Portable PSG for sleep stage monitoring in sports: Assessment of SOMNOwatch plus EEG.

Current sport-scientific studies mostly neglect the assessment of sleep architecture, although the distribution of different sleep stages is considered an essential component influencing an athlete's recovery and performance capabilities. A mobile, self-applied tool like the SOMNOwatch plus EEG might serve as an economical and time-friendly alternative to activity-based devices. However, self-application of SOMNOwatch plus EEG has not been validated against conventional polysomnography (PSG) yet. For evaluation purposes, 25 participants (15 female, 10 male; M age = 22.92 ± 2.03 years) slept in a sleep laboratory on two consecutive nights wearing both, conventional PSG and SOMNOwatch plus EEG electrodes. Sleep parameters and sleep stages were compared using paired t-tests and Bland-Altman plots. No significant differences were found between the recordings for Sleep Onset Latency, stages N1 to N3 as well as Rapid Eye Movement stage. Significant differences (Bias [95%-confidence interval]) were present between Total Sleep Time (9.95 min [-29.18, 49.08], d = 0.14), Total Wake Time (-13.12 min [-47.25, 23.85], d = -0.28), Wake after Sleep Onset (-11.70 min [-47.25, 23.85], d = -0.34) and Sleep Efficiency (2.18% [-7.98, 12.34], d = 0.02) with small effect sizes. Overall, SOMNOwatch plus EEG can be considered a valid and practical self-applied method for the examination of sleep. In sport-scientific research, it is a promising tool to assess sleep architecture in athletes; nonetheless, it cannot replace in-lab PSG for all clinical or scientific purposes.

Nightmares do result in psychophysiological arousal: A multimeasure ambulatory assessment study.

Individuals who frequently experience nightmares report compromised sleep quality, poor daytime mood, and functioning. Previous research has aimed at linking these impairments with altered sleep architecture, but results were inconclusive. One plausible explanation is that only a few studies recorded markers of autonomic nervous system activity. For the first time, this study collected such markers under ecologically valid conditions with ambulatory assessment. In 19 individuals with frequent nightmares (≥1 nightmare/week) and 19 healthy control participants (<1 nightmare/month), measures indicating autonomic activation (heart rate, heart rate variability, respiration cycle length, electrodermal fluctuations, EEG arousals, saliva cortisol, REM density) were collected while applying ambulatory polysomnographic assessment during 3 consecutive nights. When nightmare participants reported a nightmare, we analyzed the last 5 min of REM sleep before awakening and compared these data to their non-nightmares as well as to the dream episodes of control participants. Overall, there were no general differences in autonomic activation of nightmare sufferers compared to control participants. However, when nightmare participants experienced nightmares, autonomic activation was markedly increased compared to their own non-nightmares and, to some extent, to control participant's dreams. Significant intraindividual differences were found for all autonomic measures except in participant's EEG arousals and cortisol levels. Group differences were found in EEG arousals and heart rate. In conclusion, ambulatory polysomnography demonstrates that nightmares are accompanied by increased autonomic activation. Results support the notion of impaired self-reported sleep quality caused by one's autonomic response rather than altered sleep pattern.

Relevance of electroencephalogram assessment in amyloid and tau pathology in rat.

In order to contribute to a better knowledge on the relationship between amyloid and tau pathology, and electroencephalography (EEG) disturbances, the aim of this study was to evaluate the effects of injection of beta amyloid Abeta(1-42) peptide, tau (a recombinant AAV (Adeno-Associated Virus) containing the human transgene tau with the P301 L mutation on rats and the combination of both, on the power of brain's rhythm (delta, theta, alpha, beta and gamma waves) during the different sleep/wake states of animals by EEG recording. Currently, no preclinical studies explore the effect of the tau pathology on EEG. The experimentations were performed 3 weeks and 3 months post injections. Beta amyloid deposits and hyperphosphorylated Tau are observed by immunohistofluorescence, only in the hippocampus. Furthermore, using a radial arm water maze, the main effect was observed on working memory which was significantly impaired in Abeta-Tau group only 3 months post injections. However, on EEG, as early as the 3rd week, an overall decrease of the EEG bands power was observed in the treated groups, particularly the theta waves during the rapid eye movement (REM) sleep. Beta amyloid was mainly involved in these perturbations. Obviously, EEG seems to be an interesting tool in the early diagnostic of amyloid and tau pathologies, with a good sensitivity and the possibility to perform a follow up during a large period.

