cohorts with comorbidities that confound assessment of left ventricular (LV) systolic and diastolic function. We comprehensively evaluated LV function using 2-dimensional echocardiography (2DE), tissue Doppler imaging (TDI), and 3-dimensional echocardiography (3DE) in subjects moderate-severe OSA, who were compared with disease (patients with hypertension, no OSA) and healthy control subjects. Methods and Results- A total of 120 subjects (n=40 each of matched OSA, hypertension and healthy cohorts) underwent echocardiographic examination for the assessment of septal and posterior wall thickness, LV mass index, LV volumes and ejection fraction, mitral valve inflow indices (E, A), mitral annular velocity (S, E'), and left atrial volume index (LAVI). OSA subjects were treated with continuous positive airway pressure (mean duration of 26 weeks), after which the echocardiographic parameters were reassessed. Posterior wall thickness and LV mass index were significantly higher in OSA and hypertensive groups compared with healthy. Systolic S velocity was reduced in OSA and hypertensive compared with healthy control subjects (P<0.05). Diastolic function (E/A, IVRT, and E/E) was impaired in both OSA and hypertensive groups. On 3DE, mean LAVI was significantly greater in OSA and hypertensive compared with healthy. In OSA patients, continuous positive airway pressure therapy resulted in reduction of the posterior wall thickness (P=0.02) and improvement in LV ejection fraction (P<0.05), systolic S velocity (P<0.05), and diastolic LV impairment parameters. Conclusions- Moderate to severe OSA causes structural and functional changes in LV function and are comparable to that seen in hypertension. These abnormalities significantly improve after CPAP therapy.
Fischer MK, Martinez D, Cassol CM, Rahmeier L and Vieira LR (2012), "Immediate and overnight recumbence-dependent changes of neck circumference: Relationship with OSA severity in obese and nonobese subjects.", Sleep Med., Mar, 2012.
Abstract: BACKGROUND: Overnight increases in neck circumference - attributed to rostral fluid displacement - correlate with the severity of obstructive sleep apnea (OSA). No studies were found investigating the relationship between OSA severity and recumbence-related immediate changes in neck circumference. We evaluated the relationship of OSA severity with immediate recumbence-related and overnight changes in neck circumference in obese and nonobese subjects. METHODS: Male patients undergoing full-night in-laboratory polysomnography had their neck and ankle circumferences determined before and after sleep, both while standing and supine. Circumference changes were calculated by the difference between standing and recumbent positions (Immediate Change) and between before and after sleep (Overnight Change). RESULTS: Immediate Change in neck circumference showed a linear significant correlation with apnea-hypopnea index (AHI; r=0.37373; p=0.012) and with lowest O2 saturation (r=-0.35355; p=0.017). In a multivariate model to predict AHI, adjusting for age and obesity, Immediate Change in neck circumference is the only significant regressor (beta=0.34; p=0.03). The Overnight Change in neck circumference correlated neither with the AHI nor with the lowest SaO2. CONCLUSION: Correlation of AHI with the immediate increase in neck circumference on assuming recumbence indicates that fast components of tissue displacement, besides overnight fluid displacement, may have implications in the pathogenesis of OSA.
Gasparini G, Saponaro G, Rinaldo FMD, Boniello R, Marianetti TM, Torroni A, Cervelli D, Nasto V and Pelo S (2012), "Clinical Evaluation of Obstructive Sleep Apnea in Children.", J Craniofac Surg., Mar, 2012.
Abstract: BACKGROUND: Obstructive sleep apnea syndrome (OSAS) is often found in children affected by congenital or acquired craniomaxillomandibular malformations. This disease carries different levels of risk, ranging from attention problems at school to growth problems and serious disorders, such as cor pulmonale or sudden infant death. The examination that is most commonly used to evaluate the severity of OSAS is polysomnography, and the therapeutic course is often determined by the disease state. Considering the discrepancy between clinical history and polysomnographic findings, we felt the need to identify an instrument for evaluating OSA to be used as a support for polysomnography. MATERIALS AND METHODS: This study was carried out on pediatric patients affected by congenital or acquired craniomaxillofacial malformations. We selected 34 pediatric patients, including 15 boys and 19 girls, aged between 1 and 16 years, with a mean age of 7.3 years. The study consisted of individuation of common clinical history data obtained from each patient and associating those data with the level of OSA severity identified by polysomnography. We were able to isolate certain symptoms and signs that can be predictive of OSA from research in the literature and our clinical experience with pediatric patients. In the clinic, we have found that the clinical history, given by the parents, often differs significantly from the instrumental findings obtained with polysomnography. From the previously expressed considerations and comparison of clinical history data and questionnaires, we have extracted the most significant questions for our questionnaire, which are present in the literature but formulated for adults. RESULTS AND CONCLUSIONS: The obstructive airway child test was found to be a very efficient method to evaluate and diagnose OSA. In all patients, it consistently revealed the pathology and never underestimated OSA severity. The examination focuses on clinical signs and symptoms because, in our opinion, clinical history, reported by the parents, can be more accurate than any instrumental examination.
Gutiérrez-Díaz E, Pérez-Rico C, de Atauri MJ, Mencía-Gutiérrez E and Blanco R (2012), "Evaluation of the visual function in obstructive sleep apnea syndrome patients and normal-tension glaucoma by means of the multifocal visual evoked potentials.", Graefes Arch Clin Exp Ophthalmol., Mar, 2012.
