Sleep Medicine

Editorial Board

2010-09-01

Electronic media use and sleep in school-aged children and adolescents: A review

Neralie Cain, Michael Gradisar — 2010-09-01

Abstract: Electronic media have often been considered to have a negative impact on the sleep of children and adolescents, but there are no comprehensive reviews of research in this area. The present study identified 36 papers that have investigated the relationship between sleep and electronic media in school-aged children and adolescents, including television viewing, use of computers, electronic gaming, and/or the internet, mobile telephones, and music. Many variables have been investigated across these studies, although delayed bedtime and shorter total sleep time have been found to be most consistently related to media use. A model of the mechanisms by which media use may affect sleep is presented and discussed as a vehicle for future research.

Perception of sleepiness before falling asleep

Anna Anund, Torbjörn Åkerstedt — 2010-09-01

Sleepiness is well established as a cause of road crashes in registered data through crash studies . Long term video recordings in field trials also confirm this . Sleepiness may be an even stronger cause of road crashes than alcohol, and the two interact in a dramatic way . From a preventive and legal point of view, the individual’s awareness of this state is a very important question. The paper of Herrmann et al. in this issue of Sleep Medicine demonstrates that this awareness may be surprisingly low. However, the paper raises several important issues that need discussion. The paper describes an experiment using the Maintenance of Wakefulness Test (MWT) as a setting in which participants pressed a button to signal the perception of “signs of sleepiness.” This signal was compared to the occurrence of the first “fragment of sleep” (FSF). The latter was defined as a “sleep EEG” (presumably theta activity) >3s, plus closed eyes and lack of movement. More often than not the subjects failed to signal before the FSF. The authors concluded from the frequent inability to predict the FSF that it is possible to fall asleep without prior awareness.

The riddle of the sphinx: Sleep, pain, and depression

Michael T. Smith, Phillip J. Quartana — 2010-09-01

In this issue of Sleep Medicine, Chung et al. report on associations between sleep-related parameters and pain in participants with an acute major depressive episode. The authors highlight the growing recognition of the active role that sleep plays in the trajectory of both depression and clinical pain. Chung et al. found that compared to baseline, sleep was correlated more robustly with pain at three months (i.e., following pharmacotherapy for depressive symptoms) and that baseline wake after sleep onset time and changes in total sleep time correlated with changes in pain. These data provide momentum for future studies to determine whether prophylactic sleep-specific interventions can diminish pain above and beyond traditional pharmacotherapy or behavioral interventions for depression.

Sleepiness is not always perceived before falling asleep in healthy, sleep-deprived subjects

2010-09-01

Abstract: Objective: To test whether subjects spontaneously signal sleepiness before falling asleep under monotonous conditions.Methods: Twenty-eight healthy students were deprived of sleep for one night and then underwent a “maintenance-of-wakefulness test” (MWT) consisting of four 40-min trials. They were told to give a signal as soon as they felt sleepy and to try to stay awake as long as possible. In a first series of tests, the subjects were given no reward (nr); in a second series, monetary rewards (wr) were given both for an accurate perception of sleepiness and for staying awake longer.Results: Seventeen of the 28 subjects (60.7%) did not signal sleepiness before a sleep fragment occurred in at least one of the four MWT trials. Women were more reliably aware of sleepiness than men in the nr trials (p=.02), while the men’s performance improved in the wr trials (p<.02), becoming equivalent to the women’s performance.Conclusions: Our results cast doubt on the general assumption that one cannot fall asleep without feeling sleepy first. If similar results can be obtained in monotonous driving or working situations, this will imply that accidents caused by sleepiness or by falling asleep cannot necessarily be attributed to an individual’s negligence.

Relationship between insomnia and pain in major depressive disorder: A sleep diary and actigraphy study

