Showing papers in "Sleep in 1991"

A new method for measuring daytime sleepiness: the Epworth sleepiness scale.

Abstract: The development and use of a new scale, the Epworth sleepiness scale (ESS), is described. This is a simple, self-administered questionnaire which is shown to provide a measurement of the subject's general level of daytime sleepiness. One hundred and eighty adults answered the ESS, including 30 normal men and women as controls and 150 patients with a range of sleep disorders. They rated the chances that they would doze off or fall asleep when in eight different situations commonly encountered in daily life. Total ESS scores significantly distinguished normal subjects from patients in various diagnostic groups including obstructive sleep apnea syndrome, narcolepsy and idiopathic hypersomnia. ESS scores were significantly correlated with sleep latency measured during the multiple sleep latency test and during overnight polysomnography. In patients with obstructive sleep apnea syndrome ESS scores were significantly correlated with the respiratory disturbance index and the minimum SaO2 recorded overnight. ESS scores of patients who simply snored did not differ from controls.

Sleep-disordered breathing in community-dwelling elderly.

Abstract: These are the final results of a survey of sleep-disordered breathing, which examined objective and subjective information from a large randomly selected elderly sample. We randomly selected 427 elderly people aged 65 yr and over in the city of San Diego, California. Twenty-four percent had an apnea index, AI, greater than or equal to 5 and 62% had a respiratory disturbance index, RDI, greater than or equal to 10. Correlates of sleep-disordered breathing included high relative weight and reports of snoring, breathing cessation at night, nocturnal wandering or confusion, daytime sleepiness and depression. Body mass index, falling asleep at inappropriate times, male gender, no alcohol within 2 hr of bedtime and napping were the best predictors of sleep-disordered breathing. Despite statistical significance, all of the associations between interview variables and apnea indices were small. No combination of demographic variables and symptoms allowed highly reliable prediction of AI or RDI.

Quantification of subjective sleep quality in healthy elderly men and women using the Pittsburgh Sleep Quality Index (PSQI)

Abstract: Subjective sleep quality deteriorates with aging, but the extent to which this is a product of age itself, as opposed to the medical or psychiatric problems associated with aging, has not been carefully studied. To investigate this issue, we examined the subjective sleep quality of 44 healthy subjects over 80 years of age (20 men, 24 women), and 35 healthy subjects [corrected] between the ages of 20 and 30 (23 men, 12 women) using the Pittsburgh Sleep Quality Index (PSQI). All subjects underwent rigorous medical and psychiatric evaluations to verify that they were in excellent physical and psychological health. Significant age effects were noted for the global PSQI score and several PSQI component scores, but overall sleep quality for the majority (68.1%) of 80-yr-olds fell within a categorically defined range for "good" sleepers. Measures of habitual sleep quality did not correlate strongly with most polysomnographic sleep measures, number of medications used or circadian measures in elderly subjects. These results show that subjective sleep quality does deteriorate in the healthy elderly, but not to the level seen in patients with sleep disorders. Extremely healthy elderly subjects appear to adapt in their perception of objectively disturbed sleep.

Periodic limb movements in sleep in community-dwelling elderly.

Abstract: The prevalence of periodic limb movements in sleep (PLMS) in a randomly selected elderly sample is reported. In San Diego, 427 elderly volunteers aged 65 yr and over were recorded in their homes. Forty-five percent had a myoclonus index, MI greater than or equal to 5. Correlates of PLMS included dissatisfaction with sleep, sleeping alone and reported kicking at night. Although statistically significant, the strengths of the associations between interview variables and myoclonus indices were all small. No combination of demographic variables and symptoms allowed highly reliable prediction of PLMS.

Prevalence and treatment of insomnia in the community: results from the Upper Bavarian Field Study.

