SLEEP

Loeppky, Jack, A.;Miranda, Fernando, G.;Eldridge, Marlowe, W

doi: 10.1093/sleep/7.2.97pmid: 6429811

Summary: The responses of common carotid blood flow (CCF), pressure (BP), and resistance (R) to variations in respiratory gases were compared during waking periods in 10 sleep apnea patients (SA) and 10 healthy controls (N) of similar age, Respiratory gases were altered by 3-min CO2 rebreathing (RB), 3-min hyperventilation (HV), and 4-min hypoxia (HYP) procedures, CCF was measured continuously by a 5-MHz pulsed Doppler duplex scanner and R was calculated using brachial BP. During RB, which increased end-tidal Pco2 (PACO2) by 15 mm Hg, SA had a lower CCF and greater BP response and therefore a significantly different (positive) change in R compared with N, The ventilatory responses to CO2 were not significantly different. With HV the PACO2 fell by 23 mm Hg in both groups and CCF fell more markedly in SA than N with the same change in BP; therefore, R was increased significantly more in SA. The HYP results did not demonstrate a difference between groups, These results suggest that abnormal cerebrovascular responses to PACO2, initiated either by unusual vasoactive properties of cerebral resistance vessels or peculiar venous outlow patterns, may initiate or potentiate periodic breathing in SA by prolonging lung-to-brain circulation time. Sleep apnea, Cerebral blood flow, Rebreathing, Hyperventilation, Hypoxia, Circulatory time lags This content is only available as a PDF. © 1984 Raven Press, New York

Cartwright, Rosalind, Dymond

doi: 10.1093/sleep/7.2.110pmid: 6740055

Summary: Thirty male patients evaluated sequentially for sleep apnea syndrome by all-night clinical polysomnography were compared for apnea plus hypopnea index (A + HI) during the time in the side versus time in the back sleep posture. For 24 subjects of this sample, who occupied both major body positions during the evaluation night, the apnea index was found to be twice as high during the time spent sleeping on their backs as it was when they slept in the side position. This difference is reliable and inversely related to obesity. Five patients meeting diagnostic criteria for sleep apnea on an all-night basis fell within normal limits while in the side sleep position. This suggests sleep position adjustment may be a viable treatment for some nonobese sleep apnea patients. Sleep position, Apnea, Weight This content is only available as a PDF. © 1984 Raven Press, New York

Mosko, Sarah, S.;Shampain, David, S.;Sassin, Jon, F.

doi: 10.1093/sleep/7.2.115pmid: 6740056

Summary: A retrospective study of 92 narcoleptics was undertaken to investigate the significance of prolonged nocturnal REM latencies observed in approximately one in every five narcoleptics undergoing single all-night clinical polysomnograms in our laboratory. Clinical and laboratory findings were examined as a function of REM latency. Our findings emphasize a high incidence of other sleep disorders, particularly sleep-related periodic leg movements, in narcoleptics. Furthermore, sleep disturbance secondary to other sleep disorders, especially during the period of NREM sleep preceding the first REM episode, accounts in large part for prolonged REM latencies observed in some narcoleptics. This study also provides one of the most extensive compilations of clinical and laboratory findings in a large population of narcoleptics. Narcolepsy, REM latency, Sleep-related periodic leg movements, Sleep disturbance This content is only available as a PDF. © 1984 Raven Press, New York

Beersma, D. G., M.;Daan,, S.;, Van den Hoofdakker, R. H.

doi: 10.1093/sleep/7.2.126pmid: 6740057

Summary: The McCarley-Hobson model, describing the alternation of NREM and REM sleep in the cat, was applied to human electroencephalographic data. The influence of initial conditions on oscillatory behavior was especially emphasized. It appears that the distribution of REM latency in depression, the abnormal accumulation of REM sleep, the variability of NREM-REM cycle duration, the frequent stage shifts, and frequent awakenings can be explained in this model by means of a decrease in the initial value of a single variable, which may be regarded as representing the strength of REM inhibition. The observation of slow wave sleep deficiency in depression may well be another reflection of this parameter. REM sleep, Depression, Slow wave sleep, Ultradian rhythm This content is only available as a PDF. © 1984 Raven Press, New York

Roehrs, Timothy, A.;Tietz, Elizabeth, I.;Zorick, Frank, J.;Roth,, Thomas

doi: 10.1093/sleep/7.2.137pmid: 6146180

Summary: A daytime nap procedure was used to evaluate the daytime sleepiness associated with antihistamines, as well as to assess their hypnotic potential. Healthy, normal subjects received diphenhydramine (150 mg), terfenadine (120 mg), and placebo and went to bed at 900, 1100, 2000, and 2200 h with the instruction to try to fall asleep, They remained in bed for 60 min while standard sleep recordings were made. Across all conditions latency to stage 1 sleep increased significantly from nap 1 to nap 4 and the amount of sleep (all nonstage 1 sleep) decreased significantly. Over the four naps the mean latency to stage 1 sleep with diphenhydramine was significantly shorter than terfenadine and placebo, which did not differ. On the other hand, there were no differences among the drug conditions in the amount of nonstage 1 sleep. In sum, diphenhydramine at this dose produces sleepiness but shows little potential as a hypnotic, and accumulated sleep across the day makes people progressively more alert. Diphenhydramine, Terfenadine, Antihistamines, Daytime sleepiness, Hypnotic potential This content is only available as a PDF. © 1984 Raven Press, New York

