What is it? Free-running (nonentrained) type 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 free-running (nonentrained) type 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 free-running (nonentrained) type are blind. Light is the major influence on resetting the brain’s clock. As your sleep pattern drifts a little later every day, free-running (nonentrained) type 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.
Free-running (nonentrained) type 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 free-running (nonentrained) type 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 free-running (nonentrained) type are blind. Light is the major influence on resetting the brain’s clock.
As your sleep pattern drifts a little later every day, free-running (nonentrained) type 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.
Who gets it? More than half of blind people have free-running (nonentrained) type. Yet some blind people do not have this disorder. They still have a working brain pathway to the part of the brain that functions as the body clock. Also, some blind people still have a normal circadian rhythm. Their clocks can be reset to other time cues besides light. But the majority of blind people report some kind of sleep disturbances. Some people who are not blind also have this disorder. But these cases are very rare. 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 condition to occur in people who have weaker clocks. This is especially true when they do not get proper exposure to daily light. If you never left a dark room, your circadian clock may not reset. Your sleep time could drift later and later. Your body would not have the normal time cues from your surroundings. Some people with this problem may have or may develop psychiatric or personality disorders. This disorder may also be seen with other behaviors such as substance abuse. This problem has also been reported in people who are being treated for delayed sleep phase disorder. People may also have this problem if they have neurological or brain disorders such as these: Mental retardation Brain injury Dementia
More than half of blind people have free-running (nonentrained) type. Yet some blind people do not have this disorder. They still have a working brain pathway to the part of the brain that functions as the body clock. Also, some blind people still have a normal circadian rhythm. Their clocks can be reset to other time cues besides light. But the majority of blind people report some kind of sleep disturbances.
Some people who are not blind also have this disorder. But these cases are very rare. 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 condition to occur in people who have weaker clocks. This is especially true when they do not get proper exposure to daily light. If you never left a dark room, your circadian clock may not reset. Your sleep time could drift later and later. Your body would not have the normal time cues from your surroundings. Some people with this problem may have or may develop psychiatric or personality disorders. This disorder may also be seen with other behaviors such as substance abuse.
This problem has also been reported in people who are being treated for delayed sleep phase disorder.
People may also have this problem if they have neurological or brain disorders such as these:
How do I know if I have it? Does your sleep cycle seem to get later and later every night? Do you wake up later and later every day? Does your sleep time sometimes seem to jump around? If you did not have any outside interruptions, would your sleep cycle drift later and later? If your answer to these questions is yes, then you might have free-running (nonentrained) type.
If your answer to these questions is yes, then you might have free-running (nonentrained) type.
Do I need to see a sleep specialist? Yes. You should seek a doctor’s advice. This disorder causes problems with work and family. Your sleep cycle gradually moves in and out of normal sleep times. There is not one fixed sleep time, either early or late. Sometimes the main sleep time is during the night and sometimes it is during the day. People with this disorder have trouble maintaining relationships and responsibilities. This disorder may make you home bound and isolated. Being home bound can make this problem worse. Some people also try behaviors or medicines to correct the problem. This may only worsen the condition. They may get into trouble if they try to fix this problem on their own by taking pills or alcohol.
Yes. You should seek a doctor’s advice. This disorder causes problems with work and family. Your sleep cycle gradually moves in and out of normal sleep times. There is not one fixed sleep time, either early or late. Sometimes the main sleep time is during the night and sometimes it is during the day. People with this disorder have trouble maintaining relationships and responsibilities. This disorder may make you home bound and isolated. Being home bound can make this problem worse. Some people also try behaviors or medicines to correct the problem. This may only worsen the condition. They may get into trouble if they try to fix this problem on their own by taking pills or alcohol.
What will the doctor need to know? The doctor should ask you about your medical, neurologic, and sleep symptoms. The doctor also should ask you about your medications, alcohol, and your family history. Be sure to inform him or her of any past or present drug, alcohol, and medication use. Also tell the doctor if you have ever had any other sleep or neurological disorders. The doctor should do a thorough medical and neurological exam. You will be asked to complete a sleep diary to record your natural sleep and wake up times over several weeks. You may be asked to rate your sleep with the Epworth Sleepiness Scale.
