SLEEP

Sadeh,, Avi;Sharkey,, M.;Carskadon, Mary, A.

doi: 10.1093/sleep/17.3.201pmid: 7939118

Summary: The effects of actigraph placement and device sensitivity on actigraphic automatic sleep-wake scoring were assessed using concomitant polysomnographic and wrist actigraphic data from dominant and nondominant hands of 20 adults and 16 adolescents during 1 laboratory night. Although activity levels differed between dominant and nondominant wrists during periods of sleep (F = 4.57; p < 0.05) and wake (F = 15.5; p < 0.0005), resulting sleep–wake scoring algorithms were essentially the same and were equally explanatory (R2 = 0.64; p < 0.0001). When the sleep-wake scoring algorithm derived from the nondominant hand was used to score the nondominant data for sleep-wake, overall agreement rates with polysomnography scoring ranged between 91 and 93% for the calibration and validation samples. Results obtained with the same algorithm for the dominant-wrist data were within the same range. Agreement for sleep scoring was consistently higher than for wake scoring. Statistical manipulation of activity levels before applying the scoring algorithm indicated that this algorithm is quite robust toward moderate changes in activity level. Use of “twin-wrist actigraphy” enables identification of artifacts that may result from breathing-related motions. Actigraphy, Polysomnography, Sleep, Wake, Automatic scoring This content is only available as a PDF. Author notes * Current address: Department of Psychology, Tel-Aviv University, Israel. © 1994 American Sleep Disorders Association and Sleep Research Society

Vivaldi, Ennio, A.;Wyneken,, Ursula;Roncagliolo,, Manuel;Ocampo,, Adrián;Zapata, Ana, M.

doi: 10.1093/sleep/17.3.208pmid: 7939119

Summary: Distributions within a 12:12 light: dark schedule of wakefulness (W), active sleep (AS), quiet sleep (QS) and of QS rich in delta (QSD) and in spindle (QSS) activities were evaluated for 52 days from 15 rats. Angular statistics were applied for each state by equating their hourly incidence to data distributed around a circle. Measures of location (mean angle, median angle, mode angle, maximum semicircle), dispersion (mean vector, standard deviation, quartile deviation), skewness and kurtosis were computed and their intra- and interindividual variabilities were compared. Mean angles (in hours and after lights-on) averaged 5.5 for QS, 8.6 for AS, 18.4 for W, 1.9 for QSD and 10.6 for QSS. Length of vectors, representing concentration around the mean angle, averaged 0.22 for QS, 0.36 for AS, 0.22 for W, 0.38 for QSD and 0.23 for QSS. Distributions of QS and W were closely related to the light-dark step function. QSD had a leptokurtic distribution, sharply rising at the beginning of the sleep-predominant phase, whereas AS and QSS had smoother distributions reaching maxima in its second half. In rodents as in humans, QSS and AS have opposite distributions to QSD. QSS may contribute to maintain sleep through the resting phase of the light-dark schedule after restorative function associated with delta activity has been fulfilled. Sleep, Quiet sleep, Active sleep, Circadian rhythms, Light entrainment, Delta waves, Sleep spindles, Angular statistics This content is only available as a PDF. Author notes * Present address: Departamento de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Chile. © 1994 American Sleep Disorders Association and Sleep Research Society

Sanna,, Antonio;Veriter,, Claude;Kurtansky,, Alexander;Stănescu,, Dan

doi: 10.1093/sleep/17.3.220pmid: N/A

Summary: Upper airway muscles (UAM) are activated during inspiration, but little is known about their activity during expiration. We studied six healthy volunteers in supine position. Negative pressure (–10 to –30 cm H2O) was applied cyclically at the mouth during expiration. Subjects actively breathed during inspiration and either contracted or relaxed their UAM during expiration. Supraglottic pressure (Psg) was measured with a catheter with the tip at the supraglottic level. During relaxation, but not during contraction, there was expiratory flow limitation (FL) accompanied by high frequency pressure and flow oscillations (70 ± 5.7 Hz at –30 cm H2O). The average linear supraglottic resistance was higher during relaxation than during contraction at both –10 and –20 cm H2O (p < 0.05), but not at —30 cm H2O. Amplitude of expiratory genioglossus electromyogram was 3.6 ± 2.5 mm during quiet breathing, 7.0 ± 3.8 mm during contraction (p < 0.05) and 4.1 ± 1.8 mm during relaxation. Average mouth pressure, which immediately preceded pressure (and flow) oscillations was –2.1 ± 0.9 cm H2O. In one subject cineradiography of the neck during expiratory application of –30 cm H2O showed anterior flexion and high frequency oscillations of the soft palate during relaxation. During contraction, the soft palate was close to the posterior pharyngeal wall without oscillations. We conclude that cyclically applied negative pressure at the mouth during expiration produced expiratory flow limitation during relaxation but not during contraction, and that expiratory contraction of UAM stabilizes upper airways during negative pressure application at the mouth. Upper airway, Negative pressure, Expiration, Upper airway muscles, Upper airway obstruction. This content is only available as a PDF.

Ugalde,, E.;Corsi-Cabrera,, M.;Juárez,, J.;Ramos,, J.;Arce,, C.

doi: 10.1093/sleep/17.3.226pmid: 7939121

Summary: Effects of 6 hours of total sleep deprivation (TSD) by gentle handling and 6 hours of sleep on the waking electroencephalogram (EEG) activity of 14 Wistar rats were studied during the lights-on portion of the light-dark cycle under two TSD schedules: a) TSD 0800–1400 hours and sleep 1400–2000 hours, and b) sleep 0800–1400 hours and TSD 1400–2000 hours. EEG was recorded monopolarly from left and right parietals referred to ipsilateral reference electrodes. Spectral analysis was performed on samples of waking EEG during TSD (each 30 minutes) and during sleep (each 60 minutes after enforced awakening). The following significant changes were observed: TSD induced a linear increase in the absolute power of delta (1.46–3.42 Hz) and the full band (1.6–24.9 Hz) and produced a decrease in the interparietal correlation of theta. Sleep induced the opposite results. Theta relative power (power in a band expressed as a percentage of total power between 1.46 and 24.9 Hz) showed a circadian effect. It was higher at 1400 hours than at 0800 and 2000 hours after both sleep and TSD conditions. Six hours of TSD were enough to induce significant changes in the waking EEG regardless of position of TSD in the lights-on period of the light-dark cycle. EEG, Sleep deprivation, Circadian effects, Interparietal correlation This content is only available as a PDF. © 1994 American Sleep Disorders Association and Sleep Research Society

Salín-Pascual, Rafael, J.;Jiménez-Anguiano,, Anabel;Durán-Vazquez,, Adalberto;Nancy, Hugo, Merchant;Drucker-Colín,, Rene

doi: 10.1093/sleep/17.3.231pmid: 7939122

Summary: Rapid eye movement (REM) sleep deprivation and auditory stimulation (ADS), separately, increase REM sleep in rats, cats and humans. The main goal of the present study was to test whether administration of ADS during REM sleep rebound has a synergistic effect on REM sleep elicitation. Male Wistar rats were implanted with standard sleep recording electrodes. Following the recovery period, animals were randomly assigned to the following conditions: undeprived (i.e. control) and 24, 48, 96 and 120 hours of REM sleep deprivation by the platform method. Undeprived and REM sleep-deprived animals were divided into two groups, with and without ADS. ADS was a “beep” of 80 dB and 2,000 Hz, lasting 20 msec every 10 seconds. This stimulus was applied for the first 4 hours of sleep recordings after deprivation. After that, animals were recorded for another 4 hours. In the undeprived situation, the group that received ADS increased REM sleep approximately 70% above the group that did not receive ADS, as has been reported previously (REM sleep without ADS: 38.1 ± 13.84 vs. with ADS: 64.6 ± 11.8, p < 0.005). No synergistic effect was observed between REM sleep deprivation and ADS for any REM sleep-deprivation schedule. This result may be explained as an increase in the excitability pattern of pontine neurons and/or changes in the cholinergic system due to REM sleep deprivation that could not be further increased by ADS. REM sleep, Sleep deprivation, Auditory stimulation, Cholinergic system, Rats This content is only available as a PDF. © 1994 American Sleep Disorders Association and Sleep Research Society

Gillberg,, Mats;Kecklund,, Göran;Åkerstedt,, Torbjörn

doi: 10.1093/sleep/17.3.236pmid: 7939123

Summary: The present study validated the nine-point Karolinska Sleepiness Scale (KSS) and the new Accumulated Time with Sleepiness (ATS) scale against performance of laboratory tasks. The ATS scale was designed as a method for integrating subjective sleepiness over longer time periods. The subjects were asked if certain symptoms of sleepiness had occurred and, if so, for how long. Six subjects participated twice. Each time they were kept awake during the night (except for a short nap occurring during one of the nights in a counterbalanced order) and were tested at 2200, 0200, 0400 and 0600 hours. The tests included a 10-minute rest period, a 28-minute visual vigilance task and an 11 -minute single reaction time task. KSS and visual analogue scale (VAS) ratings were given before each test, and ATS ratings were given after. Performance deteriorated clearly, and all three rating scales reflected increased sleepiness with time of night. Scores on the KSS and VAS showed high correlations with performance tasks (mean intraindividual correlations were between 0.49 and 0.71). Performance correlated even higher with the ATS ratings (r = 0.73–0.79). Intercorrelations between rating scales were also high (r = 0.65–0.86). It was concluded that there were strong relations between ratings of sleepiness and performance, that the ATS rating scale was at least as good as the other scales and that the ratings were affected by type of task. Sleepiness, Self-rating scales, Performance, Sleep loss This content is only available as a PDF. © 1994 American Sleep Disorders Association and Sleep Research Society

Philip,, Pierre;Stoohs,, Riccardo;Guilleminault,, Christian

doi: 10.1093/sleep/17.3.242pmid: N/A

Summary: Eight young adults underwent 1 night of auditory sleep fragmentation followed by four naps of the multiple sleep latency test and performance testing the next day. A latin-square design was used to compare results with baseline. Efforts were made to eliminate effects of learning on repeated performance tests. A mean of 303 arousals, lasting a mean of 11 seconds, disrupted nocturnal sleep. This sleep fragmentation was induced to mimic as closely as possible the nocturnal sleep disruption seen in subjects with upper airway resistance syndrome. There was a significant disruption of nocturnal sleep architecture with a significant overall decrease in slow-wave sleep (SWS) and a significant but more moderate decrease in rapid eye movement (REM) sleep during the fragmented night. The most interesting finding related to analysis by thirds of the night, which indicated an important increase over time in arousal threshold during SWS followed by REM sleep. This threshold increase was associated with a parallel increase in dB(A) levels needed to induce an arousal. Stages 1 and 2 nonrapid eye movement (NREM) sleep were less affected by the stimulation, but the amount of stage 1 NREM sleep decreased from the beginning to the end of the night, again indicating an increase in pressure to sleep. Following 1 night of sleep fragmentation, subjects had significantly shorter sleep latencies on the multiple sleep latency test for naps 2, 3 and 4. There was a significant relationship between percent nocturnal SWS and mean sleep latencies. The selected performance tests were not affected by 1 night of sleep fragmentation, despite the obvious sleepiness. Sleep fragmentation, Upper airway resistance syndrome, Sleepiness, Performance testing. This content is only available as a PDF.