Markov modeling of sleep stage transitions and ultradian REM sleep rhythm.

OBJECTIVE: One of the highly characteristic features of sleep is the cyclic occurrence of non-rapid eye movement (NREM) and REM sleep, which is referred to as the ultradian rhythm of sleep. Even though REM sleep was discovered over half a century ago, surprisingly, the mechanism of the ultradian REM sleep rhythm has not yet been fully elucidated. In the present study, we aim to provide a mechanistic insight into the generation of the ultradian REM sleep rhythm. Approach and Main results: By simulating hypnograms with the dynamic features of sleep stage transitions, i.e. stage transition probabilities and stage-specific survival time functions, we show that the second-order Markov transition probabilities and the stage-specific survival time functions can reproduce the central position (∼90 min) of the REM-onset intervals (ROIs), but with a larger variance in distribution. In addition, we demonstrate the direct effect of the increased probability of the transitions from light to deep sleep within NREM sleep on the prolongation of the ROIs in a dose-response manner. SIGNIFICANCE: These results suggest that dynamic sleep stage transitions constitute the basis of the formation of the ultradian rhythm of sleep; however, further elaboration of the model would be required to reduce the variability in rhythmicity.

Assessment of the septal area neuronal activity during penile erections in rapid eye movement sleep and waking in the rats.

To understand the central mechanism of penile erections during rapid eye movement (REM) sleep and waking, single units were recorded from the septal area in un-anesthetized head-restrained rats simultaneous with erections. Erectile events were assessed by pressure in the bulb of the corpus spongiosum of the penis and bulbospongiosus-muscle activity. Of 143 recorded neurons, 36% showed increased activity (E-type) and 24% decreased activity (I-type) during different phases of erection in REM sleep, while 10% were E-type and 35% were I-type during erections in waking. Most E-type neurons were recorded from the dorsal and intermediate part of lateral septum, whereas I-type neurons were from the medial septum. The findings illustrate the extensive network of various types of neurons in the septal area that fire in concert in relation to erection during REM sleep and waking. This study provides a unique prospective of the septal area for perpetuation of erectile circuitry during sleep.

Assessment of tolerance to the effects of methamphetamine on daytime and nighttime activity evaluated with actigraphy in rhesus monkeys.

RATIONALE: Methamphetamine is one of the most largely consumed illicit drugs, and its use is associated with abuse liability and several adverse health effects, such as sleep impairment. Importantly, sleep quality can influence addiction treatment outcomes. Evidence suggests that tolerance can develop to the sleep-disrupting effects of stimulant drugs. OBJECTIVE: The aim of the present study was to investigate the development of tolerance to the actigraphy-based sleep-disrupting and stimulant effects of methamphetamine self-administration in rhesus monkeys. METHODS: Methamphetamine (0.03 mg/kg/inf, i.v.) self-administration was carried out following three different protocols: 14 consecutive days of self-administration, 5 days/week for 3 weeks, with a 2-day interval between 5-day blocks of self-administration, and 3 days/week for 3 weeks, with a 4-day interval between 3-day blocks of self-administration. Daytime activity and activity-based sleep measures were evaluated with Actiwatch monitors a week before (baseline parameters) and throughout each protocol. RESULTS: Methamphetamine self-administration markedly disrupted sleep-like measures and increased daytime activity. Tolerance developed to those effects with repeated methamphetamine intake exceeding five consecutive days. Inclusion of washout periods (2 or 4 days) between blocks of methamphetamine self-administration attenuated the development of tolerance, with longer breaks from methamphetamine intake being more effective in maintaining the sleep-disrupting and stimulant effects of methamphetamine. CONCLUSIONS: Tolerance can develop to the stimulant and sleep-disrupting effects of methamphetamine self-administration. Interruption of drug intake extends the effects of methamphetamine on sleep-like measures and daytime activity.

Assessment of the suitability of using a forehead EEG electrode set and chin EMG electrodes for sleep staging in polysomnography.

