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Interrater variability of sleep stage scorings has an essential impact not only on the reading of polysomnographic sleep studies (PSGs) for clinical trials but also on the evaluation of patients’ sleep. With the introduction of a new standard for sleep stage scorings (AASM standard) there is a need for studies on interrater reliability (IRR). The SIESTA database resulting from an EU-funded project provides a large number of studies ( n = 72; 56 healthy controls and 16 subjects with different sleep disorders, mean age ± SD: 57.7 ± 18.7, 34 females) for which scorings according to both standards (AASM and R&K) were done. Differences in IRR were analysed at two levels: (1) based on quantitative sleep parameter by means of intraclass correlations; and (2) based on an epoch-by-epoch comparison by means of Cohen’s kappa and Fleiss’ kappa. The overall agreement was for the AASM standard 82.0% (Cohen’s kappa = 0.76) and for the R&K standard 80.6% (Cohen’s kappa = 0.68). Agreements increased from R&K to AASM for all sleep stages, except N2. The results of this study underline that the modification of the scoring rules improve IRR as a result of the integration of occipital, central and frontal leads on the one hand, but decline IRR on the other hand specifically for N2, due to the new rule that cortical arousals with or without concurrent increase in submental electromyogram are critical events for the end of N2. [ABSTRACT FROM AUTHOR]

The objective was to examine potential trigger factors of migraine and tension-type headache (TTH) in clinic patients and in subjects from the population and to compare the patients’ personal experience with their theoretical knowledge. A cross-sectional study was carried out in a headache centre. There were 120 subjects comprising 66 patients with migraine and 22 with TTH from a headache outpatient clinic and 32 persons with headache (migraine or TTH) from the population. A semistructured interview covering biographic data, lifestyle, medical history, headache characteristics and 25 potential trigger factors differentiating between the patients’ personal experience and their theoretical knowledge was used. The most common trigger factors experienced by the patients were weather (82.5%), stress (66.7%), menstruation (51.4%) and relaxation after stress (50%). The vast majority of triggers occurred occasionally and not consistently. The patients experienced 8.9±4.3 trigger factors (range 0–20) and they knew 13.2±6.0 (range 1–27). The number of experienced triggers was smallest in the population group ( p=0.002), whereas the number of triggers known did not differ in the three study groups. Comparing theoretical knowledge with personal experience showed the largest differences for oral contraceptives (65.0 vs. 14.7%, p<0.001), chocolate (61.7 vs. 14.3%, p>0.001) and cheese (52.5 vs. 8.4%, p<0.001). In conclusion, almost all trigger factors are experienced occasionally and not consistently by the majority of patients. Subjects from the population experience trigger factors less often than clinic patients. The difference between theoretical knowledge and personal experience is largest for oral contraceptives, chocolate and cheese. [ABSTRACT FROM AUTHOR]

Presents a study that examined the involvement of the central nervous system (CRS) in myasthenia gravis (MG). Background on the disease; Possible mechanisms of CRS involvement in the disease; Benefits of a polysomnographic investigation for the detection of sleep-related breathing disorder in patients with (MG).

Actigraphy has been used for more than 60 years to objectively measure sleep–wake rhythms. Improved modern devices are increasingly employed to diagnose sleep medicine disorders in the clinical setting. Although less accurate than polysomnography, the chief advantage of actigraphs lies in the cost-effective collection of objective data over prolonged periods of time under everyday conditions. Since the cost of wrist actigraphy is not currently reimbursed, this method has not enjoyed wide acceptance to date. The present article provides an overview of the main clinical applications of actigraphy, including the recommendations of specialist societies. [ABSTRACT FROM AUTHOR]

Sleep and memory studies often focus on overnight rather than long‐term memory changes, traditionally associating overnight memory change (OMC) with sleep architecture and sleep patterns such as spindles. In addition, (para‐)sympathetic innervation has been associated with OMC after a daytime nap using heart rate variability (HRV). In this study we investigated overnight and long‐term performance changes for procedural memory and evaluated associations with sleep architecture, spindle activity (SpA) and HRV measures (R‐R interval [RRI], standard deviation of R‐R intervals [SDNN], as well as spectral power for low [LF] and high frequencies [HF]). All participants (N = 20, Mage = 23.40 ± 2.78 years) were trained on a mirror‐tracing task and completed a control (normal vision) and learning (mirrored vision) condition. Performance was evaluated after training (R1), after a full‐night sleep (R2) and 7 days thereafter (R3). Overnight changes (R2‐R1) indicated significantly higher accuracy after sleep, whereas a significant long‐term (R3‐R2) improvement was only observed for tracing speed. Sleep architecture measures were not associated with OMC after correcting for multiple comparisons. However, individual SpA change from the control to the learning night indicated that only "SpA enhancers" exhibited overnight improvements for accuracy and long‐term improvements for speed. HRV analyses revealed that lower SDNN and LF power was associated with better OMC for the procedural speed measure. Altogether, this study indicates that overnight improvement for procedural memory is specific for spindle enhancers, and is associated with HRV during sleep following procedural learning. [ABSTRACT FROM AUTHOR]