Abstract: In the Upper Bavarian Field Study a total of 1,536 persons (15 yr of age and older) were interviewed by research psychiatrists. The prevalence of insomnia (last 7 days) identified with the aid of the Clinical Interview Schedule (CIS) was 28.5% (mild: 15.0%; moderate/severe: 13.5%). For both sexes sleep disorders increased with age. The female preponderance of insomnia was mainly associated with the middle and older age groups. In contrast to other psychiatric disorders, sleep disturbances were not associated with social class. Moderate/severe insomnia was strongly related to psychiatric diagnoses, the use of psychiatric in- and outpatient services and general hospitals. It also constituted a significant burden for the primary-care physicians, whereby the average annual consultation rate among mild (10.61) and moderate/severe insomniacs (12.87) was significantly higher compared to that for those without sleep disorders (5.25). A total of 33.7% of the insomniacs were treated with hypnotic and/or other psychotropic drugs during the week prior to the interview, whereby the drug consumption among moderate/severe insomniacs (48.5%) was significantly higher than that of mild insomniacs (20.4%).

Insomnia and use of hypnotics: study of a French population.

Abstract: A cross-sectional study of insomnia and hypnotic use was performed in a sample of the French population. The quota method was used to select the sample of 1,003 subjects, with less than 3% substitution. Subjects were 15 years old and older and were representative of the French population based on gender, age, marital status and living environment. Subjects were asked questions relevant to the complaint of insomnia and hypnotic use and filled out questionnaires measuring anxiety and depression. The complaint of insomnia is common, even in the 15-24-year-old group. Overall, more women than men were afflicted. The largest group of insomniac subjects, and the group who most often used hypnotics "frequently and chronically", were women 45 years and older. Men presented a sharp increase in hypnotic use after 65 years of age. Ten percent of the entire sample used hypnotics, 8% for more than 6 months and 6.17% on a chronic and frequent basis. Retired and unemployed elderly were also chronic and frequent hypnotic users: aging and social isolation correlate with chronic and frequent hypnotic usage. Higher scores on anxiety and depression scales correlate with more frequent complaints of nocturnal sleep disturbances. Young individuals are a significant complainer group but use hypnotics rarely. A rural environment was associated, overall, with fewer insomnia complaints, but environment had much less impact on complaints and hypnotic use in the elderly than in other age groups. One may question whether, in the French population, hypnotic prescription and intake are not responses to a social rather than a medical problem.

The effect of sleep deprivation on cerebral glucose metabolic rate in normal humans assessed with positron emission tomography

Abstract: This study is the first report on the effects of total sleep deprivation (about 32 h) on regional cerebral glucose metabolism during wakefulness in man, using positron emission tomography (PET) with F-18 deoxyglucose (FDG). Sleep deprivation leads to a significant reorganization of regional cerebral metabolic activity, with relative decreases in the temporal lobes and increases in visual cortex. Absolute glucose metabolic measurements indicate a decrease in thalamus, basal ganglia, white matter, and cerebellum. No overall decrease in whole brain metabolism was noted after sleep deprivation. As expected, sleep deprivation significantly reduced visual vigilance as assessed by the continuous performance test and this decrease was correlated significantly with reduced metabolic rate in thalamic, basal ganglia, and limbic regions.

A comparative study of treatments for positional sleep apnea

Abstract: Sixty male patients all with apnea plus hypopnea indices (A + HI) above 12.5, who met a criterion of positionality by having two or more times the rate of these events during supine sleep in comparison to their lateral sleep rate, were randomly assigned to one of four treatments for 8 weeks. All were restudied for two nights, one with and one without treatment devices. On treatment more than half the patients in each group reduced their A + HI to within normal limits and a third remained WNL without the use of devices. Half of those trained to sleep in the lateral position with the help of an alarm maintained this learning without the alarm as did half of those who were encouraged to learn this sleep posture on their own. There is an additive effect for the positional patient from wearing a tongue retaining device (TRD) if they continue to sleep in the supine position. Factors associated with successful treatment include overall severity, severity in the lateral position, weight, weight change, nasal patency and motivation to help their condition.

Timed exposure to bright light improves sleep and alertness during simulated night shifts.

