SLEEP

Ohayon, Maurice M.; Guilleminault, Christian; Paiva, Teresa; Priest, Robert G.; Rapoport, David M.; Sagales, Teresa; Smirne, Salvatore; Zulley, Jürgen

doi: 10.1093/sleep/20.12.1086pmid: 9493916

Summary:The comparability among epidemiological surveys of sleep disorders has been encumbered because of the array of methodologies used from study to study. The present international initiative addresses this limitation. Many such studies using the exact same methodology are being completed in six European countries (France, the United Kingdom, Germany, Italy, Portugal, and Spain), two Canadian cities (metropolitan areas of Montreal and Toronto), New York State, and the city of San Francisco. These surveys have been undertaken with the aim of documenting the prevalence of sleep disorders in the general population according to criteria of the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) and the International Classification of Sleep Disorders (ICSD-90). Data are gathered over the telephone by lay interviewers using the Sleep-EVAL expert system. This paper describes the methodology involved in the realization of these studies. Sample design and selection procedures are discussed.

Carley, David W.; Hagan, Russell M.; Sheehan, Mike; Trbovic, Sinisa; Thai, Tony; Radulovacki, Miodrag

doi: 10.1093/sleep/20.12.1093pmid: 9493917

Summary:We tested the hypothesis that N-[(1S, trans-)-2-hydroxycyclopentyl]adenosine (GR79236), a novel adenosine Al receptor agonist, would suppress sleep-related apnea in the rat at doses not associated with hypotension or hypothermia. Nine adult Sprague-Dawley rats were instrumented for chronic recording of sleep by electroencephalographic and electromyographic monitoring. Respirations were measured by single chamber plethysmograph, and blood pressure and heart period were transduced by a telemetric implant. Each rat was poly graphically recorded for 6 hours on four occasions in random order, with recordings for an individual animal separated by at least 3 days. Fifteen minutes prior to each recording (0945 hours) each animal received a 1 ml/kg intraperitoneal bolus injection of one of four injectates: saline (control) or 0.03 mg/kg, 0.3 mg/kg, or 3 mg/kg of GR79236. The study was a repeated-measures balanced design such that each animal was recorded exactly once for each injectate. The rate of spontaneous apneas (pauses > 2.5 seconds) was significantly reduced during all sleep stages by all doses of GR79236. At the highest dose, apnea index was reduced by over 70% in both non-rapid eye movement (NREM) and rapid eye movement (REM) sleep. In contrast, GR79236 had no effect on sleep stage volumes or blood pressure at any dose tested. Heart rate and core temperature were reduced only at the highest dose (3 mg/kg). We conclude that the adenosine Al receptor agonist GR79236 significantly suppresses apnea expression in all sleep stages at doses not associated with significant changes in sleep architecture, blood pressure, heart rate, or core temperature.

Lancel, Marike

doi: 10.1093/sleep/20.12.1099pmid: 9493918

Summary:Peripheral administration of the selective γ-aminobutyric acid (GABAA) receptor agonists muscimol and 4,5,6,7-tetrahydroisoxazolo(5,4-c)pyridin-3-ol (THIP) to rats has recently been found to increase nonrapid eye movement sleep (non-REMS) duration and to enhance delta activity (0.5–4.0 Hz) within non-REMS during the light period, i.e. the circadian rest phase. In this vehicle-controlled study, we investigated the sleep response to two doses of THIP (2 and 4 mg/kg) administered intraperitoneally to eight rats at the beginning of the dark period. Electroencephalogram and electromyogram recordings were made continuously during the first 6-hours postinjection. The 4-mg/kg THIP dose significantly increased the time in non-REMS, lengthened the non-REMS episodes, and elevated delta activity within non-REMS. Quantitatively similar, but smaller effects were induced by 2 mg/kg THIP. Neither dose of THIP affected the time in REMS. These effects are very similar to those evoked by THIP and muscimol during the light period. This indicates that GABAA agonists dose-dependently promote non-REMS, by increasing non-REMS maintenance, and increase the intensity of non-REMS, and that these effects are independent of the light-dark and circadian cycle.

