William C Dement

• Stanford University

The negative effects of sleep loss on sleepiness, performance, and mood have been well-documented. Less is known, however, about possible negative effects of sleep extension and findings are inconsistent. This study investigated the Rip Van Winkle effect, comparing the effects of a single night of sleep extension (11 h time-in-bed, TIB) to control...

Sleep and sleepiness are among the most basic of human behaviors. As amply illustrated in chapters throughout this text , sleep can be disrupted not only by pathological processes but also by mismanagement and abuse. When sleep disruption occurs, regardless of the reason, the consequences for the individual and , in some circumstances, for society...

Objective: Poor and inadequate sleep negatively impact cognitive and physical functioning and may also affect sports performance. The study aim is to examine sleep quality, sleep duration, and daytime sleepiness in collegiate student-athletes across a wide range of sports. Design: Questionnaire. Setting: University setting. Participants: 628...

Study Objectives Napping is a useful countermeasure to the negative effects of acute sleep loss on alertness. The efficacy of naps to recover from chronic sleep loss is less well understood. Methods Following 2 baseline nights (10 hours TIB), participants were restricted to 7 nights of 5-hour sleep opportunity. Ten adults participated in the No Na...

Introduction Napping is a useful countermeasure to sleepiness resulting from acute sleep loss; however, the efficacy of naps to reduce sleepiness resulting from chronic sleep restriction is less well understood. This study assessed the impact of an afternoon nap on subjective and objective sleepiness during chronic sleep restriction. Methods Follo...

Objectives: This article presents the consensus findings of the National Sleep Foundation Drowsy Driving Consensus Working Group, which was an expert panel assembled to establish a consensus statement regarding sleep-related driving impairment. Methods: The National Sleep Foundation assembled a expert panel comprised of experts from the sleep co...

Study objective: To determine the neurocognitive effects of continuous positive airway pressure (CPAP) therapy on patients with obstructive sleep apnea (OSA). Design, setting, and participants: The Apnea Positive Pressure Long-term Efficacy Study (APPLES) was a 6-month, randomized, double-blind, 2-arm, sham-controlled, multicenter trial conducte...

To investigate the effects of sleep extension over multiple weeks on specific measures of athletic performance as well as reaction time, mood, and daytime sleepiness. Stanford Sleep Disorders Clinic and Research Laboratory and Maples Pavilion, Stanford University, Stanford, CA. Eleven healthy students on the Stanford University men's varsity basket...

To determine associations between obstructive sleep apnea (OSA) and neurocognitive performance in a large cohort of adults. Cross-sectional analyses of polysomnographic and neurocognitive data from 1204 adult participants with a clinical diagnosis of obstructive sleep apnea (OSA) in the Apnea Positive Pressure Long-term Efficacy Study (APPLES), ass...

SUMMARY  Cerebrospinal fluid from yellow-bellied marmots, Marmota flaviventris, was analysed for monoamine and monoamine metabolite content during euthermia and deep hibernation. Dopamine (DA) levels were decreased, while DA metabolite levels, dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), were dramatically increased in hibernating...

Regarding the causes of sleep-related accidents, this study assesses whether individuals can anticipate sleep onset accurately and how individuals acknowledge and use physiological and cognitive cues to make judgments related to sleep onset. A group of 41 partially sleep-deprived subjects predicted the likelihood of sleep in 30 consecutive two-minu...

Modafinil reduces the excessive sleepiness associated with narcolepsy, obstructive sleep apnea/hypopnea syndrome, and shift work sleep disorder. In rats, modafinil promotes dose-dependent increases in wake duration. The wake-promoting activity of the R-enantiomer of modafinil (armodafinil) was evaluated in WKY rats and compared to the classical sti...

To assess the size, time course, and durability of the effects of long-term continuous positive airway pressure (CPAP) therapy on neurocognitive function, mood, sleepiness, and quality of life in patients with obstructive sleep apnea. Randomized, double-blinded, 2-arm, sham-controlled, multicenter, long-term, intention-to-treat trial of CPAP therap...

Sleeping and dreaming always have been a fundamental part of human existence. Most early writing on these subjects was almost entirely speculation. During the twentieth century, however, scientific observation and experimentation abounded. This article emphasizes the evolution of the key concepts and research findings that characterize sleep resear...

Nearly all people, whether they consider themselves sleep deprived or not, can initially obtain extra sleep. However, as accumulating extra sleep reduces carryover sleep debt, a point is reached where it is no longer possible to obtain extra sleep. If there were a practical method to make a precise measurement of a person's daily sleep requirement,...

Sleep Medicine has only recently been recognized as a specialty of medicine. Its development is based on an increasing amount of knowledge concerning the physiology of sleep, circadian biology and the pathophysiology of sleep disorders. This review chronicles the major advances in sleep science over the past 70 years and the development of the prim...