Ka-Fai Chung, Kwok-Chu Tso — 2010-09-01

Abstract: Objectives: Insomnia and pain are frequent complaints during the course of a major depressive episode. We analyzed the association between insomnia and pain symptoms using subjective and objective sleep measures.Methods: This is a prospective, naturalistic follow-up study in a university-based psychiatric unit. Ninety-one Chinese patients were enrolled during an acute episode of major depressive disorder (mean age=48years, 73 women); 82 of them were reassessed 3months later using the same assessment on sleep, pain, depressive, and anxiety symptoms. Clinician-rated insomnia symptoms were obtained using the insomnia items of the Hamilton Rating Scale for Depression. Subjective sleep disturbances were assessed using the Insomnia Severity Index (ISI). Detailed sleep pattern was acquired using sleep diary and actigraphy. Pain intensity was evaluated using a verbal rating scale, a visual analog scale, and a multidimensional pain scale.Results: Cross-sectional analyses found that insomnia symptoms and quantitative sleep parameters were related to pain symptoms. The correlations between sleep and pain scores were more significant after 3months of pharmacotherapy as compared to baseline. After controlling for the severity of anxiety and depression, the ISI total score and actigraphy-derived wake after sleep onset and total sleep time remained significant in predicting pain.Conclusion: This study supports specific role of subjective sleep disturbances and actigraphic measures in predicting pain symptoms in major depressive disorder. Further studies using a micro-longitudinal design are necessary to find out the causal relationship between sleep and pain in depressed patients.

Double-blind, randomized, placebo controlled trial on the effect of 10 days low-frequency rTMS over the vertex on sleep in Parkinson’s disease

Pablo Arias, Jamile Vivas, Kenneth L. Grieve, Javier Cudeiro — 2010-09-01

Abstract: Objective: A recent report indicates repetitive transcranial magnetic stimulation (rTMS) improves sleep in Parkinson’s disease (PD). The aim of this work is to evaluate the effect of 10days rTMS on sleep parameters in PD patients.Methods: Double-blind, placebo-controlled design. Eighteen idiopathic PD patients completed the study. Sleep parameters were evaluated through actigraphy and the Parkinson’s Disease Sleep Scale (PDSS), along with depression (Hamilton Depression Rating Scale, HDS), and the Unified Parkinson’s Disease Rating Scale (UPDRS). Evaluations were carried out before treatment with rTMS (pre-evaluation, PRE), after the rTMS treatment programme (post-evaluation, POST), and one week after POST (POST-2). Nine PD patients received real rTMS and the other 9 received sham rTMS daily for 10days, (100 pulses at 1Hz) applied with a large circular coil over the vertex.Results: Stimulation had no effect over actigraphic variables. Conversely PDSS, HDS, and UPDRS were significantly improved by the stimulation. Notably, however, these changes were found equally in groups receiving real or sham stimulation.Conclusions: rTMS, using our protocol, has no therapeutic value on the sleep of PD patients, when compared to appropriate sham controls. Future works assessing the possible therapeutic role of rTMS on sleep in PD should control the effect of placebo.

Assessing the reliability and validity of a newly developed insomnia treatment satisfaction questionnaire (ITSAT-Q)

2010-09-01

Abstract: Purpose: To produce a valid insomnia treatment satisfaction questionnaire (ITSAT-Q) to assess treatment satisfaction with pharmacotherapy for use in patients with insomnia.Patients and methods: Items developed for a self-administered questionnaire were analyzed using exploratory factor analysis (EFA), which produced 5 dimensions. Confirmatory factor analysis was used to verify results from EFA, and structural equation modeling was used to test the hypothesized relationship among the dimensions. Data were collected from patients as part of a Sleep Research Project from January 2008 until October of 2008.Results: Approximately 69.8% of the sample (n=298) was female. Item-to-total correlations were 0.66 for convenience, ranged from 0.52 to 0.62 for expectations, from 0.54 to 0.69 for value, from 0.50 to 0.57 for effectiveness, and from 0.58 to 0.72 for treatment satisfaction. All standardized parameter estimates from confirmatory factor analysis were significant (p<0.01). Goodness of fit measures for the final structural equation model were χ2=45.2 (d.f.=45); p=0.465; CFI=1.00; TLI=1.00; and RMSEA=0.004. Treatment satisfaction was a strong and significant predictor of value, and effectiveness was a strong predictor of treatment satisfaction (p<0.01). Expectations were a strong and equal predictor of both treatment satisfaction and value (p<0.001).Conclusion: The ITSAT-Q provided acceptable results for instrument reliability and validity. Findings from this study will provide additional insight regarding patient perceptions of treatment satisfaction and other related therapeutic dimensions to help prescribers assess pharmacotherapy.

