Home » Sleep Disorders » Irregular Sleep-Wake Rhythm
November 2020 |  Reviewed by:  Shelley Hershner, MD and John Saito, MD

What is irregular sleep-wake rhythm disorder?

Irregular sleep-wake rhythm disorder (ISWRD) is one of several circadian rhythm disorders.

Normally, people are awake and asleep in rhythm with their biological clock. This is known as the circadian rhythm. It typically is a cycle that spans 24 hours and synchronizes to a 24-hour day.

If you have ISWRD, then you show no clear circadian rhythm. You struggle with wakefulness during conventional sleeping hours and sleepiness during the daytime. Your sleep and wake times show no clear pattern.

People with ISWRD may sleep off and on in a series of naps over a 24-hour period. This is similar to infants who may sleep for a few hours and then be awake for a few hours. By definition, to have ISWRD means you must have at least 3 sleep periods within a 24-hour period.

During the day, it may seem like you are sleepy because you nap so much. During the night, it may seem like you have insomnia because you are awake for long periods of time. There is not one main sleep time that occurs at any time of the day or at night. If you add up all of your sleep times, your total sleep time may not be normal for your age.

What are symptoms of irregular sleep-wake rhythm disorder?

Someone with ISWRD 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

What are risk factors for irregular sleep-wake rhythm disorder?

ISWRD 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:

  • Dementia
  • Brain damage
  • Mental health disorders

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 enough exposure to daily light.

How to diagnose irregular sleep-wake rhythm disorder?

You should seek a sleep doctor’s advice. This disorder causes problems with work and family. There is no schedule or pattern for when you are asleep or awake. Your sleep time is out of line with others. This makes it hard for you to maintain relationships and responsibilities. This disorder may make you feel homebound and isolated. Being homebound can make your symptoms worse. Trying to correct your circadian rhythm on your own with behaviors or medicine might make it worse, especially if you are taking pills or alcohol.

The doctor should ask you about your medical, neurologic, and sleep symptoms. The doctor also should ask you about your medications, alcohol use, and your family history. Be sure to inform 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 a simple questionnaire.

The diagnosis of ISWRD is made clinically and with the use of the sleep diary. You may be asked to track your sleep with actigraphy. Actigraphy uses a device that records inactive and active episodes over a period of one to two weeks. This device typically looks like a wristwatch, 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 research.

Your doctor may suspect that a neurological condition or another medical problem is involved. In this case, you may have you blood tested. You may also need a CT scan or an MRI.

A 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.

How to treat irregular sleep-wake rhythm disorder?

Treatment for ISWRD 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.

Bright light therapy is one 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. Melatonin may also be used in children and teens but should not be used in older people with dementia. Talk to your medical provider before taking any over-the-counter sleep aid.

A doctor may monitor your progress by having you complete a sleep diary during treatment. As research studies continue, more information will become available about the causes and other future treatments of this uncommon sleep disorder.