Sleep has been shown to promote memory consolidation driven by certain oscillatory patterns, such as sleep spindles. However, sleep does not consolidate all newly encoded information uniformly but rather "selects" certain memories for consolidation. It is assumed that such selection depends on salience tags attached to the new memories before sleep. However, little is known about the underlying neuronal processes reflecting presleep memory tagging. The current study sought to address the question of whether event-related changes in spectral theta power (theta ERSP) during presleep memory formation could reflect memory tagging that influences subsequent consolidation during sleep. Twenty-four participants memorized 160 word pairs before sleep; in a separate laboratory visit, they performed a nonlearning control task. Memory performance was tested twice, directly before and after 8 hr of sleep. Results indicate that participants who improved their memory performance overnight displayed stronger theta ERSP during the memory task in comparison with the control task. They also displayed stronger memory task-related increases in fast sleep spindle activity. Furthermore, presleep theta activity was directly linked to fast sleep spindle activity, indicating that processes during memory formation might indeed reflect memory tagging that influences subsequent consolidation during sleep. Interestingly, our results further indicate that the suggested relation between sleep spindles and overnight performance change is not as direct as once believed. Rather, it appears to be mediated by processes beginning during presleep memory formation. We conclude that theta ERSP during presleep memory formation reflects cortico-hippocampal interactions that lead to a better long-term accessibility by tagging memories for sleep spindle-related reprocessing. [ABSTRACT FROM AUTHOR]

Background Quantitative electroencephalogram (qEEG) recorded during cognitive tasks has been shown to differentiate between patients with Alzheimer's disease (AD) and healthy individuals. However, the association between various qEEG markers recorded during mnestic paradigms and clinical measures of AD has not been studied in detail. Objective To evaluate if 'cognitive' qEEG is a useful diagnostic option, particularly if memory paradigms are used as cognitive stimulators. Methods This study is part of the Prospective Registry on Dementia in Austria (PRODEM), a multicenter dementia research project. A cohort of 79 probable AD patients was included in a cross-sectional analysis. qEEG recordings performed in resting states were compared with recordings during cognitively active states. Cognition was evoked with a face-name paradigm and a paired-associate word list task, respectively. Relative band powers, coherence and auto-mutual information were computed as functions of MMSE scores for the memory paradigms and during rest. Analyses were adjusted for the co-variables age, sex, duration of dementia and educational level. Results MMSE scores explained 36-51% of the variances of qEEG-markers. Face-name encoding with eyes open was superior to resting state with eyes closed in relative theta and beta1 power as well as coherence, whereas relative alpha power and auto-mutual information yielded more significant results during resting state with eyes closed. The face-name task yielded stronger correlations with MMSE scores than the verbal memory task. Conclusion qEEG alterations recorded during mnestic activity, particularly face-name encoding showed the highest association with the MMSE and may serve as a clinically valuable marker for disease severity. [ABSTRACT FROM AUTHOR]

Background: The objective of this study was to assess the influence of nocturnal headaches (NH) on subjective sleep parameters prospectively in habitual snorers and their bed partners.Methods: We recruited habitual snorers and their bed partners via newspaper articles. The participants completed a semistructured interview, filled in questionnaires about quality of sleep (PSQI), daytime sleepiness (ESS), depression (SDS) and anxiety (SAS) and they kept a 90-day headache and sleep diary.Results: Seventy-six snorers (25 female) and 41 bed partners (31 female) completed the study recording a total of 6690 and 3497 diary days, respectively. NH were recorded on 222 (3.3%) and 79 (2.2%) days in 32 (42%) snorers and 17 (41%) bed partners, respectively. Snorers with NH showed significantly higher PSQI (5 ± 3 vs. 4 ± 2, p = 0.004), SAS (38 ± 11 vs. 31 ± 10, p = 0.011) and SDS scores (39 ± 12 vs. 34 ± 10, p = 0.048) than snorers without NH. For bed partners with NH we found a significant female predominance (sex ratio f:m = 16:1 vs. 12:12, p = 0.005) and significantly higher SAS scores (38 ± 6 vs. 33 ± 8, p = 0.030) compared with bed partners without NH. The subjective quality of sleep in habitual snorers (p < 0.001) as well as their bed partners (p = 0.017) was negatively influenced by NH, but not total sleep time.Discussion: NH occurred in around 40% of snorers and their bed partners at least once during the 90-day observation period. Our results confirmed a negative impact on the subjective quality of sleep in both groups. [ABSTRACT FROM AUTHOR]

