Overview
Sleep disturbances occur in about 12% to 25% of the general population [1] and
are often associated with situational stress, illness, aging, and drug
treatment.[2,3] It is estimated that 45% of people with cancer have sleep
disturbance.[4] Physical illness, pain, hospitalization, drugs, and other
treatments for cancer, and the psychological impact of a malignant disease may
disrupt the sleeping patterns of persons with cancer. Poor sleep adversely
affects daytime mood and performance. In the general population, persistent
insomnia has been associated with a higher risk of developing clinical anxiety
or depression. Sleep disturbances and, ultimately, sleep-wake cycle reversals,
can be early signs of a developing delirium. (Refer to the PDQ summary on
Delirium for more information.) Adequate sleep may increase the cancer
patient's pain tolerance.
Sleep consists of two phases: rapid eye movement (REM) and non-REM (NREM)
sleep.[5] REM sleep, also known as dream sleep, is the active or paradoxic
phase of sleep in which the brain is active. NREM is the quiet or restful
phase of sleep. NREM, also referred to as slow wave sleep, is divided into 4
stages of progressively deepening sleep based on electroencephalogram
findings.[2,6]
The stages of sleep occur in a repeated pattern or cycle of NREM followed by
REM, with each cycle lasting approximately 90 minutes. The sleep cycle is
repeated 4 to 6 times during a 7- to 8-hour sleep period.[6] The sleep-wake
cycle is dictated by an inherent biological clock or circadian rhythm.
Disruptions in individual sleep patterns can disrupt the circadian rhythm and
impair the sleep cycle.[7]
Four major categories of sleep disorders have been defined by the Sleep
Disorders Classification Committee:
- Disorders of initiating and maintaining sleep (insomnias).
- Disorders of the sleep-wake cycle.
- Dysfunctions associated with sleep, sleep stages, or partial arousals
(parasomnias).
- Disorders of excessive somnolence.
References
- Walsleben J: Sleep disorders. Am J Nurs 82 (6): 936-40, 1982.
[PUBMED Abstract]
- Kaempfer SH: Comfort: Sleep. In: Johnson BL, Gross J, eds.: Handbook of Oncology Nursing. New York: John Wiley & Sons, 1985, pp 167-84.
- Savard J, Morin CM: Insomnia in the context of cancer: a review of a neglected problem. J Clin Oncol 19 (3): 895-908, 2001.
[PUBMED Abstract]
- Beszterczey A, Lipowski ZJ: Insomnia in cancer patients. Can Med Assoc J 116 (4): 355, 1977.
[PUBMED Abstract]
- Guyton AC: Textbook of Medical Physiology. 7th ed. Philadelphia, Pa : WB Saunders, 1986.
- Feirerman JR: Disordered sleep. Emerg Med 2: 160-71, 1985.
- Taub JM, Berger RJ: The effects of changing the phase and duration of sleep. J Exp Psychol Hum Percept Perform 2 (1): 30-41, 1976.
[PUBMED Abstract]
Back to Top
Next Section > |