PubMed Health⌕ Search

Biomedical subjects

M H Bonnet

Publications and source records attributed to M H Bonnet.

At least 19 recordsLinked to original sources
PubMed1992

Training subjective insomniacs to accurately perceive sleep onset.

Subjective insomniacs overestimate sleep latency at the beginning of their nocturnal sleep period. It was hypothesized that subjective insomniacs could be trained to accurately estimate sleep latency by learning to differentiate wakefulness from sleep. Ten subjective insomniacs were randomly assigned to one of two groups. Group 1 subjects participated in both a control and a training week; group 2 subjects participated only during a training week. Each week consisted of a baseline lab night, a training lab night (treatment or control), a home (unmonitored night) and a recovery lab night. During training, subjects were taught to use sleep markers (A, B or C) to help them more accurately estimate sleep latency and were given feedback about the accuracy of their estimates. Marker A corresponded to an electroencephalographic level of wakefulness; marker B corresponded to the initial sleep spindle; marker C corresponded to 5 minutes of continuous sleep after the first sleep spindle. In the control condition, subjects had no feedback and were not taught to use markers to help them judge sleep from wakefulness. Total sleep time and percent stage 3 sleep increased, and objective sleep latency decreased on recovery nights. After training, subjective sleep latency, correctness of estimates of sleep versus wakefulness and perceived ability to fall asleep significantly improved. This study helps to establish that subjective insomniacs can learn to more accurately estimate sleep from wakefulness with the use of sleep-wake markers.

Adolescent↗
PubMed1992

Effect of ethanol on the arousal response to airway occlusion during sleep in normal subjects.

The effect of ethanol on the arousal response to airway occlusion during non-rapid eye movement sleep was studied in normal male subjects by testing the response to the occlusion of a face mask covering the nose and mouth on a control (C) and an ethanol (E) ingestion (2 ml/kg of 50% vodka) night in random order. In part A, five subjects breathed room air while in part B another five subjects breathed a mixture of air and oxygen adjusted to maintain a baseline sleeping SaO2 of 98%. In both parts, the time to arousal (TTA) was significantly longer on E nights. The TTA (mean +/- SEM) in part A on C versus E nights was 14.6 +/- 1.9 versus 20.6 +/- 1.4 s in stage 2 and 19.9 +/- 1.9 versus 29.2 +/- 1.8 in stage 3/4 (p less than 0.01). The corresponding values in part B were 22.2 +/- 3.6 versus 39.9 +/- 8.4 in stage 2 and 32.1 +/- 4.1 versus 63.7 +/- 9.6 in stage 3/4 (p less than 0.01). In part B, the maximum deflections in airway pressure were measured at a supraglottic location during airway occlusion to reflect the degree of inspiratory effort. The maximum airway suction pressure preceding arousal was significantly higher on E nights. Conversely, the rate of increase in inspiratory effort (maximum pressure) during occlusion was decreased by E. We conclude that moderate ethanol ingestion prolongs the time to arousal following airway occlusion by increasing the threshold of inspiratory effort associated with arousal and by decreasing the rate of increase in the magnitude of inspiratory efforts.

Adult↗
PubMed1992

Operation Everest II: arterial oxygen saturation and sleep at extreme simulated altitude.

