Sleep Study: What to Expect

Find out what to expect during your sleep study, or polysomnogram, at the McDaniel Sleep Center at UNC Health Lenoir in Kinston, North Carolina.

What is a Sleep Study?

A sleep study, or polysomnogram, is similar to an EEG or ECG study but makes 16 different measurements in your brain or body for the entire time you sleep. This test is not invasive; the electrodes rest on the skin attached by a special adhesive and tape. These tests begin at night and last through the morning, as would a normal night of sleep.

What Should I Bring With Me?

Prepare yourself for your night in the sleep lab as if you were going to spend a night in a hotel. Please bring with you everything you would need to spend the night away from home. This should include all medications, your pajamas, toothbrush, books to read, etc. You will NOT need to bring a pillow/blankets or an alarm clock, as the technologist will wake you in the morning. Please keep in mind that cell phones should be turned off to avoid disrupting your study or another patient’s study.

What Happens When I Get to the Sleep Center?

You will park in the Minges Wellness Center parking lot, and proceed through the Wellness Center entrance. The McDaniel Sleep Center at UNC Health Lenoir is the first department on the left side of the corridor. Please ring the doorbell, and you will be greeted by a sleep technologist and shown to your private room. You will change into your nightclothes and prepare for bed. Once in your nightclothes, a technologist will begin to apply various sensors and electrodes for the sleep study.

What do the Sensors Tell the Sleep Technologists?

From the electrodes placed on different points on your body, our computer can measure up to 16 different body signals at the same time. Usually, these include:

• Brain waves – Typically, six electrodes are attached to your scalp with a water-soluble paste or adhesive. Your hair is not cut or shaved. Needles are not used. The adhesive is removed when your sleep study is over. Brain waves allow us to determine the different stages of sleep.
• Eye movements – Most often, two electrodes are attached with tape near your right and left eyes. The electrodes don’t touch your eyes. Eye movements help us identify specific deep stages of sleep, such as rapid eye movement (REM) sleep.
• Muscle activity – Generally, two electrodes are attached with tape on or under your chin. Muscle tone plays a large role in determining your sleep stage throughout the night.
• Electrocardiogram – Normally, two electrode patches are attached to the upper chest to record your heart’s rhythm throughout the night.
• Leg movements – Typically, two electrodes are attached with tape to your lower legs to measure muscle activity.
• Breathing – Your breathing is measured in several ways. First, a sensor is attached with tape to your upper lip to measure airflow. Second, lightweight belts are placed around the chest and abdomen to measure how much effort you make to breathe. These belts are not tight; they’re sensitive to the expansion of your chest and stomach as you breathe.
• Blood oxygen levels – A sensor is attached to your finger to measure the oxygen levels in your blood.

Why is it Necessary to Record So Many Things?

Your brain and your body function very differently during sleep than during the day. Even if your heart, breathing, and brain activity are completely normal during the day, they may be abnormal during sleep. The only way to determine the degree of the sleep problem is to take a variety of measurements.

How Can I Sleep With All Those Sensors Attached to Me?

Almost every patient who comes for a sleep study asks this question. However, most patients find it is not as bad as it sounds. Most patients have a similar night’s sleep as they do in their own homes.

Can I Sleep in My Usual Position and Turn Over?

All electrodes and sensors are attached so they should not come off during sleep. You should be able to sleep as you do at home and turn over as usual. However, sleeping on your stomach is discouraged, as this can mask symptoms of obstructive sleep apnea. If you feel you cannot sleep normally because of the electrodes, please call the sleep technologist to help you. Also, if an electrode or sensor does come off, the technologist on duty will simply reapply the sensor.

Will You Give Me Medication to Help Me Sleep?

No. This might change your sleep and prevent us from identifying the source of your sleep problem. However, you may take whatever medications you usually take before bedtime. Just tell the technologists what you are taking, so it may be documented in your medical chart.

What If I Need to Use the Restroom During the Night?

All electrodes and sensors are attached to a portable box. The box can be quickly and simply unplugged, and you can go to the bathroom.

Will Anyone Else be in the Sleep Lab When I’m There?

A technologist will greet you when you arrive at the sleep lab and show you to your room. A member of our technical staff will remain present and awake in the control room all night. A two-way intercom will be left on throughout the night. Just speak, and the technician will hear you. Your room is private, and you won’t interact with other patients.

When Can I Leave?

Usually, the technologist will wake you at 6 a.m. If you need to be up earlier, tell the technologist. He or she will remove all leads and sensors. You’ll get a one-page questionnaire to fill out. As soon as you’re unhooked, you’re free to leave. Showers are available in the Minges Wellness Center. Many patients bring their clothing for the next day and leave directly for work or other daily activities.

How and When Do I Get the Results?

All sleep studies contain 1,000 pages or more of data that must be analyzed and interpreted. Analyzing a sleep study is time-consuming. Each page of the recording is examined for sleep stage, breathing abnormalities, heart arrhythmias, movements, arousal, and many other variables. Often the technologist must review the same page several times to identify all significant data. The fully analyzed data is then reviewed by a board-certified sleep physician who will provide an interpretation. This process usually takes about a week. Results will be faxed and mailed to the physician who ordered the sleep study for you. Ask your doctor, not the McDaniel Sleep Center, for the results.