Abstract: BACKGROUND: This study was designed to objectively evaluate visual function and the causal relationship between sleep apnea and optic nerve dysfunction in patients with obstructive sleep apnea syndrome (OSAS) with or without diagnosis of normal-tension glaucoma (NTG) using multifocal visual evoked potentials (mfVEP). METHODS: This observational, cross-sectional study assessed 20 patients with recently diagnosed OSAS with or without NTG. Diagnosis of sleep apnea was based on overnight polysomnography (ApnoeScreen). All participants underwent a complete physical and ophthalmologic examination. MfVEP recordings obtained using VERIS software (Electro-Diagnostic Imaging, San Mateo, USA), SITA-standard 30-2 automated perimetry (Humphrey Visual Field Analyzer II) and optic coherence tomography (Topcon 3D OCT-1000) exams were performed to evaluate the changes. RESULTS: Abnormal mfVEP amplitudes defects (interocular and monocular probability analysis) were found in 40% of the eyes in the non-glaucoma group and in 90% of eyes of the NTG patients. As well, delayed mfVEP latencies (interocular and monocular probability analysis) were seen in 30 and 60% of the eyes of the non-glaucoma and NTG groups, respectively. The average RNFL (retinal nerve fiber layer) thickness was significantly reduced in the NTG eyes compared to the control database and the non-glaucoma eyes. On the Humphrey Visual Field total deviation analysis, all the NTG eyes showed significant clusters of abnormal points but none was detected in the non-glaucoma group eyes. However, the mfVEP amplitude and latency did not show any significant correlation with the standard perimetry and OCT variables, because the mfVEP technique was able to detect far more early visual defects in these patients. Systolic blood pressure, sleep efficiency, arousal index, mean and minimum arterial oxygen saturation (SaO(2)), time SaO(2)?
Hayano J, Tsukahara T, Watanabe E, Sasaki F, Kawai K, Sakakibara H, Kodama I, Nomiyama T and Fujimoto K (2012), "Accuracy of ECG-based screening for sleep-disordered breathing: a survey of all male workers in a transport company.", Sleep Breath., Mar, 2012.
Abstract: PURPOSE: Sleep-disordered breathing (SDB) is associated with increased risk for cardiovascular morbidity and mortality and for sleepiness-related accidents, but >75 % of the patients remain undiagnosed. We sought to determine the diagnostic accuracy of ECG-based detection of SDB when used for population-based screening. METHODS: All male workers, mostly truck drivers, of a transport company (n?=?165; age, 43?±?12 years) underwent standard attended overnight polysomnography. Cyclic variation of heart rate (CVHR), a characteristic pattern of heart rate associated with SDB, was detected from single-lead ECG signals during the polysomnography by a newly developed automated algorithm of autocorrelated wave detection with adaptive threshold (ACAT). RESULTS: Among 165 subjects, the apnea-hypopnea index (AHI) was ?5 in 62 (38 , ?15 in 26 (16 , and ?30 in 16 (10 . The number of CVHR per hour (CVHR index) closely correlated with AHI [r?=?0.868 (95 % CI, 0.825-0.901)]. The areas under the receiver operating characteristic curves for detecting subjects with AHI ?5, ?15, and ?30 were 0.796 (95 % CI, 0.727-0.855), 0.974 (0.937-0.993), and 0.997 (0.971-0.999), respectively. With a predetermined criterion of CVHR index ?15, subjects with AHI ?15 were identified with 88 % sensitivity and 97 % specificity (likelihood ratios for positive and negative test, 30.7 and 0.12). The classification performance was retained in subgroups of subjects with obesity, hypertension, diabetes mellitus, dyslipidemia, and decreased autonomic function. CONCLUSIONS: The CVHR obtained by the ACAT algorithm may provide a useful marker for screening for moderate-to-severe SDB among apparently healthy male workers.
Johansson P, Alehagen U, Svanborg E, Dahlström U and Broström A (2012), "Clinical characteristics and mortality risk in relation to obstructive and central sleep apnoea in community-dwelling elderly individuals: a 7-year follow-up.", Age Ageing., Mar, 2012.
Abstract: Background: little is known about demographic and clinical characteristics associated with sleep-disordered breathing (SDB) and obstructive sleep apnoea (OSA) or central sleep apnoea (CSA) in community-dwelling elderly. We also examined these (OSA and CSA) associations to all-cause and cardiovascular (CV) mortality.Methods: a total of 331 community-dwelling elderly aged 71-87 years underwent a clinical examination and one-night polygraphic recordings in their homes. Mortality data were collected after seven years.Results: a total of 55% had SDB, 38% had OSA and 17% had CSA. Compared with those with no SDB and OSA, more participants with CSA had a left ventricular ejection fraction <50% (LVEF <50 ischaemic heart disease (IHD) and transient ischaemic attack (TIA)/stroke. There was no difference in the rate of IHD and TIA/stroke between OSA and no SDB, but more LVEF <50% was found in those with OSA. CSA significantly increased the risk for all-cause (P = 0.002) and CV mortality (P = 0.018) by more than two times. After adjustments for CV disease, diabetes and the biomarker NT-pro-brain natriuretic peptide CSA associations to all-cause mortality and CV mortality lost significance.Conclusion: OSA, in persons >75 years does not appear to be associated with cardiovascular disease (CVD) disease or mortality, whereas CSA might be a pathological marker of CVD and impaired systolic function associated with higher mortality.
Kent BD, McNicholas WT and Verbraecken J (2012), "Disturbed sleep and COPD outcomes: Cart meets horse.", Sleep Med., Mar, 2012.
Mesquita J, Solà-Soler J, Fiz JA, Morera J and Jané R (2012), "All night analysis of time interval between snores in subjects with sleep apnea hypopnea syndrome.", Med Biol Eng Comput., Mar, 2012.