Abstract: Objective: In several modern society duties individuals have to maintain their attention or vigilance over prolonged periods of time, even if the monitoring task is monotonous. The aim of our study was to obtain reference data on the 60-minute monotonous Siesta sustained attention test. Methods: Normative data were gathered in an age-stratified sample of 234 healthy participants (118 men; 116 women) between the ages of 20 and 79years. The impact of age, gender, time of day, and time on task during performance was analyzed. Results: At least 20 participants from each age group and gender group were tested either in the morning or in the afternoon. The sample sizes were only smaller in the age group of 70 to 79years. There was a notable age effect on all performance measures, with an increase in reaction times and false response rates from the youngest to the oldest group as well as a decrease in correct reactions with increasing age. Statistical analysis revealed no differences in speed and accuracy measures between men and women participants. There was no notable time-of-day effect but a clear impact of time-on-task speed and of correct reactions during the course of the test. The vigilance decrement had already occurred during the first half of the test. Conclusions: Our results provide a normative database of performance parameters for different age groups in healthy adult participants. As sustained attention is sensitive to sleep loss and nonrestorative sleep, our data can be used as a reference for performance-based assessment of daytime sleepiness in participants with hypersomnia. [Copyright &y& Elsevier]

Objectives: The Pupillographic Sleepiness Test (PST) measures the level of alertness based on spontaneous oscillations in pupillary size. Reference data are available for male and female adults within the age range 20-60 years. The aim of the present multicenter study was to extend the age range for reference data from 20 to 79 years. Methods: A total of 239 healthy subjects, selected from three different centers (Berlin, Regensburg, and Vienna), were administered the PST. Data were analyzed with respect to possible effects of age, gender, and time of day on the pupillary unrest index (PUI) and the pupil diameter (PD). Results: Reliable data were available in 85.8% of the entire study sample and in 82.4% of elderly subjects (60+ years). Age-related changes were identified for the PUI and PD. There was no effect of gender on pupillometric variables as revealed by univariate analysis. The PD was found to be smaller in the afternoon compared with the morning. However, if subjects aged 60+ years were excluded from the analyses, the age-related changes disappeared and a time-of-day effect regarding the PUI became apparent. Conclusions: PUI and PD were found to decrease with increasing age. In addition, the present data show that nonreliable PST data occur more frequently in the elderly probably because of dry eyes, inadequate testing conditions, and technical resolution limitations. Thus, the PST results obtained here from elderly subjects are limited and have to be interpreted with caution. Additional research on elderly specific assessment tools is needed. Am. J. Hum. Biol. 2012. © 2012Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Background: The prevalence and characteristics of morning headaches (MH) in habitual snorers are not well known, with only one retrospective study reporting MH in 23.5% of snorers. The role of MH in bed partners of snorers has not yet been examined. Therefore, the objective of this study was to assess MH prospectively in habitual snorers and their bed partners.Methods: We recruited habitual snorers and their bed partners via newspaper articles. The participants completed a semistructured interview, filled in questionnaires about sleep quality, daytime sleepiness, depression and anxiety and kept a 90-day headache and sleep diary.Results: We included a total of 102 snorers and 63 bed partners. Seventy-six snorers (25 female) and 41 bed partners (31 female) completed the study, recording a total of 6690 and 3497 diary days, respectively. MH was present on at least 1 day in 57% of the snorers and in 61% of the bed partners and recorded on 7.2% and 3.6% of the diary days, respectively. Independent predictors of MH in snorers were pre-study headache frequency (p < 0.001), anxiety disorder (p < 0.001), waking up because of pain (p = 0.002) and waking up too early (p < 0.001); and independent predictors in bed partners were migraine (p = 0.02), difficulties breathing during sleep (p < 0.001), waking up because of pain (p = 0.01) and waking up too early (p < 0.001). The analysis of couples only (n = 41) revealed pre-study headache frequency (p < 0.001), waking up too early (p < 0.001) and nocturnal confusion (p < 0.001) as independent predictors of MH in snorers, and migraine (p = 0.02), difficulties breathing during sleep (p < 0.001), waking up because of pain (p = 0.01) and waking up too early (p < 0.001) as independent predictors in bed partners.Discussion: MH shows a 90-day prevalence of around 60% in habitual snorers as well as in their bed partners. Predictors of MH are related to sleep, headache and psychiatric comorbidity. [ABSTRACT FROM PUBLISHER]

