Circadian Rhythm Sleep-Wake Disorders

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 Delayed sleep-wake phase disorder (DSP) is a circadian rhythm disorder. It consists of a typical sleep pattern that is "delayed" by two or more hours. This delay occurs when one’s internal sleep clock (circadian rhythm) is shifted later at night and later in the morning. Once sleep occurs, the sleep is generally normal. But the delay leads to a pattern of sleep that is later than what is desired or what is considered socially acceptable.

This pattern can be a problem when it interferes with work or social demands.  A person with DSP is likely to prefer late bedtimes and late wake-up times. When left to his or her own schedule, a person with DSP is likely to have a normal amount and quality of sleep. It simply occurs at a delayed time. 

One sign of this disorder is difficulty falling asleep until late at night. Another sign is having a hard time getting out of bed in the morning for work or school. These signs can make DSP look like insomnia. Daytime functioning can be severely impaired by DSP. It can lead to excessive sleepiness and fatigue. When able to sleep on their own schedules, people with DSP often stay up until they get tired and then sleep until they awaken late in the morning. In this case, they tend to have no complaint of difficulty falling to sleep or feeling poorly during the day.  

Someone with DSP may:

• Have a delay in their sleep pattern in relation to their desired sleep and wake times
• Have trouble falling asleep at the desired time of night
• Be unable to awaken at the desired or socially acceptable time
• Have a normal duration and quality of sleep when left to their own sleep schedule, but this sleep occurs in a stable, but delayed time period in relation to what is desired or socially acceptable
• Have this kind of stable but delayed sleep time for at least seven days

 Advanced sleep-wake phase disorder (ASP) is one of several circadian rhythm sleep disorders. These disorders occur in people who sleep at times that seem to be out of order with “normal” sleep times. People with ASP have an “early bird” circadian clock. They fall asleep several hours before a normal bedtime. As a result, they also wake up hours earlier than most people wake in the morning.  People with ASP feel sleepy in the late afternoon. Bedtime tends to occur between 6 p.m. and 9 p.m. Since bedtime is early, they also wake up early. 

They tend to wake up between 2 a.m. and 5 a.m. While the timing of sleep is early, sleep itself is normal.  All of the circadian rhythms related to sleep also occur at early times. This includes an earlier release of melatonin and other hormones. The body temperature curve is also moved earlier. This has been used as a marker to detect this disorder.  Some people with ASP are able to follow this early schedule. But problems often occur when social plans take place during the late afternoon or evening. This makes them struggle to stay awake.

They may appear very sleepy to others during these evening hours. Missing a few hours of evening sleep over time can cause chronic sleep deprivation. This results in true sleepiness. Even when deprived of sleep, people with ASP still tend to wake up early.  People with ASP may mistake their problem for something else. They may think that waking up too early is a sign of either insomnia or depression. They may worry about being awake so early. It is hard for them to be awake at a time when others are asleep. They may develop a secondary form of insomnia as a result of their worries.  

People with ASP may adjust their lifestyles or jobs around their natural “early bird” clock. For example, an “early bird” clock would be ideal for working the early shift. This includes jobs such as a baker or surgeon. Other people with ASP do things to worsen their condition. They try to realign their early clock to match the schedules of others. For example, they may drink too much coffee or take stimulants to stay awake at night. They may also try to stay asleep during the morning hours. To do this, they may drink alcohol or take sleeping pills. These choices will only make their sleep worse.  

 Irregular sleep-wake rhythm is one of several circadian rhythm disorders. People with these disorders have sleep times that seem to be out of alignment. Their sleep patterns do not follow the “normal” sleep times at night. The sleep of patients with irregular sleep-wake rhythm is so disorganized that there is no clear sleep or wake pattern.  People with irregular sleep-wake rhythm may sleep off and on in a series of naps over a 24-hour period. The sleep pattern is broken up into pieces. This is similar to infants who may sleep for a few hours and then be awake for a few hours. If you add up all of the sleep times, the total sleep time may be normal for that age.   During the day, it may seem like they are sleepy because they nap so much. During the night, it may seem like they have insomnia because they are awake for long periods of time during the night. Their sleep is broken up into pieces all day and all night. There is not one main sleep time that occurs at any time of day.
Someone with irregular sleep-wake rhythm may:

• Sleep off and on in a series of naps during the day and at night
• Have no regular pattern of when they sleep and are awake
• Have a hard time sleeping well, or are very sleepy when they are awake
• Have a total sleep time that is not normal for their age

Irregular sleep-wake rhythm is rare. We do not even know how many people have it. It is believed that some people may have it because they have a weak body clock. This may happen in neurological conditions like the following:

• Dementia
• Brain damage
• Mental disability

This can also happen in people who do not have a neurological problem. There are conditions that may make it easier for this problem to occur. Daily light and other activities are important in resetting our sleep clocks. Bad sleep habits may allow this disorder to occur in people who have weaker clocks. This is especially true for people who do not get proper exposure to daily light.  

 Non-24-Hour Sleep-Wake Rhythm is one of several circadian rhythm disorders. People with these disorders have sleep times that seem to be out of alignment. Their sleep patterns do not follow the “normal” sleep times at night.   The sleep time of people who have Non-24-Hour Sleep-Wake Rhythm shifts a little later every day. Sleep time and wake up time continue to move later and later every day. Sleep times go in and out of alignment with other people as weeks go by.  