Abstract: Sleep apnea-hypopnea syndrome (SAHS) is a serious sleep disorder, and snoring is one of its earliest and most consistent symptoms. We propose a new methodology for identifying two distinct types of snores: the so-called non-regular and regular snores. Respiratory sound signals from 34 subjects with different ranges of Apnea-Hypopnea Index (AHI = 3.7-109.9 h(-1)) were acquired. A total number of 74,439 snores were examined. The time interval between regular snores in short segments of the all night recordings was analyzed. Severe SAHS subjects show a shorter time interval between regular snores (p = 0.0036, AHI cp: 30 h(-1)) and less dispersion on the time interval features during all sleep. Conversely, lower intra-segment variability (p = 0.006, AHI cp: 30 h(-1)) is seen for less severe SAHS subjects. Features derived from the analysis of time interval between regular snores achieved classification accuracies of 88.2 % (with 90 % sensitivity, 75 % specificity) and 94.1 % (with 94.4 % sensitivity, 93.8 % specificity) for AHI cut-points of severity of 5 and 30 h(-1), respectively. The features proved to be reliable predictors of the subjects' SAHS severity. Our proposed method, the analysis of time interval between snores, provides promising results and puts forward a valuable aid for the early screening of subjects suspected of having SAHS.
Narayan J, Amatoury J, Cho J-G, Verma M, Kairaitis K, Wheatley J and Amis T (2012), "Snoring effects on the baroreflex: an animal model.", Respir Physiol Neurobiol., Mar, 2012. Vol. 180(2-3), pp. 342-351.
Abstract: Baroreflex sensitivity (BRS) is reduced in humans during snoring, however the mechanisms are unknown. We used an anaesthetised rabbit induced snoring (IS) model, to test: (1) whether IS was associated with reduced BRS; and (2) if snoring related vibration transmission to peri-carotid tissues influenced BRS levels. BRS was quantified using the spontaneous sequence technique. During IS, BRS fell by 40 without any associated change in blood pressure (BP) but accompanied by an increase in heart rate (HR). Direct application of a snore frequency and intensity matched vibratory stimulus to the peri-carotid tissues of non-snoring tracheostomised rabbits had no effect on BRS, HR or BP. In conclusion, IS induced depression of BRS is likely mediated via a HR driven change in BRS operating point that is unrelated to snoring-related vibration transmission to carotid baroreceptors. The anaesthetised IS rabbit provides a model in which mechanistic interactions between snoring and BRS can be further explored.
Omachi TA, Blanc PD, Claman DM, Chen H, Yelin EH, Julian L and Katz PP (2012), "Disturbed sleep among COPD patients is longitudinally associated with mortality and adverse COPD outcomes.", Sleep Med., Mar, 2012.
Abstract: OBJECTIVE: To investigate the cross-sectional association between COPD severity and disturbed sleep and the longitudinal association between disturbed sleep and poor health outcomes. METHODS: Ninety eight adults with spirometrically-confirmed COPD were recruited through population-based, random-digit telephone dialing. Sleep disturbance was evaluated using a 4-item scale assessing insomnia symptoms as: difficulty falling asleep, nocturnal awakening, morning tiredness, and sleep duration adequacy. COPD severity was quantified by: FEV(1) and COPD Severity Score, which incorporates COPD symptoms, requirement for COPD medications and oxygen, and hospital-based utilization. Subjects were assessed one year after baseline to determine longitudinal COPD exacerbations and emergency utilization and were followed for a median 2.4years to assess all-cause mortality. RESULTS: Sleep disturbance was cross-sectionally associated with cough, dyspnea, and COPD Severity Score, but not FEV(1). In multivariable logistic regression, controlling for sociodemographics and body-mass index, sleep disturbance longitudinally predicted both incident COPD exacerbations (OR=4.7; p=0.018) and respiratory-related emergency utilization (OR=11.5; p=0.004). In Cox proportional hazards analysis, controlling for the same covariates, sleep disturbance predicted poorer survival (HR=5.0; p=0.013). For all outcomes, these relationships persisted after also controlling for baseline FEV(1) and COPD Severity Score. CONCLUSIONS: Disturbed sleep is cross-sectionally associated with worse COPD and is longitudinally predictive of COPD exacerbations, emergency health care utilization, and mortality.
Passàli D, Tatti P, Passàli FM and Bellussi L (2012), "The undisclosed role of disturbed sleep and hypoxia on metabolism: the importance of upper airways pathology.", Sleep Breath., Mar, 2012.
Sinha A-M (2012), "[Sleep-disordered breathing and cardiac resynchronization therapy.]", Herzschrittmacherther Elektrophysiol., Mar, 2012.
Abstract: Patients with progressive heart failure often suffer from sleep-disordered breathing (SDB). Upon receiving cardiac resynchronization therapy (CRT), there is an improvement of cardiac function and central sleep apnea syndrome (CSA) with Cheyne-Stokes respiration; however, effects of CRT on obstructive sleep apnea syndrome seemed to be without clinical relevance. Likewise, additional atrial overdrive pacing did not improve CRT effects relevantly in CSA patients. During CRT, there is an improvement in sleep parameters, sleep quality by reduction of depressive syndromes, and in long-term survival. Therefore, all patients with chronic heart failure and indication for CRT should be monitored regarding SDB before and after CRT device implantation.
Yiallourou TI, Odier C, Heinzer R, Hirt L, Martin BA, Stergiopulos N and Haba-Rubio J (2012), "The effect of continuous positive airway pressure on total cerebral blood flow in healthy awake volunteers.", Sleep Breath., Mar, 2012.
