in-lab-sleep-study

In Lab Sleep Study

A polysomnogram (PSG), or sleep study, is the most accurate and objective method for evaluating sleep and establishing a diagnosis. The polysomnogram charts your brain waves, heartbeat and breathing as you sleep. It also records your eye and leg movements as well as muscle tension. Sensors are placed on your head, face, chest and legs. They send tiny electrical signals to a computer.

The signals show when you are asleep and awake during the night. The brain-wave and eye-movement detectors show when you are in REM sleep. This stands for rapid eye movement sleep. This is a stage of sleep where your eyes twitch and your brain waves are very active. It is also the stage of sleep when you have most of your dreams.

The breathing monitors show the number of times you stop breathing. They can also detect low air flow and minor changes in oxygen level.

For FAQs about the sleep study, please click here.

CPAP Study

This study is used to set the right level of continuous positive airway pressure (CPAP) therapy. This therapy is used for people with sleep related breathing disorders. These disorders include the following:

  • Obstructive sleep apnea (OSA)
  • Central sleep apnea (CSA)
  • Hypoventilation and hypoxemia

CPAP is most commonly used to treat OSA. A CPAP study is performed on someone with a sleep related breathing disorder, usually OSA.

What happens when I have it?

Will my insurance cover my sleep study? During an overnight sleep study, you may show signs of having OSA. If it seems to be very severe, then a CPAP study may be performed right away. Doing both studies in one night is known as a split-night sleep study.

How should I prepare for my sleep study? If the sleep study shows that the OSA is fairly mild, then the CPAP study may not be performed right away. The doctor may wait to review the results of the entire night of the sleep study. Then he or she will decide if you need to come in for a second sleep study. If you do, then the CPAP study would be performed at that time.

Should I take my usual over-the-counter
or prescription drugs before my sleep study?
During the CPAP study, you are fitted with a nasal mask. The mask is connected by a tube to a small electric unit. The unit has a fan that pushes air through the tube. The mask allows the air to gently blow into the back of your throat.

Will I be given any shots, injections
or medications during my study?
Pressure is started at a very low level. It is then increased at various intervals during the night. The goal is to find the right level of air pressure that will prevent the collapse of your upper airway. This eliminates pauses in your breathing as you sleep.

Test Results

How will I get my results following my sleep study? The results of the CPAP study are reviewed by a specially trained physician who then prepares an official study report complete with recommendations for treatment such as optimal PAP pressures. Your primary care or referring physician will receive the report and make the final decision about the course of therapy. If PAP therapy is prescribed for you, arrangements are made with a home medical equipment provider that will make an appointment with you for mask fitting and obtaining a PAP unit, and training, for use in your home.

MSLT Study

The Multiple Sleep Latency Test (MSLT) is a daytime sleep study that measures how sleepy you are on a day to day basis.

“The MSLT is primarily used to diagnose excessive daytime sleepiness and narcolepsy.”

The MSLT is primarily used to diagnose excessive daytime sleepiness and narcolepsy. Learn More.

Here’s how it works:

The daytime nap study is taken right after you do an overnight sleep study. For the MSLT to be accurate, you should have had a total sleep time of at least six hours during the overnight sleep study.

The MSLT consists of five nap opportunities with breaks lasting for two hours in between them. A shorter four-nap study may also be used. But the five-nap version is more reliable at detecting narcolepsy. The first nap trial begins between 1.5 and three hours after you wake up from the overnight sleep study. You will be given a light breakfast at least one hour before the first nap trial.

Sensors which send tiny and painless electrical signals to a computer are placed on your head, face, and chin. The signals show when you are asleep and awake during the study. The brain-wave and eye-movement detectors show when you are in REM sleep. This is a stage of sleep where your eyes twitch and your brain waves are very active.

A low-light video camera allows a technologist to see you from a nearby room. For each nap trial, you are asked to lie quietly in bed and try to go to sleep. Then the lights are turned off. Once the lights are out, the test will measure how long it takes you to fall asleep. Your vital signs will continue to be measured as you sleep.

After sleeping for 15 minutes, you will be awakened. Each trial will end if you do not fall asleep within 20 minutes. Between nap trials, you will have to stay out of bed and occupy yourself so that you remain awake.

To ensure the nap study results are accurate, you may be asked to take a test to screen for drugs the morning before the nap study. It will be helpful if you fill out a sleep diary for at least one week before the MSLT. This will allow the doctor to see your normal sleep-wake pattern. Smoking should be stopped at least 30 minutes before each nap trial.

You will not be allowed to have any drinks with caffeine during the study. You will also not be able to see any bright sunlight. Outside factors that might affect your sleep are limited. Your room is made dark and quiet. The room temperature is set at your personal comfort level.

Test results

What are some possible treatments for a sleep disorder? An abnormal result occurs if you fall asleep in less than eight minutes.

Your entire testing will be reviewed by a specially trained physician who then prepares an official study report complete with recommendations. Your primary care or referring physician will receive the report and make the final decision about the course of therapy.

MWT Study

The Maintenance of Wakefulness Test (MWT) is a daytime sleep study that measures your ability to stay awake and alert during the day.  The MWT can also tell your doctor how well your treatment is working.

Here’s how the MWT works:

All sunlight will be kept out of your room. A dim light will be located behind your bed. Outside factors that might affect your sleep are limited. Your room will be very calm and quiet. The room temperature is set at your personal comfort level.

The MWT consists of four sleep trials with breaks lasting for two hours in between them. Sometimes you will also do an overnight sleep study the night before the MWT. It is vital that you get a normal amount and quality of sleep the night before the test. If this does not happen, then your test may need to be moved to another day.

Sensors which send tiny electrical signals to a computer are placed on your head, face, and chin. The signals show when you are asleep and awake during the test. A low-light video camera allows a technologist to see you from a nearby room.

For each trial, you will sit quietly in bed with your back and head supported by a pillow. It is important that you are as comfortable as you can be. You will be asked to sit still and look directly ahead of you. Then you simply try to stay awake for as long as you can.

You are not allowed to do other things to try and keep yourself awake. If you fall asleep, then you will be awakened after sleeping for only about 90 seconds. The test will end if you do not fall asleep within 40 minutes.

“If you fall asleep, then you will be awakened after sleeping for only about 90 seconds.”

Between trials, you will have to stay out of bed and occupy yourself so that you remain awake.

The sleep specialist will help you decide what you can and cannot have. You may be asked to take a test to screen for drugs on the morning of the MWT. It will help show that the results of the MWT are accurate.

Before the test

An MWT may be done the day after a polysomnogram (PSG) and takes most of the day. You will need to refrain from tobacco and caffeine before or during the test. Your doctor will discuss any changes to your medication schedule before the test. You should have a light breakfast at least one hour before the first trial.

Test results

What are some possible treatments for a sleep disorder? Your entire testing will be reviewed by a specially trained physician who then prepares an official study report complete with recommendations. Your primary care or referring physician will receive the report and make the final decision about the course of therapy.