Abstract: Many of the health and safety problems reported by shift workers result from the chronic sleep deprivation associated with shorter, fragmented daytime sleep. This reduction in the quality and duration of sleep has been attributed to a change in the phase relationship between the work period and the circadian system, timing the propensity for sleep and wakefulness. This study examined the extent to which appropriately timed exposure to bright light would accelerate the circadian readjustment of physiological parameters thought to contribute to impaired performance in shift workers. A control (n = 7) and treatment group (n = 6) underwent a 3-day transition to simulated night work. The treatment group received a single 4-hour pulse of bright light (6,000 lux) between 2400 and 0400 hours on the first night shift and dim light (less than 200 lux) for the remainder of the study. The control group received dim light throughout. By the third night shift, the phase position of the core body temperature rhythm for the treatment group had delayed by 5-6 hours whereas the control group had delayed by only 2-3 hours. When compared to the control group, the greater delay in core temperature rhythm for the treatment group was associated with significantly higher alertness across the night shift and improved sleep quality during the day. By the third day sleep, mean sleep efficiency in the treatment group was not significantly different from normal night sleep. Similarly, onshift alertness was improved relative to the control group. The treatment group did not show the typical decline in alertness observed in the control group between 0300 and 0700 hours. These data indicate that a single 4-hour pulse of bright light between midnight and 0400 hours is effective in ameliorating the sleep and alertness problems associated with transition to night shift.

Evaluation of the upper airway in patients with obstructive sleep apnea.

Abstract: Multiple methods have been used to study the structure and physiological behavior of the upper airway (UA) in patients with obstructive sleep apnea (OSA). Valuable information may be obtained from the physiologic measurement of pressure and resistance along the UA, as well as from imaging techniques that include: direct or fiberoptic visualization, cephalometric roentgenograms, fluoroscopy, acoustic reflection, computerized tomography, and magnetic resonance imaging. This review summarizes the information that each of these methods has contributed to our understanding of the UA. The results obtained with these different methodologies have generally been complementary with structural narrowing being identified in the majority of patients with OSA. This narrowing is usually focal and located in the velopharyngeal or retropalatal segment of the UA. This is also the predominant site of initial UA collapse. Although obesity with enlargement of soft tissue structures is considered the predominant mechanism leading to UA narrowing, abnormal craniofacial development on a genetic or developmental basis plays an important contributory role.

Circadian rhythm disorders in sleep-waking and body temperature in elderly patients with dementia and their treatment.

Abstract: Circadian rhythms in elderly patients with severe dementia and behavioral disorders such as wandering, agitation and/or delirium were examined. The subjects consisted of 24 patients with dementia (5 with senile dementia of Alzheimer's type and 19 with multi-infarct dementia), aged 56-89 (means = 75.5 +/- 8.7) and 8 control patients without dementia or with dementia of slight degree, aged 65-81 (means = 75 +/- 5.4). The sleep-wake state of the patients was judged every hour by nurses over periods of 1-4 mo and recorded in the form of a sleep diary. Oral temperature was recorded for 4-7 consecutive days. For the treatment of sleep-wake rhythm disorders, social interaction with nurses was encouraged in addition to drug therapy. The patients showed various types of sleep-wake disorders such as reversed day-night rhythm or irregular sleep-wake rhythm corresponding to a decreased amplitude of the sleep-wake rhythm. Circadian rhythm of oral temperature was irregularly disturbed in 59.0% of the patients in the dementia group and in only 12.5% of the patients in the control group. The effects of treatment by enforcement of social interaction with nurses was effective in reducing behavioral problems and sleep-wake rhythm disorder in 30.0% of the patients tested. However, body temperature rhythm disorganization remained after the treatment. These observations indicate that behavioral disorders such as delirium, agitation or wandering in patients with severe dementia might be closely related to disrupted biological rhythms of sleep-waking and the autonomic system (body temperature).

Increases in number of REMS and REM density in humans following an intensive learning period.