Sleep maintenance insomnia complaints predict poor CPAP adherence: A clinical case series

Emerson M. Wickwire, Michael T. Smith, Sandra Birnbaum, Nancy A. Collop — 2010-09-01

Abstract: Background: Although CPAP is a highly efficacious treatment for obstructive sleep apnea (OSA), low adherence presents a significant challenge for sleep medicine clinicians. The present study aimed to evaluate the relationship between insomnia symptoms and CPAP use. We hypothesized that pre-treatment insomnia complaints would be associated with poorer CPAP adherence at clinical follow-up.Methods: This was a retrospective chart review of 232 patients (56.5% men, mean age=53.6±12.4years) newly diagnosed with OSA (mean AHI=41.8±27.7) and prescribed CPAP in the Johns Hopkins Sleep Disorder Center. Difficulty initiating sleep, difficulty maintaining sleep, and early morning awakening were measured via three self-report items. CPAP use was measured via objective electronic monitoring cards.Results: Thirty-seven percent of the sample reported at least one frequent insomnia complaint, with 23.7% reporting difficulty maintaining sleep, 20.6% reporting early morning awakening and 16.6% reporting difficulty initiating sleep. After controlling for age and gender, sleep maintenance insomnia displayed a statistically significant negative relationship with average nightly minutes of CPAP use (p<.05) as well as adherence status as defined by the Centers for Medicaid and Medicare Services (p<.02).Conclusions: To our knowledge, these are the first empirical data to document that insomnia can be a risk factor for poorer CPAP adherence. Identifying and reducing insomnia complaints among patients prescribed CPAP may be a straightforward and cost-effective way to increase CPAP adherence.

Insomnia symptoms and CPAP compliance in OSAS patients: A descriptive study using Data Mining methods

Xuân-Lan Nguyên, Joël Chaskalovic, Dominique Rakotonanahary, Bernard Fleury — 2010-09-01

Abstract: Background: Obstructive Sleep Apnoea Syndrome (OSAS) and insomnia are common pathologies sharing a high comorbidity. CPAP is a cumbersome treatment. Yet, CPAP compliance must remain optimal in order to reverse excessive daytime sleepiness and prevent the cardiovascular consequences of OSAS. But chronic insomnia could negatively affect CPAP compliance.Objective: To assess the consequences of insomnia symptoms on long-term CPAP use.Methods: A prospective study was conducted on 148 OSAS patients (RDI=39.0±21.3/h), age=54.8±11.8years, BMI=29.1±6.3kg/m2, Epworth Score=12.2±5.4, on CPAP. Using the Insomnia Severity Index (ISI) as an indicator of insomnia (ISI⩾14=moderate to severe insomnia) and baseline data (anthropometric data, sleeping medication intakes, CPAP compliance, Epworth, Pittsburgh Sleep Quality and ISI scores, polygraphic recording data), Data Mining analysis identified the major rules explaining the features “High” or “Low ISI” and “High” or “Low Use” in the groups defined, according to the median values of the ISI and the 6th month-compliance, respectively.Results: Median ISI was 15 and median 6th month-compliance was 4.38h/night. Moderate to severe insomnia complaint was found in 50% of patients. In the “High” and “Low ISI,” the 6th month-compliance was not significantly different (3.7±2.3 vs 4.2±2.3h/night). In the classification models of compliance, the ISI was not a predictor of CPAP rejection or of long-term use, the predictor for explaining CPAP abandonment being the RDI, and the predictor of the 6th month-compliance being the one month-compliance.Conclusion: Insomnia symptoms were highly prevalent in OSAS patients, but had no impact on CPAP rejection or on long-term compliance.

Restless legs syndrome in end-stage renal disease: Clinical characteristics and associated comorbidities

2010-09-01

Abstract: Background: Despite being frequently described in patients with end-stage renal disease (ESRD), clinical characteristics and comorbidities in association with restless legs syndrome (RLS) are still to be confirmed.Objectives: The aim of this study was to investigate clinical factors associated with RLS in ESRD patients in hemodialysis.Methods: This is a cross-sectional study of 400 patients on hemodialysis, evaluating RLS, clinical features and other sleep abnormalities.Results: Out of 400, 86 patients presented RLS (21.5%; mean age 48.8±13.8y), being more frequent in females (p<0.005). Forty-eight individuals (12% mean age 50.7±13.1y) had moderate/severe RLS, 14 reported symptoms prior to hemodialysis, 13 described family history of RLS, and eight described symptoms as disturbing during dialysis. RLS cases showed lower hemoglobin (p<0.005), poorer quality of sleep (Pittsburgh Sleep Quality Index >5, p=0.002), higher scores on the Beck Depression Inventory Scale (p<0.005), greater scores on the Charlson Comorbidity Index (p=0.01) and the Epworth Sleepiness Scale (p=0.001) and higher risk of obstructive sleep apnea (OSA; Berlin questionnaire, p=0.01). Hypertension was more frequent in cases with moderate/severe RLS (p=0.01) and remained after controlling for the risk of OSA (p=0.02).Conclusion: In ESRD patients in hemodialysis, RLS is present in 21.5%; 16% report symptoms prior to hemodialysis and a family history of RLS. Symptoms are disturbing during hemodialysis in 9% of cases. RLS is associated with lower hemoglobin, worse sleep quality, excessive daytime sleepiness, depressive symptoms and higher risk of OSA. Hypertension is associated with moderate/severe RLS.

