Measures Of Sleep Latency Research Articles

Determination of sleep latency in polysomnographic evaluations of daytime somnolence in patients with sleep apnea and patients with narcolepsy.

Sleep onset during the multiple sleep latency test was scored by three criteria for 21 patients with narcolepsy and 21 patients with obstructive sleep apnea: a single epoch of stage 1, three consecutive epochs of stage 1, and a single epoch of stage 2 or REM. Mean sleep latency for both groups was predictably shortest using a single epoch of stage 1 and longest using a single epoch of stage 2 or REM. All estimates of sleep latency were highly correlated. It was concluded that a single epoch of any stage of sleep is an appropriate measure of sleep latency for patients with narcolepsy, although a modified scoring system should be developed for patients with sleep apnea. The obstructive apneic episodes prevented or delayed sleep onset on 4.8% to 33.3% of trials depending on the specific criteria used to determine sleep latency. Such apnea-related interruptions to sleep should be taken into account when assessing daytime somnolence in patients with sleep apnea.

A comparison of multiple and single sleep latency and cerebral evoked potential (P300) measures in the assessment of excessive daytime sleepiness in narcolepsy-cataplexy.

A direct comparison was made between the amplitude of evoked potential (EP) component P3 (by the P300 paradigm), a known sensitive EP correlate of sleepiness, and sleep latency measures (both to stage 1 or rapid eye movement [REM] and to stage 2 or REM) of the Multiple Sleep Latency Test (MSLT) in 11 untreated narcoleptics and matched controls. Repeated P3 measures were performed immediately prior to standard MSLT naps at 10:00 a.m., 12:00 noon, 2:00 p.m., 4:00 p.m., and 6:00 p.m. Using discriminant analysis and F tests, all three measures (P3 and both by MSLT) were found to distinguish the two groups for collapsed five-nap data, and all showed essentially parallel circadian time-of-day effects, with greatest sleepiness in the midafternoon. The MSLT, however, was somewhat more powerful for collapsed data. Both tests misclassified some subjects as belonging to the other group, with greater misclassification for both tests in the control group and more overall for the P3 measure. Adding the two sleep onset REM period (SOREMP) criteria on MSLT for narcolepsy, one patient was still classified as normal. Analysis of data from individual naps indicated that the MSLT was considerably more powerful in discriminating groups than was P3 amplitude, and it did so for all five naps.

Empirical note: self-report versus recorded sleep in healthy seniors.

ABSTRACTAlthough insomnia is a major public health problem in the elderly, little information concerning the relation between subjective reports of sleep and laboratory measures in the elderly has been published. Also, while laboratory studies of the healthy elderly typically show that women steep better than men, epidemiologic studies suggest that women complain more often than men about disturbed sleep. We report here a study of 20 healthy elderly subjects without sleep complaints (10M. 10F), in which relations between subjective and objective measures of sleep were explored.Both men and women showed significant correlations between objective measures of Sleep Latency (SL) and subjective estimates of fall asleep time; similarly, in both groups, subjective estimates of sleep duration were significantly and positively correlated with Time Spent Asleep (TSA).However, in the women, but not in the men, “restlessness” of sleep was significantly correlated with WASO (wake time after sleep onset), while “soundness” of sleep was positively related to amount of slow wave sleep.In general, women showed a higher proportion of significant and more stable correlations between subjective and objective measures than did men. These findings suggest that elderly women may report sleep loss more accurately than elderly men.

Effects of long term exposure to tone pulse noise on human sleep.

ABSTRACTElectrophysiological and self‐report data were obtained from 10 and 20 Ss, respectively, during 15 days of baseline, 30 days of 24‐hr per day exposure to a 660 msec, 3.5K Hz tone pulse with a 22 sec interstimulus interval (10 days each at 80, 85, and 90 dB), and during a 10‐day post‐exposure period. A self‐reported increase in difficulty falling asleep was not substantiated by objective sleep latency measures. Changes in total hours of sleep, number of awakenings, and percent time for sleep stages were of small magnitude and not consistently related to stimulus intensity. All 10 monitored Ss gave clear EEG and autonomic responses to the stimulus, with no evidence of response extinction over the 30‐day exposure period. There was no change in average all‐night heart rate. Total number of body movements during the night did not change. However, the movements that did occur, tended to be triggered by the stimulus, with most movements closely following the tone pulse. The youth and good health of the Ss, and the 24‐hr per day exposure, favoring rapid adaptation to the stimulus, are suggested to account for the lack of disruption of sleep.