Abstract: Animal studies have recently demonstrated that increases in rapid eye movement (REM) sleep and actual number of rapid eye movements (REMs) over normal levels followed successful learning of an avoidance task. These increases persisted for many days following the end of the training sessions. It was hypothesized that similar extended increases in REM sleep parameters would follow an intensive learning task in humans. Senior college students were sleep monitored following the end of their Christmas examinations. Results showed that there was a significant increase in the number of REMs observed following the exams as compared to baseline and control subject values. The number of extra REMs was mot prominent during the fifth REM period of the night. A significantly increased REM density was observed at the fourth REM sleep period of the night. Results support the idea of REM sleep and/or the REMs themselves being involved in long-term memory processing several days after the end of training.

Sleep-related eating disorders: polysomnographic correlates of a heterogeneous syndrome distinct from daytime eating disorders.

Abstract: Over a 5-yr period, 19 adults presented to our sleep disorders center with histories of involuntary, nocturnal, sleep-related eating that usually occurred with other problematic nocturnal behaviors. Mean age (+/- SD) at presentation was 37.4 (+/- 9.1) yr (range 18-54); 73.7% of the patients (n = 14) were female. Mean age of sleep-related eating onset was 24.7 (+/- 12.9) yr (range 5-44). Eating occurred from sleep nightly in 57.9% (n = 11) of patients. Chief complaints included excessive weight gain, concerns about choking while eating or about starting fires from cooking and sleep disruption. Extensive polysomnographic studies, clinical evaluations and treatment outcome data identified three etiologic categories for the sleep-related eating: (a) sleepwalking (SW), 84.2% (n = 16); (b) periodic movements of sleep (PMS), 10.5% (n = 2) and (c) triazolam abuse (0.75 mg hs), 5.3% (n = 1). DSM-III Axis 1 psychiatric disorders (affective, anxiety) were present in 47.4% (n = 9) of the patients, and only two patients had a daytime eating disorder (anorexia nervosa), each in remission for 3-7 yr. Nearly half of all patients fulfilled established criteria for being overweight, based on the body mass index. Onset of sleep-related eating was linked directly to the onset of SW, PMS, triazolam abuse, nicotine abstinence, chronic autoimmune hepatitis, narcolepsy, encephalitis or acute stress. In the SW group, 72.7% (8/11) of patients had nocturnal eating and other SW behavior suppressed by clonazepam (n = 7) and/or bromocriptine (n = 2) treatment. Both patients with PMS likewise responded to treatment with combinations of carbidopa/L-dopa, codeine and clonazepam. Thus, sleep-related eating disorders can generally be controlled with treatment of the underlying sleep disorder.

Status dissociatus--a perspective on states of being.

Abstract: During the course of routine clinical study, it has become apparent that the all-or-none concept of state determination (wakefulness, nonrapid eye movement sleep, rapid eye movement sleep) does not always exist, and that ambiguous, multiple, or rapid oscillation of state-determining variables appear in a wide variety of experimental and clinical situations. Six cases of extreme state dissociation are presented, with a review of the human and animal clinical and experimental literature. This multiple component concept of state determination must be kept in mind when pharmacologic or lesion studies are employed to suppress one or another state. Such manipulation may suppress some of the commonly used markers for that state (i.e., polygraphic) without affecting other variables of that state. The existence of mixed states will be a challenge to the development of automated computerized polysomnogram scoring.

Periodic movements of the legs during sleep associated with rises in systemic blood pressure

Abstract: We report the relationship between periodic leg movements during sleep and recurrent rises in systemic blood pressure in a patient with narcolepsy. The mean increase in systolic blood pressure following leg movements was 23%, which is of the same order as the rises seen in patients with obstructive sleep apnea. Following treatment with temazepam, the swings in blood pressure were unchanged despite considerably less electroencephalographic evidence of cortical arousal.

Subjective sleepiness ratings: the effects of sleep deprivation, circadian rhythmicity and cognitive performance.