Effects of NREM sleep instability on cognitive processing

2010-09-01

Abstract: Objective: Cyclic alternating pattern (CAP) A1 subtypes, characterized by high-voltage slow waves, are generated by the frontal cortex and are suspected to have a role in cognitive processing during NREM sleep. Conversely, CAP A2 and A3 subtypes are characterized by variable amounts of rapid EEG potentials arising from the parietal–occipital areas and often coincide with arousals. We tested the hypothesis that CAP subtypes differentially correlate with cognitive functions.Subjects and methods: Eight healthy participants were recruited. Two nocturnal polysomnography studies and a series of neuropsychological tests were obtained in the subjects during the morning and afternoon of the first day and on the morning of the second day.Results: In agreement with our original hypothesis, we found that CAP A1 subtypes were correlated with better neuropsychological functioning the day after, for verbal fluency, working memory, and both delayed recall and recognition of words. These same neuropsychological test results were found to be negatively correlated with CAP A2 subtypes. CAP A3 subtypes were negatively correlated with the Trial Making test Parts A and B.Conclusions: The results suggest that CAP A1 might be related to better cognitive functioning, whereas CAP A2 and A3 correlated with worse cognitive functioning. Further studies are needed to better understand how CAP influences cognitive performance, especially frontally-dependent functions and memory.

Introduction to Images in Sleep Medicine

2010-09-01

Epilepsy with continuous spikes and waves during slow wave sleep in a child diagnosed with pervasive developmental disorder-not otherwise specified

2010-09-01

A 9-year-old boy with an unremarkable birth history, normal neurological examination and a neurodevelopmental history for language delay was diagnosed at 3years of age with atypical autism, also known as pervasive developmental disorder-not otherwise specified (PDD-NOS). In 2005, at 4years of age, he was referred to an outside hospital for a 24-h ambulatory EEG recording to evaluate multiple nocturnal events associated with vomiting and lethargy. Initial EEG findings suggested left sided frontal and temporal sharp waves. Despite weekly speech therapy, he continued to exhibit expressive language delays and a failure to gain developmental milestones. From 2005 to 2009 he had multiple abnormal EEG recordings demonstrating epileptiform activity during sleep. A video-EEG monitoring session eventually lead to the correct diagnosis of continuous spike waves in slow wave sleep (CSWS). At the time of the diagnostic EEG he was taking daily vitamin D, calcium, B12 and l-carnitine, and his child neurologist had recently initiated valproate and diazepam at night to treat the CSWS.

The evidence that cyclic alternating pattern subtypes affect cognitive functioning is very weak

Gregory D. Roach, Diana Carolina Cicua Navarro, Charli Sargent — 2010-09-01

In their recent paper, Ferri et al. examined the relationships between cognitive functioning and three subtypes of the cyclic alternating pattern (CAP) in non-REM sleep. They concluded that “CAP A1 subtypes are associated with higher [i.e., better] cognitive functioning, whereas CAP A3 subtypes are associated with lower [i.e., poorer] cognitive functioning” (p. 378). For the reasons summarised below, we contend that this conclusion is not warranted based on the data presented.

Response to “The evidence that cyclic alternating pattern subtypes affect cognitive functioning is very weak”

2010-09-01

We thank Dr. Roach and colleagues for their comments on our paper on the effects of sleep fragmentation on cognitive processing . It is evident that they do not take into full consideration previously published reports on the association between cyclic alternating pattern (CAP) and cognitive processing. For example, Marshall et al. have recently shown that transcranial application of intermittent trains of slow (0.75Hz) oscillating potentials during the initial phase of sleep cycle can induce significant improvements in memory . These intermittent trains of slow-wave oscillations closely mimic CAP A1 subtypes observed during natural sleep. There is also additional evidence that CAP slow components are associated with enhancements of memory .

