Sleep Studies

HSAT

A Home Sleep Apnea Test (HSAT) is a test which is done at home to see if you have Obstructive Sleep Apnea. A device is attached to you while you sleep to monitor your breathing patterns and oxygen levels. This test is suitable for some adults patients who have symptoms of Obstructive Sleep Apnea.  

PSG

A Polysomnogram (PSG) is a detailed sleep test which is usually done at a sleep center by a sleep technician or sleep technologist. During a PSG you will be connected to wires/leads which monitor your brain activity, eye movements, limb movements, breathing patters and oxygen levels among other things. You will also be monitored by video. A PSG is used to diagnosed Obstructive Sleep Apnea, Parasomnias, REM Behavior disorder among other conditions. 

PAP TITRATION

A Positive Airway Pressure (CPAP or BiPAP) titration study is done for  patients diagnosed with Obstructive Sleep Apnea (OSA). During this study patients undergo a PSG while wearing a mask which is connected to a machine which provides pressure to keep your airway open. The pressure is gradually increased with the goal of determining the pressure level where your airway remains open and you are able to breathe properly in your sleep.  

SPLIT STUDY

A Split Study is a sleep test where part of the night is a PSG to determine if you have sleep apnea and the second part of the night is a  CPAP titration study to determine the pressure level needed to treat your sleep apnea. This study is usually done when your sleep apnea is moderate to severe for at least 2 hours and there is at least three hours available for pressure titration. A Split study may also be indicated in some other situations. 

MSLT

The Multiple Sleep Latency Test (MSLT) is a test which is used to objectively measure your tendency to fall asleep. It is based on the assumption that the tendency to fall asleep should increase as physiological sleepiness increases. The MSLT is part of the routine evaluation of patients who are suspected of having narcolepsy and may also be helpful in the evaluation of patients with suspected idiopathic hypersomnia. 

It is important to note that certain medications may have to be discontinued for about two weeks prior to the MSLT. You should consult with your doctor before stopping any medication.

The MSLT is done the day following a polysomnography recorded during your major sleep period. You should ideally have at least six hours of sleep prior to the MSLT.  The test consists of five nap opportunities performed at two-hour intervals. Sleep latency is determined by the time from lights out to the first sleep episode of any stage of sleep. Each nap session continues for 15 minutes after sleep onset to detect any occurrence of REM sleep. The absence of sleep on a nap opportunity is recorded as a sleep latency of 20 minutes and the sleep opportunity is terminated. This is repeated at two-hour intervals until the patient has had five opportunities to nap. The primary measures from the MSLT are the mean sleep latency and presence or absence of sleep onset REM periods (SOREMPs). A mean sleep latency of eight minutes or less, plus two or more SOREMPs support a diagnosis of narcolepsy in a patient with suggestive history.

MWT

The Maintenance of Wakefulness Test (MWT) is a test used to objectively measure your ability to stay awake/ maintain wakefulness.  It is based on the assumption that individuals with a greater degree of sleepiness are less likely to remain awake than individuals with less sleepiness. The MWT may be used to assess a patient's response to therapy. Stimulating activities such as consuming nicotine and use of electronic devices should end at least 30 minutes prior to each wake trial.

The MWT begins 1.5 to three hours after your usual wake-up time. During this test you will be seated in a dimly lit room without stimuli. The test consists of four 40-minutes trials in which you are placed in the sitting position and instructed to sit still and remain awake for as long as possible. The four trials are with two hour breaks in between each trial. A session is ended after unequivocal sleep, or after 40 minutes if sleep does not occur. Between trials, you will have to stay out of bed and occupy yourself so that you remain awake. The primary measure from the MWT is the mean sleep latency. Falling asleep in an average of less than eight minutes during the test is considered abnormal.