Abstract: Computerized self-report sleepiness scales were administered before and after cognitive testing in a 72-hour sleep deprivation study. The cognitive test battery was administered every 2 hours and took approximately 1-1.25 hours. Two computerized measures of subjective sleepiness were used, one a visual analog scale, the other a Hebrew version of the Stanford sleepiness scale. The results indicated that both accumulated sleep loss, circadian and ultradian (2 cycles/day) factors were significant in determining subjective estimates of sleepiness. The extent of the differences between subjective sleepiness ratings before cognitive testing and after testing was dependent upon the phase of the circadian cycle. These differences were greatest at approximately 0200-0600 hours and least around 1000 hours. A second low point occurred at 1800-2000 hours. Analysis by complex demodulation of the individual subjects' sleepiness rating curves indicated that the amount of variance accounted for by the circadian component increased significantly after cognitive testing.

A clinical and polysomnographic comparison of neuroleptic-induced akathisia and the idiopathic restless legs syndrome.

Abstract: Neuroleptic-induced akathisia (NIA) is motor restlessness caused by dopamine receptor blocking antipsychotic agents. Nine patients with NIA and 11 patients with idiopathic restless legs syndrome (RLS) were studied polysomnographically. The sleep disturbances were milder in NIA than idiopathic RLS but increased numbers of awakenings and decreased sleep efficiencies were common to both groups. In addition, RLS patients demonstrated prolonged sleep latencies. Periodic movements in sleep (PMS) were present in only 5 of 9 patients with NIA but in all 11 patients with idiopathic RLS. In no NIA patient did we see the multiple, large amplitude, violent, resting myoclonic jerks of the legs that we saw during wakefulness in some of our more severe cases of idiopathic RLS. NIA patients tended to experience inner restlessness and idiopathic RLS patients tended to experience leg paresthesias as an antecedent to motor restlessness. Idiopathic RLS patients had symptoms that were worse at night and in repose far more frequently than patients with NIA. NIA and idiopathic RLS have similarities and differences. Because both NIA and idiopathic RLS are characterized by motor restlessness and sleep disturbances, the pharmacodynamics of antipsychotic medications may give clues as to both the cause and treatment of idiopathic RLS.

Atrial natriuretic peptide and catecholamines in obstructive sleep apnea syndrome.

Abstract: Nocturnal polyuria with repeated micturitions during the night is a clinically evident feature of obstructive sleep apnea syndrome (OSAS). These effects are reversed by continuous positive airway pressure (CPAP). There is some evidence that atrial natriuretic peptide (ANP) and catecholaminergic activity may be implicated in the pathogenesis of these symptoms. We studied these biochemical parameters in six patients with severe OSAS during two nights: the first (basal) in their normal conditions and the second during CPAP treatment. CPAP treatment reversed apnea episodes in all our patients. A significant (p less than 0.035) reduction of nocturnal urine volume (from 902 +/- 297 to 447 +/- 130 ml; mean +/- SD), sodium excretion (from 150 +/- 33 to 89 +/- 35 mEq/12 h), noradrenaline excretion (from 95 +/- 101 to 52 +/- 16 micrograms/g creatinine), noradrenaline plasma concentrations (from 325 +/- 96 to 259 +/- 75 pg/ml), ANP plasma concentrations (from 35 +/- 20 to 19 +/- 5 pg/ml) was observed during the night under CPAP application. These data suggest that in OSAS patients the high ANP plasma concentration is responsible for the observed elevated diuresis and sodium excretion. These effects are rapidly reversible, as they are reversed during the first CPAP treated night.

The Effects of Sleep Posture and Sleep Stage on Apnea Frequency

Abstract: The Apnea Plus Hypopnea Index (A + HI) of 60 male positional sleep apneics was analyzed by sleep stage to determine if positional differences are limited to NREM sleep. Differences in apnea severity by sleep position were found to persist in REM sleep and to be of equal extent to those differences found in NREM sleep, despite the fact that there is also a significant increase in the frequency of apneic events associated with REM sleep. The positional effect persists in REM sleep, making treatments to control sleep posture a viable option.