Recently, a number of portable devices designed for full polysomnography at home have appeared. However, current scalp electrodes used for electroencephalograms are not practical for patient self-application. The aim of this study was to evaluate the suitability of recently introduced forehead electroencephalogram electrode set and supplementary chin electromyogram electrodes for sleep staging. From 31 subjects (10 male, 21 female; age 31.3 ± 11.8 years), sleep was recorded simultaneously with a forehead electroencephalogram electrode set and with a standard polysomnography setup consisting of six recommended electroencephalogram channels, two electrooculogram channels and chin electromyogram. Thereafter, two experienced specialists scored each recording twice, based on either standard polysomnography or forehead recordings. Sleep variables recorded with the forehead electroencephalogram electrode set and separate chin electromyogram electrodes were highly consistent with those obtained with the standard polysomnography. There were no statistically significant differences in total sleep time, sleep efficiency or sleep latencies. However, compared with the standard polysomnography, there was a significant increase in the amount of stage N1 and N2, and a significant reduction in stage N3 and rapid eye movement sleep. Overall, epoch-by-epoch agreement between the methods was 79.5%. Inter-scorer agreement for the forehead electroencephalogram was only slightly lower than that for standard polysomnography (76.1% versus 83.2%). Forehead electroencephalogram electrode set as supplemented with chin electromyogram electrodes may serve as a reliable and simple solution for recording total sleep time, and may be adequate for measuring sleep architecture. Because this electrode concept is well suited for patient's self-application, it may offer a significant advancement in home polysomnography.

Probabilistic characterization of sleep architecture: home based study on healthy volunteers.

The quantification of sleep architecture has high clinical value for diagnostic purposes. While the clinical standard to assess sleep architecture is in-lab based polysomnography, higher ecological validity can be obtained with multiple sleep recordings at home. In this paper, we use a dataset composed of fifty sleep EEG recordings at home (10 per study participant for five participants) to analyze the sleep stage transition dynamics using Markov chain based modeling. The statistical analysis of the duration of continuous sleep stage bouts is also analyzed to identify the speed of transition between sleep stages. This analysis identified two types of NREM states characterized by fast and slow exit rates which from the EEG analysis appear to correspond to shallow and deep sleep respectively.

Polysomnographic Assessment of Sleep Comorbidities in Drug-Naïve Narcolepsy-Spectrum Disorders--A Japanese Cross-Sectional Study.

This is a large cross-sectional study which aimed to investigate comorbidity rate, degree of sleep-related breathing disorder, polysomnigraphically diagnosible rapid eye movement sleep behavior disorder/rapid eye movement sleep without atonia and periodic limb movements during sleep in Japanese drug-naïve patients with narcolepsy-spectrum disorders. A total of 158 consecutive drug naïve patients with narcolepsy with cataplexy, 295 patients with narcolepsy without cataplexy and 395 patients with idiopathic hypersomnia without long sleep time were enrolled. From retrospectively analyzed data of nocturnal polysomnography and multiple sleep latency test, higher rates of periodic limb movements during sleep (> = 15 h(-1)) (10.2%) and polysomnographically diagnosable rapid eye movement sleep behavior disorder (1.9%) were found in patients with narcolepsy with cataplexy. They had more severe periodic limb movements during sleep especially during rapid eye movement sleep and higher percentages of rapid eye movement sleep without atonia than the other two patient groups. In the present large sample study, Japanese drug naïve patients with narcolepsy with cataplexy showed the highest comorbidity rates of periodic limb movements during sleep, polysomnographically diagnosable rapid eye movement sleep behavior disorder and rapid eye movement sleep without atonia among those with the other narcolepsy-spectrum disorders; the rates were lower than those for Western patients.

Endothelial Function Assessment in Patients with Erectile Dysfunction.

BACKGROUND: Erectile dysfunction (ED), a common problem in males of all ages, can be of organic, psychogenic or combined etiology. Organic ED is mainly caused by vascular and neurological disorders. One of the available tests for differentiating organic from inorganic ED is measuring penile tumescence and rigidity during the REM phase of sleep. However, this test lacks the ability to differentiate between a vascular and non-vascular cause of organic ED. OBJECTIVES: To compare the results of the EndoPAT test and the nocturnal penile tumescence (NPT) test in patients with erectile dysfunction. METHODS: Twenty patients with ED were recruited for the study. Each participant was evaluated by the SHIM score, RigiScan during polysomnography, and two EndoPAT tests (at the beginning and end of the study). RESULTS: Seventeen patients had a SHIM score 21; 4 of them had organic ED with a mean EndoPAT score of 1.49, significantly lower than the 1.93 mean EndoPAT score of the 11 patients in the psychogenic ED group (P = 0.047). Two participants had a neurological impairment (spinal trauma and herniated disk). The average SHIM score in the vascular organic group was 6.25 points as compared to 11.69 for the psychogenic group (P = 0.027). The positive predictive value was 43% and the negative predictive value 90%. CONCLUSIONS: EndoPAT could be helpful in excluding organic ED.

Chronic escitalopram treatment attenuated the accelerated rapid eye movement sleep transitions after selective rapid eye movement sleep deprivation: a model-based analysis using Markov chains.

BACKGROUND: Shortened rapid eye movement (REM) sleep latency and increased REM sleep amount are presumed biological markers of depression. These sleep alterations are also observable in several animal models of depression as well as during the rebound sleep after selective REM sleep deprivation (RD). Furthermore, REM sleep fragmentation is typically associated with stress procedures and anxiety. The selective serotonin reuptake inhibitor (SSRI) antidepressants reduce REM sleep time and increase REM latency after acute dosing in normal condition and even during REM rebound following RD. However, their therapeutic outcome evolves only after weeks of treatment, and the effects of chronic treatment in REM-deprived animals have not been studied yet. RESULTS: Chronic escitalopram- (10 mg/kg/day, osmotic minipump for 24 days) or vehicle-treated rats were subjected to a 3-day-long RD on day 21 using the flower pot procedure or kept in home cage. On day 24, fronto-parietal electroencephalogram, electromyogram and motility were recorded in the first 2 h of the passive phase. The observed sleep patterns were characterized applying standard sleep metrics, by modelling the transitions between sleep phases using Markov chains and by spectral analysis. Based on Markov chain analysis, chronic escitalopram treatment attenuated the REM sleep fragmentation [accelerated transition rates between REM and non-REM (NREM) stages, decreased REM sleep residence time between two transitions] during the rebound sleep. Additionally, the antidepressant avoided the frequent awakenings during the first 30 min of recovery period. The spectral analysis showed that the SSRI prevented the RD-caused elevation in theta (5-9 Hz) power during slow-wave sleep. Conversely, based on the aggregate sleep metrics, escitalopram had only moderate effects and it did not significantly attenuate the REM rebound after RD. CONCLUSION: In conclusion, chronic SSRI treatment is capable of reducing several effects on sleep which might be the consequence of the sub-chronic stress caused by the flower pot method. These data might support the antidepressant activity of SSRIs, and may allude that investigating the rebound period following the flower pot protocol could be useful to detect antidepressant drug response. Markov analysis is a suitable method to study the sleep pattern.

Statistical properties of sleep-wake behavior in the rat and their relation to circadian and ultradian phases.

STUDY OBJECTIVES: To examine the statistical characteristics of short-term sleep-wake architecture and to evaluate their dependence on ultradian and circadian phase. DESIGN: Observational, time series. SETTING: Laboratory. PARTICIPANTS: Ten male adult Sprague-Dawley rats. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: States of wakefulness (WAKE), rapid eye movement sleep (REM) and nonrapid eye movement sleep (NREM) were recorded in 5-sec epochs over 7 consecutive days. State bout durations were analyzed using parametric regression of survival curves, comparing exponential, biexponential, and power law models. WAKE survival curves were best fit by biexponential models, suggesting that there are two statistically distinct stochastic mechanisms generating two types of WAKE--"brief" WAKE and "long" WAKE. Exponential time constants varied as a function of circadian and ultradian phase, with "long" WAKE showing the largest effect. NREM survival curves exhibited biexponential and monoexponential distributions in light and dark, respectively, with weak effects of ultradian phase. REM survival curves approximated a monoexponential distribution that varied with circadian but not ultradian phase. χ(2) analysis was used in a three-state Markov model to evaluate whether conditional state transition probabilities exhibit the property of first-order dependence. This was partially confirmed, but only after accounting for heterogeneity associated with circadian and ultradian phase. However, there was evidence of residual second-order dependence indicating that additional sources of statistical heterogeneity may remain to be identified. CONCLUSIONS: Sleep-wake state is regulated over short timescales by stochastic mechanisms. When the major sources of heterogeneity are taken into account, including two-component WAKE and NREM states, the sleep-wake system of the rat behaves, to a reasonable approximation, as a Markovian system that is modulated over ultradian and circadian timescales.