This authoritative guide to sleep medicine is also available as an e-dition, book (ISBN: 1416003207) plus updated online reference! The new edition of this definitive resource has been completely revised and updated to provide all of the latest scientific and clinical advances. Drs. Kryger, Roth, and Dementand over 170 international expertsdiscuss...

To measure the effects of prolonged sleep extension on daytime alertness, vigilance, and mood in healthy young adults. Little research has documented the effects of increased sleep on daytime function despite a high prevalence of daytime fatigue and sleepiness in the adult population. Past extension studies report conflicting results with regard to...

There are relatively few studies on the prevalence of restless legs syndrome (RLS) in the general population, even fewer that used diagnostic questions covering all 4 essential diagnostic criteria defining the RLS symptom complex, and none that have reported on the 2 RLS phenotypes for patients seen by family physicians. To determine the prevalence...

A 3.5-hour workshop was developed to teach family medicine medical students about sleep disorders. This family medicine clerkship requirement engages students in role-plays and provides them with didactic information about common sleep problems. Fifty-one students completed questionnaires assessing their knowledge prior to the workshop, 2 weeks and...

A time-tested protocol for intrathoracic pressure monitoring during sleep is described. This method of esophageal manometry uses a fluid-filled catheter to measure variations in transmitted intrathoracic pressure with respiration. Esophageal manometry is an invaluable tool for the sleep specialist in the diagnosis of sleep-related breathing disorde...

Comparison of polysomnography (PSG)-derived sleep parameters (total sleep time, sleep efficiency, and number of awakenings) to those derived from actigraphy and subjective questionnaires. Actigraphy is commonly used to assist sleep specialists in the diagnosis of various sleep and circadian-rhythm disorders. However, few validation studies incorpor...

The objective of this study was to assess whether cervical positioning could improve mild to moderate cases of the obstructive sleep apnea syndrome (OSAS). Eighteen subjects recruited from a tertiary sleep disorders clinic population with mild to moderate cases of OSAS were evaluated using a custom-fitted cervical pillow designed to increase upper...

The prevalence of sleep disorders in a primary care physician practice in Moscow, Idaho, was studied between February 7, 1997, and February 6, 1998. This primary care clinic visit population was surveyed for this 1-year period. Every patient above the age of 18 years who visited the Moscow Clinic in this time period was either approached by our on-...

Sleep and sleepiness are among the most basic of human behaviors. As amply illustrated throughout this volume, a person's sleep can be disrupted not only by pathological processes but also by the person's lifestyle and by societal demands on the sleep-wake schedule. When sleep disruption occurs, regardless of the reason, the consequences for the in...

We examined the effects of cervical position on the Obstructive Sleep Apnea Syndrome (OSAS) through the use of a custom-designed cervical pillow which promoted neck extension. Twelve subjects with OSAS were recruited from a tertiary sleep disorder clinic population. Of the twelve subjects, three had mild cases of OSAS, four had moderate cases, and...

Since this is an historic meeting which will address one of the most important clinical issues in the field of sleep medicine, it is appropriate to examine how we arrived at this moment. Accordingly, I will present a brief review of the history of sleep medicine. I have addressed this topic on several previous occasions.(1-3) In my view the history...

Forty-two genetically narcoleptic Doberman puppies [20 pure narcoleptic (N) puppies (from four narcoleptic x narcoleptic crosses) and 22 backcross narcoleptic (BN) puppies (from six narcoleptic x heterozygous crosses)] were systematically observed during the developmental period (4-24 weeks) to assess the age at onset and severity of cataplexy, a p...

Individual effects of corticotropin-releasing hormone (CRH) and glucocorticoids on sleep have been difficult to discern due to the feedback effects each hormone exerts on the other. In addition, it is not known whether hypothalamic-pituitary-adrenal axis hormones alter sleep homeostasis or circadian influences on sleep propensity. We therefore anal...

Individual effects of corticotropin-releasing hormone (CRH) and glucocorticoids on sleep have been difficult to discern due to the feedback effects each hormone exerts on the other. In addition, it is not known whether hypothalamic-pituitary-adrenal axis hormones alter sleep homeostasis or circadian influences on sleep propensity. We therefore anal...

Previous research has shown evidence of a widening gap between scientific research and clinical teaching in sleep and sleep disorders. To address the deficiencies in current medical education in sleep, the Taskforce 2000 was established by the American Sleep Disorders Association. The present study was undertaken to assess the teaching activities,...

Basal forebrain (BF) cholinergic regulation of cataplexy was investigated in narcoleptic canines. Specific cholinergic agonists and antagonists, and excitatory or inhibitory amino acid neurotransmitter receptor agonists, were perfused through microdialysis probes implanted bilaterally in the BF of narcoleptic canines. Cataplexy was monitored using...