Normal people have a circadian rhythm that is longer than 24 hours. Every day, morning light and other behaviors reset the sleep-wake clock to a 24 hour schedule. Without light and this clock resetting, people’s sleep time will drift later and later. This is why many people who have Non-24-Hour Sleep-Wake Rhythm are blind. Light is the major influence on resetting the brain’s clock. 

As your sleep pattern drifts a little later every day, Non-24-Hour Sleep-Wake Rhythm can be confused with other circadian rhythm disorders. As sleep time drifts later, you do not fall asleep until morning. It may seem like you have delayed sleep phase disorder. After days of later and later bedtime, you are sleeping during the day. After more days, you begin to sleep in the early afternoon and evening. This makes it look like you have advanced sleep phase disorder. After more days, you are back to sleeping during normal night hours. Then the drifting sleep time continues around the clock again. 

The sleep time is not broken up into pieces as with irregular sleep-wake type. The sleep time is only broken if there are outside disturbances. Your main sleep time does not occur at the same time every day. It continues to get later and later every day. 
Someone with Non-24-Hour Sleep-Wake Rhythm may:

• Have a sleep cycle that seems to get later and later every night
• Wake up later and later every day
• Have a sleep time that sometimes seems to jump around
• Have their sleep cycle drift later and later without any outside interruptions

  Shift work disorder occurs when you have difficulties adjusting to a work schedule that takes place during a time which most people sleep. When you have shift work disorder, there is a conflict between your body’s circadian rhythms and your work schedule. You may have to be at work when your body wants to sleep. Then when you have to sleep, you body expects to be awake.

People with shift work disorder may sleep up to four hours less than the average worker. Shift work disorder causes you to have trouble sleeping or be severely tired. The quality of sleep may be poor, and you may wake up feeling unrefreshed. You may feel fatigued or exhausted. This can hurt your performance at work, and can put you at risk for making a costly mistake or getting injured on the job.

Not everyone who does shift work has shift work disorder. Many people have difficulty initially adjusting to a new shift. If after several weeks you have difficulty falling asleep or staying asleep or you feel tired even after sleeping 7-8 hours, you may have shift work disorder. The symptoms of shift work disorder usually last as long as you keep the shift work schedule. The sleep problems tend to go away once you begin sleeping at a normal time again. Some people may have sleep problems even after the shift work schedule ends.

Shift work disorder is a circadian rhythm sleep disorder. Your circadian rhythms are your body’s internal clock that signals when you are supposed to feel sleepy or alert. Your circadian rhythms operate on a roughly 24-hour schedule. Your body uses sunlight to determine how much of the sleep-promoting hormone melatonin it produces. In shift work disorder, melatonin production may occur when you need to be awake and alert for your job. Exposure to sunlight may prevent you from producing melatonin when you are supposed to sleep.

There are several variations of shift work schedules that can cause difficulties. This includes:

• Early-morning shifts
• Night shifts
• Overnight shifts
• Rotating shifts

Some people have a more difficult time with certain shift work schedules. Night owls may adjust more easily to working an evening shift than morning-types. Likewise, morning larks may have an easier time with early morning shifts. Many people have difficulty adjusting to overnight or rotating shifts.
Shift Work Self Test: 

Do you have a schedule that requires you to work when you would normally sleep?

Do you have trouble sleeping or are severely tired due to your work schedule? 

Have you had this work-related sleep problem for at least one month? 

Does this problem hurt your social, family or work life?

If your answer is yes to each of these questions then you might have shift work disorder. Dr. Mathur can provide you with methods to help your body adjust to your work schedule and to improve your sleep. 

 Jet lag occurs when you travel across multiple time zones and have trouble adjusting to the new schedule. After traveling a long distance by air, your circadian rhythms may still be aligned with the previous time zone. Your body may expect to sleep when it is daytime in the new time zone or be awake when you are supposed to sleep.

Jet lag is a temporary condition. It may begin after you travel across at least two time zones. The severity of the jet lag depends on how many time zones you crossed and which direction you traveled. Flying east is usually more difficult of an adjustment than westward travel. It is estimated that it takes one day per time zone for your body clock to fully adjust to local time.You may have a difficult time functioning when you are jet lagged. You may not feel awake and alert when you need to do your job, socialize or sightsee. Anyone of any age can have jet lag, although older adults are likely to have more severe jet lag, and may need a much longer time to recover. Some people are able to adjust more quickly than others to rapid shifts in time zones. Pilots, flight attendants and business travelers are most likely to have jet lag due to their lifestyle.Jet lag can be worsened by:

• Sleep loss due to travel
• Spending a long time sitting in an uncomfortable position, such as in an airplane
• Stress
• Caffeine and alcohol use
• Air pressure or poor air quality

Jet lag is a circadian rhythm sleep disorder. Your circadian rhythms are your body’s internal clock that signals when you are supposed to feel sleepy or alert. Your circadian rhythms operate on a roughly 24-hour schedule. Your body uses sunlight to determine how much of the sleep-promoting hormone melatonin it produces. Melatonin production is high during the evening and very low during the day. As a result, you are alert during the daytime and sleepy at night.

Traveling across multiple time zones can disrupt your circadian rhythms. Jet lag from traveling across time zones can be difficult to cope with. You may feel fatigue as you are expected to be awake and alert for your daytime activities. The symptoms are likely to be worse and longer lasting the further you have traveled, especially if you travel eastward. Complaints related to jet lag include:

• Trouble falling asleep
• Feeling tired or disoriented
• Being unable to function normally during the daytime
• Mild sickness
• Stomach problems
• Menstrual symptoms in females

If you feel that you have any of the above symptoms or conditions please call and make an appointment for consultation with Dr. Mathur.