Eastward long distance flights, sleep and wake patterns in air crews in connection with a two-day layover.
The present study describes the spontaneous sleep/wake pattern in connection with an eastward (Stockholm to Tokyo, +8 h) transmeridian flight and short (51 h) layovers. To describe all sleep episodes and the recovery process across 4 days, and to relate adjustment to individual differences, 49 Scandinavian Airlines System (SAS) air crew were monitored for 9 days with activity monitors and sleep/wake diary before-during-after flight. The outbound flight involved a period of wakefulness extended to 21 h, frequently (87% of air crew) terminated by a long nap in Tokyo which was calm but difficult to wake up from. Then followed two night oriented sleep periods of normal length but of reduced efficiency, containing many and long awakenings. Napping was common during the extended periods of wakefulness, particularly during flights. During the recovery days, ease of rising from sleep in the mornings was difficult throughout, and feelings of not being refreshed returned to baseline levels on the third recovery sleep. Elevated daytime sleepiness (24% of the day) was observed on the first recovery day. No individual differences related to gender, age or position (cabin/pilot) was found in sleep strategy. Poor adjusters, subjects with a perceived lowered capacity on recovery days, showed more premature awakenings abroad and less refreshing sleep during the last 12 months, suggesting a decreased ability to cope with air crew scheduling. Comparisons with a westbound flight showed the eastbound flight layover sleep to be more problematic and containing more napping. (+info)
Interface of epilepsy and sleep disorders.
Obstructive sleep apnoea was first brought to prominence by Henri Gastaut, a French epileptologist. Since that time the interface between epilepsy and sleep disorders has received less attention than might be justified, recognizing that sleep deprivation is a poignant provocateur for seizures. Sleep deprivation is often used as a diagnostic procedure during electroencephalography (EEG) when waking EEG has failed to demonstrate abnormality. Patients referred to an outpatient neurological clinic for evaluation of possible seizures in whom sleep disorder was suspected, either due to snoring during the EEG or based on history, were evaluated with all-night diagnostic polysomnography (PSG) and appropriate intervention administered as indicated. Patient and seizure demography, sleep disorder and response to therapy were reviewed and the interface explored. Fifty patients aged between 10 and 83 years underwent PSG. Approximately half were diagnosed with epilepsy and almost three-quarters had sleep disorders sufficiently intrusive to require therapy (either continuous positive air pressure (CPAP) or medication). With co-existence of epilepsy and sleep disorders, proper management of sleep disorders provided significant benefit for seizure control. Snoring during EEG recordings could alert to the possibility of a sleep disorder even with epilepsy diagnosed. Where both epilepsy and sleep disorder coexist appropriate management of the sleep disorder improves control of the epilepsy. (+info)
The effects of sleep inertia on decision-making performance.
Sleep inertia, the performance impairment that occurs immediately after awakening, has not been studied previously in relation to decision-making performance. Twelve subjects were monitored in the sleep laboratory for one night and twice awoken by a fire alarm (slow wave sleep, SWS and REM sleep). Decision making was measured over 10 3-min trials using the 'Fire Chief' computer task under conditions of baseline. SWS and REM arousal. The most important finding was that sleep inertia reduces decision-making performance for at least 30 min with the greatest impairments (in terms of both performance and subjective ratings) being found within 3 min after abrupt nocturnal awakening. Decision-making performance was as little as 51% of optimum (i.e. baseline) during these first few minutes. However, after 30 min. performance may still be as much as 20% below optimum. The initial effects of sleep inertia during the first 9 min are significantly greater after SWS arousal than after REM arousal, but this difference is not sustained. Decision-making performance after REM arousal showed more variability than after SWS arousal. Subjects reported being significantly sleepier and less clear-headed following both SWS and REM awakenings compared with baseline and this was sustained across the full 30 min. In order to generalize this finding to real-life situations, further research is required on the effects of continuous noise, emotional arousal and physical activity on the severity and duration of sleep inertia. (+info)
Bright light treatment used for adaptation to night work and re-adaptation back to day life. A field study at an oil platform in the North Sea.
Night workers complain of sleepiness, reduced performance and disturbed sleep due to lack of adjustment of the circadian rhythm. In simulated night-work experiments scheduled exposure to bright light has been shown to reduce these complaints. Here we studied the effects of bright light treatment on the adaptation to 14 days of consecutive night work at an oil platform in the North Sea, and the subsequent readaptation to day life at home, using the Karolinska sleep/wake diary. Bright light treatment of 30 min per exposure was applied during the first 4 nights of the night-shift period and the first 4 days at home following the shift period. The bright light exposure was scheduled individually to phase delay the circadian rhythm. Bright light treatment modestly facilitated the subjective adaptation to night work, but the positive effect of bright light was especially pronounced during the re-adaptation back to day life following the return home. Sleepiness was reduced and the quality of day was rated better after exposure to bright light. The modest effect of bright light at the platform was, possibly, related to the finding that the workers seemed to adapt to night work within a few days even without bright light. These results suggest that short-term bright light treatment may help the adaptation to an extended night-work period, and especially the subsequent re-adaptation to day life. (+info)
Periodic breathing during sleep in patients affected by fibromyalgia syndrome.