Frequent sleep disturbances and desaturation during sleep are common at high altitude, but few data are available from the highest altitudes at which humans are known to sleep. Because sleep fragmentation at low altitude may impair mental function and oxygen deprivation produces lasting central nervous system abnormalities, a better understanding of the severity of sleep disturbances and oxygen desaturation at extreme altitudes is important. The purpose of this study was to determine the severity of sleep disturbance and the extent of arterial oxygen desaturation at extreme simulated altitude. Out of eight healthy male subject volunteers who started, five aged 27.2 +/- 1.5 yr completed the study during 6 weeks of progressive hypobaric hypoxia in a decompression chamber. The men were studied at barometric pressures of 760, 429, 347, 282 mm Hg and following return to 760 mm Hg. All demonstrated frequent nighttime awakenings (37.2 awakenings per subject per night at 282 mm Hg, decreasing significantly to 14.8 on return to sea level, p less than 0.05). Total sleep time decreased from 337 +/- 30 min at 760 mm Hg to 167 +/- 44 min at 282 mm Hg (p less than 0.01). Rapid eye movement (REM) sleep decreased from 17.9% +/- 6.0% of sleep time at sea level to 4.0% +/- 3.3% at 282 mm Hg (p less than 0.01). Sleep continuity as reflected by brief arousals increased from 22 +/- 6 arousals per hour of sleep at sea level to 161 +/- 66 arousals per hour at 282 mm Hg (p less than 0.01). All subjects showed arterial oxygen desaturation proportional to the altitude. The average oxygen saturation (SaO2) was 79% +/- 3% at 429 mm Hg, 66% +/- 6% at 347 mm Hg, and 52% +/- 2% at 282 mm Hg. Sleep stage had only a minimal effect on SaO2 at any altitude. SaO2 was negatively correlated with brief sleep arousals, r = -0.72, p less than 0.01. All subjects demonstrated periodic breathing with apneas throughout much of the night at 347 and 282 mm Hg. These data indicate that sleep quality progressively worsens as SaO2 decreases despite lack of progressive changes in sleep stages at altitude. This study extends previous information on the severity of desaturation during sleep, and suggests that improvements in oxygenation might prove beneficial in restoring consolidated sleep, possibly even improving daytime performance.

Adult↗
PubMed1992

Caffeine use as a model of acute and chronic insomnia.

It was hypothesized that the metabolic effects of caffeine, which can be objectively measured (i.e. physiological, "arousal"), could be used to develop a physiological arousal model of chronic insomnia in a group of normal young adults. Twelve normal young adult males participated for 11 nights after laboratory adaptation. Subjects received 400 mg of caffeine three times a day for 7 nights and days. As predicted, the use of caffeine resulted in increased metabolic rate. Sleep efficiency was significantly reduced by caffeine and multiple sleep latency tests (MSLTs) were significantly increased. Some adaptation to the metabolic, sleep efficiency, and MSLT effects of caffeine was seen over the week of administration. Withdrawal effects (i.e. rebound sleep or sleepiness) were not seen for metabolic, MSLT or sleep variables. The data indicated that caffeine was effective in producing significant metabolic and sleep effects and that those effects were related. The results were consistent with the interpretation that a chronic decrease in sleep efficiency associated with increased physiological arousal, although producing subjective dysphoria, does not produce a physiological sleep debt.

Acute Disease↗
PubMed1991

Chronic use of triazolam in patients with periodic leg movements, fragmented sleep and daytime sleepiness.

Many studies have shown a relationship between fragmented nocturnal sleep and daytime sleepiness. In the current study, 9 patients, aged 55-79, with fragmented nocturnal sleep secondary to periodic leg movements and objective daytime sleepiness, as verified by Multiple Sleep Latency Test (MSLT), had 12 weeks of treatment with 0.125 mg of triazolam following 2 screening nights and 2 placebo baseline nights; 2 final placebo nights were placed 5 nights following the last medication night. The medication increased total sleep time and sleep efficiency throughout the administration period, as compared to average placebo values; total leg movements were not changed. Generally, daytime performance, as measured by a vigilance task, and objective alertness, as measured by MSLT, were improved following the use of triazolam. No adverse reactions or significant side effects were noted. It was concluded that 0.125 mg triazolam, when used for up to 3 months, could improve sleep and daytime function in older patients with periodic leg movements, fragmented sleep, and daytime sleepiness.

Aged↗
PubMed1991

The effect of varying prophylactic naps on performance, alertness and mood throughout a 52-hour continuous operation.