Background: In 2007, the AASM Manual for the Scoring of Sleep and Associated Events was published by the American Academy of Sleep Medicine (AASM). Concerning the visual classification of sleep stages, these new rules are intended to replace the rules by Rechtschaffen and Kales (R&K). Methods: We adapted the automatic R&K sleep scoring system Somnolyzer 24 × 7 to comply with the AASM rules and subsequently performed a validation study based on 72 polysomnographies from the Siesta database (56 healthy subjects, 16 patients, 38 females, 34 males, aged 21-86 years). Scorings according to the AASM rules were performed manually by experienced sleep scorers and semi-automatically by the AASM version of the Somnolyzer. Manual scorings and Somnolyzer reviews were performed independently by at least 2 out of 8 experts from 4 sleep centers. Results: In the quality control process, sleep experts corrected 4.8 and 3.7% of the automatically assigned epochs, resulting in a reliability between 2 Somnolyzer-assisted scorings of 99% (Cohen's kappa: 0.99). In contrast, the reliability between the 2 manual scorings was 82% (kappa: 0.76). The agreement between the 2 Somnolyzer-assisted and the 2 visual scorings was between 81% (kappa: 0.75) and 82% (kappa: 0.76). Conclusion: The AASM version of the Somnolyzer revealed an agreement between semi-automated and human expert scoring comparable to that published for the R&K version with a validity comparable to that of human experts, but with a reliability close to 1, thereby reducing interrater variability as well as scoring time to a minimum. Copyright © 2010 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Abstract: Objective: Cyclic alternating pattern (CAP) is defined as periodic EEG activity during NREM sleep that reflects unstable sleep and represents a marker of instability of the sleep process. The aim of the present investigation was to analyze sleep quality of 28 healthy subjects (mean age 53.3±21.3 years) over two consecutive nights and determine potential differences between them (“first-night effect”). Methods: Evaluations comprised objective and subjective sleep variables as well as macrostructural and microstructural variables of sleep. Results: Macrostructural analysis showed significant differences between the first and the second sleep laboratory night in REM latency (122.39±60.46min vs. 95.43±36.60min; T =3.431; p =0.002) and the amount of sleep stage 1 (42.60±21.80min vs. 39.70±18.95min; T =2.223; p =0.035). Microstructural analysis revealed a significant decrease in the CAP rate (1st night: 33.29%; 2nd night: 26.34%; T =3.288; p =0.003) and in the amount of subtype A2 (74.79±43.47 vs. 58.50±23.22; T =2.185; p =0.038). Subjective variables also demonstrated a significant increase of drive (T =2.564; p =0.016). Conclusion: Healthy subjects show hardly any macrostructural differences between the first and the second night in the sleep laboratory. On the microstructural level differences in CAP variables were found. Significance: Microstructural analysis can be seen as a further approach to the classification of sleep and CAP turned out to be sensitive to environmental influences on sleep. [Copyright &y& Elsevier]

Abstract: Background and purpose: Recent neuroimaging studies in narcolepsy discovered significant gray matter loss in the right prefrontal and frontomesial cortex, a critical region for executive processing. In the present study, event-related potential (ERP) low-resolution brain electromagnetic tomography (LORETA) was used to investigate cognition before and after modafinil as compared with placebo. Patients and methods: In a double-blind, placebo-controlled cross-over design, 15 patients were treated with a 3-week fixed titration scheme of modafinil and placebo. The Epworth Sleepiness Scale (ESS), Maintenance of Wakefulness Test (MWT) and auditory ERPs (odd-ball paradigm) were obtained before and after the 3weeks of therapy. Latencies, amplitudes and LORETA sources were determined for standard (N1 and P2) and target (N2 and P300) ERP components. Results: The ESS score improved significantly from 15.4 (± 4.0) under placebo to 10.2 (± 4.1) under 400mg modafinil (p =0.004). In the MWT, latency to sleep increased nonsignificantly after modafinil treatment (11.9±6.9 versus 13.3±7.1min). In the ERP, N2 and P300 latencies were shortened significantly. While ERP amplitudes showed only minor changes, LORETA revealed increased source strengths: for N1 in the left auditory cortex and for P300 in the medial and right dorsolateral prefrontal cortex. Conclusion: LORETA revealed that modafinil improved information processing speed and increased energetic resources in prefrontal cortical regions, which is in agreement with other neuroimaging studies. [Copyright &y& Elsevier]

Aim: The aim of the present study was the evaluation of actigraphy as a tool to objectify the recovery process after motor paresis due to stroke. Methods: The motor activity of both arms of patients suffering from stroke was actigraphically recorded at four different time points during the course of rehabilitation: 24–36 h, 5–7 days, 3 months, and 6 months after stroke. Results: Motor activity monitored by wrist-worn actigraphs located at the impaired side revealed an increase in activity between the first two time points and the subsequent ones. Additionally, actigraphic recordings showed lower total motor activity at the impaired side as compared to the nonimpaired side. A significant positive correlation was found between the actigraphically recorded motor activity and the results of the Scandinavian Stroke scale, the Barthel Index, the Rankin Scale Score and with the Motoricity Index during the 1st week, which corresponds to the time when neurological deficits were most pronounced. Conclusion: Our results suggest that actigraphy is a useful tool in the objective evaluation of motor activity after stroke. Moreover, actigraphy covers additional aspects that are not reflected by the usual stroke scales in a clinical situation. Copyright © 2008 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Abstract: Objective: Event-related potentials (ERPs) are sensitive measures of both perceptual and cognitive processes. The aim of the present study was to identify brain regions involved in the processes of cognitive dysfunction in narcolepsy by means of ERP tomography. Methods: In 17 drug-free patients with narcolepsy and 17 controls, ERPs were recorded (auditory odd-ball paradigm). Latencies, amplitudes and LORETA sources were determined for standard (N1 and P2) and target (N2 and P300) ERP components. Psychometry included measures of mental performance, affect and critical flicker fusion frequency (CFF). Results: In the ERPs patients demonstrated delayed cognitive N2 and P300 components and reduced amplitudes in midline regions, while N1 and P2 components did not differ from controls. LORETA suggested reduced P300 sources bilaterally in the precuneus, the anterior and posterior cingulate gyri, the ventrolateral prefrontal cortex and the parahippocampal gyrus. In psychometry, patients demonstrated deteriorated mood, increased trait anxiety, decreased CFF and a trend toward reduced general verbal memory and psychomotor activity. Conclusions: Narcoleptic patients showed prolonged information processing, as indexed by N2 and P300 latencies and decreased energetic resources for cognitive processing. Significance: Electrophysiological aberrations in brain areas related to the ‘executive attention network’ and the ‘limbic system’ may contribute to a deterioration in mental performance and mood at the behavioral level. [Copyright &y& Elsevier]