Sleep quality in CCU patients after controlling for environmental factors

Ahmed S. BaHammam — 2010-09-01

Schiza et al. have recently reported sleep patterns in patients with acute myocardial infarction (AMI) using full-night polysomnography (PSG) within 3days of the acute event and 6months later . The authors referred to our study that addressed the same topic with the same methodology; however, they stated that our study recruited heterogeneous group of patients and did not control for circadian rhythm disturbances and associated sleep disorders that may influence sleep quality . In fact, Schiza et al. followed the same methodology, protocol, inclusion and exclusion criteria we used in our study. We studied a homogenous group of 20 patients with first-ever-AMI who underwent full-night PSG in the sleep disorders center within 3days of the acute event and 6months later. We excluded patients with poor cardiac function, patients on ionotropes, confused patients, patients who had received sedatives or narcotics within the previous 48h, post-cardiac-arrest patients, patients with chronic obstructive pulmonary disease (COPD), history of psychiatric disorders, stroke, or sepsis, patients who complained of chest pain on the day of the study, patients who reported a previous history of insomnia, choking attacks during sleep, or sleep apnea, as well as those with excessive daytime sleepiness. Schiza et al. applied the same protocol we described in our paper to avoid “first-night-effect.” Additionally, we controlled for the effects of disturbed light–dark cycle, as all participants were kept in single rooms with windows, and the light was dimmed every night at 9PM. On the day of the sleep study, the patients were instructed to minimize napping after 11AM, and the assigned nurse was asked to objectively document the time and duration of any nap after 11AM . As both studies used a highly selected group of patients, the results of both studies cannot be generalized to all CCU patients.

Sleep in acute coronary syndrome patients

Sophia E. Schiza, Charalampos Mermigkis — 2010-09-01

The aim of our recently published study was to assess nocturnal sleep in acute coronary syndrome patients away from the Critical Care Unit (CCU) environment and to evaluate potential connection with the disease process. This topic was previously assessed by BaHammam et al. , although there are significant differences between these studies related to the study protocol-population and the measures taken to avoid environmental factors that may influence sleep quality and quantity. The first essential difference is related to the time points selected for polysomnographic (PSG) evaluation. BaHammam et al. performed the initial PSG 2.9±1.4days after the acute event and a second follow up PSG six months later. On the other hand, we used three time points of PSG evaluation, namely 3days after the acute event and 2 additional time points during the follow up period (1month and 6months later).The use of an additional PSG during the beginning of the follow up period is crucial, giving an insight into the evolution of sleep architecture alteration in a relatively short time period (1month) after the acute event. The second difference is related to measures taken to avoid environmental factors (circadian rhythm, emotional stress, etc.) in the two studies. BaHammam et al. tried to control for the effects of disturbed light–dark cycle, as all participants were kept in single rooms with windows, and the light was dimmed every night at 9PM. On the day of the sleep study, the patients were instructed to minimize napping after 11AM, and the assigned nurse was asked to document in writing the time and duration of any nap after 11AM. In addition we performed continuous video recording to document normal sleep schedule before the sleep study in conjunction with the nurse’s report. Our CCU psychologist tried to minimize emotional stress by giving psychological support. Our study population is different from that of BaHammam. Our statement that BaHammam recruited a heterogeneous group of patients was based on the data provided in the above study. Their inclusion criteria were strict and possibly somewhat similar to ours, but some of the data do not support this. The main question is if patients included in BaHammam study had Obstructive Sleep Apnea (OSA) or not. They state that OSA patients were excluded although there are no data available related to the apnea–hypopnea index or nocturnal oxygen saturation parameters of the studied population. On the other hand, the data in the first PSG showed a high arousal index (44.5±4.5/hour) with a spontaneous arousal index (18.5±2.4/hour). What about the rest of the scored arousals? A possible explanation is that the remaining arousals were related to respiratory events or leg movements that usually represent the majority of scored arousals in routine sleep studies. In regard to limb movement related arousals, BaHammam et al. did not report restless legs syndrome (RLS) patients or periodic limb movement disorder (PLMD) cases in the exclusion criteria as was clearly done in our study. Another unusual feature is the fact that the increased arousal index persisted in the 6month PSG (total arousal index 25.3±2.4/hour with spontaneous arousal index only 2.7±0.5/hour), indicating the persistence of the previously suspected underlying sleep disorder. In conclusion, the question remains whether the included patients actually had OSA (even mild) or another sleep disorder (such as RLS or PLMD) that may result in significant alterations in sleep macro- and microarchitecture. The increased arousal index (after the exclusion of spontaneous arousals) in the initial and the follow up PSGs seems to suggest the latter.

News and announcement

2010-09-01