Multiple Sleep Latency Test

A Multiple Sleep Latency Test (MSLT) provides an objective measure of the tendency to fall asleep when put in a quiet dark situation. It can be done to document excessive sleepiness or to show elimination of excessive sleepiness after treatment of a sleep disorder. Four separate 20 minute nap opportunities are provided. The subject is asked to try to fall asleep. Brain wave measurements are used to determine how many minutes it takes to fall asleep. This test lasts all day, usually from 8 a.m. to 3 p.m. since 2 hours wake time is required in between each of the 4 naps. The average time to fall asleep in the four naps is the “average MSLT sleep latency.”

Things to know before your MSLT:

  • If you cannot keep your appointment, please call at any time to inform us. Our phone number is (717) 316-2229.
  • Please get out of bed by 6 a.m. the day of the test.
  • Eat a light breakfast. NO COFFEE, TEA, COLA, CHOCOLATE (caffeine products). Decaffeinated products are allowed.
  • Bring a list of your current medications, including herbal products. Your doctor may ask you to stop taking some of your medications prior to testing.
  • Please bring any medications you may need to take while you are here. This includes prescription medications, inhalers, nitroglycerin, etc.
  • Plan to arrive at the hospital at 7 a.m. Report to the Outpatient Registration. They will direct to the Sleep Lab which is on the second floor.
  • You will be staying most of the day, so bring something along that will keep you AWAKE in between your nap periods.
  • Complete and bring along your sleep diary of the past 2-3 weeks. Include sleep habits: time to bed, time out of bed, any naps taken and how you feel during the day.
  • The test will be performed in your regular clothes. Wear something comfortable and loose fitting.
  • Your lunch will be provided.
  • Electrodes will be attached to your head through the hair using a special gel. Your hair must be clean and dry for the test (shampoo only). No hairspray, conditioners, gels, etc.
  • Your sleeping patterns will be monitored during a series of 4-5 naps lasting approximately 20 minutes or longer and 2 hours apart.
  • You will be observed in a quiet, smoke-free, private room.
  • A courteous staff person will explain the procedure to you and answer any questions.