Narcolepsy is a disabling sleep disorder of unknown aetiology. In humans, the disease is mostly sporadic, with a few familial cases having been reported. In 1973 a sporadic case of narcolepsy was reported in a poodle, and in 1975 familial cases of narcolepsy occurred in dobermanns. As with human narcoleptics, these narcoleptic dogs exhibited excess...

Snoring is a common sleep-related behaviour. Increased body mass index (BMI), cranio-facial anatomical features, and older age have been linked to the occurrence of snoring. While mostly middle-aged populations have been studied for the occurrence of snoring and sleep-related breathing abnormality, this study was designed to assess the subjective r...

Photic and non-photic stimuli phase shift and entrain circadian rhythms through distinct but interacting mechanisms which impinge on the suprachiasmatic nucleus (SCN), the circadian pacemaker. Our understanding of this mechanism is incomplete. Serotonin (5-HT) injected locally at the SCN reduces light-induced glutamate release and decreases the exp...

The problem of drowsiness in commercial truck drivers has received considerable attention. Many people believe that drowsy truckers are only the most obvious example of sleep-deprived workers in all forms of transportation and in many different jobs. In this issue of the Journal, Mitler et al.1 report the results of recording electroencephalograms...

Resumen Un número creciente de personas está preocupado por su sueño en Estados Unidos. Hay una cantidad estimada de 40 millones de ciudadanos estadounidenses con trastornos crónicos del sueño. El coste de los trastornos del sueño para la sociedad se ha estimado en más de 90.000 millones de dólares estadounidenses. A pesar de este enorme coste para...

The therapeutic potential of thyrotropin-releasing hormone (TRH) and TRH analogs in narcolepsy, a sleep disorder characterized by abnormal rapid eye movement (REM) sleep and daytime sleepiness, was examined using the canine model. The effects of TRH and the biologically stable TRH analogs CG3703, CG3509, and TA0910 on daytime sleep and cataplexy, a...

The morbidity of sleep problems has been well documented; however, they are frequently associated with and are symptomatic of several psychiatric disorders. It is unclear how much of the morbidity can be accounted for by the associated psychiatric and substance abuse disorders and medical problems, and how much by the sleep problems per se. Sleep p...

The circadian pacemaker located in the suprachiasmatic nuclei (SCN) of the hypothalamus receives serotonergic afferents from the midbrain raphe nuclei, but the functional role of this projection is unclear. In rodents, locomotor activity increases serotonin content in the SCN, and serotonergic agonists phase shift the circadian clock in a manner cl...

Like human narcoleptics, narcoleptic dogs display cataplexy, fragmented sleep and excessive daytime sleepiness. Cataplexy in dogs can easily be quantified using a simple behavioural bioassay, the Food Elicited Cataplexy Test. In contrast, daytime sleepiness and fragmented sleep are more difficult to measure, as long-term, labour-intensive polygraph...

Narcolepsy is a sleep disorder that has been shown to be tightly associated with HLA DR15 (DR2). In this study, 58 non-DR15 patients with narcolepsy-cataplexy were typed at the HLA DRB1, DQA1 and DQB1 loci. Subjects included both sporadic cases and narcoleptic probands from multiplex families. Additional markers studied in the class II region were...

Canine narcolepsy is a unique experimental model of a human sleep disorder characterized by excessive daytime sleepiness and cataplexy. There is a consensus recognition of an imbalance between cholinergic and catecholaminergic systems in narcolepsy although the underlying mechanisms remain poorly understood. Possible substrates could be an abnormal...

Primary care medicine plays a key role in the delivery of health care. Sleep disorders medicine is a new specialty and standard medical school curricula do not contain any or only very little training in sleep medicine. Unrecognized and therefore untreated sleep disorders account for a large loss of human life and socio-economic damage. Recognition...

Several groups of investigators have assessed the impact of nasal obstruction on the obstructive sleep apnea syndrome. These studies evaluated patients with either naturally occurring partial nasal obstruction (e.g., allergic rhinitis, septal deviation) or experimentally induced nasal occlusion. The results of these studies are summarized and discu...

Patients with sleep disorders are common in primary care, yet most physicians lack training in the diagnosis and treatment of such patients. To enhance recognition of sleep disorders by community physicians and transfer the diagnostic testing and care of such patients from tertiary care centers to the local community. To present our polysomnogram e...

A growing number of people are concerned about their sleep in the United States. There are an estimated 40 million US citizens with chronic sleep disorders. The cost to society of sleep disorders has been estimated at greater than $90 billion US dollars. Despite this enormous cost to society, there remains a pervasive lack of attention provided to...