Kant, G., Jean;Genser, Sander, G.;Thorne, David, R.;Pfalser, Hohn, L.;Mougey, Edward, H.

doi: 10.1093/sleep/7.2.142pmid: 6740058

Summary: Cortisol, urea, glucose, electrolytes, and other compounds were measured in five consecutive 24 h urine collections during a 72 h sleep deprivation study in six young men. Urine was collected during a 24 h pre deprivation day, 3 days of sleep deprivation, and a recovery day. Whereas urinary cortisol decreased only slightly, marked changes in other urinary constituents were observed. During sleep deprivation, urinary urea rose markedly, glucose decreased, and urinary electrolytes decreased. These data indicate that sleep deprivation under ad lib food and water conditions can cause disturbances in normal metabolism. Sleep deprivation, Cortisol, Urine, Electrolytes, Urea This content is only available as a PDF. © 1984 Raven Press, New York

Sewitch, Deborah, E.

doi: 10.1093/sleep/7.2.147pmid: 6740059

Summary: We assessed the effects of the length of sleep prior to awakening on the sense of having been asleep in 11 normal, healthy, young adults. They were awakened a total of 194 times out of stage 2 sleep, 153 times out of REM sleep, and 13 times out of slow-wave sleep over 54 nights in the laboratory. At each awakening, subjects were asked if they had been awake or asleep prior to the arousal. Continuous sleep time prior to the awakening was calculated in minutes to the first visually scorable alpha intrusion exceeding 10 s on either the central or occipital electroencephalogram (EEG) tracings. The sense of having been asleep prior to a NREM sleep awakening is dependent on the length of continuous, prior sleep time. However, the sense of having been asleep when aroused out of REM sleep shows no relationship to the length of continuous, prior sleep time. Sleep continuity, Sleep perception, NREM sleep, EEG, Normal sleepers This content is only available as a PDF. © 1984 Raven Press, New York

Grosvenor,, Andrea;Lack, Leon, C.

doi: 10.1093/sleep/7.2.155pmid: 6740060

Summary: Early studies in which it was found that learning followed by sleep was better remembered than learning followed by wakefulness were interpreted as giving support for the Interference Theory of Forgetting. More recent studies have shown better retention over the first half of the night's sleep (slow-wave sleep) than over the second half (REM sleep), and conclusions have been drawn that a Decay Theory of Forgetting is more strongly supported. Those studies, however, confounded the type of sleep following learning with sleep prior to learning. When prior sleep was controlled in the present study, there was no support for a first half-night sleep benefit, and, contrary to Decay Theory, there was a second half-night benefit for high imagery material. The strong detrimental effect of sleep prior to learning was inconsistent with the Interference Theory of Forgetting and suggested, instead, the importance of the consolidation process for long-term memory. Sleep stages, Long-term memory, Forgetting theories, Memory consolidation This content is only available as a PDF. © 1984 Raven Press, New York

Horne, J., A.;Pettitt, A., N.

doi: 10.1093/sleep/7.2.168pmid: 6740061

Summary: Seven physically untrained subjects underwent 72 h total sleep deprivation, following a baseline day. Daily, at 0400 and 1600 h, subjects pedalled on a bicycle ergometer under individually set work loads of 40, 60, and 80% Vo2max: This was not a study oriented towards endurance but towards capacity, requinng steady-state measurement. From assessments 9fheart rate, VO2 and VCO2 were calculated: VO2max' gross mechanical efficiency, VO2 at a heart rate of 150, and respiratory quotient. To assess possible training effects, a control group underwent identical procedures except that they slept at night and had the morning measure delayed until 0830 h. A series of statistical models were applied to the data, which centered on quantifying the inherent underlying variability, to estimate the level any main effect had to reach to become significant. The analysis showed that the noise level was small enough for any real effect of importance to have been detected, with a reasonably large probability. No statistically significant effects were found for any of the parameters with respect to conditions, days, and time. The main significant outcome was with mechanical efficiency, which displayed greater variability during sleep deprivation. Both groups displayed similar trends in training effects. It was concluded that the physiological ability to do work of the type and duration used here was not adversely affected by 72 h of sleep loss. Sleep deprivation, Physical work capacity This content is only available as a PDF. © 1984 Raven Press, New York

Dyson,, R.J.;Thornton,, C.;Doré,, C.J.

doi: 10.1093/sleep/7.2.180pmid: 6740062

Summary: This study investigated the use of electroencephalographic (EEG) electrode placements outside the hairline to monitor sleep. Six subjects slept for I night during which the EEG was recorded from “standard” electrode placements and simultaneously from the “test” placements outside the hairline where adhesive pregelled electrodes could be used. Each subject's EEG record was scored independently by two observers. The standard and test electrode placements were assessed separately. Cohen's kappa (κ) was used to quantify the agreement in the sleep scores (a) between observers when both scored the standard placements and (b) between the test and standard placements when scored by the same observer. The agreement for all stages between observers (a) was excellent (κ = 0.82); and the agreement within observers, between placements (b) was even better [κ = 0.86 for the six sleep stages considered separately; when stages awakell and 3/4 were combined (a) κ=0.88 and (b) κ=O.90]. It is concluded that EEG electrode placements outside the hairline can be used effectively to record sleep EEGs. The adoption of these electrode placements would simplify the monitoring procedure for many applied physiological studies especially when usual laboratory techniques for EEG are precluded. Electroencephalography, Sleep, Electrodes, Diving, Aerospace medicine, Evaluation studies This content is only available as a PDF. © 1984 Raven Press, New York