The doctor should ask you about your medical, neurologic, and sleep symptoms. The doctor also should ask you about your medications, alcohol, and your family history. Be sure to inform him or her of any past or present drug, alcohol, and medication use. Also tell the doctor if you have ever had any other sleep or neurological disorders.
The doctor should do a thorough medical and neurological exam.
You will be asked to complete a sleep diary to record your natural sleep and wake up times over several weeks. You may be asked to rate your sleep with the Epworth Sleepiness Scale.
Will I need to take any tests? The diagnosis of free-running (nonentrained) type is made clinically and with the use of the sleep diary. You may be asked to wear an actigraph. This is a device that records inactive and active episodes over a period of one to two weeks. An actigraph looks like a funny wrist watch, and you wear it day and night. Other testing methods to measure body temperature or melatonin levels may be used. Most often these methods are used for the purpose of research. Your doctor may suspect that a neurological or other medical problem is involved. In this case, you may be asked to have blood testing performed. You may also need a CT scan or an MRI. An overnight sleep study is usually not needed to detect this disorder. You may need to do a sleep study if you are at risk for other sleep disorders. The sleep study is called a polysomnogram. It charts your brain waves, heart beat, muscle activity, and breathing as you sleep. It also records how your arms and legs move. This shows if there are other sleep disorders that are causing or increasing your sleep problems. Examples include sleep apnea and periodic limb movement disorder. A sleep study is not used to make the diagnosis of free-running (nonentrained) type.
The diagnosis of free-running (nonentrained) type is made clinically and with the use of the sleep diary. You may be asked to wear an actigraph. This is a device that records inactive and active episodes over a period of one to two weeks. An actigraph looks like a funny wrist watch, and you wear it day and night. Other testing methods to measure body temperature or melatonin levels may be used. Most often these methods are used for the purpose of research.
Your doctor may suspect that a neurological or other medical problem is involved. In this case, you may be asked to have blood testing performed. You may also need a CT scan or an MRI.
An overnight sleep study is usually not needed to detect this disorder. You may need to do a sleep study if you are at risk for other sleep disorders. The sleep study is called a polysomnogram. It charts your brain waves, heart beat, muscle activity, and breathing as you sleep. It also records how your arms and legs move. This shows if there are other sleep disorders that are causing or increasing your sleep problems. Examples include sleep apnea and periodic limb movement disorder. A sleep study is not used to make the diagnosis of free-running (nonentrained) type.
How is it treated? Treatment for free-running (nonentrained) type is aimed at trying to increase stimulation to reset the sleep clock in the brain. The goal is to have one long sleep time at night and one long awake time during the day. Melatonin is becoming an important treatment for both blind and sighted people with this disorder. For sighted people, light treatment is a way to help a weakened body clock. Other scheduled behaviors can also help. Education and behavioral counseling can be helpful. Following the rules of good sleep hygiene is an important way to keep one main sleep time. Vitamin B12, sleep aids, awake aids, and other medications also may be used. A doctor may monitor your progress by having you complete sleep logs during treatment. As research studies continue, more information will become available about the causes and other future treatments of this uncommon sleep disorder. By Sharon L. Schutte-Rodin, MD Updated March 27, 2006
Treatment for free-running (nonentrained) type is aimed at trying to increase stimulation to reset the sleep clock in the brain. The goal is to have one long sleep time at night and one long awake time during the day.
Melatonin is becoming an important treatment for both blind and sighted people with this disorder.
For sighted people, light treatment is a way to help a weakened body clock. Other scheduled behaviors can also help.
Education and behavioral counseling can be helpful. Following the rules of good sleep hygiene is an important way to keep one main sleep time. Vitamin B12, sleep aids, awake aids, and other medications also may be used. A doctor may monitor your progress by having you complete sleep logs during treatment. As research studies continue, more information will become available about the causes and other future treatments of this uncommon sleep disorder. By Sharon L. Schutte-Rodin, MD Updated March 27, 2006