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

Abstract: 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.

Manifest sleepiness and the spectral content of the EEG during shift work

Abstract: Twenty-five three-shift workers in a process industry were subjected to ambulatory polysomnography during one afternoon and one night shift. The electroencephalographic (EEG) recordings were analyzed with spectral analysis. Subjective sleepiness increased during the night work but did not reach an extreme level. Five subjects fell asleep during night work and the involuntary naps were preceded by a few minutes of increased alpha (8-11.9 Hz) power density. Alpha and theta activity occurred in very short bursts. The hourly mean EEG alpha power density increased significantly but moderately during the night shift and correlated with subjective ratings of sleepiness. Theta power density (4-7.9 Hz) did not increase during the night shift, nor did it correlate with subjective sleepiness. It was suggested that the shift workers could prevent much of the polysomnographic manifestations of sleepiness by various types of activity (including succumbing to sleep). It was also suggested that averaging power density values across long time periods might not be an optimal strategy for detection of sleepiness, but rather some method of emphasizing the occurrence of alpha or theta bursts.

Sleep Laboratory Studies on the Single-Dose Effects of Serotonin Reuptake Inhibitors Paroxetine and Fluoxetine on Human Sleep and Awakening Qualities

Abstract: Paroxetine is a novel antidepressant drug with selective serotonin (5-HT) reuptake inhibitory properties. In a double-blind placebo-controlled crossover sleep laboratory study the single-dose effects on objective and subjective sleep and awakening qualities were investigated after paroxetine 20, 30 and 40 mg morning doses (PX 20, 30, 40), paroxetine 30 mg evening dose, fluoxetine 40 mg morning dose (FX 40) and placebo in 18 healthy young volunteers. The drugs were orally administered in 2-wk intervals. In addition to each drug night, the adaptation night and washout night were recorded. Polysomnographic investigations (10:30 p.m. to 6:00 a.m.) showed a delayed sleep onset only after the morning intake of paroxetine, PX 40 being statistically different from placebo. Total sleep time and sleep efficiency deteriorated under morning PX 30, PX 40 and evening PX 30 as compared to placebo. The nocturnal wake time and sleep stage 1 increased under the paroxetine. Rapid eye movement (REM) reduction (min and %) occurred dose dependently after all paroxetine doses, but the REM latency was lengthened only after the morning intake. The suppressant effect on REM sleep is characteristic for antidepressants and was still significant in the washout nights following PX 40 and evening PX 30. The only statistically relevant finding under 40 mg fluoxetine referred to the increase of REM latency in both drug and washout nights. In contrast to objective results, subjective sleep quality remained generally unchanged. Attention, concentration and reaction performance improved under paroxetine as compared to baseline. The deterioration of well-being under PX 40 might be related to the appearance of drowsiness and nausea. Blood pressure and pulse rate were unaffected.

Relative Efficacy of Drugs for the Treatment of Sleepiness in Narcolepsy

Abstract: A survey was conducted on 10 polysomnographic studies on the pharmacologic treatment of the sleepiness of narcolepsy. Three studies employed the MSLT and 7 employed the MWT as their polygraphic measure of sleep tendency. Statistically and clinically significant therapeutic changes were apparent for pemoline, modafinil, dextroamphetamine and methylphenidate. Codeine, ritanserin and protriptyline did show statistically significant effects. The common feature among the drugs that did produce clinically significant improvements seems to be facilitatory action on central catecholaminergic transmission. Within this group of drugs, only methylphenidate and dextroamphetamine brought MWT sleep latencies to approximately 70% of normal levels.

Subjective versus objective evaluation of hypnotic efficacy: experience with zolpidem.