Abstract: Objective: To elucidate the relationship between excessive daytime sleepiness (EDS) in obstructive sleep apnea (OSA) and carotid atherosclerosis determined by ultrasonography and serum surrogate markers. Methods: One hundred and forty-seven patients (102 males) with snoring and sleep-disordered breathing were investigated. Carotid atherosclerosis was evaluated by serum analysis of high-sensitivity C-reactive protein and fibrinogen and four sonographic indices: intima media thickness (IMT) of the common carotid artery (CCA), IMT from the bulb to the internal carotid artery (ICA), combined IMT measurements from all segments and a plaque score. EDS was assessed by the Epworth Sleepiness Scale (ESS). Pearson correlation analysis, intergroup comparison (ANOVA) and two multiple regression models explored associations between confounders, surrogate markers and EDS. Results: Forty-four patients had no OSA (apnea–hypopnea index AHI<5h−1), 27 mild (5–15), 25 moderate (15–30) and 51 severe OSA (>30). The ESS significantly distinguished severe OSA from non-OSA patients (p =0.003). It showed significant correlations with the BMI, HbA1c, systolic RR, the AHI, sleep time spent with an oxygen saturation <90%, the respiratory arousal index, IMT of the CCA and combined IMT measurements, but no correlation with serum markers. The ESS was found to be an independent predictor of CCA-IMT in the pre-polysomnographic multiple regression model (p =0.008), but not in the post-polysomnographic model after including respiratory variables. Conclusion: EDS is associated with obesity, diabetes and all respiratory variables in OSA patients and may serve as an independent predictor of carotid atherosclerosis before polysomnography. [Copyright &y& Elsevier]

Abstract: We reported earlier that overnight change in explicit memory is positively related to the change in sleep spindle activity (between a control and a learning night). However, it remained unclear whether this effect was restricted to good memory performers and whether a general association of sleep spindles and a “sleep-related learning trait” may not account for this effect. Here we now present a secondary and more detailed analysis of our randomized multicenter study. Subjects were studied over a 4-week study period (including actigraphy and daily sleep diaries), including three overnight stays in the sleep laboratory. In the course of the study, subjects completed test-batteries of memory (Wechsler-Memory-Scale-revised; WMS) and other cognitive abilities (Raven''s Advanced-Progressive-Matrices; APM) and were asked to study 160 word pairs in the evening before being tested by cued-recall. Afterwards, subjects went to bed in the laboratory with full polysomnographic montages. Additionally, subjects participated on another occasion in a non-learning control (perceptual priming) task that was counterbalanced either before or after the learning condition. Slow as well as fast spindle activities were analyzed at frontopolar and central topographies. Although it was found that spindle activity is generally (in learning as well as control nights) elevated in highly gifted subjects, spindle analyses revealed that spindle increase (control to learning night) is specifically related to explicit memory improvement overnight, independent of individual learning traits. Together these findings suggest that the spindle increase after learning is related to elaborate encoding before sleep, whereas an individual''s general learning ability is well reflected in interindividual (and trait-like) differences of absolute sleep spindle activity. [Copyright &y& Elsevier]

Couples sleeping in pairs is a modern phenomenon with potential side-effects on sleep structure and circadian rhythms. In order to examine its effects, 10 healthy heterosexual couples with stable relationships who regularly sleep apart or together in their home environments were recruited. The participants were asked to spend at least 10 nights alone and 10 nights together over the course of the study. Their sleep was monitored over 28 days in their homes with actigraphic techniques and sleep diaries. Group analyses were performed on their sleep efficiency and subjective sleep quality according to sleep condition. The daily variations in sleep fragmentation indices of the partners were used as a measure of their nocturnal activity synchronization. Sharing a sleeping space with a partner had negative effects on sleep in women, as documented in the actigraphic measurements of sleep efficiency and subjective assessments of sleep and awakening quality. Sexual contact mitigated the negative subjective report, without changing the objective results. Subjective assessments of sleep quality were lower in men than women when sleeping alone. They increased to the same level as women while sleeping in pairs with or without sexual contact. The sleep efficiency in men was not reduced by the presence of their partner unless sexual contact occurred. Analyses of sleep fragmentation showed that there was no synchronization of deviation from the norm levels between the partners on individual nights either when they slept alone or in couples. The sex differences in the nocturnal sleep reactions to partner presence may be attributed to sex-specific behavioral traits associated with cultural norms or parenting in women and the desire for group sleep in men. [ABSTRACT FROM AUTHOR]

