Sleep Disorders

The name is strange, but it is something we go through literally every 24 hours. Circadian rhythm is the approximately 24-hour cycle that every animal experiences relating to the time spent sleeping and awake. It is appropriate to look at the things that disturb this natural cycle and how to treat them.

The most common circadian rhythm disorders are Delayed Sleep-Phase Syndrome (DSPS), characterized by a persistent inability to fall asleep at the desired bedtime and awaken on time in the morning; Advanced Sleep-Phase Syndrome (ASPS), marked by persistent early evening sleep onset, between 6:00 and 9:00 p.m., and waking-up earlier than one wants by an hour or two or even more; and Irregular Sleep-Wake Cycle, which features multiple sleep episodes and disturbed nighttime sleep without recognizable circadian characteristics or sleep patterns.

Circadian rhythm disorders are accompanied by complaints of insomnia and/or being too sleepy during the day. Impaired quality of life is the most common feature but it can be deadly serious. Thousands of serious or fatal automobile or work-related accidents each year result from impaired performance caused by sleep deprivation. Cardiovascular problems, increased smoking and alcohol use, and depression are more prevalent in individuals with circadian rhythm disorders.

While circadian rhythm disorders happen in all age groups, two that are affected more than others are adolescents and the elderly. Many teenagers show signs of DSPS and have a hard time getting out of bed in the morning, while older individuals are more prone to ASPS and find themselves waking up too early.

CAUSES

When the 24-hour day and night sleep pattern does not fall within the conventional or desired cycle, circadian rhythm disorders are considered. Some factors that may contribute to this problem include a sleep environment in which there are higher levels of light or noise and a room temperature that is not conducive to a good night’s sleep. This problem particularly affects shift and night workers.

Many circadian rhythm disorder patients have a heavy travel schedule and jet lag plays a large part in their sleep problems. Other factors that can contribute to sleep disruption include psychiatric disorders, neurological diseases such as Alzheimer’s disease, and lifestyle and social pressure to stay up late.

SYMPTOMS A persistent or recurrent pattern of sleep disruption leading to excessive sleepiness or insomnia that is due to a mismatch between the sleep-wake schedule required by a person's environment and his or her circadian sleep-wake pattern.

The sleep disturbance causes clinically significant distress or impairment in social, occupational, or other important areas of functioning.

The disturbance does not occur exclusively during the course of another Sleep Disorder or other mental disorder.

The disturbance is not due to the direct physiological effects of a substance (e.g., a drug of abuse, a medication) or a general medical condition.

DIAGNOSIS

Diagnosis of circadian rhythm disorders is based on taking a thorough history, looking at duration of symptoms and pattern of the sleep-wake cycle. Factors that could affect sleep patterns, such as shift work, travel history, alcohol and/or medication history, sleeping environment, and caffeine use, are all clues. In addition, a thorough physical examination is needed to determine if there are any underlying physical problems, such as neurological disease, hormone disorders, enlarged tonsils, or heart problems, contributing to the sleep disorder. After a thorough history is taken, specific causes and treatment plans can be initiated.

TREATMENT

Treatment of circadian rhythm disorders may begin with a sleep log. While not technically a laboratory test, this diary allows the sleep-wake cycles to be determined and defined. Behavioral treatment can be based on the results of a two-week log of sleep patterns.

Many testing methods are available to determine sleep disruption and patterns, including actigraphy, which is a small motion-sensing device worn on the nondominant wrist for about a week. Based on the theory that wrist motion is decreased during sleep, this test allows a broad measure of sleep/wake cycles over time. Overnight polysomnography is another way to determine sleep cycles. It is a detailed study of overnight brainwave, breathing, and movement patterns during sleep.

Once a specific determination of the type and degree of circadian rhythm disorder affecting the patient is made, treatment can be undertaken. Luckily, for most people, it is not very difficult to reset the circadian rhythm to the desired schedule. It may involve short-term use of hypnotics, however, the mainstay of treatment in circadian rhythm disorders is behavior modification.

Good sleep habits need to be initiated. Patients are encouraged to keep a dark, quiet room during sleep and a well-lit room upon awakening. Bright light exposure in the morning or evening can be prescribed. Regular eating and exercising times are encouraged. Careful use of caffeine-containing beverages is important.

Mapping out a plan of good sleep hygiene, bright light therapy, support, and reward is very effective in returning a balance to sleep/wake patterns. This will keep the beat of the circadian rhythm strong and in step with your life.