Thalidomide is a sedative hypnotic that was widely used in the 1950s but was withdrawn due to its teratogenic properties. The compound has recently been reintroduced as an immune modulating agent. Thalidomide significantly aggravates canine cataplexy, a pathological manifestation of rapid eye movement (RFM) sleep atonia seen in narcolepsy. This com...

Human narcolepsy is a neurological disorder known to be closely associated with HLA-DR2 and DQB1*0602. Because most autoimmune diseases are HLA-associated, a similar mechanism has been proposed for narcolepsy. However, neither systemic nor CNS evidence of an autoimmune abnormality has ever been reported. In this study, major histocompatibility (MHC...

Predisposition to narcolepsy involves genetic factors both in humans and in a canine model of the disorder. In humans, narcolepsy is strongly associated with HLA DR15 and DQB1*0602. In Dobermans and Labradors, narcolepsy is transmitted as a single autosomal recessive gene with full penetrance (canarc-1). Canine narcolepsy is not linked with DLA, th...

Predisposition to narcolepsy involves genetic factors both in humans and in a canine model of the disorder. In humans, narcolepsy is strongly associated with HLA DR15 and DQB1*0602. In Dobermans and Labradors, narcolepsy is transmitted as a single autosomal recessive gene with full penetrance (canarc-1). Canine narcolepsy is not linked with DLA, th...

The effects of modafinil and amphetamine on daytime sleep (polysomnographic recordings) and cataplexy (the food-elicited cataplexy test) were compared using the narcoleptic canine model. Results indicate that both modafinil (5 and 10 mg/kg body weight i.v.) and amphetamine (100 and 200 micrograms/kg i.v.) increase wakefulness and reduce slow-wave s...

Alpha adrenergic agonists such as clonidine are widely used for their antihypertensor effects, but they also cause sedation. The mechanisms underlying soporific effects of such compounds are poorly understood, but appear to involve the alpha-2 adrenergic receptor sub-type. To further investigate the role of this receptor in sleep-wake regulation, r...

Narcolepsy is a sleep disorder characterized by excessive daytime sleepiness and rapid eye movement (REM) sleep-related symptoms, such as cataplexy. The exact pathophysiology underlying the disease is unknown but may involve central cholinergic systems. It is known that the brainstem cholinergic system is activated during REM sleep. Furthermore, RE...

We have performed a study assessing the prevalence of sleep-disordered breathing in a large US trucking company using a validated portable monitor (MESAM-4) and a validated symptom questionnaire. Three hundred eighty-eight drivers with a mean age of 36 years filled out the questionnaire. One hundred fifty-nine drivers with a mean age of 35 years sp...

Pharmacological studies using a canine model of narcolepsy have demonstrated that adrenergic rather than serotonergic or dopaminergic uptake inhibition is the primary mode of action of antidepressants on cataplexy, a pathological manifestation of rapid eye movement (REM) sleep atonia that occurs in narcolepsy. This result is in line with the known...

Narcolepsy is a neurological disorder known to be associated with human leukocyte antigen (HLA)-DQB1 ∗0602 in humans. In a canine model, the disorder is also genetically linked to a gene of high homology with the human μ-switch-like immunoglobulin (Ig) gene (current LOD score 13.6 at 0% recombination). Since association with HLA or other immune fun...

In the present study, we tested 19 Caucasian and 28 Black American narcoleptics for the presence of the human leucocyte antigen (HLA) DQB1*0602 and DQA1*0102 (DQ1) genes using a specific polymerase chain reaction (PCR)-oligotyping technique. A similar technique was also used to identify DRB1*1501 and DRB1*1503 (DR2). Results indicate that all but o...

Canine narcolepsy is an animal model of the human disorder that is transmitted as a single autosomal recessive gene with full penetrance (canarc-1) in Dobermans and Labradors. In previous experiments, we have identified a very tight linkage marker for canarc-1. This marker, a 0.85-kb band cross reacting with a human mu-switch Heavy-Chain Immunoglob...

It is believed that narcolepsy involves abnormalities of rapid eye movement (REM) sleep, especially of REM sleep atonia. Compelling evidence suggests that the regulation of REM sleep and REM sleep atonia involves a reciprocal interaction of cholinergic and monoaminergic systems. Using our canine model of narcolepsy and a pharmacological approach, w...

This study assesses a possible independent effect of sleep-related breathing disorders on traffic accidents in long-haul commercial truck drivers. The study design included integrated analysis of recordings of sleep-related breathing disorders, self-reported automotive and company-recorded automotive accidents. A cross-sectional population of 90 co...

Both rapid eye movement sleep and cataplexy in the narcoleptic canine have been shown to increase after both systemic and local administration of cholinergic agonists in the pontine reticular formation. Furthermore, binding studies indicate an increase in the number of M2 muscarinic receptors in the pontine reticular formation of narcoleptic canine...