The current study reports the effect of 0-8-hr naps placed prior to two consecutive nights of total sleep deprivation. A total of 104 young adult male subjects were randomly assigned to one of four prophylactic nap conditions (0, 2, 4 or 8 hr). After a normal baseline night of sleep and a morning of baseline test performance, subjects returned to bed at 1200, 1600 or 1800 hr or not at all prior to a continuous operation that extended until each subject's normal bedtime on the third following night. All subjects who napped arose at 2000 hr, and all subjects maintained the same schedule of computer-administered performance tests throughout the sleep-loss period. Results indicated that performance and alertness in all nap conditions were improved in a dose-response fashion compared to a no-nap control throughout the first 24 hr of sleep loss. However, significant improvement in nap conditions compared to the no-nap condition was not seen in many variables during the second night of sleep loss. Whereas an 8-hr nap prior to an operation maintained performance at a high level for 24-30 hr, significant improvement in alertness and performance as compared to the no-nap control was also documented by shorter naps. No nap could reverse the profound loss of alertness seen during the second night of sleep loss.

Adolescent↗
PubMed1991

Metabolism during normal, fragmented, and recovery sleep.

Average metabolic data (O2 uptake and CO2 output) were obtained for each 3-min period during consecutive nights of normal, experimentally fragmented, and recovery sleep in a group of 12 normal young adult males. Naturally occurring arousals and awakenings resulted in a characteristic increase in metabolism on the baseline night. The placement of brief frequent experimental arousals on the following night resulted in significantly increased metabolism throughout the night and significantly decreased sleep restoration as measured by morning performance, mood, and alertness tests, even though total sleep time was minimally reduced. Metabolic variables were significantly decreased compared with baseline on the nondisturbed recovery night that followed the sleep fragmentation night. The data cannot be used to infer that increased metabolism during sleep causes nonrestorative sleep, but the direction and time course of metabolic change accompanying arousal are consistent with that hypothesis.

Adolescent↗
PubMed1990

The use of triazolam in older patients with periodic leg movements, fragmented sleep, and daytime sleepiness.

Many studies have shown a relationship between fragmented nocturnal sleep and daytime sleepiness. In the current study, 11 patients, aged 55-75, were identified with fragmented nocturnal sleep secondary to periodic leg movements and objective daytime sleepiness as verified by the Multiple Sleep Latency Test (MSLT). In a double-blind, repeated measures, cross-over design, patients had three nights of treatment with placebo, 0.125 mg of triazolam, or 0.25 mg of triazolam following an adaptation night. Although total leg movements were not changed, the medication increased total sleep time and sleep efficiency while decreasing the number of stage changes. Generally, daytime performance and objective alertness were significantly improved following the use of triazolam. It was concluded that acute use of triazolam, particularly the 0.125 mg dose, could improve sleep and daytime function in older patients with periodic leg movements, fragmented sleep, and daytime sleepiness.

Aged↗
PubMed1990

The effect of triazolam on arousal and respiration in central sleep apnea patients.

It was hypothesized that triazolam might decrease central apneas associated with arousal periods in patients with central sleep apnea by hastening the onset of consolidated sleep. Five male patients, diagnosed as having central sleep apnea on a screening night, participated in a double-blind randomized crossover study of the effect of placebo, 0.125 mg triazolam, and 0.25 mg triazolam on sleep, respiration, and daytime function. Results indicated that the medication increased total sleep and decreased central apnea index and number of brief arousals. Improved sleep quality was reflected in improved daytime psychomotor performance and alertness. These data, if replicated, imply that benzodiazepine use may be beneficial in patients with central sleep apnea.

Aged↗
PubMed1989

Infrequent periodic sleep disruption: effects on sleep, performance and mood.

In the first of two experiments, 12 normal young adults had their sleep periodically disturbed for two nights in the laboratory at three different rates: 10 min of sleep followed by 20 min of disturbance, 20 min of sleep followed by 40 min of disturbance and 40 min of sleep followed by 80 min of disturbance. Sleep and disturbance alternated throughout the night. While all disturbance conditions resulted in decreased daytime performance and increased sleepiness, the disturbance conditions did not differ from each other. In the second experiment, sleep was periodically disturbed for two nights at three new rates to act as control conditions for Experiment 1. The three conditions were: 2 min of sleep followed by 4 min of disturbance, 20 min of sleep followed by a single awakening, and 40 min of sleep followed by a single awakening. Sleep and disturbance again alternated throughout the night. As expected, sleep was less disturbed and daytime decrements were smaller in the conditions allowing 20 and 40 min of sleep followed by a single awakening. The data from both experiments were interpreted as support for sleep continuity theory; i.e., as the length of periods of consolidated sleep decrease, residual decrements increase.