Abstract: There is little published literature on the correlation between subjective and objective efficacy of hypnotics. We wanted to determine whether there was a correlation between the patient's subjective evaluation of the efficacy of the hypnotic with the polysomnographic (PSG) findings. We studied 16 patients with chronic insomnia (sleep latency, greater than or equal to 30 minutes; total sleep time, greater than 240 but less than 420 minutes) for 11 nights who took placebos on nights 1 and 2, zolpidem (imidazopyridine) on nights 3-9 and placebo on nights 10 and 11. Patients completed a questionnaire each morning following PSG, which evaluated subjective sleep quality, sleep latency and total sleep time. These data were compared to PSG findings to answer specific questions about sleep latency reduction, efficacy of the hypnotic after a week's use, sleep quality after discontinuing the drug, and any correlation between subjective and objective measures. PSG findings indicated a shortened sleep latency, increased total sleep time, decreased total wake time and increased sleep efficiency when patients ingested zolpidem 30 minutes before bedtime. We found that after 7 nights (nights 3-9) the drug was still effective in reducing sleep latency and increasing total sleep time. Upon withdrawal (nights 10 and 11) sleep returned to baseline (nights 1 and 2). Subjectively, the patients confirmed those findings on the questionnaire, as well as a subjective reduction in the number of awakenings and, interestingly, a subjective increase in the time spent awake after sleep. Many of the objective variables we examined correlated highly with the subjective variables. While on zolpidem, subjects believed and were objectively shown to have a decreased sleep latency, increased total sleep time and decreased time awake before persistent sleep, although they tended to overestimate sleep latency and time spent awake before persistent sleep and underestimated total sleep time. Although the correlation between objective and subjective measures was high for the group, in individual patients there was an impressive difference between the two, and the highest coefficient of variation between a subjective and objective measures was 0.453. No correlations were found with subjective measures of refreshing quality of sleep, decrease in number of awakenings, how sleepy patients felt in the morning or their ability to concentrate in the morning. Thus, we believe the PSG remains the keystone in the evaluation of hypnotic efficacy.

The exploding head syndrome: polysomnographic recordings and therapeutic suggestions.

Abstract: Attention has recently been drawn to a condition termed the exploding head syndrome, which is characterized by unpleasant, even terrifying sensations of flashing lights and/or sounds during reported sleep. Nine patients complaining of sensations of explosions in the head during sleep or drowsiness were investigated with polysomnographic recordings. None of them had any neurological disorder. Five patients reported explosions during the recording sessions. According to the recordings, the attacks always took place when the patients were awake and relaxed. In two cases abrupt electroencephalographic (EEG) and electromyographic changes indicating increasing alertness were recorded at the time of the reported attacks. In the remaining three cases no EEG changes were seen. Thus, there were no indications of an epileptic etiology to the condition. In all patients the symptoms ameliorated spontaneously with time. The severity of the symptoms was reduced by reassurance of the harmlessness of the condition. Clomipramine was prescribed to three patients who all reported immediate relief of symptoms. It is concluded that symptoms of this type are probably not true hypnagogic phenomena but may be an expression of emotional stress in the awake state.

The distribution of slow-wave sleep across the night: a comparison for infants, children, and adults.

Abstract: This study describes the temporal distribution of slow-wave sleep (SWS) (defined as the visually scored stages 3 + 4) across the night for 16 infants aged between 20 weeks and 1 year, 17 children between 1 and 6 years, and 17 adults between 20 and 36 years. In all three groups the amounts of SWS peaked during the first nonrapid eye movement (NREM) episode. SWS decreased across the night for adults and children, but not for infants. In infants the amounts of SWS remained at a fairly constant level from the second cycle onward, although many cycles were observed with zero SWS. The latter was evident from the very low tendency for SWS to appear in consecutive NREM/REM cycles. Rather, SWS was observed in alternate cycles. In children this phenomenon was less prominent but still well visible, and the tendency for SWS to appear in consecutive cycles had increased. In adults SWS occurred predominantly in consecutive cycles. The results suggest that whereas REM recurrence time increases twofold from infancy to adulthood, SWS recurrence time remains of similar length in infants, children, and adults.