Seventeen patients affected by fibromyalgia syndrome (FMS) (16 females and one male) and 17 matched healthy subjects underwent formal polysomnography, a sleep questionnaire and lung function tests. FMS patients slept significantly less efficiently than the healthy controls (p<0.01), had a higher proportion of stage 1 sleep (mean+/-SD, 21+/-6% versus 11+/-4%; p<0.001), less slow wave sleep (p<0.01) and twice as many arousals per hour of sleep (p<0.001). The respiratory pattern of FMS patients showed a high occurrence of periodic breathing (PB) (15+/-8% of total sleep time) in 15/17 patients, versus 2/17 control subjects. The short length of apnoeas and hypopnoeas did not affect the apnoea/hypopnoea index (5.1+/-3.5 versus 3.2+/-1.6; NS), but FMS patients had a greater number of desaturations per hour of sleep (8+/-5 versus 3+/-3; p<0.01). Pulmonary volumes did not differ between the two groups, but FMS patients had a lower transfer factor of the lung for carbon monoxide (TL,CO (5.8+1 versus 7.7+1 mmol x min(-1) x kPa(-1); p=0.001). PB occurrence correlated with TL,CO (r=-0.62; p=0.01), number of desaturations (r=0.76, p=0.001) and carbon dioxide tension in arterial blood (Pa,CO2) (r=-0.50; p=0.05). Stepwise multiple linear regression analysis showed desaturation frequency (p=0.0001) and TL,CO (p=0.029) to be the best predictors of PB percentage (R2 0.73; p=0.0001). Patients complaining of daytime hypersomnolence had a higher number of tender points, about twice as many arousals per hour and a lower sleep efficiency than patients who did not report this symptom. TL,CO was more impaired and the occurrence of PB was higher. The occurrence of periodic breathing in fibromyalgia syndrome patients, which was previously unreported, and is shown to be linked to a reduction of transfer factor of the lung for carbon monoxide could play a major role in the symptoms of poor sleep of these patients. (+info)
Hypersomnia following uvulopalatopharyngoplasty for snoring.
This report describes three cases who underwent uvulopalatopharyngoplasty for severe snoring and who subsequently developed progressive excessive daytime sleepiness. All three cases were shown to have sleep fragmentation as a result of non-apnoeic episodic upper airway narrowing. These cases raise the possibility that increased upper airway resistance during sleep may be exacerbated or even caused by uvulopalatopharyngoplasty. Ideally, sleep-disordered breathing should be carefully excluded before this surgery is offered as treatment for severe snoring. (+info)
Snoring and excessive daytime somnolence among Polish middle-aged adults.
There is considerable interest in the association of snoring and health consequences that have been linked to more severe sleep-disordered breathing, including obstructive sleep apnoea syndrome. The goal of this investigation was to assess the independent association of heavy, habitual snoring and daytime sleepiness. For this, a cross-sectional, population based study of snoring, sleepiness and other factors was conducted using the Warsaw sample of the Multinational Monitoring of Trends and Determinants of Cardiovascular Diseases (MONICA) study, a population-based multicentre study of cardiovascular disease. The well-defined MONICA sample of middle-aged males and females also allowed estimation of age- and sex-specific prevalences of habitual snoring in Polish adults. Data on self-reported snoring frequency and loudness, and daytime sleepiness using the Epworth Sleepiness Scale (ESS) and other questions, were collected with a postal questionnaire. Seventy-nine per cent of the MONICA sample completed the questionnaire, yielding a total of 1,186 participants. Of the total sample, 27% of the females and 48% of the males reported habitual snoring ("often" or "always"). There was an independent association of habitual snoring and excessive daytime sleepiness (EDS), sleepiness that interfered with work and with increasing ESS scores. Habitual snorers were 5.8 and 3.1 times more likely to report EDS in active and passive situations, respectively, compared to nonsnorers (all p<0.01). It is concluded that habitual snorers, most of whom are probably unlikely to have frank sleep apnoea syndrome, are at substantial risk for daytime sleepiness. These findings add support to the hypothesis that simple snoring is not benign and underscores the need for further research on health outcomes associated with this prevalent condition. (+info)
Does sleep fragmentation impact recuperation? A review and reanalysis.
Studies have shown that next-day performance and alertness are impaired by sleep fragmentation procedures even when total sleep time (TST) is unaffected. Based on these studies it has been hypothesized that both the duration and continuity of sleep determine its recuperative value. This review of the literature suggests that when sleep fragmentation procedures increase the relative amount of stage 1 sleep, next-day performance and alertness are impaired. Other studies suggest that stage 1 sleep has little or no recuperative value. Total sleep time, however, is typically defined as the sum of time spent in sleep stages 1, 2, 3, 4, and REM. In the present paper it is shown that when stage 1 sleep is excluded from TST, a stronger relationship between TST and subsequent alertness and performance emerges--and the need to invoke 'sleep continuity' as a variable that contributes independently to recuperative sleep processes is obviated. In the same way that partial or total sleep deprivation impairs alertness and performance, it is proposed that sleep disruption also impairs alertness and performance by reducing true recuperative sleep time. (+info)