Malow, Beth A.; Bowes, Robert J.; Lin, Xihong

doi: 10.1093/sleep/20.12.1105pmid: 9493919

Summary:Sleepiness, a common complaint of epilepsy patients, is frequently attributed to antiepileptic medications. To determine predictors of subjective sleepiness in epilepsy patients, we gave self-administered, validated surveys of sleepiness [Epworth sleepiness scale (our major outcome measure)] and sleep apnea [sleep apnea scale of the sleep disorders questionnaire (SA/SDQ)] to 158 epilepsy patients and 68 neurology patients without epilepsy (controls). An elevated Epworth score (>10) was more likely in epilepsy patients compared to controls after controlling for age and gender (p < 0.05). When Epworth scores were adjusted for SA/SDQ scores and restless legs symptoms (RLS), however, epilepsy patients showed only a nonsignificant trend toward elevated Epworth scores compared to controls (p = 0.08). SA/SDQ scores (p < 0.005) and RLS (p < 0.007) were significant predictors of elevated Epworth score in both epilepsy patients and controls. Among the epilepsy patients, the number or type of antiepileptic medication, seizure frequency, epilepsy syndrome (partial vs. generalized), and the presence of sleeprelated seizures were not significant predictors (p > 0.10) of elevated Epworth score. Before attributing sleepiness in epilepsy patients to antiepileptic medications or uncontrolled seizures, clinicians should consider the possibility of a coexisting sleep disorder.

Hauri, Peter J.

doi: 10.1093/sleep/20.12.1111pmid: 9493920

Summary:This study asks whether insomniacs undergoing behavioral training need to do so while totally free of hypnotics. Twenty-six insomniacs participated in the study, which included extensive monitoring of sleep both in the laboratory and at home. All subjects received six sessions of training in sleep hygiene and relaxation. About half the subjects were also given a hypnotic for occasional use; the others were asked to abstain from all hypnotics. Follow-up was performed immediately after treatment and again 10 months later. When compared with a waiting list, 6 hours of behavioral therapy improved insomniacs' sleep latency and sleep efficiency immediately after treatment, whether or not hypnotics were given concomitantly. Immediately following the 6 hours of therapy, those who had combined pharmacotherapy and behavior therapy improved about the same as those who had received behavior therapy alone. However, on the 10-month follow-up, those who had learned sleep hygiene and relaxation without the help of occasional hypnotics had more sleep and a better sleep efficiency than those who had been allowed an occasional hypnotic. We conclude that when teaching sleep hygiene and behavioral therapy to insomniacs, it might be advantageous to disallow the concomitant use of hypnotics as needed.

Edinger, Jack D.; Fins, Ana I.; Sullivan, Robert J.; Marsh, Gail R.; Dailey, Dorothy S.; Hope, T. Victor; Young, Margaret; Shaw, Edmund; Carlson, Donna; Vasilas, Diane

doi: 10.1093/sleep/20.12.1119pmid: 9493921

Summary:Many laboratory polysomnographic (LPSG) studies have shown only modest sleep differences between insomniacs and matched, noncomplaining normal controls. However, the extent to which LPSG methodology affects the outcome of such comparisons has yet to be tested. In the current investigation, 32 (16 females, 16 males) older (age ≥ 60 years) insomniacs and an age-matched and gender-matched sample of 32 noncomplaining normal sleepers underwent three consecutive nights of LPSG monitoring and another three consecutive nights of PSG monitoring in their homes (HPSG). By random assignment, one-half of the subjects in each group underwent LPSG first, whereas the remaining subjects underwent HPSG first. Each PSG recording was blindly scored using conventional scoring criteria, and resulting measures of total sleep period, total sleep time, sleep efficiency percent, stage 1 time, slow-wave sleep time, and rapid eye movement latency were used to compare the two subject groups within each PSG recording site (i.e. lab and home). Statistical analyses showed the normals sleepers and insomniacs evidenced similar pronounced first night effects (FNEs) when undergoing LPSG. However, neither mean values of the selected sleep parameters nor measures reflecting their night-to-night variability differentiated the insomniacs from the normal sleepers when such measures were derived from LPSG. In contrast, FNEs were generally absent for both subject groups when they underwent HPSG. Moreover, the insomniacs displayed significantly greater variability in several of their sleep measures during HPSG than did the normal sleepers. Overall, results suggest FNEs are a concern mainly when using LPSG, and HPSG may be more sensitive than LPSG for documenting sleep differences between normal sleepers and insomniacs. Additional studies are needed to determine if the findings reported herein are similar for young and middle-aged adults.