Adolescent↗
PubMed1989

Sleep loss in aging.

Tests of performance and alertness in normal older subjects undergoing sleep loss reveal loss of performance and alertness similar to that seen in younger individuals. Recovery of performance ability occurs with one night of normal sleep, even following periods of sleep loss up to 64 hours in length. Older individuals, including older individuals with primary insomnia, may tolerate sleep loss with less decrease in ability compared with their baseline than young adults and may recover function more quickly than young adults. While it has been frequently shown that older individuals perform more poorly than young adults on a broad range of tasks, these findings do not hold well for periods of nocturnal performance or performance during sleep loss. It is possible that these findings may be accounted for to some extent by the decrease in amplitude of the circadian body temperature curve in older individuals. It is unfortunate that Reynolds et al did not attempt to collect performance data in their depressed and demented patients to determine if the differential effects on mood and EEG would also be reflected in psychomotor performance.

Adult↗
PubMed1988

The use of triazolam in phase-advanced sleep.

The need for optimal nocturnal performance continues to increase in our society. Nighttime function is dependent upon the ability to sleep effectively during the day. The current study examined daytime sleep after placebo, 0.125 mg (364 nmol), 0.25 mg (729 nmol), or 0.50 mg (1458 nmol) of triazolam, and nocturnal performance in the work shift that followed. Forty-one normal young adult subjects participated in a repeated-measures design in which each subject received each medication dose level in a separate week. The results indicated that day sleep increased as a linear function of drug dose from 234 to 374 minutes. Nocturnal alertness, as measured by subjective report and objective nap latency test, increased significantly following the use of triazolam, 0.25 and 0.50 mg, for the day sleep period. Nocturnal performance, as measured by auditory vigilance and additions, also increased significantly following the use of triazolam. Marginal evidence for medication hangover was found at the 0.50-mg dose, and it was therefore recommended that the use of the 0.50-mg dose be monitored carefully if performance demand were to follow medication use by less than 12 hours. The results for the study were interpreted as indicating that under certain conditions, triazolam could effectively increase daytime sleep and improve alertness and performance in the following nocturnal work period.

Adult↗
PubMed1987

Sleep and performance in young adults and older normals and insomniacs during acute sleep loss and recovery.

Many changes occur in sleep as a function of aging, but it is not known whether these changes result in sleep being less restorative. To examine the sleep restorative process, groups of 12 normal young adults and 12 normal and 12 insomniac male subjects, age 55-71, were totally sleep deprived for 64 hours and then allowed recovery sleep. Response speed, immediate recall, sleepiness, and body temperature were tested at approximately 2300, 0115, 0330, 0530 and 0800 during baseline, sleep loss, and recovery nights. Significant group (age or insomnia) by sleep loss condition interactions were found for reaction time and immediate recall performance measures. Similar significant interactions were found for oral temperature and all EEG sleep variables except total time in bed, percent stage 1, and percent REM. It was concluded that performance recovery following sleep loss was no slower in older subjects than in younger subjects despite very different recovery sleep stage parameters. This implied that aging effects on sleep are developmental rather than degenerative.

Adolescent↗
PubMed1987

Performance during frequent sleep disruption.

