摘要:

SUMMARYThe conventional approach to the analysis of human sleep uses a set of pre‐defined rules to allocate each 20 or 30‐s epoch to one of six main sleep stages. The application of these rules is performed either manually, by visual inspection of the electroencephalogram and related signals, or, more recently, by a software implementation of these rules on a computer. This article evaluates the limitations of rule‐based sleep staging and then presents a new method of sleep analysis that makes no such use of pre‐defined rules and stages, tracking instead the dynamic development of sleep on a continuous scale. The extraction of meaningful features from the electroencephalogram is first considered, and for this purpose a technique called autoregressive modelling was preferred to the more commonly‐used methods of band‐pass filtering or the fast Fourier transform. This is followed by a qualitative investigation into the dynamics of the electroencephalogram during sleep using a technique for data visualization known as a self‐organizing feature map. The insights gained using this map led to the subsequent development of a new, quantitative method of sleep analysis that utilizes the pattern recognition capabilities of an artificial neural network. The outputs from this network provide a second‐by‐second qualification of the sleep/wakefulness continuum with a resolution that far exceeds that of rule‐based sleep staging. This is demonstrated by the neural network's ability to pinpoint micro‐arousals and highlight periods of severely disturbed sleep caused by certain sleep disorders. Both these phenomena are of considerable clinical value, but neither are scored satisfactorily using rul

ISSN:0962-1105    

DOI:10.1111/j.1365-2869.1996.00201.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

SUMMARYIt has been suggested that two types of insomnia, sleep onset insomnia and early morning awakening insomnia, may be caused by delays and advances respectively of circadian rhythms. Evidence supports the circadian rhythm phase delay of sleep onset insomniacs. The present study investigated the phase timing of circadian rhythms of early morning awakening insomniacs compared with a group of age matched good sleepers. A 24‐h bed rest laboratory session was used to evaluate the endogenous core body temperature and urinary melatonin rhythms. Objective and subjective sleepiness were also measured every 30 min across the session with 10 min multiple sleep latency tests and Stanford Sleepiness Scale. Maximum and minimum phases of each individual's rhythm were identified using two‐component cosine curve fitting. Compared with the good sleepers, the insomniacs had significant phase advances of 2 4 h for the temperature and melatonin rhythms. However, the 0‐4 h advances of the sleepiness rhythms were not significant. This latter unexpected result was explained on the basis of variability of sleepiness measures. It was suggested that early morning awakening insomnia arises from phase advanced circadian rhythms which evoke early arousal's from

ISSN:0962-1105    

DOI:10.1111/j.1365-2869.1996.00211.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

SUMMARYThe brain has been reported to be more preoccupied with dreams during phasic than during tonic REM sleep. Whether these periods also differ in terms of the processing of external stimuli was examined. Event‐related brain potentials (ERPs) to a frequent standard tone of 1000 Hz (P= 97%) and infrequent deviant tones of 1100 and 2000 Hz (P= 1.5% for each) were recorded (n= 13) during wakefulness and nocturnal sleep. An ERP wave (called REM‐P3) resembling a waking P3 wave was larger for the 2000 Hz deviant during tonic than during phasic REM sleep. Also the P210 wave was larger during tonic than during phasic REM sleep. A reliable mismatch negativity component appeared only in wakefulness. In summary, these results support the hypothesis that the brain is more ‘open’ for changes in an auditory input during tonic than phasic RE

ISSN:0962-1105    

DOI:10.1111/j.1365-2869.1996.00220.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

SUMMARYA postal questionnaire survey aimed at exploring the relationship between accidents and daytime sleepiness was sent to 9000 male drivers of which 4621 (51.3%) responded (mean age 47.7, SD 17.1). Drivers provided details of the accidents they had experienced in the last 3 y, and identified those factors, including tiredness, they thought contributed to the accident. In addition, drivers completed the Epworth scale measuring daytime sleepiness and reported whether they had felt close to falling asleep whilst driving during the past 12 mo. Analysis of the data showed that 29% of drivers had felt close to falling asleep at the wheel in the last 12 mo, the probability of which depended on Epworth score, age, occupational group, annual mileage, the proportion of time spent driving on motorways and in built‐up areas, how long the driver is prepared to drive before taking a break, and whether the driver is driving a company car o r not. Overall, about 7% of accident ‘involvements’ were associated with tiredness (representing 9‐10Y0 of accidents)‐a figure which is higher on motorways than on rural roads or built‐up roads and higher still in the early hours of the morning. Accident rates of company car drivers and for those who have felt close to falling asleep at the wheel in the last year are shown to be associated with daytime sleepiness. For example, a company car driver who has felt close to falling asleep at the wheel in the last 12 mo and who scores highly on the Epworth scale has an accident liability which is 70% higher than a similar driver who scores zero on the Epworth scale. Snoring every night increases accident liability by

ISSN:0962-1105    

DOI:10.1111/j.1365-2869.1996.00229.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