Abstract: Low-resolution brain electromagnetic tomography (LORETA) showed a functional deterioration of the fronto-temporo-parietal network of the right hemispheric vigilance system in narcolepsy and a therapeutic effect of modafinil. The aim of this study was to determine the effects of modafinil on cognitive and thymopsychic variables in patients with narcolepsy and investigate whether neurophysiological vigilance changes correlate with cognitive and subjective vigilance alterations at the behavioral level. In a double-blind, placebo-controlled crossover design, EEG-LORETA and psychometric data were obtained during midmorning hours in 15 narcoleptics before and after 3 weeks of placebo or 400 mg modafinil. Cognitive investigations included the Pauli Test and complex reaction time. Thymopsychic/psychophysiological evaluation comprised drive, mood, affectivity, wakefulness, depression, anxiety, the Symptom Checklist 90 and critical flicker frequency. The Multiple Sleep Latency Test (MSLT) and the Epworth Sleepiness Scale (ESS) were performed too. Cognitive performance (Pauli Test) was significantly better after modafinil than after placebo. Concerning reaction time and thymopsychic variables, no significant differences were observed. Correlation analyses revealed that a decrease in prefrontal delta, theta and alpha-1 power correlated with an improvement in cognitive performance. Moreover, drowsiness was positively correlated with theta power in parietal and medial prefrontal regions and beta-1 and beta-2 power in occipital regions. A less significant correlation was observed between midmorning EEG LORETA and the MSLT; between EEG LORETA and the ESS, the correlation was even weaker. In conclusion, modafinil did not influence thymopsychic variables in narcolepsy, but it significantly improved cognitive performance, which may be related to medial prefrontal activity processes identified by LORETA. [Copyright &y& Elsevier]

Introduction Subjective sleep perception, as measured against objective parameters such as those obtained by polysomnography, have not been examined thoroughly to date. Little is known about subjective sleep perception in patients with chronic somatic diseases. Patients and methods Patients with Parkinson's disease (PD) and healthy elderly controls filled in a sleep log over 14 days, which included a self-rating questionnaire concerning sleep and quality of time awake, sleep times and somatic complaints. All participants underwent polysomnography in the sleep lab on nights 7 and 8, and slept all other nights at home. Results Seventeen patients with PD (64±6 years, 6 female, Hoehn and Yahr median=2), and 62 healthy controls of the same age without sleep disturbances (64±8 years, 36 female) were included. Patients with PD showed reduced subjective sleep (p=0.001) and quality of time awake (p=0.02), decreased sleep duration (p=0.01) and reduced sleep efficiency (p=0.004) compared with the controls. Subjective sleep efficiency at home was no different from that in the sleep lab for both groups. Patients with PD reported more somatic complaints (p=0.001) than controls but did not show a first-night effect. Conclusion In summary, patients with PD have subjectively and objectively disturbed sleep as compared to healthy controls of the same age. However, they may not rate this poor sleep as much changed from their baseline sleep at home, and they have more somatic complaints. Increasing sleep efficiency might be of importance in PD patients, as it shows an association with subjective quality of time awake in the morning. [ABSTRACT FROM AUTHOR]

To date, the only standard for the classification of sleep-EEG recordings that has found worldwide acceptance are the rules published in 1968 by Rechtschaffen and Kales. Even though several attempts have been made to automate the classification process, so far no method has been published that has proven its validity in a study including a sufficiently large number of controls and patients of all adult age ranges. The present paper describes the development and optimization of an automatic classification system that is based on one central EEG channel, two EOG channels and one chin EMG channel. It adheres to the decision rules for visual scoring as closely as possible and includes a structured quality control procedure by a human expert. The final system (Somnolyzer 24 × 7™) consists of a raw data quality check, a feature extraction algorithm (density and intensity of sleep/wake-related patterns such as sleep spindles, delta waves, SEMs and REMs), a feature matrix plausibility check, a classifier designed as an expert system, a rule-based smoothing procedure for the start and the end of stages REM, and finally a statistical comparison to age- and sex-matched normal healthy controls (Siesta Spot Report™). The expert system considers different prior probabilities of stage changes depending on the preceding sleep stage, the occurrence of a movement arousal and the position of the epoch within the NREM/REM sleep cycles. Moreover, results obtained with and without using the chin EMG signal are combined. The Siesta polysomnographic database (590 recordings in both normal healthy subjects aged 20–95 years and patients suffering from organic or nonorganic sleep disorders) was split into two halves, which were randomly assigned to a training and a validation set, respectively. The final validation revealed an overall epoch-by-epoch agreement of 80% (Cohen’s kappa: 0.72) between the Somnolyzer 24 × 7 and the human expert scoring, as compared with an inter-rater reliability of 77% (Cohen’s kappa: 0.68) between two human experts scoring the same dataset. Two Somnolyzer 24 × 7 analyses (including a structured quality control by two human experts) revealed an inter-rater reliability close to 1 (Cohen’s kappa: 0.991), which confirmed that the variability induced by the quality control procedure, whereby approximately 1% of the epochs (in 9.5% of the recordings) are changed, can definitely be neglected. Thus, the validation study proved the high reliability and validity of the Somnolyzer 24 × 7 and demonstrated its applicability in clinical routine and sleep studies. Copyright © 2005 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