Abstract: PURPOSE: Continuous positive airway pressure (CPAP) is the gold standard treatment for obstructive sleep apnea. However, the physiologic impact of CPAP on cerebral blood flow (CBF) is not well established. Ultrasound can be used to estimate CBF, but there is no widespread accepted protocol. We studied the physiologic influence of CPAP on CBF using a method integrating arterial diameter and flow velocity (FV) measurements obtained for each vessel supplying blood to the brain. METHODS: FV and lumen diameter of the left and right internal carotid, vertebral, and middle cerebral arteries were measured using duplex Doppler ultrasound with and without CPAP at 15 cm H(2)O, applied in a random order. Transcutaneous carbon dioxide (PtcCO(2)), heart rate (HR), blood pressure (BP), and oxygen saturation were monitored. Results were compared with a theoretical prediction of CBF change based on the effect of partial pressure of carbon dioxide on CBF. RESULTS: Data were obtained from 23 healthy volunteers (mean?±?SD; 12 male, age 25.1?±?2.6 years, body mass index 21.8?±?2.0 kg/m(2)). The mean experimental and theoretical CBF decrease under CPAP was 12.5 % (p?
Zhang X-B, Lin Q-C, Deng C-S, Chen G-P, Cai Z-M and Chen H (2012), "Elevated serum cystatin C in severe OSA younger men without complications.", Sleep Breath., Mar, 2012.
Abstract: PURPOSE: Serum cystatin C is a promising new biomarker of glomerular filtration rate and cardiovascular events, but few studies focused on serum cystatin C levels in obstructive sleep apnea (OSA) patients. The aim of our study was to evaluate the association between serum cystatin C and OSA in younger men (?40 years old of age) without complications. METHODS: We prospectively recruited consecutive participants without comorbidities who underwent polysomnography. Fasting blood samples were obtained from all subjects for biological profile measurements. Statistical analysis was used to evaluate the relationship between serum cystatin C and other parameters. RESULTS: The population consisted of 98 subjects (mean age?=?32.5 years, mean body mass index?=?27.93 kg/m(2)) that were divided according to polysomnographic finding into control group (n?=?23), mild (n?=?15), moderate (n?=?24), and severe (n?=?36) OSA group. Compared with the control group, patients with severe OSA were significantly heavier (body mass index, 29.69?±?3.81 vs. 26.42?±?3.10) and presented significantly higher levels of high sensitive C-reactive protein (hsCRP) (1.10?±?0.28 vs. 0.88?±?0.20 mg/l) and serum cystatin C (0.87?±?0.12 vs. 0.74?±?0.10 mg/l) (p?
Other Disorders
Baker FC, Sassoon SA, Kahan T, Palaniappan L, Nicholas CL, Trinder J and Colrain IM (2012), "Perceived poor sleep quality in the absence of polysomnographic sleep disturbance in women with severe premenstrual syndrome.", J Sleep Res., Mar, 2012.
Abstract: Women with severe premenstrual syndrome report sleep-related complaints in the late-luteal phase, but few studies have characterized sleep disturbances prospectively. This study evaluated sleep quality subjectively and objectively using polysomnographic and quantitative electroencephalographic measures in women with severe premenstrual syndrome. Eighteen women with severe premenstrual syndrome (30.5?±?7.6?years) and 18 women with minimal symptoms (controls, 29.2?±?7.3?years) had polysomnographic recordings on one night in each of the follicular and late-luteal phases of the menstrual cycle. Women with premenstrual syndrome reported poorer subjective sleep quality when symptomatic in the late-luteal phase compared with the follicular phase (P?
Blyton F, Chuter V and Burns J (2012), "Unknotting night-time muscle cramp: a survey of patient experience, help-seeking behaviour and perceived treatment effectiveness.", J Foot Ankle Res., Mar, 2012. Vol. 5(1), pp. 7.
Abstract: ABSTRACT: BACKGROUND: Night-time calf cramping affects approximately 1 in 3 adults. The aim of this study was to explore the experience of night-time calf cramp; if and where people seek treatment advice; and perceived treatment effectiveness. METHODS: 80 adults who experienced night-time calf cramp at least once per week were recruited from the Hunter region, NSW, Australia through newspaper, radio and television advertisements. All participants completed a pilot-tested survey about muscle cramp. Quantitative data were analysed with independent-sample t-tests, Chi square tests and Fisher's tests. Qualitative data were transcribed and sorted into categories to identify themes. RESULTS: Median recalled age of first night-time calf cramp was 50 years. Most participants recalled being awoken from sleep by cramping, and experiencing cramping of either calf muscle, calf-muscle soreness in the days following cramp and cramping during day-time. Despite current therapies, mean usual pain intensity was 66 mm on a 100 mm visual analogue scale. Participants described their cramps as being 'unbearable', 'unmanageable' and 'cruel'. One participant stated that 'sometimes I just wish I could cut my legs open' and another reported 'getting about 2 h sleep a night due to cramps'. Most participants had sought advice about their night-time calf cramps from a health professional. Participants identified 49 different interventions used to prevent night-time calf cramp. Of all treatment ratings, 68% described the intervention used to prevent cramp as being 'useless' or of 'a little help'. Of 14 participants who provided additional information regarding their use of quinine, eight had a current prescription of quinine for muscle cramp at the time of the survey. None had been asked by their prescribing doctor to stop using quinine. CONCLUSION: Night time calf cramps typically woke sufferers from sleep, affected either leg and caused ongoing pain. Most participants experienced little or no relief with current therapies used to prevent muscle cramp. Most people who were taking quinine for muscle cramp were unaware that the Australian Therapeutic Goods Administration withdrew support of quinine for muscle cramp in 2004 due to the risk of thrombocytopaenia. Case-control studies are required to identify therapeutic targets so that clinical trials can evaluate safe interventions to prevent recurrent cramp.
Crum-Cianflone NF, Roediger MP, Moore DJ, Hale B, Weintrob A, Ganesan A, Eberly LE, Johnson E, Agan BK and Letendre S (2012), "Prevalence and Factors Associated With Sleep Disturbances Among Early-Treated HIV-Infected Persons.", Clin Infect Dis., Mar, 2012.