SUMMARYSleep deprivation (SD) for one night induces mood improvement in depressed patients. However, relapse often occurs on the day after deprivation subsequently to a sleep episode. In light of the possible involvement of central serotonin (5–hydroxytryptamine, 5‐HT) neurotransmission in both depression and sleep mechanisms, we presently investigated, in the rat, the effects of SD and recovery sleep on the electrophysiological response of 5–HT neurons in the nucleus raphe dorsalis (NRD) to an acute challenge with the 5–HT reuptake blocker citalopram. In all rats, citalopram induced a dose–dependent inhibition of the firing of NRD neurons recorded under chloral hydrate anaesthesia. After SD, achieved by placing rats in a slowly rotating cylinder for 24 h, the inhibitory action of citalopram was significantly reduced (with a concomitant 53% increase in its ED5, value). After a recovery period of 4 h, a normal susceptibility of the firing to citalopram was restored. The decreased sensitivity of 5‐HT neuronal firing to the inhibitory effect of citalopram after SD probably results in an enhancement of 5‐HT neurotransmission. Such an adaptive phenomenon (similar to that reported after chronic antidepressant treatment), and its normalization after recovery sleep, parallel the mood improvement effect of SD and the subsequent relapse observed in depressed patients. These data suggest that the associated changes in 5–HT autocontrol of the firing of NRD serotoninergic neurons are relevant to the antidepressa

ISSN:0962-1105    

DOI:10.1111/j.1365-2869.1996.00238.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

SUMMARYWe evaluated the performance of the static‐charge‐sensitive bed (SCSB), a non‐ invasive movement sensor, in detecting nocturnal periodic movement activity using simultaneous bilateral anterior tibialis electromyography (EMG,) as a reference. Two different study setups were used, one with 500 random record extracts, another with 10 continuous recordings. The inter‐rater reliability between two independent scorers was 0.92 in scoring EMG, and 0.91 in scoring SCSB. In an epoch based analysis, depending on the study setup and scorer, the sensitivity of the SCSB to detect periodic leg movements was 0.81‐0.94 whereas the specificity was 0.84‐0.89. In a movement‐by‐movement analysis, despite incomplete concordance between the two methods the total number of movements per hour were comparable. Our findings support the use of the SCSB as a non‐invasive alternative to anterior tibialis EMG recordings to reveal the presence of nocturnal periodic movement activity and estim

ISSN:0962-1105    

DOI:10.1111/j.1365-2869.1996.00246.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

SUMMARYTo attempt a categorization of sleep disorders in children, we developed a 27 item Likert‐type rating scale (Sleep Disturbance Scale for Children: SDSC) and assessed the psychometric properties was developed. The scale was distributed to the mothers of 1304 children (1157 controls, mean age 9.8y; 147 sleep disorder subjects, mean age 9.2y, composed of four clinical groups: Insomnia 39 subjects, Hypersomnia 12 subjects, Respiratory disturbances during sleep 25 subjects and Parasomnias 71 subjects). The internal consistency was high in controls (0.79) and remained at a satisfactory level in sleep disorder subjects (0.71); the test/retest reliability was adequate for the total (r = 0.71) and single item scores. The factor analysis (variance explained 44.21%) yielded six factors which represented the most common areas of sleep disorders in childhood and adolescence. Enuresis was the only item with a factor loading lower than 0.40 and with a low inter‐item correlation and was therefore eliminated, resulting in a final scale of 26 items. The re‐evaluation of the sample, using the factor scores, supported the validity and the discriminating capacity of the scales between controls and the four clinical groups. The correlation between factor scores corroborated the hypothesis that childhood sleep disturbances are not independent entities nor do they cluster into different groupings related to each other. The SDSC appears to be a useful tool in evaluating the sleep disturbances of school‐age children in clinical and non‐clinical po

ISSN:0962-1105    

DOI:10.1111/j.1365-2869.1996.00251.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

SUMMARYWe investigated dopamine D, receptors in the putamen and caudate nucleus with positron emission tomography in six patients with narcolepsy and five healthy controls using [11C]NNC 756 as ligand. The caudate‐to‐cerebellum and putamen‐to‐cerebellum ratios of [11C]NNC 756 were within normal limits in patients with narcolepsy. No evidence of increased D1, receptor binding in narcolepsy wa

ISSN:0962-1105    

DOI:10.1111/j.1365-2869.1996.00262.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

SUMMARYPupillometry has a long but inconclusive history as a means of measuring human alertness. Spontaneous pupillary oscillations in narcoleptics and the sleep deprived are a recognized but quantitatively elusive indication of alertness. Stimulation of the pupillary light reflex (PLR) has provided contradictory or confusing indications of alertness levels. Results from 10 diagnosed narcoleptics and 10 control subjects in which the PLR system was stimulated and a reliable (90%) discriminator derived for classifying narcoleptics and controls was reported. Random pupillary oscillations, which is called pupillary noise to distinguish these oscillations from spontaneous ones, were estimated from continuous pupil diameter recordings using a recursive least squares method applied to a subject–specific PLR system model. Pupillary noise sum of squares indicate that narcoleptics have significantly (P<0.005) less PLR noise than controls. This difference was attributed to supranuclear inhibition of randomly active Edinger‐Westphal neurons long hypothesized to be the source of random papillary oscillations. This inhibition also has been suggested as a cause of PLR sensitivity to nocturnal sleep quality so it may be that these findings apply to the sleep deprived and not just specifically to narcolept

ISSN:0962-1105    

DOI:10.1111/j.1365-2869.1996.00265.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

ISSN:0962-1105    

DOI:10.1111/j.1365-2869.1996.00272.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY