0280 Change in Sleep Depth Across the Night as a Measure of Sleep Adequacy

Introduction

It is well known that sleep becomes lighter towards the end of the night reflecting the reduction in homeostatic sleep pressure. We hypothesized that more adequate nocturnal sleep (i.e. sufficient quantity and quality for the individual) would result in a greater reduction in sleep depth across the night and would be reflected in decreased next-day sleep tendency.

Methods

In a secondary analysis of data from a study in which sleep depth was altered by sleep restriction combined with either placebo or gaboxadol (a delta-promoting drug) we correlated change across the night in two measures of sleep depth with next-day Multiple Sleep Latency Test (MSLT) latencies. Forty-one healthy subjects underwent 8 consecutive sleep studies; two baseline, four sleep restriction (5 hours) and two recovery nights. MSLT was performed following each baseline night and the last two restriction nights. Sleep depth in the first and last hours of NREM sleep was determined by two

methods

1) Log delta spectral power; 2) The odds-ratio-product (ORP), a recently introduced continuous measure of sleep depth. The difference between initial and final values was calculated (ΔDelta, ΔORP). Post-restriction MSLT latency was correlated with baseline MSLT latency, ΔDelta, ΔORP, log delta power and ORP in the last hour, lost total sleep time and lost REM time.

Results

ΔDelta was -0.27 ±0.13 and ΔORP was 0.17 ±0.13, both changes reflecting lightening of sleep across the night. In both univariate and multivariate analysis only baseline MSLT latency (p &lt 0.001) and ΔORP (p &lt 0.01) were significantly and positively correlated with post-restriction MSLT latency.

Conclusion

The reduction in sleep depth across the night as measured by ORP, but not by delta power, is significantly correlated with reduced objective sleepiness following sleep restriction. ΔORP may be a useful index that reflects sleep adequacy during the night.

Support

None

0282 Correlation Between Sleep Depth in the Right and Left Cerebral Hemispheres Following Sleep Deprivation, Restriction or Noise Exposure

Introduction

The Odds-Ratio-Product (ORP) is a highly-validated continuous index of sleep depth (range 0=deep sleep; 2.5=full wakefulness). ORP values fluctuate within this range as sleep state changes between wake and different sleep stages. In healthy non-sleep deprived adults, intra-class correlation coefficient of concurrent right vs. left ORP values (R / L coefficient) is typically >0.80. In a recent study R / L coefficient was markedly reduced in many critically-ill patients and these patients failed to be weaned from mechanical ventilation. Given the high prevalence of sleep loss in such patients we hypothesized that reduction in R/L coefficient might result from sleep loss. This retrospective EEG analysis of data from 3 independent research studies investigated if R / L coefficient decreases in pure models of sleep deprivation, restriction or noise exposure during sleep in healthy subjects.

Methods

Polysomnograms were obtained from three studies: A) 200 subjects who underwent 36 hours of total sleep deprivation; B) 21 subjects who underwent 4 consecutive nights of sleep restriction (5 hrs. / night); C) 72 subjects who were exposed to intermittent traffic noise events with maximum sound pressure levels ranging from 45–65 dB(A) for 10 consecutive nights. For study A, R / L coefficient was calculated from pre- and post-deprivation sleep studies and the two values were compared. For study B, coefficient was calculated at baseline and in each restriction night. For study C, the coefficient was calculated in each of the 10 exposure nights and the slope of the change was calculated.

Results

In study A, the coefficient decreased from 0.82±0.12 at baseline to 0.74±0.16 after sleep deprivation (p &lt 0.0001). In study B, the coefficient decreased from 0.83±0.11 at baseline to 0.75±0.15 on the 4th restriction night (p &lt 0.01). In study C, coefficient decreased at a rate of 0.003±0.001 per exposure night (p &lt 0.001).

Conclusion

The correlation between sleep depth in the right and left hemispheres deteriorates following sleep deprivation, restriction or noise-induced sleep fragmentation.

Support

NIH P50 HL060287

0150 Comparing Two Measures of Sleep Depth/ Intensity

Introduction

There is currently no well-validated method for evaluating objective sleep depth/intensity. Delta power is thought to reflect sleep depth based upon limited evidence. Odds-ratio-product (ORP) is a recently introduced continuous measure of sleep depth. We compared delta spectral power (delta) and ORP as measures of sleep depth/intensity during manipulations that altered sleep depth (sleep restriction with placebo or with a delta-promoting drug). We hypothesized that ORP will provide a more robust measure of sleep depth.

Methods

This is a secondary analysis of data from a study in which forty-one healthy subjects were sleep restricted and randomized to receive placebo or gaboxadol 15mg. Participants underwent consecutive in-laboratory sleep studies on two baseline, four sleep restriction (5 hours) and two recovery nights. The relation between delta or ORP during any given 30s epoch and sleep depth, operationally defined as the probability of arousal / awakening occurring during the next 30 seconds (arousability), was assessed.

Results

Mean ORP values differed significantly among the four sleep / wake stages, but delta power did not differentiate wake, N1 and N2. The relation between ORP and arousability was linear across the entire range of ORP whereas delta power detected differences in arousability only with delta values &lt 300 μV2. Correlations with arousability in individual subjects were stronger with ORP (p &lt 0.0001). Receiver operating characteristic analysis found the ability to predict imminent arousal to be significantly greater with ORP than with delta power for all experimental conditions (p &lt 0.0001). The increase in sleep depth with restriction alone was detected on the second day of restriction by ORP (p &lt 0.01) but not by delta.

Conclusion

As compared to delta power, ORP is more discriminating among sleep stages, more sensitive to sleep restriction, and more closely associated with arousability. These observations indicate ORP better reflects sleep depth/intensity.

Support

None

Presleep Cognitive Hyperarousal and Affect as Factors in Objective and Subjective Insomnia

The role of presleep cognition in insomnia was studied in normal sleepers and insomniacs with either (1) psychophysiological insomnia, an objective disorder of initiating and maintaining sleep (DIMS), or (2) DIMS without objective findings (subjective insomnia), as defined by two nights’ polysomnographic baseline data. During the experimental night in the sleep laboratory, 24 subjects were interviewed at intervals during the presleep/sleep-onset period. Judges’ ratings of subjects’ spontaneous reports and subjects’ responses to questionnaire items were analyzed for cognitive quality. Objective insomniacs had more frequent cognitive activity than the subjective insomniacs. Both insomnia groups reported more negative thoughts than the controls. Cognitive hyperarousal as a factor in objective insomnia was not clearly supported.

Sex differences and the effect of gaboxadol and zolpidem on EEG power spectra in NREM and REM sleep

Hypnotics that interact with the GABA(A) receptor have marked effects on the electroencephalogram (EEG) during sleep. It is not known whether the effects of hypnotics on EEG power spectra differ between the sexes. The effects of 5, 10 and 15 mg of gaboxadol (GBX) and 10 mg of zolpidem (ZOL) on EEG power spectra were assessed in a randomized, double-blind, placebo-controlled, 5-way cross-over design study using a phase-advance model of transient insomnia. Sleep stage specific EEG power spectra were computed in 36 men and 45 women. GBX enhanced power density in delta and theta activity in non-rapid eye movement (NREM) and rapid eye movement (REM) sleep, and suppressed sleep spindle activity in NREM sleep. The increase of delta and theta activity in NREM and REM sleep was significantly larger for women than for men but the suppression of spindle activity did not differ between the sexes. After ZOL administration, no sex differences were observed in the reduction of delta and theta activity in NREM sleep, but the increase in sleep spindle activity in NREM sleep was greater in women than in men. These sex dependent and differential effects of GBX and ZOL may be related to their differential affinity for GABA(A) receptor subtypes and their modulation by neurosteroids.

A comparison of placebo and no-treatment during a hypnotic clinical trial

OBJECTIVE

Sleep parameters commonly improve during placebo treatment in insomnia clinical trials. We examined whether the improvement seen with placebo was related to taking pills or other non-specific factors.

METHOD

95 insomniacs took either a placebo pill (pill+) or no pill (pill-) on nights of their choosing over 12 weeks.

RESULTS

Pills were consumed on about half of the nights. Consistent improvement was seen with reduced reported sleep latency, wakefulness after sleep onset, number of awakenings, and total sleep time over the 12 weeks for both the pill+ and pill condition. A difference between pill+ and pill- was detected only for total sleep time, and this difference favored pill+.

CONCLUSIONS

This study suggests that improvement seen during placebo treatment is more related to non-specific factors of participating in clinical trial than to pill taking behavior.

The challenge of chronic insomnia: is non-nightly hypnotic treatment a feasible alternative?

The adverse effects of insomnia on health and quality of life are matters receiving increasing attention. Yet, surveys have consistently shown that most people suffering from insomnia do not seek medical help, perhaps, in part, because of a concern of becoming dependent on hypnotic medication. The treatment of chronic insomnia poses a particular dilemma in that continuous hypnotic treatment is restricted in many countries to a maximum of 4 weeks, and behavioural treatment is not readily available. Non-nightly hypnotic treatment of chronic insomnia offers a promising alternative option for the many patients whose symptoms do not necessitate nightly drug intake, allaying fears of psychological dependence on medication and respecting regulatory constraints on hypnotic use while providing patients with adequate symptom relief. The practical feasibility and efficacy of this approach has been demonstrated with zolpidem using various treatment regimens and study designs. So far, six clinical trials have been completed on over 4000 patients. Published results show effective treatment of insomnia without any evidence of either adverse event associated with a discontinuous regimen or increased hypnotic use over the treatment period.

Zolpidem reduces the sleep disturbance of jet lag

OBJECTIVE

To determine the degree to which zolpidem 10 mg would reduce the sleep disruption associated with rapid, eastward transatlantic travel.

BACKGROUND

Subsequent to rapid transmeridian travel, individuals often complain of jet lag which includes transient disturbances in sleep patterns, alertness, appetite and mood. Disturbed sleep and impaired alertness appear to be the most debilitating symptoms of jet lag.

METHODS

This multi-center, double-blind randomized, placebo-controlled, parallel-groups study involved 138 adult (mean age 44.9 years) experienced travelers while on their regular eastward transatlantic assignments originating in the US and crossing 5-9 time zones. Subjects were normal sleepers when not traveling and had to have traveled overseas at least twice during the last 24 months. Subjects were randomized to zolpidem 10 mg or placebo for three (optionally four) consecutive nights starting with the first nighttime sleep after travel. Sleep was assessed with daily questionnaires.

RESULTS

A total of 130 subjects completed the study. Compared to placebo, zolpidem was associated with significantly improved sleep (statistically significant differences at nights indicated) longer total sleep time (night 1), reduced number of awakenings (nights 1 and 2), and improved sleep quality (nights 1, 2 and 3). Zolpidem was not associated with improvement in sleep latency. No unexpected or serious adverse events were reported and the most common adverse event was headache in both groups (9.2 and 17.6% for placebo and zolpidem, respectively).

CONCLUSION

In seasoned travelers, zolpidem 10 mg produced significant improvement in sleep following rapid transmeridian travel.

Eight weeks of non-nightly use of zolpidem for primary insomnia

CONTEXT

Intermittent use (i.e., a few nights per week) of hypnotic medication is often recommended for the treatment of chronic insomnia despite an absence of efficacy and safety data using this regimen.

STUDY OBJECTIVES

To evaluate the clinical efficacy and safety of intermittent pharmacotherapy for chronic insomnia.

DESIGN AND SETTING

Randomized, double-blind, placebo-controlled, parallel groups, clinical trial at six sleep research sites.

PATIENTS

One hundred-sixty-three (115 women, 48 men; mean age 44.1+ SE. 0.9 years), DSM-IV-defined primary insomnia patients were randomized, 134 patients completed the study.

INTERVENTIONS

Eight weeks of treatment with either zolpidem 10 mg or placebo. Patients were instructed to take medication when they felt they needed it, but at least three and no more than five times per week.

MAIN OUTCOME MEASURES

Investigator and Patient Global Ratings were the primary outcome variables. Secondary measures from daily questionnaires to assess efficacy, rebound insomnia and drug taking behavior.

RESULTS

The Investigator's Global Rating indicated that intermittent use of zolpidem produced a significantly better therapeutic effect and significantly reduced insomnia severity throughout the 8-week study relative to placebo. Zolpidem was found to be effective in initiating and maintaining sleep on nights taken, as compared to placebo, based upon the Patient's Global Ratings and all subjective sleep variables. No evidence of rebound insomnia was found on nights that zolpidem was not taken. The number of nights a pill was taken did not differ between groups, nor did frequency of pill taking change in either group across the duration of the study. There were no significant effects of treatment upon quality of life or neurocognitive measures.

CONCLUSIONS

Zolpidem 10 mg is effective in treating insomnia when used intermittently, without evidence of discontinuation effects or increased frequency of pill taking.

Lack of residual sedation following middle-of-the-night zaleplon administration in sleep maintenance insomnia

The present randomized, double-blind, placebo and active-drug controlled, crossover study assessed residual sedation after zaleplon 10 mg, flurazepam 30 mg (as an active control), and placebo, taken during a nocturnal awakening in patients with sleep maintenance insomnia. Twenty-two healthy sleep maintenance insomniacs (11 men; mean age, 42 y) received zaleplon, flurazepam, or placebo after an experimental awakening 3.5 hours after bedtime on two consecutive nights in each of three conditions. Residual sedation was measured with sleep latency testing (5 and 6.5 h postdrug), digit symbol substitution, symbol copying, and subjective sleepiness by visual analog scale, each twice each morning. Zaleplon did not differ from placebo on any measure of residual sedation; flurazepam showed significant sedation on all measures. No residual sedative effects were detected 5 or 6.5 hours after ingestion of zaleplon during the middle of the night by sleep maintenance insomniacs.

Zolpidem for persistent insomnia in SSRI-treated depressed patients

BACKGROUND

Depressed individuals effectively treated with selective serotonin reuptake inhibitors (SSRIs) often report persistent insomnia and require adjunctive sleep-promoting therapy.

METHOD

Men (N = 40) and women (N = 150) with a mean age of 41.6 years who had persistent insomnia in the presence of effective and stable treatment (at least 2 weeks) with fluoxetine (< or =40 mg/day), sertraline (< or =100 mg/day), or paroxetine (< or =40 mg/day) for DSM-IV major depressive disorder, dysthymic disorder, or minor depressive disorder of mild-to-moderate severity (and score of < or =2 on item 3 of the Hamilton Rating Scale for Depression [HAM-D]) participated in this randomized, double-blind, parallel-group study. At study entry, patients were required to score < or =12 on the HAM-D. During a 1-week single-blind placebo period, patients had to report on at least 3 nights a latency of > or =30 minutes or a sleep time of <6.5 hours and clinically significant daytime impairment. Patients received either placebo (N = 96) or zolpidem, 10 mg (N = 94) nightly, for 4 weeks and single-blind placebo for 1 week thereafter. Sleep was measured with daily questionnaires and during weekly physician visits.

RESULTS

Compared with placebo, zolpidem was associated with improved sleep: longer sleep times (weeks 1 through 4, p<.05), greater sleep quality (weeks 1 through 4, p<.01), and reduced number of awakenings (weeks 1, 2, and 4; p<.05), together with feeling significantly more refreshed, less sleepy, and more able to concentrate. After placebo substitution, the zolpidem group showed significant worsening relative to pretreatment sleep on the first posttreatment night in total sleep time and sleep quality, reverted to pretreatment insomnia levels on the other hypnotic efficacy measures, or maintained improvement (fewer number of awakenings). There was no evidence of dependence or withdrawal from zolpidem (DSM-IV criteria). Incidence rates of adverse events were similar in both treatment groups (74% and 83% for placebo and zolpidem, respectively), but 7 zolpidem patients discontinued compared with 2 placebo patients.

CONCLUSION

In this defined patient population, zolpidem, 10 mg, was effectively and safely co-administered with an SSRI, resulting in improved self-rated sleep, daytime functioning, and well-being.

Ten-year trends in the pharmacological treatment of insomnia

STUDY OBJECTIVE

To assess patterns of pharmacological treatment of insomnia during the period 1987-1996.

DESIGN AND MEASUREMENTS

Data were obtained from the National Disease and Therapeutic Index (NDTI; IMS America, Ltd., Plymouth Meeting, PA) which samples office-based physicians in 24 specialties. Drug mentions, a measure of patient contacts in which drug therapy is recommended, with a physician-indicated desired action of "promote sleep" or "sedative night" were compiled for each year. Z-scores were calculated to determine statistical differences over time for total drug mentions, drug mentions by category (hypnotics, non-hypnotic benzodiazepines, antidepressants, or other), and for some individual drugs.

RESULTS

Total drug mentions for the treatment of insomnia fell 24.4% from 1987 to 1996. From 1987 to 1996 hypnotic mentions decreased 53.7%, antidepressants increased 146%, "other" drugs decreased by 63.2%, and benzodiazepine non-hypnotics remained relatively unchanged.

CONCLUSIONS

Since 1987, overall pharmacological treatment of insomnia has decreased substantially although surveys indicate a stable or increasing prevalence of sleep disturbance. There has also been a dramatic shift to use of antidepressants in lieu of hyponotics for the symptomatic treatment of insomnia despite a paucity of data regarding their efficacy and the potential for serious side effects.

The direct economic costs of insomnia in the United States for 1995

STUDY OBJECTIVES

To assess the direct economic costs of insomnia in the United States in 1995.

METHODS

The costs of prescription medications were based on 1995 data compiled by IMS America, Ltd. (Plymouth Meeting, PA). Non-prescription medication expenditures were provided by Information Resources, Inc. (Chicago, IL). The costs of physician visits related to insomnia were estimated from unpublished data of the 1994 National Ambulatory Medical Care Survey conducted by the National Center for Health Statistics and from the America Medical Association Center for Health Policy Research. Several other sources were used for other cost estimates.

RESULTS

Total cost for substances used to treat insomnia was $1.97 billion, less than half of which was for prescription medication. Health care services for insomnia totaled $11.96 billion, 91% of which is attributable to nursing home care. The total direct costs in the United States for insomnia in 1995 were estimated to be $13.9 billion.

CONCLUSIONS

Increased efforts are needed in several domains to offset the cost of insomnia including clinical research on the consequences of untreated and treated insomnia, development and implementation of curricula to provide knowledge about sleep and sleep disorders for medical students, physicians, and other health professionals, education to increase public awareness of insomnia and sleep disorders, and more support for basic research on neural mechanisms involved in healthy and disordered sleep.

Cognitive function following acute sleep restriction in children ages 10-14

STUDY OBJECTIVES

Various aspects of human performance were assessed in children after sleep loss.

PARTICIPANTS

Sixteen children (7 males, 9 females) between the ages of 10 and 14 years.

DESIGN AND INTERVENTIONS

Children were randomly assigned to either a control (CTRL) group, with 11 hours in bed, or an experimental sleep restriction (SR) group, with 5 hours in bed, on a single night in the sleep laboratory.

MEASUREMENTS

Both groups were evaluated the following day with a battery of performance and sleepiness measures. Psychomotor and cognitive performance tests were given during four 1-hour testing sessions at 2-hour intervals.

RESULTS

A multiple sleep latency test (MSLT) documented shorter latencies for SR children than controls. Significant treatment differences were discovered in three of four variables of verbal creativity, including fluency, flexibility, and average indices. There were also group differences found on the Wisconsin Card Sorting Test (WCST), which may be indicative of difficulty learning new abstract concepts. Measures of rote performance and less-complex cognitive functions, including measures of memory and learning and figural creativity, did not show differences between groups, perhaps because motivation could overcome sleepiness-related impairment for these tasks.

CONCLUSIONS

Higher cognitive functions in children, such as verbal creativity and abstract thinking, are impaired after a single night of restricted sleep, even when routine performance is relatively maintained.

The sleep of long-haul truck drivers

BACKGROUND

Fatigue and sleep deprivation are important safety issues for long-haul truck drivers.

METHODS

We conducted round-the-clock electrophysiologic and performance monitoring of four groups of 20 male truck drivers who were carrying revenue-producing loads. We compared four driving schedules, two in the United States (five 10-hour trips of day driving beginning about the same time each day or of night driving beginning about 2 hours earlier each day) and two in Canada (four 13-hour trips of late-night-to-morning driving beginning at about the same time each evening or of afternoon-to-night driving beginning 1 hour later each day).

RESULTS

Drivers averaged 5.18 hours in bed per. day and 4.78 hours of electrophysiologically verified sleep per day over the five-day study (range, 3.83 hours of sleep for those on the steady 13-hour night schedule to 5.38 hours of sleep for those on the steady 10-hour day schedule). These values compared with a mean (+/-SD) self-reported ideal amount of sleep of 7.1+/-1 hours a day. For 35 drivers (44 percent), naps augmented the sleep obtained by an average of 0.45+/-0.31 hour. No crashes or other vehicle mishaps occurred. Two drivers had undiagnosed sleep apnea, as detected by polysomnography. Two other drivers had one episode each of stage 1 sleep while driving, as detected by electroencephalography. Forty-five drivers (56 percent) had at least 1 six-minute interval of drowsiness while driving, as judged by analysis of video recordings of their faces; 1067 of the 1989 six-minute segments (54 percent) showing drowsy drivers involved just eight drivers.

CONCLUSIONS

Long-haul truck drivers in this study obtained less sleep than is required for alertness on the job. The greatest vulnerability to sleep or sleep-like states is in the late night and early morning.

Minimal rebound insomnia after treatment with 10-mg zolpidem

This study examined rebound insomnia after discontinuation of chronic use of zolpidem (10 mg), a short elimination half-life imidazopyridine. The zolpidem group was bracketed by a placebo group and a positive control group taking 0.5 mg of triazolam (twice the recommended dose), which is known to produce rebound insomnia. Ninety-nine patients with sleep complaints that were polysomnographically documented participated in the study. After randomization, patients completed a 2-night, single-blind, placebo baseline period, a 28-night double-blind treatment phase, and a 3-night, single-blind, placebo substitution period. Polysomnographic and subjective sleep variables indicated a lack of rebound insomnia for the zolpidem group. The positive triazolam control group had rebound insomnia only on the first discontinuation night. There was no significant correlation between rebound insomnia and the level of initial insomnia, the degree of response to treatment in week 4, or the amount of tolerance that developed during drug use. During the 4-week treatment period, efficacy diminished for both drugs. From these data, it cannot be determined whether the lack of rebound insomnia with zolpidem is a result of drug dose or some property of the drug such as receptor selectivity.

Effects of triazolam on sleep, daytime sleepiness, and morning stiffness in patients with rheumatoid arthritis

OBJECTIVE

To evaluate the effects of triazolam upon insomnia and daytime sleepiness in patients with rheumatoid arthritis (RA).

METHODS

Triazolam or placebo was administered during two 7 night periods to 15 patients with RA in a double blind crossover study. Polysomnographic recordings were conducted on the last 2 nights of each condition, and multiple sleep latency tests and mood and arthritis assessments were performed during the intervening day in each condition.

RESULTS

In the triazolam condition, total sleep time was increased, daytime sleepiness was reduced, and morning stiffness was improved compared to placebo. Objective measures of sleep fragmentation were unchanged. Clinical arthritis assessments were similar during both conditions.

CONCLUSION

Short term hypnotic therapy improves sleep in patients with RA and appears to improve morning stiffness and daytime sleepiness.

Hypnotics and caffeine as countermeasures for shiftwork-related sleepiness and sleep disturbance

Hypnotic medication reliably improves sleep during the day, in terms of increasing total sleep time (TST) and reducing awakenings and light sleep. Middle-aged individuals may benefit more than young adults. In addition, the time of day during which sleep is attempted may influence the efficacious dose of short-acting drugs. Available data suggest that improving sleep during the day may improve alertness/performance at night to a mild degree, but significant circadian-related sleepiness remains. Hypnotic medication may help minimize the cumulative effects of sleep loss associated with daytime sleep. Use for more than one week has not been adequately studied; however, as most night and rotating workers' schedules allow for night-time sleep for two or more nights per week, available evidence indicates that hypnotics can be used effectively on an intermittent basis, e.g. for the first 2-4 day-sleep periods of night shifts. Caffeine has been shown to increase alertness and improve psychomotor performance during usual night-shift hours when taken between 22.30 and 01.20 hours. Available data indicate that at approximate dosages of 250-400 mg, the beneficial effects persist until at least 05.30 hours. For most subjects, caffeine taken at the start of the night-shift does not interfere significantly with daytime sleep beginning at 09.00 hours. There is also some evidence that single doses of caffeine at the beginning of a night shift may be more alerting than divided doses. If caffeine is to be used therapeutically, avoidance of social use may be required to avoid tolerance to CNS stimulant effects. Despite the positive results of laboratory research examining hypnotics or caffeine as shiftwork countermeasures, field trials have not been conducted.

The effects of caffeine on simulated night-shift work and subsequent daytime sleep

Thirty healthy volunteers were randomly assigned to either a caffeine or a placebo group to investigate the alerting effects of caffeine at night. Subjects adhered to a simulated night-shift schedule for 5 consecutive nights. On the first 3 nights, 2 mg/kg caffeine was added to decaffeinated coffee at 2220 and 0120 hours for the caffeine group. On nights 4 and 5 both groups received placebo. Each night, subjects completed five 60-minute sessions of a computerized simulated assembly line performance task (SALT), a multiple sleep latency test (MSLT) and questionnaires. Daytime sleep was recorded in the laboratory between 0900 and 1700 hours each day following nighttime testing. Caffeine decreased physiological sleep tendency on the night shift compared with placebo; however, the two groups performed at equivalent levels on the SALT. On nights 4 and 5, when both groups received placebo, there were no differences between the groups on the MSLT, suggesting the absence of a discontinuation effect. There were no differences on daytime polysomnograms between the groups.

Sleepiness and performance during three-day administration of cetirizine or diphenhydramine

OBJECTIVE

The sedative effects of cetirizine (10 mg once daily), diphenhydramine (50 mg three times daily), and placebo, each administered during a 3-day period, were compared with objective measures of sleepiness and performance.

METHODS

Twelve atopic subjects received each of the three treatments for 3 consecutive days in a double-blind Latin square design. Subjects received either cetirizine at 8:00 AM and placebo at 3:00 PM and 10:00 PM; diphenhydramine at 8:00 AM, 3:00 PM, and 10:00 PM; or placebo at all three times. Sleepiness was measured on days 1 and 3 with the multiple sleep latency test at 9:00 AM, 11:00 AM, 1:00 PM, 3:00 PM, and 5:00 PM. Performance was assessed with a 60-minute simulated assembly line task at 9:30 AM, 11:30 AM, 1:30 PM, and 3:30 PM. Nightly sleep duration was estimated with actigraphy.

RESULTS

Compared with placebo and cetirizine, diphenhydramine produced marked impairment only on the first day of drug administration. The multiple sleep latency test and the simulated assembly line task values remained stable across days with cetirizine and placebo but improved with diphenhydramine, resulting in no differences among the three conditions on the third day.

CONCLUSION

Unlike cetirizine, diphenhydramine produced acute impairment of alertness and performance. By the third day of administration, however, this impairment was no longer present, apparently because of development of tolerance to the sedative effects.

A multicenter, placebo-controlled study evaluating zolpidem in the treatment of chronic insomnia

BACKGROUND

Zolpidem is a short-acting, nonbenzodiazepine hypnotic with rapid onset of action. Even though it is not a benzodiazepine, it binds to one of three types of central benzodiazepine receptors, showing selective binding to the type 1 benzodiazepine receptor subtype. Therapeutic hypnotic dosages do not disturb normal sleep patterns (sleep architecture).

METHOD

A randomized, double-blind, placebo-controlled, parallel group multicenter trial was conducted to determine the effectiveness of 10 mg and 15 mg of zolpidem in the long-term (35 nights) treatment of chronic insomnia in 75 patients. Sleep stage effects and motor and cognitive effects during the 35-night treatment period and the 3-night posttreatment period were also investigated.

RESULTS

Within the first week of treatment, 10 mg of zolpidem had a significant effect on latency to persistent sleep and sleep efficiency. Efficacy was maintained throughout the 35 nights of drug administration. There was no evidence of residual effect with 10 mg of zolpidem. Stage 3-4 sleep was preserved at both the 10-mg and 15-mg zolpidem dosages. There was no evidence of tolerance at either dose and no significant treatment differences between the 10-mg zolpidem group and placebo in latency to persistent sleep or sleep efficiency during the posttreatment period. Also, the 10-mg zolpidem dosage was judged by the patients to have helped them fall asleep. Similar results were observed with the 15-mg zolpidem dosage. However, there were significant decreases in REM sleep at Weeks 3 and 4 with 15 mg of zolpidem compared with placebo. Overall, incidence rates of treatment-emergent adverse events in the zolpidem groups were similar to those in the placebo group.

CONCLUSION

This is the first sleep laboratory study using a parallel placebo group to demonstrate efficacy for longer than 4 weeks with a hypnotic agent. In this study 10 mg of zolpidem was found to be safe and effective for the long-term treatment of chronic insomnia, demonstrating hypnotic efficacy without affecting sleep stages or producing tolerance effects, rebound effects, or detrimental effects on psychomotor performance. The 15-mg zolpidem dosage provided no clinical advantage over the 10-mg zolpidem dosage.

Slow-wave sleep deprivation and waking function

Slow-wave sleep (SWS) has been theorized to be an intense form of nonREM sleep, but selective deprivation of SWS or Stage 4 sleep has not been shown to cause greater decrements in alertness or performance, compared to deprivation or disruption of the other stages of sleep. The present experiment examined the effects of marked SWS deprivation (SD) for two nights, a control sleep disruption (CD) condition in which minutes of SWS were preserved, and a no sleep disruption (ND) condition. Daytime sleepiness was assessed with the multiple sleep latency test (MSLT) and performance was evaluated with the simulated assembly line task (SALT), neither of which was used in previous studies of SWS or Stage 4 sleep deprivation. In agreement with prior studies, two nights of SD did not cause greater daytime sleepiness than did CD, although sleepiness in both conditions was increased compared to the ND condition. In addition, neither SD nor CD caused declines in performance or mood. However, post hoc analysis suggests an interaction between SWS and sleep duration, such that sufficient SWS may tend to prevent adverse effects of mild sleep loss on waking function.

Two- and 4-hour bright-light exposures differentially effect sleepiness and performance the subsequent night

The effect of two durations of bright light upon sleepiness and performance during typical night shift hours was assessed. Thirty normal, healthy young adults participated in a 2-night protocol. On the 1st night subjects were exposed to bright or dim light beginning at 2400 hours, under one of the following three conditions: bright light for 4 hours, dim light for 2 hours followed by bright light for 2 hours or dim light for 4 hours. Following light exposure, subjects remained awake until 0800 hours in a dimly lit room and slept in the laboratory between 0800 and 1600 hours, during which time sleep was estimated with actigraphy. Throughout the 2nd night, the multiple sleep latency test (MSLT), simulated assembly line task (SALT) performance, and subjective sleepiness were recorded. The single, 4-hour exposure to bright light was found to significantly increase MSLT scores and improve SALT performance during the early morning hours on the night following bright-light exposure. No significant effects were noted with a 2-hour exposure. The most likely explanation for these findings is a phase delay in the circadian rhythm of sleepiness-alertness.

Effect of freezing on the concentration of drugs of abuse in urine

Benzoylecgonine, 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid (THC-acid), phencyclidine, codeine, morphine, amphetamine, methamphetamine, and lysergic acid diethylamide were dissolved in urine, stored frozen in plastic tubes at -16 to -18 degrees C, defrosted, transferred to other tubes, and analyzed by gas chromatography/mass spectrometry (GC/MS); no significant loss of compound was observed, except for THC-acid, which showed an average loss of 11%, ranging from 0 to 34% of the total concentration. The loss is attributed to the decrease in solubility of the compound and to adherence to the side of the container during freezing.

Trends in the pharmacologic treatment of insomnia

Data from the National Disease and Therapeutic Index for the time period 1987-1991 (IMS, America) were examined for recent trends in the pharmacologic treatment of insomnia. All medications given with the desired action of promoting sleep or sedation at night were categorized as benzodiazepine hypnotics, benzodiazepine nonhypnotics, antidepressants, or other. From 1987 to 1991, the following trends were found: (1) overall pharmacologic treatment for insomnia decreased by approximately 10%, (2) use of benzodiazepine hypnotics fell about 30% during this time period, (3) use of antidepressants for insomnia increased by 100%, and (4) the noted changes were somewhat stronger for institutionalized patients than for ambulatory patients. These changes in the pharmacologic treatment of insomnia may be related to widespread media attention and are not supported by scientific data.

Sleepiness/alertness on a simulated night shift schedule and morningness-eveningness tendency

This study examined the influence of morningness-eveningness on night shift sleepiness in 15 subjects. Sleepiness was assessed during a five-night protocol involving the multiple sleep latency test (MSLT), repeated test of sustained wakefulness (RTSW) and the Stanford Sleepiness Scale (SSS). Daytime sleep was estimated by sleep diaries and wrist actigraphy. The sample was divided by median score on the Horne and Ostberg Morningness-Eveningness Questionnaire. Physiological sleep tendency was significantly worse between 0030 and 0430 hours for the Morning Tendency group than for the Non-Morning Tendency group. The Morning Tendency group reported obtaining less daytime sleep than the Non-Morning Tendency group; however, there was no difference between groups in total daytime sleep estimated by actigraphy. This preliminary study suggests that morning types are sleepier during night shift hours than non-morning types.

Sedative effects of ethanol at night

The sedative effect of 0.7 g/kg of 100% ethanol, ingested at 9:30 PM, was investigated to examine the combined effects of ethanol and circadian sleepiness/alertness levels. Fourteen healthy young adults participated in a placebo-controlled, double-blind crossover design. Each subject, on two separate occasions (placebo or ethanol), completed multiple sleep latency testing and the repeated test of sustained wakefulness as objective measures of physiological sleep tendency, and completed the Stanford Sleepiness Scale as a measure of subjective sleepiness. The results indicate that a moderate dose of ethanol significantly increases physiological sleepiness during early morning hours even in individuals that are relatively alert at these times. Therefore, the marked reduction in alertness and related performance deficits that normally occur at night are worsened by ethanol ingestion. Sleepiness, due to any cause, and ethanol may well be a dangerous combination.

Triazolam diminishes daytime sleepiness and sleep fragmentation in patients with periodic leg movements in sleep

Fifteen subjects (9 men and 6 women) exhibiting objective evidence of excessive daytime somnolence and periodic leg movements in sleep underwent 4-7 days of treatment with triazolam (0.25 or 0.50 mg) and placebo in a double-blind crossover design. One night of polysomnography followed by daytime multiple sleep latency testing were conducted on the first and last days of each treatment block. By the last day of treatment, the mean multiple sleep latency test score after triazolam (9.0 minutes) was significantly greater than that after placebo (5.7 minutes). Thus, triazolam treatment led to a decrease in daytime somnolence. Triazolam also improved sleep architecture and continuity; it increased total sleep time, decreased the number of awakenings and arousals, and decreased stage 1 and increased stage 2 percentages. Although the frequency of periodic electromyographic bursts remained unchanged, the frequency of associated arousals decreased after treatment. Short-term treatment with triazolam is thus effective in diminishing daytime sleepiness and in improving sleep architecture, continuity and duration in patients with periodic leg movements in sleep. These effects do not seem to be mediated through a decrease in periodic leg movement activity.

Avoiding the blanket approach to insomnia. Targeted therapy for specific causes

A systematic approach to the common complaint of insomnia usually results in a specific clinical diagnosis with clear therapeutic implications. Use of effective treatment strategies tailored to the situation can make treating insomnia a gratifying experience instead of a frustrating one.

Sleepiness/alertness on a simulated night shift following sleep at home with triazolam

Physiological sleep tendency during a simulated night shift schedule was examined in 15 middle-aged subjects following daytime sleep after administration of triazolam or placebo. A double-blind, counterbalanced, crossover design involving two tours of five laboratory nights and four daytime home sleep periods was used. Triazolam lengthened daytime sleep as measured by wrist actigraph and improved nighttime alertness as measured by the MSLT. Sleepiness was most profound during the early morning hours (0430 to 0630) but improved significantly across nights for both conditions. Repeated test of sustained wakefulness latencies and simulated assembly line task performance decreased slightly across the night, but there were no significant condition effects. Subjective data tended to support objective measures, although Stanford Sleepiness Scale ratings indicated that subjects did not perceive improved alertness at night after triazolam-aided daytime sleep.

Effects of uvulopalatopharyngoplasty on sleep architecture and patterns of obstructed breathing

In this retrospective study, 72 obstructive sleep apnea patients with polysomnograms taken before and after uvulopalatopharyngoplasty were evaluated. Postoperatively, there was a significant improvement of sleep architecture and respiratory indices. In addition, a second group of 17 patients also had position recordings with their polysomnograms. Time spent in supine and lateral sleep positions changed postoperatively. There was significant decrease of the apnea plus hypopnea index in the lateral position. This study indicates that there is significant improvement of sleep architecture and respiratory indices in the majority of patients after uvulopalatopharyngoplasty, particularly in the lateral sleep position.

Transient insomnia associated with a 3-hour phase advance of sleep time and treatment with zolpidem

A 3-hour phase advance of sleep time was employed to produce a model of transient insomnia. The degree to which this manipulation was effective varied substantially among young, healthy normal sleepers. Zolpidem, an imidazopyridine hypnotic compound, was effective in reversing the sleep disruption in those individuals displaying transient insomnia in this model.

Intervention factors for promoting adjustment to nightwork and shiftwork

This chapter reviews a broad range of factors that, if controlled, might promote adaptation to nightwork, shiftwork, and extended workshifts. Systematic study has begun in four of the areas reported here: work schedule design, napping, bright light stimulation, and drugs. Physical activity, ambient temperature, diet, and individual behaviors have been studied only superficially.

Role of hypnotic drugs in general practice

General practice physicians commonly deal with patients who report experiencing insomnia. Advances in our understanding of insomnia should result in much more effective diagnosis and therapeutic intervention for insomnia patients at the primary care level. This presentation highlights the new knowledge of insomnia pertinent to general practice physicians and discusses the rational use of hypnotic medications in primary care.

The surgical treatment of snoring: a patient's perspective

An increasing number of loud snorers seek medical attention because of the social impact of snoring as well as its association with sleep apnea. Uvulopalatopharyngoplasty is reported to reduce or eliminate snoring in the majority of patients; however, little data are available to document the procedure's success. From February 1987 through August 1988, 125 patients underwent uvulopalatopharyngoplasty for habitual snoring; many of these patients had also documented sleep apnea. Of the 74 patients who responded to a postoperative questionnaire, 64 (86.48%) indicated that their snoring was either completely eliminated or markedly reduced. Only two patients reported significant side effects.

Characteristics of narcolepsy in preteenaged children

Narcolepsy is rarely diagnosed in preteenaged children. Its clinical and polysomnographic manifestations, some of which are unusual, are described in four children who were observed prospectively. The mean age at onset of hypersomnia was 10.2 years (range 8.4 to 11.2 years). Daytime naps among these children were lengthy, ranging from 20 to 120 minutes, and generally were considered unrefreshing. Cataplexy was present at the onset in all four children. Three of the four children were obese, with the concurrent nocturnal snoring prompting a misleading concern about obstructive sleep apnea syndrome in two children. The histocompatibility DR2 antigen was present in all four children. Significant behavioral manifestations appeared in all of them. The response to stimulant medications was, at best, modest. Narcolepsy may be difficult to diagnose in this age group. However, a careful history eliciting sleep/wake dysfunction (including cataplexy), leukocyte assays for the histocompatibility DR2 antigen, and serial polysomnographic studies may enable early recognition and treatment of this disease.

Effect of caffeine on physiological sleep tendency and ability to sustain wakefulness at night

Marked sleepiness occurs during typical night shift work hours and this reduced alertness is associated with marked performance deficits. The effect of caffeine (versus placebo) upon sleepiness at night was studied using objective measures of physiological sleep tendency and ability to sustain wakefulness. Both measures show caffeine to reduce sleepiness at a single dose roughly the equivalent of two to four cups of coffee. Despite impressive objective differences in alertness with caffeine, subjects did not consistently differentiate between drug conditions on subjective alertness assessments. The use of CNS stimulants to promote alertness during night shift hours should be considered, particularly for occupations for which alertness is critical.

Presleep cognitive hyperarousal and affect as factors in objective and subjective insomnia

The role of presleep cognition in insomnia was studied in normal sleepers and insomniacs with either (1) psychophysiological insomnia, an objective disorder of initiating and maintaining sleep (DIMS), or (2) DIMS without objective findings (subjective insomnia), as defined by two nights' polysomnographic baseline data. During the experimental night in the sleep laboratory, 24 subjects were interviewed at intervals during the presleep/sleep-onset period. Judges' ratings of subjects' spontaneous reports and subjects' responses to questionnaire items were analyzed for cognitive quality. Objective insomniacs had more frequent cognitive activity than the subjective insomniacs. Both insomnia groups reported more negative thoughts than the controls. Cognitive hyperarousal as a factor in objective insomnia was not clearly supported.

The predictive efficacy of the Müller maneuver in uvulopalatopharyngoplasty

Flexible pharyngoscopy with the Müller maneuver has been proposed as a method for selection of uvulopalatopharyngoplasty candidates. In this prospective study, its predictive efficacy has been evaluated in 24 consecutive obstructive sleep apnea patients undergoing uvulopalatopharyngoplasty. FPMM enabled us to accurately predict the uvulopalatopharyngoplasty outcome in 12 of the 24 patients (50%). Although flexible pharyngoscopy with the Müller maneuver appears to be helpful in the selection of candidates for UPP, its distinct predictive efficacy is low.

Physiological sleep tendency and ability to maintain alertness at night

The maintenance of wakefulness test (MWT) and repeated test of sustained wakefulness (RTSW) were compared to the multiple sleep latency test (MSLT) during nighttime hours to evaluate differential sensitivity to variation in physiologic sleepiness/alertness. The degree of sleepiness varied by time of night and was further manipulated by varying prior sleep. Seven healthy normal sleepers were evaluated on the MWT, RTSW, MSLT, a digit symbol substitution test and the Wilkinson addition test in a protocol beginning at 2200 h and terminating at 0830 the following morning. A counterbalanced, crossover design compared an evening nap condition to a no-nap condition. The MWT and RTSW discriminated between nap and no-nap conditions, but the MSLT did not. This suggests that in some situations the MWT and RTSW may be more sensitive to changes in physiologic sleepiness/alertness than the MSLT. The data are discussed in terms of possible methodologic limits of the MSLT and the relationship between physiologic sleep tendency and the capacity to maintain alertness.

Physiological sleep tendency on a simulated night shift: adaptation and effects of triazolam

Daytime sleep and nocturnal sleepiness were examined in 18 normal sleepers (9 young adults, 9 middle-age adults) for 5.5 days following acute sleep/wake schedule inversion. Triazolam and placebo were compared in a counterbalanced, crossover design. Triazolam improved daytime sleep, but did not produce significant changes in sleep tendency at night. Physiological sleep tendency in the early morning hours (0200 to 0600) was profound, but decreased significantly within 3 to 4 days following sleep/wake inversion, irrespective of treatment condition. Nocturnal performance data generally were consistent with changes in physiological sleep tendency. We conclude that extending daytime sleep by an average of approximately 50 min per day via administration of a hypnotic does not appear to significantly reduce circadian sleep tendency in the early morning hours. Further, considerable adaptation, in terms of sleep tendency, occurred within a weak of simulated night shift despite a relatively constant daytime sleep pattern.

Management of obstructive sleep apnea: comparison of various treatment modalities

From July, 1982 through March, 1986, 253 patients with moderate to severe sleep apnea (OSA) were treated and had polysomnographic assessment of treatment. The treatment modalities were: 1. uvulopalatopharyngoplasty (UPP), 2. nasal continuous positive airway pressure (CPAP), 3. tracheostomy, 4. medication (tricyclic antidepressants), 5. tongue retaining device (TRD), and 6. orthodontic device. Uvulopalatopharyngoplasty was performed in 98 patients. The patients were categorized according to post-treatment improvement in the apnea/hypopnea index (A+HI) and severity index (SI) into good, moderate, and poor responders. There were 37 (37.7%) good, 33 (33.6%) moderate, and 28 (28.5%) poor responders in this group. Twenty-four patients underwent tracheostomy. Eighteen (75%) patients continue to have their tracheostomies without complications (mean follow-up time 32 months). One hundred thirty-eight patients were evaluated with CPAP. Of the 100 patients who began home CPAP use, 53 continue to use CPAP successfully at 18 months. Medical treatment (tricyclic antidepressants) was used in 35 patients. The response to this modality was generally poor. Six patients were fitted with TRD. The compliance to this device was poor, although two have had significant improvement in their apnea. An orthodontic appliance was used in two patients with one responding successfully.

Nasopharyngeal complications following uvulopalatopharyngoplasty

This report presents our experience with nasopharyngeal complications of UPPP in 85 patients undergoing the procedure from May, 1982 to January, 1985. Three patients developed nasopharyngeal stenosis and one patient developed permanent velopharyngeal insufficiency. Surgical management in two patients with nasopharyngeal stenosis resulted in adequate nasopharyngeal airway, while one patient still has a moderate stenosis following two surgical procedures. The patient with velopharyngeal insufficiency underwent Teflon paste injection in the posterior pharyngeal wall. This resulted in complete alleviation of his nasal regurgitation.

Evaluation of insomnia

The effective treatment of patients with a complaint of insomnia requires an appreciation of the range of etiologic factors underlying the symptom of insomnia, as well as sound clinical judgment and appropriate application of available therapeutics. Systematic inquiry regarding nocturnal and daytime aspects of a patient's life is helpful in narrowing the range of diagnostic possibilities. Specialized evaluation at a sleep disorders center may be useful in cases of chronic insomnia that remain refractory to initial interventions.

Somnofluoroscopy: its role in the selection of candidates for uvulopalatopharyngoplasty

The purpose of this study was to evaluate the efficacy of somnofluoroscopy in the selection of candidates for uvulopalatopharyngoplasty (UPPP). Somnofluoroscopy is a lateral fluoroscopic examination of the upper airway with synchronous polysomnography that provides information about the dynamic function of the airway and the level of stenosis or occlusion during sleep. Somnofluoroscopies were performed preoperatively in 26 consecutive patients undergoing UPPP. Preoperative and postoperative polysomnographic data were obtained on each patient. On review of the somnofluoroscopic recordings, two levels of the airway were considered: level 1, above the horizontal plane through the midportion of body of the second cervical disk, and level 2, below this plane. The examinations were then scored for the following: (A) most narrow level of airway during wakefulness, (B) first level(s) of airway to collapse during apnea, and (C) all levels of the airway to collapse during apnea. It was shown that patients whose narrowest part of the upper airway is at level 1 and whose first point of airway collapse during apnea episodes is at level 1 are good candidtates for the UPPP. Only three of 15 patients in this group did not respond to the operation. Patients with other patterns are uniformly poor candidates for this procedure. Results are encouraging but preliminary because of the small number of patients. It appears that somnofluoroscopy is a reliable selection criterion for UPPP in patients with obstructive sleep apnea.