What Is A Polysomnogram (PSG) with MSLT?

A polysomnogram (PSG) is a sleep study that helps determine whether or not you have a sleep disorder.  While you sleep, sleep patterns and behaviors such as brain waves, heart rate and breathing, eye and leg movements, and the oxygen level in your blood are recorded.  A PSG can be done at night or during the day and a trained sleep technologist supervises the sleep study.

The multiple sleep latency test (MSLT) determines excessive daytime sleepiness by measuring how quickly you fall asleep in a quiet situations during the day, and how quickly and how often you enter REM sleep.  The MSLT is sometimes referred to as the daytime nap study and is used to diagnose narcolepsy or idiopathic hypersomnia.  It is always a follow-up test to the overnight PSG which is used to rule out other sleep disorders such as sleep apnea, restless leg syndrome and parasomnias.


What to Expect

When you arrive for your sleep study, your sleep technologist will be at the site to greet you and show you to your room.  After you make yourself comfortable, your technologist will take a brief history, explain the study process, and answer any questions you may have prior to applying the sensors.  This procedure is completely painless and generally takes about 40 minutes to make sure everything is placed correctly.

First, the technologist will use stickers to affix leads on your legs, chest and abdomen.  Next, your head will be marked and measured with a paper ruler and a grease pencil.  This is done because each electrode on your head needs to be in a precise location.  Once this is complete, a prep solution will be applied to clean the scalp for the electrodes.  Lastly, the electrodes are placed on the surface of your scalp with a small amount of paste.  The prep, paste, and tape are hypoallergenic.

Once you are fitted with the sensors, you are free to stay in your room where you can relax, catch up on phone calls or read until Lights Out at 11pm.  You may bring your own pillow and food/snacks.  Throughout the study, your technologist will monitor your sleep, but will be available to ask questions and ensure you’re comfortable.

In the morning, the technologist will remove some of the sensors used the night before and will explain the multiple sleep latency test (MSLT), during which you will have 5 half hour naps with the first one beginning at about 8:00am.  In between naps, you can relax, catch up on phone calls or read.  Lunch is provided; please notify us of any special dietary needs in the morning when you arrive.

When the study is done, the technologist will remove all the wires and sensors.

Sleep Insights offers a relaxing environment with private, hotel-like rooms, WI-FI and TV.  At certain locations, a shower may be available.

At your follow-up appointment, you will receive your sleep study results and discuss them with your provider.


Preparing For Your Sleep Test
  • Plan to be at our center from approximately 7:00-9:00 pm until 5:00-7:00 am the next morning for nighttime testing, and from approximately 8:00 am until 5:00 pm for daytime testing
  • Wash your hair thoroughly but do not use conditioners or other hair products
  • Remove any hair weaves or extensions
  • If you have acrylic nails, remove an index finger nail polish for the oxygen reading
  • Bring comfortable, loose-fitting, two-piece pajamas to sleep in (we will be placing sensors on your legs and chest).  Once the sensors are applied you will be able to move about, use the restroom or get a drink
  • Bring – and take – all of your normally scheduled medications unless otherwise directed by your doctor or the staff at Sleep Insights
  • Notify us of any special needs prior to your arrival.  If you are supervising a child or older patient who is having a sleep test, we have rooms equipped with an additional bed.  Please let us know in advance if you need special accommodations
  • Smoking, vaping and the use of alcohol are not permitted in the building or on the premises at any time
  • Failure to show up for your scheduled procedure will result in a $100.00 no-show charge

If you have any questions please contact us, call our Rochester site (585) 385-6070 or your local site.