A Nocturnal Polysomnogram (also known as a overnight sleep study) is a test that involves the continuous recordings of brain waves (EEG), electrical activity of muscles, eye movement (electrooculogram), breathing rate, blood oxygen level, heart rate and direct observation of the person during sleep. There is also a video camera to look at behavior during sleep.
There are two states of sleep: non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep. REM sleep is associated with dreaming and paralysis of body muscles (except for the eye and diaphragm muscles). NREM sleep has three stages distinguishable by EEG waves. REM sleep alternates with NREM sleep approximately every 90 minutes. A person with normal sleep usually has four to five cycles of REM and NREM sleep during a night.
Nocturnal Polysomnogram is conducted in a sleep study center. Nocturnal Polysomnograms are offered for children of all ages. The test is performed during the night. Electrodes are placed noninvasively on the chin, the scalp, legs, outer edge of the eyes. An air outflow detector is also placed below the nose in preparation for the test. These electrodes will monitor activities such as brain waves, muscle movements, eye movements, breathing, snoring, and heart rate and leg movements during sleep. All of the electrodes and monitors are temporary and can be disconnected during the night to allow you to go to the bathroom.
Characteristic patterns from the electrodes are recorded while you are awake with your eyes closed and during sleep. The time it takes for the child to fall asleep is measured, as well as the time it takes for you to get into REM sleep. The movements of a child during sleep are recorded by video camera.
The test is performed to evaluate possible sleep disorders, such as, excessive daytime sleepiness, obstructive sleep apnea, narcolepsy, breathing difficulties, or other sleep disorders.
If your child is having certain types of sleep problems, the best way to understand the condition may be for sleep specialists to actually watch him sleeping and monitor his body while he's asleep.
The Maintenance of Wakefulness Test (MWT)
The Maintenance of Wakefulness Test (MWT) is a way to evaluate the ability to stay awake during the day and it is typically ordered once patients with daytime sleepiness approach driving age.
An overnight diagnostic sleep study called a nocturnal polysomnogram (NPSG) is occasionally required the night prior to the daytime MWT. After the NPSG is complete, the MWT testing is performed the following day. There are 4 tests spaced 2 hours apart. A urine drug screen is part of the protocol.
After being asked to stay awake, sensors on the head and chest record your brain wave activity, eye movements, and heart activity to accurately detect if you fall asleep.
The information we collect during your study is reviewed and analyzed by our sleep specialists
Positive Airway Pressure Titration Study
As a result of the initial sleep study (NPSG), a child may be diagnosed with Obstructive Sleep Apnea (OSA), and may be sent back to the sleep center for another sleep study with CPAP or BiPAP. CPAP stands for Continuous Positive Airway Pressure, while BiPAP stands for Bi-Level Positive Airway Pressure.
While asleep, this system gently delivers air into your airway through a specially designed mask which fits over the nose or mouth, thereby creating enough pressure to keep the airway open and make breathing easier for the child. Most patients find they get used to CPAP or BiPAP after a few minutes and have little difficulty sleeping with it in place. It is important to note that the CPAP or BiPAP does not breathe for the patient, but instead allows the patient to breathe on their own without having to fight obstruction of the airway that was previously a barrier to normal breathing during sleep. At the beginning of a CPAP/BiPAP study sensors are applied to your body as they were for the polysomnogram and again brain waves, eye movements, muscle tone, breathing patterns and blood oxygen levels are monitored. Before you fall asleep; the sleep technologist will fit you with the nasal or oral PAP mask.
Multiple Sleep Latency Test (MSLT)
A MSLT is always performed the day after an overnight sleep study. The purpose of this study is to assess the sleepiness of your child after an overnight study in which the quality of sleep has been monitored. Your child will be awakened by 6:00 a.m. so that the first nap can begin between 8:00 a.m. and 8:30 a.m.
The electrodes that were placed on your child for the overnight study will remain but some adjustment or reapplication may be necessary in the morning. The MSLT study is performed throughout the day with the child taking "naps"every 2 hours after the prior "nap". A total of 5 Naps will be recorded. You and your child should plan on being in the Sleep Center until approximately 5 p.m. Aurine drug screen is part of the protocal for an MSLT
Your child should wear loose, comfortable street clothing. You may bring activities for your child, and we also have the Harbor Center on the second floor of the hospital. The Harbor Center offers computer usage, computer games, pool table, and other activities.
Your child will not be allowed to lay in bed or sleep between naps.
A meal menu will be provided for the patient for breakfast, morning snack, lunch, and afternoon snack. The parent(s) will have the option to purchase each meal for $3.50, or you may walk down to the cafeteria. There are also restaurants nearby, and some restaurants will deliver.
If your child is on medications for neurological disorders or excessive daytime sleepiness, please notify us by calling the Sleep Disorder Center at 205-638-9386. Please do not let your child consume foods or beverages which contain caffeine on the day of the study.