Abstract: Background.?Sleep disturbances are reportedly common among persons infected with human immunodeficiency virus (HIV), but recent data, including comparisons with HIV-uninfected persons, are limited.Methods.?We performed a cross-sectional study among early-treated HIV-infected military beneficiaries (n = 193) to determine the prevalence and factors associated with insomnia (Pittsburgh Sleep Quality Index [PSQI]) and daytime sleepiness (Epworth Sleepiness Scale [ESS]). Data were compared with HIV-uninfected persons (n = 50) matched by age, sex, race or ethnicity, and military rank.Results.?Forty-six percent of HIV-infected persons had insomnia (PSQI >5), and 30% reported daytime drowsiness (ESS ?10). The prevalence of insomnia and daytime sleepiness was not significantly higher compared with the HIV-uninfected group (38% [P = .30] and 20% [P = .18], respectively). In the multivariate model, factors associated with insomnia among HIV infected patients included depression (odds ratio [OR], 16.8; 95% confidence interval [CI], 2.0-142.1; P = .01), increased waist size (OR, 2.7; 95% CI, 1.4-5.1; P = .002), and fewer years of education (OR, 0.8; 95% CI, .7-.95; P = .006). Neurocognitive impairment (diagnosed in 19% of HIV-infected participants) was not associated with insomnia; however, HIV-infected persons with insomnia were 3.1-fold more likely to have a decline in activities of daily living than those without insomnia (23% vs 9 P = .01). Only 18% of HIV-infected persons reported using a sleep medication at least weekly.Conclusions.?HIV-infected persons have a high prevalence of insomnia, but among an early-treated cohort this rate was not significantly higher compared with HIV-uninfected persons. Factors associated with insomnia among HIV-infected patients include depression and increased waist size. Prompt diagnosis and treatment of sleep disturbances are advocated and may improve quality of life.
Ferri R, Fulda S, Cosentino FII, Pizza F and Plazzi G (2012), "A preliminary quantitative analysis of REM sleep chin EMG in Parkinson's disease with or without REM sleep behavior disorder.", Sleep Med., Mar, 2012.
Abstract: OBJECTIVES: To compare REM sleep chin EMG quantitative features between Parkinson's disease (PD) patients with or without REM sleep behavior disorder (RBD). SUBJECTS AND METHODS: Twenty-seven consecutive PD patients (mean age 67.9years) and 19 normal controls (mean age 67.5years) were enrolled. Detailed clinical, laboratory, and polysomnographic studies were obtained in all participants and characteristics of chin electromyographic amplitude during rapid eye movements sleep were analyzed by means of an automatic quantitative approach (Atonia Index). RESULTS: Sixteen of the 27 patients were affected by RBD. An Atonia Index below 0.90 showed high sensitivity (0.938) and specificity (0.909) for the diagnosis of RBD within the group of PD patients. CONCLUSION: This study recommends the Atonia Index as an objective measure to support and aid the diagnosis of RBD in PD.
Huang Z, Zhan S, Li N, Ding Y and Wang Y (2012), "Abnormal recovery function of somatosensory evoked potentials in patients with primary insomnia.", Psychiatry Res., Mar, 2012.
Abstract: Neurobiological correlates underlying insomnia are poorly understood. The hyperarousal of the central nervous system indicates that cortical excitability may be abnormal in patients with insomnia. The purpose of the present study was to investigate changes in cortical excitability by examining the recovery function of median nerve somatosensory evoked potentials (SEPs) in patients with primary insomia (PI). We studied the recovery function of median nerve SEPs in 12 medication-naive PI patients and in 12 age- and sex-matched healthy subjects. SEPs in response to single stimulus and paired stimuli at interstimulus intervals (ISIs) of 20, 60, 100 and 150ms were recorded. The recovery function of the cortical components of frontal P20 and parietal N20 showed significantly reduced suppression in PI patients as compared to healthy controls. In conclusion, this is the first study investigating changes in cortical excitability in PI patients by examining the recovery function of median nerve SEPs. The present study suggests that cortical excitability is increased in PI patients. Dysfunction of inhibitory GABAergic interneurons of the cerebral cortex might contribute to the increased cortical excitability in PI patients.
Jensen ME, Gibson PG, Collins CE, Hilton JM, Latham-Smith F and Wood LG (2012), "Increased sleep latency and reduced sleep duration in children with asthma.", Sleep Breath., Mar, 2012.
Abstract: STUDY OBJECTIVE: Sleep disturbance is reported to be more prevalent in children and adolescents with asthma than those without. However, this has not been described adequately using objective measures. The aim of this study was to objectively characterise sleep disturbance in asthmatic and non-asthmatic children and adolescents. METHODS: A retrospective analysis of polysomnography recordings from children aged 5-17 years old, with (n?=?113) and without asthma (n?=?104), referred for a sleep study over the period 2005-2010 at the Paediatric Sleep Unit, John Hunter Children's Hospital in Newcastle, NSW Australia, was carried out. RESULTS: Polysomnographic recordings were analysed to compare sleep quality and quantity between asthmatic and non-asthmatic children. Sleep latency was significantly longer in asthmatic children compared to controls. However, this result was significant for females only (46.2 (5.6) vs 33.2 (2.7) min, p?
Maglione JE, Ancoli-Israel S, Peters KW, Paudel ML, Yaffe K, Ensrud KE and Stone KL (2012), "Depressive Symptoms and Subjective and Objective Sleep in Community-Dwelling Older Women.", J Am Geriatr Soc., Mar, 2012.
Abstract: OBJECTIVES: To examine the relationship between depressive symptoms and subjective and objective sleep in older women. DESIGN: Cross-sectional. SETTING: Four U.S. clinical centers. PARTICIPANTS: Three thousand forty-five community-dwelling women aged 70 and older. MEASUREMENTS: Depressive symptoms were assessed using the Geriatric Depression Scale, categorizing participants as normal (0-2, reference), some depressive symptoms (3-5), or depressed (?6). Subjective sleep quality and daytime sleepiness were assessed using the Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS). Objective sleep measures were assessed using wrist actigraphy. RESULTS: In multivariable-adjusted models, there were graded associations between greater level of depressive symptoms and worse subjective sleep quality and more subjective daytime sleepiness (P-trends < .001). Women with some depressive symptoms (odds ratio (OR) = 1.82, 95% confidence interval (CI) = 1.48-2.24) and depressed (OR = 2.84, 95% CI = 2.08-3.86) women had greater odds of reporting poor sleep (PSQI>5). Women with some depressive symptoms (OR = 1.97, 95% CI = 1.47-2.64) and depressed women (OR = 1.70, 95% CI = 1.12-2.58) had greater odds of reporting excessive daytime sleepiness (ESS>10). There were also graded associations between greater level of depressive symptoms and objectively measured wake after sleep onset (WASO) (P-trend = .03) and wake episodes longer than 5 minutes (P-trend = .006). Depressed women had modestly higher odds of WASO of 1 hour or longer (OR = 1.37, 95% CI = 1.03-1.83). Women with some depressive symptoms (OR = 1.49, 95% CI = 1.19-1.86) and depressed women (OR = 2.04, 95% CI = 1.52-2.74) had greater odds of being in the highest quartile for number of nap episodes longer than 5 minutes. No associations between depressive symptom level and prolonged sleep latency, poor sleep efficiency, or short or long total sleep time were found. CONCLUSION: Greater depressive symptom levels were associated with more subjective sleep disturbance and objective evidence of sleep fragmentation and napping.
Murray CB, Murphy LK, Palermo TM and Clarke GM (2012), "Pain and Sleep-Wake Disturbances in Adolescents With Depressive Disorders.", J Clin Child Adolesc Psychol., Mar, 2012.
Abstract: The aims of this study were to (a) assess and compare sleep disturbances (including daytime and nighttime sleep patterns) in adolescents with depressive disorders and healthy peers, (b) examine the prevalence of pain in adolescents with depressive disorders and healthy peers, and (c) examine pubertal development, pain intensity, and depressive symptom severity as predictors of sleep disturbance. One hundred six adolescents (46 depressed, 60 healthy), 12 to 18 years (M = 15.10 years; 67% female; 77% Caucasian) completed subjective measures of sleep, presleep arousal, fatigue, and pain. Participants also underwent 10 days of actigraphic monitoring to assess nighttime and daytime sleep duration, sleep efficiency, and wake after sleep onset. Results indicated that youth with depression exhibited greater sleep disturbances on subjective and actigraphic sleep variables than healthy controls. Depressed youth also reported more frequent and severe pain than healthy youth. Linear regression analysis indicated that pain intensity and depressive symptoms predicted worse sleep quality across groups. The interaction term was also significant, such that adolescents with high levels of depressive symptoms had poor sleep quality when pain intensity levels were high. These results indicate that sleep is important to assess in youth with depression, and that pain may be an important target for sleep intervention in this population.
Park JB, Nakata A, Swanson NG and Chun H (2012), "Organizational factors associated with work-related sleep problems in a nationally representative sample of Korean workers.", Int Arch Occup Environ Health., Mar, 2012.
Abstract: PURPOSE: The purpose of this study was to assess the association of organizational factors with work-related sleep problems (WRSP) among Korean workers. METHODS: The data were derived from the First Korean Working Conditions Survey conducted in 2006 with a representative sample of the Korean working population (n = 10,039). RESULTS: The overall prevalence of WRSP was 5.1  % (95  % confidence interval (CI) 4.7-5.5). Those who experienced sexual harassment at work (adjusted odds ratio (aOR) 3.47: 95 % CI 1.77-6.81), discrimination due to sex (aOR 2.44: 95 % CI 1.36-4.36) or age (aOR 2.22: 95 % CI 1.52-3.23), violence at work (aOR 1.98: 95 % CI 1.06-3.68), threat of violence (aOR 1.96: 95 % CI 1.05-3.66), poor work-life balance (aOR 1.78: 95 % CI 1.44-2.20), low job satisfaction (aOR 1.69: 95 % CI 1.37-2.09), high cognitive (OR 1.64: 95 % CI 1.32-2.03) and emotional (aOR 1.53: 95 % CI 1.22-1.91) demands, job insecurity (aOR 1.32: 95 % CI 1.07-1.63), and high work intensity (aOR 1.55: 95 % CI: 95 % CI 1.25-1.92) had an increased risk of WRSP compared to their respective counterparts (p < 0.01). Low social support was not significantly associated with WRSP (aOR 0.88: 95 % CI 0.67-1.15). CONCLUSION: The results revealed that poor psychosocial working conditions may be related to a high prevalence of WRSP among representative Korean workers.
Pereira AM, Bruni O, Ferri R and Nunes ML (2012), "Sleep instability and cognitive status in drug-resistant epilepsies.", Sleep Med., Mar, 2012.
Abstract: OBJECTIVE: The aims of this study were to evaluate the sleep habits of children with drug resistant epilepsy and to correlate sleep abnormalities with epilepsy and level of intelligence. SUBJECTS AND METHODS: Twenty five subjects with drug resistant epilepsy (14 males, age range 2-16.4years) were recruited for this study. A control group was formed by 23 normal children. Two instruments to assess sleep habits were administered to the patients with epilepsy: a questionnaire on sleep habits (to preschool children) and a questionnaire on sleep behavior (for children aged more than seven years old); a cognitive test (Wechsler Intelligence Scale for Children-WISC) was also performed. Patients underwent a complete polysomnographic study and sleep parameters, including CAP, were analyzed and correlated according to cognitive-behavioral measures in children with epilepsy. RESULTS: Children with drug-resistant epilepsy and severe mental retardation showed sleep abnormalities such as low sleep efficiency, high percentage of wakefulness after sleep onset, reduced slow wave sleep, and reduced REM sleep. Sleep microstructure evaluated by means of CAP analysis showed a decrease in A1 index during N3 in patients with more severe cognitive impairment. Children with epilepsy and cognitive impairment (n=10) had higher Sleep Behavior Questionnaire for Children (SBQC) total scores (65.60±18.56) compared to children with epilepsy and normal IQ (50.00±10.40), p<0.05. CONCLUSIONS: Children with drug-resistant epilepsy have a greater incidence of sleep problems regarding qualitative aspects, macrostructure, and CAP. The decrease of CAP rate and of A1, mainly during slow wave sleep (associated to REM sleep reduction), might represent a sleep microstructural pattern of intellectual disability.
Plantinga L, Rao MN and Schillinger D (2012), "Prevalence of Self-Reported Sleep Problems Among People With Diabetes in the United States, 2005-2008.", Prev Chronic Dis., Mar, 2012. Vol. 9, pp. E76.
Abstract: INTRODUCTION: Sleep problems, including insomnia, apnea, and restless legs syndrome, are common, burdensome, and under-recognized in the United States. We sought to examine the association of sleep problems with diabetes among community-dwelling US adults. METHODS: We examined self-reported sleep problems in 9,848 adults (aged ?20 y) participating in the National Health and Nutrition Examination Survey 2005 through 2008. Sleep problem information was elicited via validated questionnaire. Diabetes was defined by self-reported diagnosis or glycohemoglobin of 6.5% or higher. Multivariable logistic regression with US population-based weighting was used to obtain adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for various sleep problems by diabetes status. RESULTS: Sleep problems were common (>90% for any problem; 1040% for individual problems) overall, and people with diabetes were more likely than those without diabetes to report multiple problems (mean, 3.1 vs 2.5, respectively, P < .001). After adjustment for potential confounders (including demographics, body mass index, cardiovascular and kidney disease, and alcohol use), restless legs symptoms (OR, 1.40; 95% CI, 1.12-1.78), sleep apnea (OR, 1.45; 95% CI, 1.06-1.98), and nocturia (OR, 1.51; 95% CI, 1.22-1.87) were all positively associated with diabetes status. CONCLUSION: Diabetes is associated with a higher risk of sleep problems, including not only sleep apnea but also inadequate sleep, excessive sleepiness, leg symptoms, and nocturia, independent of body mass index. Clinicians should be aware of the high prevalence of sleep problems among their patients with diabetes and should consider screening and treatment, which may improve patients quality of life.
Singareddy R, Vgontzas AN, Fernandez-Mendoza J, Liao D, Calhoun S, Shaffer ML and Bixler EO (2012), "Risk factors for incident chronic insomnia: A general population prospective study.", Sleep Med., Mar, 2012.
Abstract: OBJECTIVE: The few population-based, prospective studies that have examined risk factors of incident insomnia were limited by small sample size, short follow-up, and lack of data on medical disorders or polysomnography. We prospectively examined the associations between demographics, behavioral factors, psychiatric and medical disorders, and polysomnography with incident chronic insomnia. METHODS: From a random, general population sample of 1741 individuals of the adult Penn State Sleep Cohort, 1395 were followed-up after 7.5years. Only subjects without chronic insomnia at baseline (n=1246) were included in this study. Structured medical and psychiatric history, personality testing, and 8-h polysomnography were obtained at baseline. Structured sleep history was obtained at baseline and follow-up. RESULTS: Incidence of chronic insomnia was 9.3 with a higher incidence in women (12.9 than in men (6.2. Younger age (20-35years), non-white ethnicity, and obesity increased the risk of chronic insomnia. Poor sleep and mental health were stronger predictors of incident chronic insomnia compared to physical health. Higher scores in MMPI-2, indicating maladaptive personality traits, and excessive use of coffee at baseline predicted incident chronic insomnia. Polysomnographic variables, such as short sleep duration or sleep apnea, did not predict incident chronic insomnia. CONCLUSION: Mental health, poor sleep, and obesity, but not sleep apnea, are significant risk factors for incident chronic insomnia. Focusing on these more vulnerable groups and addressing the modifiable risk factors may help reduce the incident of chronic insomnia, a common and chronic sleep disorder associated with significant medical and psychiatric morbidity and mortality.
Yoshioka E, Saijo Y, Kita T, Satoh H, Kawaharada M and Kishi R (2012), "Effect of the Interaction Between Employment Level and Psychosocial Work Environment on Insomnia in Male Japanese Public Service Workers.", Int J Behav Med., Mar, 2012.
Abstract: BACKGROUND: Little is known about the combined risk of socioeconomic status and psychosocial environment for insomnia. PURPOSE: The purpose of this study was to investigate the combined risk of employment level and psychosocial work environment for insomnia in a large Japanese male working population. METHOD: We investigated 5,951 male employees aged 34-59 years from two local governments in Japan. Data were obtained from a questionnaire distributed in advance of their annual health check-up. Employment level was categorized as higher-level non-manual workers, lower-level non-manual workers, and manual workers. Psychosocial work environment was assessed using the Demand-Control Model and the Effort-Reward Imbalance Model (ERI). Insomnia was assessed using the Athens Insomnia Scale. RESULTS: The results showed that 1,382 (23.2 participants suffered from insomnia. Lower employment level was significantly associated with a higher risk of insomnia. Job strain (ratio of job demand to job control), E/R (ratio of job effort to job reward), and OC (over commitment) were also significantly associated with insomnia. The relative excess risk due to the interaction between employment level and psychosocial environment (job strain, E/R, and OC) was 0.09 (95 % CI -0.57 to 0.76), 2.61 (0.74 to 4.48), and 3.14 (0.82 to 5.45), respectively; synergy index?=?1.07 (0.66 to 1.74), 1.99 (1.37 to 2.90), and 2.25 (1.46 to 3.46), respectively. CONCLUSION: We found supra-additive interactions between employment level and psychosocial environment, assessed by the ERI (E/R and OC). Our findings suggested that lower level workers are more vulnerable to an adverse psychosocial environment than those at a higher level.