One of the aims of the SIESTA project was to establish a normative database of sleep parameters for healthy and sleep-disturbed patients. Reference data for sleep parameters in non-sleep-disturbed subjects are scarce and usually refer to means and standard deviations. However, since most of the parameters do not follow a Gaussian distribution, percentiles of the distribution provide more detailed information.The present results are based on data from 198 healthy, non-sleep-disturbed subjects (104 females) in the age range of 20 to 95 years. For every subject, two consecutive nights were polysomnographically recorded in one of the eight participating clinical centres. Percentile charts were created on the basis of moving averages computed for 10 year age intervals with the presented age being the midpoint of the underlying interval. The resulting percentile curves were smoothed by a spline function. Since sample size in the oldest age groups is comparatively small, the percentile curves are restricted to the age range of 20 to 80 years.Percentile curves have been created for the parameters sleep period time (SPT), total sleep time (TST), sleep onset latency, REM sleep latency, sleep efficiency index, and percentages of NREM1, NREM2, REM sleep, SWS, and WAKE (with reference to SPT). The charts reflect the known changes of sleep parameters with age, e.g. decrease of TST and sleep efficiency with increasing age.The reference charts are intended to be a helpful tool to evaluate selected aspects of sleep quality in sleep-disturbed patients. [ABSTRACT FROM AUTHOR]

The aim of the present study was to investigate the role of EEG mapping as an objective and quantitative measure of vigilance in untreated and modafinil-treated narcoleptics, and compare it with the conventional neurophysiological method of the Multiple Sleep Latency Test (MSLT) and the subjective Epworth Sleepiness Scale (ESS). In 16 drug-free narcoleptics and 16 normal controls a baseline 3-min vigilance-controlled EEG (V-EEG) and a 4-min resting EEG (R-EEG) were recorded during midmorning hours. Thereafter, in a double-blind, placebo-controlled crossover design, patients were treated with a 3-week fixed titration of modafinil (200, 300, 400 mg) and placebo. EEG-mapping, MSLT and ESS measures were obtained before and at the end of the third week of therapy. Statistical overall analysis by means of the omnibus significance test demonstrated significant EEG differences between untreated patients and controls in the resting condition only (R-EEG). Subsequent univariate analysis revealed an increase in absolute and relative theta power, a decrease in alpha-2 and beta power as well as a slowing of the dominant frequency and the centroids of the alpha, beta and total power spectrum and thus objectified a vigilance decrement in narcolepsy. Modafinil 400 mg/d significantly improved vigilance as compared with placebo (p = 0.01), inducing changes opposite to the aforementioned baseline differences (key-lock principle). The MSLT and the ESS also improved under modafinil as compared with placebo, but changes were less consistent. Spearman rank correlations revealed the highest correlations between EEG mapping and the ESS, followed by those between EEG mapping and the MSLT, while the lowest correlation was found between the MSLT and the ESS. In conclusion, EEG mapping is a valuable instrument for measuring vigilance decrements in narcolepsy and their improvement under psychostimulant treatment. [ABSTRACT FROM AUTHOR]

Objectives Along with spindles, K-complexes are well known hallmarks of stage 2 (S2) sleep. However, little is known about their quantity in S2 sleep of patients with Parkinson's disease (PD). Setting Sleep laboratory, Department of Neurology, University of Vienna, Austria. Patients and methods Whole-night polysomnography (PSG) was performed in twelve treated PD patients and ten healthy controls without history of sleep complaints. The quantity of spontaneous K-complexes, K-alpha-complexes, and sleep spindles in one hour S2 sleep, distributed in four epochs of 15 minutes all through the night, were visually selected and analysed. The quantity and the temporal course of these phasic events were compared with the quantity in age-matched healthy controls. Nine of the twelve PD patients underwent [123I]Β-CIT SPECT for calculating dopamine transporter binding in the striatum and serotonin transporter density in the thalamus-hypothalamus region. Results There was no difference between the quantity of K-complexes, K-alpha-complexes, and sleep spindles in PD patients and in the healthy control group. K-complexes but not sleep spindles decreased over the night in both groups. The number of sleep spindles did not correlate with the dopamine transporter binding in the striatum or the serotonin binding in the thalamic/hypothalamic region. Conclusion K-complexes and sleep spindles are not reduced and do not seem to be related to the degree of dopaminergic degeneration in treated PD patients. [ABSTRACT FROM AUTHOR]

