What Is A Polysomnogram (PSG) with MSLT Test?

A sleep study or polysomnogram (PSG) is a painless test that electronically transmits and records your specific physical activities while you sleep. Your sleep patterns and behaviors are monitored remotely by a trained sleep technologist. The recordings become data that are analyzed by a qualified sleep specialist to determine whether or not you have a sleep disorder.

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, parasomnias, and others.

What to Expect

Your Sleep Technologist will be at our site to greet you when you arrive. After you make yourself comfortable, your Technologist will take a brief history, explain the testing procedure and answer any questions you may have. He/she will then begin the process of applying the sensors for your study. First, the Technologist will run the necessary wires for your legs (applied with stickers), chest and abdomen. Next, the Technologist will mark and measure your head with a paper ruler and a grease pencil. This is done because each electrode on your head needs to be in a very 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.

In the morning, the Technologist will remove some of the sensors used the night before and will explain your Multiple Sleep Latency Test. 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. Sandwiches for lunch are provided; please notify us of any special dietary needs in the morning when you arrive.

You may bring your own pillow and food/snacks, if preferable. Sleep Insights offers a private, hotel-like environment with wifi and TV. While you are asleep, your technologist will make every effort to ensure your comfort. You will be monitored remotely--no one will be in your room watching you. After your last nap is completed, the Technologist will remove all of the wires and electrodes.

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

For the most accurate 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 fingernail for the oxygen reading
  • 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
  • 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 alcohol are not allowed 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

Please call our main site at (585) 385-6070, your local site or contact us if you have any questions.