Anatomy of a Lullaby

The Power of Sleep
Exploring disorder and disturbance

Kathy P. Parker, Edith F. Honeycutt Professor of Nursing


 

Vol. 7 No. 4
February/March 2005

Anatomy of a Lullaby
In Emory's growing sleep research program, scholars encounter mystery and paradox

Stealing breath and life
Sleep Apnea

We do have some very good people [in sleep research], and we’re gaining a critical mass to do this kind of work.
Donald L. Bliwise, Professor of Neurology, Program Director, Sleep, Aging and Chronobiology


I think there are valuable things we can learn about how plastic or mutable the circadian system is by looking at people who travel abroad and contend with jet lag, or people from different cultures.
Hillary Rodman, Associate Professor of Psychology


The Power of Sleep
Exploring disorder and disturbance
Kathy P. Parker, Edith F. Honeycutt Professor of Nursing

What’s A Few Drinks Between Friends?
Exploring the ancient drinking party with students
Peter Bing, Associate Professor of Classics

Transforming
and Transformative Knowledge

Practicing what we profess
Karen D. Scheib, Associate Professor of Pastoral Care and Pastoral Theology

Further reading

Endnotes

Return to Contents


Throughout millennia, poets, philosophers, scientists, and literary figures have been fascinated by sleep. Although most recognized it as an essential human need, the phenomenon itself has been poorly understood. Before the twentieth century, many believed that sleep was a simple, passive phenomenon, similar in many aspects to death, and often valued it for its mystical properties. Today, sleep is described as an active process regulated by numerous behavioral, hormonal, and central nervous system factors. It is also well appreciated that sleep deprivation and/or disruption of sleep can adversely affect quality of life and overall health status. Yet despite numerous scientific advances recently made in the field, much remains to be discovered about the nature and purposes of sleep.

Individual sleep needs vary significantly and appear to have a strong genetic component. On average, people report needing approximately seven to eight hours of sleep per night. Some need as little as five hours, while others report needing ten or more. The sleep need is fulfilled when an individual reports feeling refreshed after a nocturnal sleep period and is able to maintain the desired alertness level through the day. In addition to appropriate quantity, the restorative functions of sleep depend on its quality—not being uninterrupted and having limited nighttime awakenings and arousals. Fragmented sleep, whether secondary to a sleep disorder or medical illness, is associated with daytime sleepiness, fatigue, and other functional decrements.

The three symptoms most commonly associated with sleep disturbances or disorders are insomnia, excessive daytime sleepiness, and abnormal or undesirable nocturnal movements, behaviors, or sensations. Insomnia is defined as difficulty falling asleep, staying asleep, waking up too early in the morning, or feeling unrefreshed after the major nocturnal sleep period. It is a very common complaint, and studies of large, representative national samples revealed that over a third had insomnia-related complaints. Factors that appear to predispose an individual to insomnia include female gender, low socioeconomic status, marital status (divorced or widowed as opposed to married), stress, drug/alcohol use, and other health problems. Triggers of insomnia include stressful events, environmental disturbances, anxiety, depression, pain or discomfort, or medical or surgical conditions—all problems that may stimulate physiological and cognitive arousal and delay the onset and continuity of sleep. Spending too much time in bed, irregular sleep-wake schedules, concern about daytime fatigue, too much napping, caffeine
consumption, and alcohol ingestion may all perpetuate the problem. Interventions designed to treat insomnia include a vast array of pharmacologic and behavioral therapies. Adequate management of the condition is important. Persons with untreated insomnia report significant impairment of their daytime functioning and may have decreased immune function and increased mortality.

Excessive daytime sleepiness (EDS), the inability to maintain an alert, awake state, is the most common consequence of impaired sleep and sleep disorders. Because of its often vague and nonspecific clinical presentation, health care providers frequently fail to recognize the condition. Patients themselves may have very little insight into both the nature and severity of the problem and the negative effects that EDS has on their lives. In its milder forms, eds may cause only minor, barely perceived decrements in social and occupational functioning. When severe, it can be debilitating, causing a broad range of deficits in mental capabilities that affect both daytime functioning and quality of life. EDS can even be life threatening because of associated alterations in alertness and reactivity. Behavioral signs of sleepiness include yawning, drooping eyelids, reduced activity, lapses in attention, and head nodding. Daytime sleepiness can be subjectively measured using instruments such as the Epworth Sleepiness Scale. Daytime sleepiness can also be quantified with a polysomnograph (an instrument for measuring physiologic changes during sleep) and the Multiple Sleep Latency Test.

Numerous abnormal or undesirable movements, behaviors, and/or sensations can occur during sleep. For example, sleep starts, sleep talking, body rocking, and leg cramps can occur in otherwise healthy individuals but may lead to discomfort, pain, embarrassment, anxiety, or disturbance of the bed partner’s sleep. Abnormal arousals from deep sleep (such as sleep terrors and sleep walking) often occur in young children and disappear by adolescence; in the elderly, in contrast, these behaviors are more commonly associated with pathology. Nightmares, sleep paralysis (being unable to move after waking), impaired or painful erections, and periods of dream enactment typically emerge from rapid eye movement sleep. Bruxism (teeth grinding), abnormal swallowing or choking, snoring, shortness of breath, chest pain, leg kicking, panic attacks, seizures, and apnea may occur during sleep and be related to one of several sleep disorders or other pathologies.

Physiologically, sleep loss results in changes in body temperature regulation, autonomic function, metabolic regulation involving glucose tolerance and insulin production, hormonal secretions including cortisol (a hormone related to stress levels), circadian rhythms, and immunocompetence. The accumulation of these changes is significant. The 2000 Cardiovascular Health Study (Journal of the American Geriatric Society) found that increased daytime sleepiness is associated with increased risk of mortality or incident cardiovascular disease of acute myocardial infarction. Additional consequences of sleep loss are cognitive and behavioral changes in the form of mood disturbances, problems with impaired short-term memory, and excessive daytime sleepiness. In the 2001 Sleep Heart Health Study (American Journal of Epidemiology), an assessment of over five thousand adults, sleep difficulties were associated with impaired quality of life and vitality. In the social realm, sleep loss can lead to impaired interactions with family and co-workers, reduced productivity, and efficiency in work-related tasks. Significant relationships are found between sleep loss and increased risk for accidents as well as increased overall health care use.

Unfortunately, sleep has become a “casualty” of our complex, twenty-four-hour society, and time slept is often believed to be time wasted. Research is increasingly demonstrating, however, that a well-rested individual is clearly more productive, has less depression and anxiety, performs better on a wide variety of tasks, is safer on the road, has better life quality, and may even live longer. Science is thus documenting what we have actually known all along—there is nothing like a good night’s sleep.


Parker is one of five nurses in the country certified in Clinical Sleep Disorders by the American Board of Sleep Medicine. She maintains an active clinical practice in the Emory Sleep Center and has a secondary appointment as a professor in the Department of Neurology.