Edinger, Jack D.; Fins, Ana I.; Sullivan, Robert J.; Marsh, Gail R.; Dailey, Dorothy S.; Hope, T. Victor; Young, Margaret; Shaw, Edmund; Carlson, Donna; Vasilas, Diane

doi: 10.1093/sleep/20.12.1127pmid: N/A

Summary:Complaints of daytime dysfunction are common among chronic insomniacs, but laboratory comparisons of insomniacs and age-matched and gender-matched normal controls have generally failed to document these complaints. However, a few studies, which allowed subjects to sleep in their homes on the nights before daytime testing, have shown some relative diurnal deficits among insomniacs. The current study compared the effects of nocturnal laboratory and home polysomnogram (PSG) studies on subsequent daytime test results among older insomniacs and normal sleepers. Insomniacs (n = 32) and normal sleepers (n = 32) were randomly assigned to first undergo three nights of nocturnal PSG monitoring either in the sleep laboratory (16 insomniacs, 16 normal sleepers) or in their homes (16 insomniacs, 16 normal sleepers). Following the third night of PSG monitoring, subjects spent 1 day in the sleep laboratory, where they completed a four-trial multiple sleep latency test along with four trials of a computer-administered performance test battery. Results showed that insomniacs, as a group, were slightly, albeit consistently, sleepier than were normal sleepers following nights of home sleep monitoring, but a reverse of this trend was found among subjects who underwent nocturnal laboratory PSG before daytime testing. Furthermore, normal sleepers showed faster reaction times on a signal detection task than did insomniacs within the subgroup who underwent home PSGs prior to such testing. However, within the subgroup that underwent nocturnal laboratory PSGs, insomniacs' signal detection reaction times were significantly faster than those shown by normal sleepers. Results provide some support for the speculation that the nocturnal PSG monitoring site, used as a precursor to daytime testing, may systematically affect daytime comparisons between insomniacs and matched controls. Moreover, these results suggest that the use of home-based nocturnal PSG monitoring prior to daytime testing may provide an enhanced understanding of insomniacs' diurnal complaints.

Lushington, Kurt; Pollard, Katherine; Lack, Leon; Kennaway, David J.; Dawson, Drew

doi: 10.1093/sleep/20.12.1135pmid: 9493923

Summary:Melatonin has been shown to have hypnotic and hypothermic effects in young adults and has been proposed as treatment for insomnia. However, the hypnotic and thermoregulatory effects of melatonin remain to be simultaneously investigated for aged good and poor sleepers. The aim of this study was to explore the shortterm effects of exogenous oral daytime melatonin on core body temperature, sleep latency, and subjective vigor and affect in aged women. Twelve sleep maintenance insomniacs and 10 good sleeping postmenopausal female subjects [mean (SD) age = 65.2 (7.4) years] participated in a double-blind, crossover study in which they received a capsule containing either melatonin (5 mg) or a placebo at 1400 hours. Continuous core body temperature and hourly multiple sleep latency tests (MSLT) were collected from 1100–2030 hours. Self-reported estimates of global vigor (sleepiness) and affect were collected prior to each MSLT using visual analog scales. Comparison of good and poor sleepers failed to reveal any significant differences in core body temperature, sleep latency, or subjective vigor and affect. However, for both groups combined, melatonin administration [absolute postadministration mean (SEM) = 36.9 (0.05)°C] significantly lowered core body temperature compared with placebo [37.1 (0.05)°C]. Similarly, melatonin administration significantly reduced latency to stage 1 (SOL1) and stage 2 (SOL2) [absolute postadministration mean SOL1 = 20.1 (1.7) and SOL2 = 20.7 (1.6) minutes] compared with placebo [SOL1 = 24.3 (1.2) and SOL2 = 25.2 (1.1) minutes]. Treatment had no significant effect on either vigor or affect. Overall, our results suggest that although short-term exogenous oral daytime melatonin has significant hypothermic and hypnotic effects in aged women, the size of the effects is modest.