Ingram,, Fred;Henke, Kathe, G.;Levin, Harvey, S.;Fishel Ingram, Pamela, T.;Kuna, Samuel, T.

doi: 10.1093/sleep/17.3.248pmid: 7939125

Summary: Impaired vigilance performance has been reported in older subjects with sleep apnea syndrome (SAS). The current study is an attempt to extend these findings and to investigate additional factors that might have implications for vigilance in the older adult. Fifty-nine older adults [age: 62 ± 5 (mean ± SD), range 54–75 years; respiratory disturbance index (RDI): 8.8 ± 14.4 (mean ± SD), range 0–67.5] were categorized as SAS or NotSAS, based on various classification criteria [i.e. apnea index (AI) ≥5 and 10, RDI ≥5, 10 and 15], and were compared on their vigilance performance as assessed by the computer program “Steer Clear”. Vigilance performance did not discriminate the groups, independent of how they were formed. Groups were then formed based on vigilance performance (HiVig vs. LowVig) and compared on assorted sleep variables, periodic leg movements, and self-reported hypersomnolence and depression. Only age discriminated vigilance performance (an inverse relationship), accounting for 31% of the observed variance. Our findings suggest that subject selection may unintentionally bias findings regarding the neuropsychological functioning of individuals with SAS, that vigilance may be impaired only in relatively more “severe” SAS, and that severity of SAS in older adults may not be well characterized by current classification standards. Age clearly impacted vigilance performance, despite the constricted age range sampled, and should be taken into account in future research. Sleep apnea, Aging, Sleep, Attention, Vigilance This content is only available as a PDF. © 1994 American Sleep Disorders Association and Sleep Research Society

Broughton,, R.;Billings,, R.;Cartwright,, R.;Doucette,, D.;Edmeads,, J.;Edwardh,, M.;Ervin,, F.;Orchard,, B.;Hill,, R-;Turrell,, G.

doi: 10.1093/sleep/17.3.253pmid: N/A

Summary: A case of a homicide and an attempted homicide during presumed sleepwalking is reported in which somnambulism was the legal defense and led to an acquittal. Other possible explanations including complex partial seizures, dissociative state, rapid eye movement sleep behavior disorder and volitional waking behavior are discussed. The evidence supporting the probability that this act occurred during an episode of somnambulism and sleep-related confusional arousal is reviewed and weighed. This evidence includes personal and family history of somnambulism and related disorders; neurological, psychiatric and psychological assessments; presence of possible precipitating factors; and polysomnographic data. Somnambulism, Homicide, Aggression. This content is only available as a PDF.

Gelb,, Michael;Guilleminault,, Christian;Kraemer,, Helena;Lin,, Stephanie;Moon,, Samina;Dement, William, C.;Mignot,, Emmanuel

doi: 10.1093/sleep/17.3.265pmid: 7939127

Summary: Twenty-seven narcoleptic patients severely affected with cataplexy completed four symptom diaries over a 4-month period in order to clarify some of the controversies surrounding assessment of anticataplectic medications. The home diary method was found to be a viable model for the assessment of anticataplectic activity. Assessment of reliability in 1-, 2-, 3-, 4-, 5- and 10-day intervals indicated that reliability increases with the number of days included. A 10-day design was found to be optimal. Reliability decreased, however, with each successive diary over the 4-month period. Power analysis indicates that two groups of 30–40 subjects in a parallel design, or one group of 30–40 subjects in a crossover design, would be sufficient to demonstrate a significant therapeutic anticataplectic effect in most cases. A “first diary effect” was observed, suggesting that a training period prior to the actual trial might improve reliability. Whether the patient was treated or untreated with stimulant medications did not affect severity or fluctuation of cataplexy, suggesting that both groups of patients could be included in therapeutic trials. No time-of-day fluctuation was observed in the daily distribution of cataplexy attacks. Sudden increases in cataplexy were often, although not always, caused by unusual emotional events or sleepiness. The finding of a long-lasting “precataplectic” feeling or “aura” pointed to the need to carefully clarify the symptom prior to beginning a therapeutic trial. Cataplexy, Narcolepsy, Anticataplectic medications, Therapeutic trials This content is only available as a PDF. © 1994 American Sleep Disorders Association and Sleep Research Society