Overnight energy expenditure determined by whole-body indirect calorimetry does not differ during different sleep stages.

BACKGROUND: Sleep has been associated with the regulation of energy balance, yet the relation between sleep stages and energy expenditure remains unclear. OBJECTIVE: The objective was to investigate the relation between sleep stages and energy expenditure, with sleep stage and overnight energy expenditure patterns taken into account. DESIGN: Thirteen subjects aged (mean ± SD) 24.3 ± 2.5 y with a BMI (in kg/m(2)) of 23.6 ± 1.7 slept in a respiration chamber while sleep was polysomnographically recorded to determine wake after sleep onset (WASO), slow-wave sleep (SWS), and rapid eye movement (REM) sleep. Energy expenditure was calculated during each sleep stage for the whole night and separately for sleeping metabolic rate (SMR; ie, 3-h period during the night with the lowest mean energy expenditure) and non-SMR. RESULTS: Energy expenditure and sleep stages showed characteristic patterns during the night, independently of each other. Sleep stages exerted no effect on energy expenditure during the whole night, except for WASO compared with SWS (P < 0.05) and WASO compared with REM sleep (P < 0.05). During the SMR and non-SMR periods of the night, no overall effect of sleep stage on energy expenditure, except for WASO compared with SWS (P < 0.05) and WASO compared with REM sleep (P < 0.01) during the non-SMR period of the night, was found. Energy expenditure and activity counts during the night were positively correlated (r = 0.927, P < 0.001). CONCLUSIONS: Energy expenditure does not vary according to sleep stage overnight, except for higher energy expenditure during wake episodes than during SWS and REM sleep. Coincidence of the sleep stage pattern and the overnight energy expenditure pattern may have caused accidental relations in previous observations. This trial was registered at http://apps.who.int/trialsearch as NTR2926.

Objective assessment of drowsiness and reaction time during intermittent Ramadan fasting in young men: a case-crossover study.

BACKGROUND: Ramadan fasting and its attendant lifestyle changes induce changes in the circadian rhythm and in associated physiological and metabolic functions. Previous studies that have assessed psychomotor performance during Ramadan fasting have reported conflicting results. Therefore, we designed this study to objectively assess the effects of intermittent fasting during and outside Ramadan (to control for lifestyle changes) on drowsiness, blink total duration and mean reaction time (MRT) test while controlling for potential confounders. METHODS: Eight healthy volunteers with a mean age of 25.3 ± 2.9 years and a mean body mass index (BMI) of 23.4 ± 3.2 kg/m2 reported to the sleep laboratory on four occasions for polysomnography (PSG) and drowsiness and psychomotor assessments as follows: 1) adaptation; 2) 4 weeks before Ramadan while performing the Islamic fasting for 1 week (baseline fasting) (BLF); 3) 1 week before Ramadan (non-fasting baseline) (BL); and 4) during the second week of Ramadan while fasting (Ramadan). OPTALERT™ was used to objectively assess daytime drowsiness using the Johns Drowsiness Scale (JDS), and blink total duration and a visual reaction time test were used to assess MRT. RESULTS: Rapid eye movement (REM) sleep percentage was significantly lower at BLF (17.7 ± 8.1%) and at Ramadan (18.6 ± 10.7%) compared with BL (25.6 ± 4.8%) (p < 0.05). There were no significant differences between JDS scores and blink total duration during the two test periods in BL, BLF and Ramadan. There were no significant changes in MRT during BL, BLF and Ramadan. CONCLUSIONS: Under controlled conditions of fixed light/dark exposure, caloric intake, sleep/wake schedule and sleep quality, the Islamic intermittent fasting has no impact on drowsiness and vigilance as measured by the JDS, total blink duration and MRT.

Manual quantitative assessment of amplitude and sleep stage distribution of excessive fragmentary myoclonus.

INTRODUCTION: Excessive fragmentary myoclonus (EFM) consists of brief, asynchronous, twitch-like movements appearing asymmetrically in sleep. The new AASM Manual for the Scoring of Sleep and Associated Events identifies some EFM scoring criteria but does not provide amplitude criteria for scoring EFM. Older observational series have used 50 µVs. We report data from various amplitude criteria using blinded comparisons. METHODS: EFMs were analyzed on the polysomnograms of 8 patients (7 men and 1 woman, mean age 57 years, range: 47-79) using a standardized protocol for sensitivity, tonus threshold, impedance, amplitude measurements, and sleep stage. The first 20 minutes each of wake, Stage 1-2, SWS, and REM were analyzed. EFMs ≥ 25, ≥ 40, and ≥ 50 microvolts (µVs) in negative deflection above the baseline were counted in tibialis anterior muscle electromyography (EMG) channels bilaterally. RESULTS: The mean EFM index per minute for wake, regardless of impedance, was: 7.19 ± 5.90 for ≥ 25 µV amplitude; 2.43 ± 2.02 for ≥ 40 µVs; and 2.08 ± 2.23 for ≥ 50 µVs. For sleep stages, the EFM index by stage and amplitude criteria used for measurements were: Stage 1-2: 7.38 ± 5.79 for ≥ 25 µVs; 3.13 ± 3.33 for ≥ 40 µVs; and 2.36 ± 2.66 for ≥ 50 µVs; SWS: 10.05 ± 8.04 for ≥ 25 µVs; 2.71 ± 3.13 for ≥ 40 µVs; and 1.38 ± 1.92 for ≥ 50 µVs; Total REM: 15.96 ± 11.32 for ≥ 25 µVs; 6.32 ± 4.25 for ≥ 40 µVs; and 3.94 ± 3.73 for ≥ 50 µVs; Phasic REM: 19.69 ± 15.45 for ≥ 25 µVs; 8.63 ± 7.06 for ≥ 40 µVs; and 5.52 ± 6.44 for ≥ 50 µVs; Non-phasic REM: 13.93 ± 11.31 for ≥ 25 µVs; 5.16 ± 3.57 for ≥ 40 µVs; and 3.20 ± 2.92 for ≥ 50 µVs. CONCLUSION: EFM rates increase with SWS and total REM with the highest EFM rates occurring during phasic REM. EFM rates were increased across all sleep stages when impedance was > 30 KΩ.

Assessing REM sleep in mice using video data.

STUDY OBJECTIVES: Assessment of sleep and its substages in mice currently requires implantation of chronic electrodes for measurement of electroencephalogram (EEG) and electromyogram (EMG). This is not ideal for high-throughput screening. To address this deficiency, we present a novel method based on digital video analysis. This methodology extends previous approaches that estimate sleep and wakefulness without EEG/EMG in order to now discriminate rapid eye movement (REM) from non-REM (NREM) sleep. DESIGN: Studies were conducted in 8 male C57BL/6J mice. EEG/EMG were recorded for 24 hours and manually scored in 10-second epochs. Mouse behavior was continuously recorded by digital video at 10 frames/second. Six variables were extracted from the video for each 10-second epoch (i.e., intraepoch mean of velocity, aspect ratio, and area of the mouse and intraepoch standard deviation of the same variables) and used as inputs for our model. MEASUREMENTS AND RESULTS: We focus on estimating features of REM (i.e., time spent in REM, number of bouts, and median bout length) as well as time spent in NREM and WAKE. We also consider the model's epoch-by-epoch scoring performance relative to several alternative approaches. Our model provides good estimates of these features across the day both when averaged across mice and in individual mice, but the epoch-by-epoch agreement is not as good. CONCLUSIONS: There are subtle changes in the area and shape (i.e., aspect ratio) of the mouse as it transitions from NREM to REM, likely due to the atonia of REM, thus allowing our methodology to discriminate these two states. Although REM is relatively rare, our methodology can detect it and assess the amount of REM sleep.

Validation of the Thai SCOPA-sleep scale for assessment of sleep and sleepiness in patients with Parkinson's disease.

OBJECTIVE: To validate the Thai version of the Scale for Outcomes in Parkinson 's disease-Sleep Scale (SCOPA-Sleep scale)for assessment of nighttime sleep problems (NSP) and daytime sleepiness (DS). MATERIAL AND METHOD: A Thai version of SCOPA-Sleep scale has been developed with the permission of the originator. Fifty-one patients with Parkinson's disease were asked to complete the Thai SCOPA-Sleep scale (consisting of NSP and DS sections), plus the Pittsburg Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS). A second group of twenty patients completed the Thai SCOPA-Sleep scale, twice, two weeks apart. The reliability and validity were subsequently analyzed. RESULTS: The Thai SCOPA-Sleep scale showed a Cronbach 's alpha coefficient of 0.87 and 0.74 for SCOPA-NSP and SCOPA-DS, respectively with no significant difference between initial and follow-up scores. The content validity of SCOPA-NSP and SCOPA-DS were 0.9 and 0.9, respectively. There was a strong correlation between the Thai SCOPA-NSP and PSQI as well as the Thai SCOPA-DS and ESS (p < 0.01 and p < 0.01, respectively). CONCLUSION: The Thai SCOPA-Sleep scale is a reliable, valid instrument for assessing NSP and DS

Intraindividual variability of REM sleep behavior disorder in Parkinson's disease: a comparative assessment using a new REM sleep behavior disorder severity scale (RBDSS) for clinical routine.

OBJECTIVES: To develop a polysomnographic video-based scale for rating the severity of REM sleep behavior disorder (RBD), to classify the severity of RBD and to determine the intraindividual variability of RBD in patients with Parkinson disease (PD). METHODS: Twenty PD patients identified with RBD were investigated with video-supported polysomnography (PSG). Seventy-three motor behavior events during REM sleep were graded visually and polysomnographically on an event-to-event basis according to categorical location of movements: "0" = no visible movement; "1" = slight movements or jerks "2" = movements involving proximal extremities, including violent behavior; "3" = axial involvement including bed falls. Vocalizations were rated as "1" for present or "0" for absent. Ratings were performed by 2 blinded raters. Reliability was calculated with Cohen's κ. Final RBD severity was determined by the highest score given. This rating scale was then used to compare RBD severity and density, calculated as RBD episodes per REM sleep minute over 2 consecutive nights in 10 additional PD patients with RBD. Statistical significance was determined by effect size (Hedges' g) and calculation of the confidence interval. RESULTS: Interrater reliability of the scale was 0.8 for movement data and 0.89 for vocalization data. Intraindividual RBD density varied significantly (effect size 0.5 ± 0.22; confidence interval 0.2 to 0.79) by factor 2.5 between the 2 PSG nights. Final RBD severity score differed in 60% of patients between nights 1 and 2. Forty percent of patients showed violent behavior, but only on one night. All patients had severely disturbed sleep with reduced sleep efficiency, loss of slow wave sleep, sleep fragmentation, and an increased periodic limb movement (PLM) index. CONCLUSION: The RBD severity scale (RBDSS) is a reliable, easy-to-use tool for assessing motor events during REM sleep with PSG. Severity and phenomenology of RBD shows a significant variability in the individual PD patient.

Home set-up polysomnography in the assessment of suspected obstructive sleep apnea.

Home set-up polysomnography (PSG) has advantages over other portable monitoring devices, but remains unendorsed by professional bodies despite excellent utility in the Sleep Heart Health Study (SHHS). The study aims to determine technical reliability and diagnostic accuracy of unattended, home set-up versus attended laboratory-based PSG in patients with suspected obstructive sleep apnea (OSA). Thirty patients with suspected OSA without significant co-morbidity were recruited. After initial lab-PSG (Compumedics S series), patients underwent home set-up PSG (Compumedics Siesta) and lab-based PSG in random order. Studies were compared for study success, signal loss and likelihood ratio for OSA diagnosis [apnea-hypopnea index (AHI) >10]. Thirty subjects (mean age 49±13.8 years, body mass index 31±6.1 kg m(-2) ) completed investigations. SHHS technical acceptability criteria were met by all lab-based PSGs and 90% of home-based PSGs (93% clinically acceptable). Signal loss was higher at home (P=0.008). Sleep efficiency was similar between sites, but more preferred home-based PSG (50%). ancova revealed AHI was significantly different if initial AHI >26 per h (P=0.006), with an average underestimate of 5.1 per h at home. In technically acceptable studies the likelihood ratios to 'rule in' and 'rule out' OSA were 8.1 and 0.1, respectively. Unattended, home set-up PSG is technically reliable and achieves excellent diagnostic utility. Signal loss was higher at home but mitigated by multi-channel redundancy. Success rate was similar to SHHS and superior to laboratory set-up home studies. Home set-up PSG is a valid alternative to laboratory-based PSG for suspected OSA.