Dopaminergic agents such as ropinirole are the drugs of first choice in treating restless legs syndrome (RLS). Recently, gabapentin, a structural analogue of γ-aminobutyric acid, has also been shown to improve sensorimotor symptoms in RLS. Therefore, the tolerability and efficacy of randomized treatment with either gabapentin or ropinirole in patients with idiopathic RLS was evaluated in this 4-week open clinical trial. Patients with idiopathic RLS were treated with either 300 mg of gabapentin (n = 8) or 0.5 mg of ropinirole (n = 8) as the initial dose, and the dose was up-titrated until relief of symptoms was achieved (gabapentin mean dosage 800 ± 397 mg, range 300–1,200 mg; ropinirole mean dosage 0.78 ± 0.47 mg, range 0.25–1.50 mg). In both groups, International Restless Legs Syndrome Study Group questionnaire scores improved significantly (p ≤ 0.018), whereas the scores of the Epworth sleepiness scale remained unchanged within normal limits. Polysomnographic data showed a reduction of periodic leg movements during sleep (PLMS; p < 0.03) and PLMS index (p < 0.02) in both groups. Side effects were only mild and mostly transient. After 6–10 months of follow-up, in most patients, RLS symptoms were still improved. We conclude that gabapentin and ropinirole provide a similarly well-tolerated and effective treatment of PLMS and sensorimotor symptoms in patients with idiopathic RLS.Copyright © 2003 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Investigates the role of sleep in memory consolidation. Involvement of the hippocampal formation in memory consolidation during sleep; Electroencephalography studies during sleep; Experience-dependent changes in cerebral activation during human rapid eye movement sleep.

Summary: Many studies investigating sleep and memory consolidation have evaluated full‐night sleep rather than alternative sleep periods such as daytime naps. This multi‐centre study followed up on, and was compared with, an earlier full‐night study (Schabus et al., 2004) investigating the relevance of daytime naps for the consolidation of declarative and procedural memory. Seventy‐six participants were randomly assigned to a nap or wake group, and performed a declarative word‐pair association or procedural mirror‐tracing task. Performance changes from before to after a 90‐min retention interval filled with sleep or quiet wakefulness were evaluated between groups. Associations between performance changes, sleep architecture, spindles, and slow oscillations were investigated. For the declarative task we observed a trend towards stronger forgetting across a wake period compared with a nap period, and a trend towards memory increase over the full‐night. For the procedural task, accuracy was significantly decreased following daytime wakefulness, showed a trend to increase with a daytime nap, and significantly increased across full‐night sleep. For the nap protocol, neither sleep stages, spindles, nor slow oscillations predicted performance changes. A direct comparison of day and nighttime sleep revealed that daytime naps are characterized by significantly lower spindle density, but higher spindle activity and amplitude compared with full‐night sleep. In summary, data indicate that daytime naps protect procedural memories from deterioration, whereas full‐night sleep improves performance. Given behavioural and physiological differences between day and nighttime sleep, future studies should try to characterize potential differential effects of full‐night and daytime sleep with regard to sleep‐dependent memory consolidation. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented commenting on the case report of the 68-year-old man suffering from jumping stump syndrome in a lower limb with a history of arterial hypertension and peripheral arterial occlusive disease.

The precise etiology of the restless legs syndrome (RLS) is unknown. Sensory and motor symptoms of RLS worsen during evening/night, coincident with the physiological peak of pineal melatonin excretion. Decreased melatonin levels have been reported in insomnia, which is an associated feature of RLS. Melatonin substitution improved insomnia. A potential association between the idiopathic RLS (iRLS) and alterations in melatonin excretion was therefore explored. Daytime (7:00–22:00 hr) and night-time (22:00–7:00 hr) urinary excretion of 6-OH-melatonin-sulfate (aMLTs) was measured in 15 patients with iRLS and 11 controls by a radioimmunoassay. There was no significant difference between daytime and night-time urinary aMLTs excretion in iRLS as compared with controls (daytime: 6.14 ± 5.20 ng versus 5.02 ± 5.11 ng, NS; night-time: 21.07 ± 17.05 ng versus 22.92 ± 16.52 ng, NS). Our data do not provide evidence for a decrease of cumulative melatonin production in iRLS. Insomnia in RLS does not seem to be correlated with a deficit of melatonin. [ABSTRACT FROM AUTHOR]

Describes the progesterone treatment of a woman with a most likely congenital myopathy and shows that interdisciplinary cooperation can be productive. Symptoms presented by the patient; Medical history; Overview of myopathy; Progesterone dosage.

There is growing evidence of the active involvement of sleep in memory consolidation. Besides hippocampal sharp wave-ripple complexes and sleep spindles, slow oscillations appear to play a key role in the process of sleep-associated memory consolidation. Furthermore, slow oscillation amplitude and spectral power increase during the night after learning declarative and procedural memory tasks. However, it is unresolved whether learning-induced changes specifically alter characteristics of individual slow oscillations, such as the slow oscillation up-state length and amplitude, which are believed to be important for neuronal replay. 24 subjects (12 men) aged between 20 and 30 years participated in a randomized, within-subject, multicenter study. Subjects slept on three occasions for a whole night in the sleep laboratory with full polysomnography. Whereas the first night only served for adaptation purposes, the two remaining nights were preceded by a declarative word-pair task or by a non-learning control task. Slow oscillations were detected in non-rapid eye movement sleep over electrode Fz. Results indicate positive correlations between the length of the up-state as well as the amplitude of both slow oscillation phases and changes in memory performance from pre to post sleep. We speculate that the prolonged slow oscillation up-state length might extend the timeframe for the transfer of initial hippocampal to long-term cortical memory representations, whereas the increase in slow oscillation amplitudes possibly reflects changes in the net synaptic strength of cortical networks. [ABSTRACT FROM AUTHOR]