What to Expect
Our experienced neurologists and specially-trained sleep disorders team utilize various testing modalities to effectively diagnosis and treat a wide range of both common and complex sleep disorders. These tests can be divided into two categories: In-Center Sleep Testing and Out-of-Center Sleep Testing.
Polysomnography (Sleep Test)
Polysomnography monitors several functions of the body relevant to sleep, including brain activity, eye movements, breathing, movement, heart rate, and oxygenation. For this study, a technician will attach electrodes to your head with a glue-like substance known as collodion. Additional electrodes will be attached to the area around your eyes, on your cheeks, chest and legs. Two bands will be placed around your chest and abdomen to monitor respirations while you sleep. The wires from the electrodes will be inserted into a box which will be placed at the head of our bed during the night. There is also a video recording of your sleep so that the doctor and technologist can observe for movements and possible sleep disorders. You will have plenty of freedom to move about in the bed as you normally do during your sleep at home. If you need assistance during the night (e.g., to go to the bathroom) you will be able to signal the technologist to come help you.
Measuring these things while you sleep allows the physician to determine the characteristics of your sleep, including the overall pattern, depth, and amount. It also looks for common sleep disorders.
Throughout the night your brain waves (EEG), respirations, heart rate, movements and other physiological measurements will be monitored continuously and recorded to a computer system for further analysis after your study is completed. Additionally, you will be monitored by video and audio instruments as well.
Video-EEG monitoring is useful in diagnosing unusual events or activities during the night, especially when these might be seizures. For example, people with known seizure disorders may have behavioral changes during sleep that are not clear to their physician and may be seizures, or other behaviors could be occurring that could be seizures, a sleep disorder, or normal sleep (such as vivid nightmares). Video-EEG monitoring can be performed independently or in conjunction with polysomnography. The test consists of more electrodes on the scalp than for polysomnography, as it looks in much more detail at brain activity.
Multiple Sleep Latency Testing (MSLT; "Nap Test")
Multiple sleep latency testing is a way to measure your sleepiness and tendency to fall asleep during the day. It is particularly important in the evaluation of possible narcolepsy. The test is similar to polysomnography, except that it requires fewer monitors (only electrodes on your head, chin, and eyes; breathing and leg movements are not usually measured).
The MSLT consists of four to five "nap opportunities", each two hours apart. The test almost always follows an overnight recording with polysomnography as the previous night's sleep is essential in interpreting the MSLT. About two hours after awakening, you will be asked to lie down and try to sleep. The room will be quiet, and the lights off. After 20-30 minutes, the technologist will wake you up. This will be repeated every 2 hours during the day. For this test, you should bring reading material or work to keep yourself occupied between tests.
Maintenance of Wakefulness (MWT)
The maintenance of wakefulness test (MWT) is a way to measure your ability to stay awake during the optimal sleep conditions. The test is similar to polysomnography, except that it requires fewer monitors (only electrodes on your head, chin, and eyes; breathing and leg movements are not usually measured).
The MWT may be used to evaluate how well a person with a sleep disorder is able to stay awake. This is critical when the person's job involves public transportation or safety. The results of the test will be only one factor used to assess the potential risk of a work-related accident.
The MWT consists of five sessions each two hours apart. It consists of 40 minute sessions where you must remain awake for as long as possible in a dimly lit, quiet room. This is repeated every 2 hours during the day. For this test, you should bring reading material or work to keep yourself occupied between tests. This does not require overnight recording from the night prior.
Please note that the test only provides supportive documentation that a person's alertness is no different to the general population without a sleep condition.
Polysomnography with Titration
If you are diagnosed with sleep apnea either prior to or during the polysomnography, you may be given the opportunity to try a treatment for this condition. This treatment is called PAP (positive airway pressure) and involves you wearing a mask attached to a machine while you sleep. This machine then blows air into your throat and allow you to have better rested, quality sleep. There are different types of machines and masks that may be used and we aim to provide you with the best and most suitable for your condition.
Dim Light Melatonin Assay (DLMO)
DLMO is useful in patients where a body clock/circadian rhythm disturbance is being considered. It is a test performed at home requiring you to be relaxed in dim light conditions for several hours. We give you equipment to collect samples of your saliva every half hour in the evening and it is then sent for analysis at a specialized laboratory. This is not covered by your insurance and would be charged separately to the visit or other procedures required.
Home Sleep Test
A home sleep test is a simple device that is taken home and the individual sets up themselves. It is typically given to healthy individuals where there is a high suspicion of obstructive sleep apnea without any other conditions. It is a small device that monitors your breathing using monitors around the nose and torso as well as monitoring your oxygen levels through a sensor on the finger.
The test typically gathers limited information and has a higher risk of errors compared to in-lab testing. However for some people it is an effective and more convenient way of testing for obstructive sleep apnea.
Home Sleep Test with EEG
We can provide a more detailed home sleep test that also monitors the brain waves of a person during the night. This is typically given to individuals who are unable to stay in the sleep center.
Typically an appointment is arranged for the patient to come to the center during the daytime. At this time electrodes are glued to the head, chin and eyes. Belts are placed around the chest and belly area. Tubing is also placed around the nose and mouth to monitor breathing.
The test gathers useful information about your sleep architecture and breathing patterns. However as it is not performed under supervision there is a chance that data recorded will be more limited, and there is no video monitoring performed in conjunction with this test.
Actigraphy monitors cycles of rest and activity. A sensor that looks like a watch, is placed on your non-dominant wrist (ie not the hand you write with). It measures movement continually and is typically used for 14 days. The sensor should be worn at all times except when showering. Usually it is kept in conjuction with a diary documenting activity.
The test is useful for those where a body clock problem is suspected - a circadian rhythm disorder - where longer monitoring than a single night is required. It is also sometimes used to evaluate restless sleep or when a person complains of not sleeping for several days at a time.
This is a simple procedure to document the patient's schedule of wake and sleep.
This information can be helpful in diagnosing body clock problems and sleep hygiene problems. It is usually performed in conjunction with other tests such as actigraphy or preceding a polysomnogram.
If you have a smartphone there are various applications that can be downloaded to track sleep. Please feel free to use one of these and provide us with the data at your visit.