Sleep quality subtypes in midlife women.

Abstract: Eighty-two midlife women (40-59 years) were classified as poor or good sleepers according to either self-reported sleep quality or a sleep efficiency index (SEI) criterion, for comparison of wakefulness, fragmentation and other somnographic sleep variables; as well as psychological (SCL-90) and somatic symptom distress. When classified solely by self-report, the good and poor sleeper groups did not differ on any somnographic variables but self-declared poor sleepers had higher psychological distress scores than good sleepers (p less than or equal to 0.01). When classified solely by the SEI criterion, the good and poor sleepers did not differ on psychological distress but, as expected, differed on various somnographic wakefulness as well as rapid eye movement and stage 2 sleep variables. Further analysis of four subgroups derived by combining objective and subjective, good and poor sleep scores indicated that 15% of this sample (n = 12) perceived but had no objective evidence of poor sleep, and this group scored highest in psychological distress. Only seven women perceived poor sleep in concert with demonstrating low SEI. They scored highest in menopausal symptoms but not in general psychological distress.

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

Abstract: 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.

Sleep variability across consecutive nights of home monitoring in older mixed DIMS patients.

Abstract: Twenty patients with difficulties initiating and maintaining sleep (DIMS) were monitored in their homes for three consecutive nights using ambulatory polysomnography (PSG). Following each night of monitoring, patients provided subjective ratings of sleep disturbance and tolerance of the PSG equipment. Friedman analyses of variance performed on the objective and subjective parameters showed that the sample, as a whole, evidenced no systematic first night effects (FNE) in response to monitoring. Inspection of the data from each individual subject, nevertheless, showed that half of the sample did experience multiple FNE. Further, several scales from the Minnesota Multiphasic Personality Inventory discriminated those patients who showed multiple FNE from those who did not. However, far more striking was the finding that clinically and statistically significant intrasubject variability across nights was observed for each sleep parameter measured. Given this finding, a single ambulatory PSG study may not fully convey the nature of the sleep disturbance experienced by the DIMS patient even when FNE are absent. We thus, recommend multiple ambulatory sleep studies for those clinical and research situations in which it is necessary to document patients' night-to-night sleep variability. In contrast, when the goal of the PSG study is that of determining a sleep diagnosis, a single ambulatory study, in combination with other clinical data, may be sufficient.

Obstructive sleep apnea treatment: peripheral and central effects on plasma renin activity and aldosterone.

Abstract: To assess the effect of obstructive sleep apnea treatment on plasma renin activity (PRA) and plasma aldosterone seven male patients were studied under two conditions: untreated and treated with nasal continuous positive airways pressure (CPAP). PRA and plasma aldosterone were measured at 10-min intervals for both nights. CPAP treatment diminished the urinary and Na+ excretion, whereas plasma volume increased. The mean levels of PRA and aldosterone were significantly enhanced by the treatment, increasing respectively from 1.5 +/- 0.3 to 3.0 +/- 0.7 ngAI ml-1.hr-1 (p less than 0.05) and from 8.0 +/- 1.0 to 12.0 +/- 1.7 ng.100 ml-1 (p less than 0.05). PRA curves reflected the overall sleep structure as similarly described in normal subjects. The apnea-induced sleep disturbance led to flat PRA profiles and the restoration of a normal sleep pattern by treatment restored the PRA oscillations related to the sleep cycles and consequently restored aldosterone oscillations. The mean amplitude of these oscillations increased respectively from 1.0 +/- 0.1 to 1.8 +/- 0.4 ngAI ml-1.hr-1 and from 5.4 +/- 1.2 to 10.9 +/- 1.9 ng.100 ml-1. These results suggest that CPAP treatment modifies the nocturnal patterns of PRA and aldosterone by increasing their mean levels and their oscillation amplitude. This indicates increased secretion, which contributes to the normalization of urine and Na output.