Performance on a simple addition task was measured during three schedules of frequent sleep disruption for 2 nights. Five young adults had their sleep briefly disturbed for 2 nights in 3 separate weeks either every 1 min, every 10 min, or at sleep onset after an undisrupted 2.5-h sleep period. Subjects were required to perform a two-number, two-digit addition problem as rapidly as possible on awakening. Main effects were found for sleep disruption condition and time of night, and a significant interaction between the two was also observed. Latency to response was longest for the 10-min condition on night 1, on night 2, however, response latencies were longest in the 1-min condition. Response latencies were fastest in the 2.5-h condition for both nights of disruption. Arousal thresholds were also gathered across both nights. Arousal thresholds were consistently the highest in the 1- and 10-min conditions for both nights of disruption, reaching maximum threshold levels at the end of night 1. Arousal threshold was significantly positively correlated with response latency. Sleep stages (slow-wave sleep (SWS), SWS + REM (SWSR), and total sleep time minus stage 1 sleep) were poor predictors of performance changes across the 2 disruption nights. The data were best explained by sleep continuity theory, which posits that a period of at least 10 min of uninterrupted sleep is required for restoration to take place.

Adolescent↗
PubMed1987

Sleep restoration as a function of periodic awakening, movement, or electroencephalographic change.

Eleven young adults had their sleep briefly disturbed following each 2 min of accumulated sleep for 2 consecutive nights in 3 different weeks. During 1 week the disturbance was a brief awakening followed by a subjective response. During another week subjects were required to make a quarter-body turn response. During the final week, the disturbance was an ongoing electroencephalographic (EEG) change. As expected, the three disturbance conditions differentially impacted sleep, with the most sleep disturbance seen in the awakening condition and the least disturbance seen in the EEG change condition. Morning vigilance performance and nap latency were decreased and fatigue was increased as compared with baseline following all three disturbance conditions. However, no significant condition interaction was found for any performance variable or for morning nap latency. For the mood scales, significant condition interactions indicated that subjects reported being sleepier only after the awakening condition. The data were interpreted as providing evidence that the restorative function of sleep is equally impaired by any periodic change in ongoing EEG and that impairment does not require a return to waking consciousness. However, mood, as a subjective rating, is dependent upon conscious events that occur during the sleep period.

Adolescent↗
PubMed1986

Auditory thresholds during continuing sleep.

Five subjects were asked to respond to a 1000 Hz tone with a standard button push response during sleep. A method of limits procedure was used to track their auditory thresholds when awake and during various stages of sleep. Subjects adapted to the procedure and were able to make consistent responses while their EEG indicated stage 1 or stage 2 sleep. While the threshold level at which a response was made was directly related to EEG state, there was no significant correlation between the interval between responses and the threshold level. It was concluded that stable auditory thresholds could be obtained during stage 1 and stage 2 sleep after little laboratory adaptation and that this behavioral response could be a useful indicator of central processing ability during sleep.

Acoustic Stimulation↗
PubMed1986

Performance and sleepiness following moderate sleep disruption and slow wave sleep deprivation.

Recent studies have shown that periodically disrupted sleep resulted in significant daytime sleepiness and performance loss in normal young adults. One study suggested that the periodicity of disturbance rather than the total number of sleep disturbances was the primary factor in causing degraded function. However, in that study, increased performance levels could have been associated with increased levels of slow wave sleep. The present study was designed to determine whether the amount of SWS rather than the periodic disruption of sleep accounts for decreased performance of Ss with disrupted sleep. Twelve normal young adults spent two 4-night periods in the laboratory. During one 4-night series, Ss were briefly aroused either following each 10 min of sleep or whenever they entered stage 3 sleep (No SWS condition). During the second series of nights, Ss were briefly aroused after each 10 min of sleep (SWS condition). In the second series, additional arousals were performed after 5-min periods (but not when Ss were in SWS) to equalize the total number of arousals in the SWS conditions with those in the No SWS condition. Total experimental arousals were equal in the disruption conditions, and the experimental manipulation was successful in reducing total SWS to infrequent epochs of stage 3 in the No SWS condition while allowing significantly more SWS in the SWS condition. In terms of sleep stages, this difference was balanced by increased stage 2 in the No SWS condition. Despite the differential occurrence of SWS, no performance, mood, or nap latency measure was different in the SWS vs.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