Methodology / Miscellaneous
Kidokoro H, Inder T, Okumura A and Watanabe K (2012), "What does cyclicity on amplitude-integrated EEG mean?", J Perinatol., Mar, 2012.
Abstract: In the context of amplitude-integrated electroencephalography (aEEG), the term 'sleep-wake cycling' (SWC), which is frequently used by clinicians and researchers, should be changed to 'cyclicity'. SWC is a technical term that refers to the biological pattern of alternating sleeping and waking states, which is difficult to define with only aEEG and no physical parameters. Additionally, the absence of cyclicity on aEEG is a more robust reflection of the sequence of the suppressed background patterns of an aEEG following cerebral injury or dysfunction than are sleep/wake states.Journal of Perinatology advance online publication, 22 March 2012; doi:10.1038/jp.2012.25.
Mariani S, Manfredini E, Rosso V, Grassi A, Mendez MO, Alba A, Matteucci M, Parrino L, Terzano MG, Cerutti S and Bianchi AM (2012), "Efficient automatic classifiers for the detection of A phases of the cyclic alternating pattern in sleep.", Med Biol Eng Comput., Mar, 2012.
Abstract: This study aims to develop an automatic detector of the A phases of the cyclic alternating pattern, periodic activity that generally occurs during non-REM (NREM) sleep. Eight polysomnographic recordings from healthy subjects were examined. From EEG recordings, five band descriptors, an activity descriptor and a variance descriptor were extracted and used to train different machine-learning algorithms. A visual scoring provided by an expert clinician was used as golden standard. Four alternative mathematical machine-learning techniques were implemented: (1) discriminant classifier, (2) support vector machines, (3) adaptive boosting, and (4) supervised artificial neural network. The results of the classification, compared with the visual analysis, showed average accuracies equal to 84.9 and 81.5% for the linear discriminant and the neural network, respectively, while AdaBoost had a slightly lower accuracy, equal to 79.4 The SVM leads to accuracy of 81.9 The performance achieved by the automatic classification is encouraging, since an efficient automatic classifier would benefit the practice in everyday clinics, preventing the physician from the time-consuming activity of the visually scoring of the sleep microstructure over whole 8-h sleep recordings. Finally, the classification based on learning algorithms would provide an objective criterion, overcoming the problems of inter-scorer disagreement.
Short MA, Gradisar M, Lack LC, Wright H and Carskadon MA (2012), "The discrepancy between actigraphic and sleep diary measures of sleep in adolescents.", Sleep Med., Mar, 2012.
Abstract: OBJECTIVE: To explore the discrepancy between sleep diary and actigraphic measures of sleep in adolescents and to ascertain whether these discrepancies may vary according to characteristics of the participant. METHODS: Participants were 385 adolescents aged 13-18years (X=15.6, standard deviation [SD]=0.95; 60% male) from eight high schools in South Australia. Adolescents completed the School Sleep Habits Survey and Pediatric Daytime Sleepiness Scale during class time, followed by an 8-day sleep diary and wrist actigraphy. The Flinders Fatigue Scale was completed on the final day of the study. Parents completed a sleep, medical, education, and family history survey. RESULTS: Actigraphic estimates of wake after sleep onset (WASO) were substantially greater than sleep diary estimates (74min actigraphy vs. 7min sleep diary) and actigraphic estimates of total sleep time were substantially less than sleep diary and parent report (6h 51min actigraphy vs. 8h 16min sleep diary vs. 8h 51 parent report). Actigraphy displayed no significant relationship with daytime functioning and weak relationships with concomitantly recorded sleep diary variables. Sex and puberty-related differences in actigraphic scoring were found, with more WASO and less sleep scored in boys compared to girls and more WASO scored amongst pubertally-mature boys than boys of less advanced pubertal development. CONCLUSIONS: There may be differences in the sleep of adolescents that result in less actigraphic total sleep scored than perceived, particularly in boys, possibly because of increased sleep motor activity in adolescents that actigraphic algorithms score as wake. This is a significant concern that requires further examination with polysomnography.
Zeng T, Mott C, Mollicone D and Sanford LD (2012), "Automated determination of wakefulness and sleep in rats based on non-invasively acquired measures of movement and respiratory activity.", J Neurosci Methods., Mar, 2012. Vol. 204(2), pp. 276-287.
Abstract: The current standard for monitoring sleep in rats requires labor intensive surgical procedures and the implantation of chronic electrodes which have the potential to impact behavior and sleep. With the goal of developing a non-invasive method to determine sleep and wakefulness, we constructed a non-contact monitoring system to measure movement and respiratory activity using signals acquired with pulse Doppler radar and from digitized video analysis. A set of 23 frequency and time-domain features were derived from these signals and were calculated in 10s epochs. Based on these features, a classification method for automated scoring of wakefulness, non-rapid eye movement sleep (NREM) and REM in rats was developed using a support vector machine (SVM). We then assessed the utility of the automated scoring system in discriminating wakefulness and sleep by comparing the results to standard scoring of wakefulness and sleep based on concurrently recorded EEG and EMG. Agreement between SVM automated scoring based on selected features and visual scores based on EEG and EMG were approximately 91% for wakefulness, 84% for NREM and 70% for REM. The results indicate that automated scoring based on non-invasively acquired movement and respiratory activity will be useful for studies requiring discrimination of wakefulness and sleep. However, additional information or signals will be needed to improve discrimination of NREM and REM episodes within sleep.
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