What Is An MSLT (Multiple Sleep Latency Test)?
The MSLT is a daytime sleep study involving a series of several nap opportunities spaced throughout the day. The purpose of the test is to identify people who are unusually drowsy during the day despite getting adequate sleep. It is performed in conjunction with an overnight sleep study (usually always the night before the MSLT). Depending on what we observe during the overnight portion, we will usually proceed with the MSLT. Based on department protocols, there are instances where the MSLT must be cancelled such as significant sleep apnea or insufficient sleep.
Preparing for Your Study
- Please check with your doctor on which medications you should discontinue prior to your study. Certain medications may interfere with test results.
- You will be required to provide a urine sample the morning of the MSLT. The results of the analysis are used to ensure that the MSLT will be accurate.
- You will be asked to keep a 2 week sleep log prior to your study. To print the log click here: (if unable to print, please call us right away at 925-313-4931 and we can mail you one.) Sleep Diary
- Bring loose, comfortable daytime clothing for the second portion of the test, ex: shorts, sweats, t-shirt.
- Bring breakfast and lunch along with snacks. A mini refrigerator will be available on request. You will not be able to leave the building once the study has started.
- Smoking, caffeine and any stimulants are not allowed.
- Bring things to keep you busy between naps – e.g., reading material, knitting, tablet, cards etc.
- In order to make your sleep study successful, please make sure you read the instruction/appointment letter for the overnight sleep study.
What to Expect During the Study
- The first portion of the study will be overnight and approximately 9-10 hours long. Your sleep tech will wake you up in the morning and disconnect the wires that will not be used for the MSLT. The rest of the wires will remain on you until the MSLT study has ended.
- The MSLT begins about 2 hours after you are awakened from your overnight sleep study.
- Typically, the MSLT consists of 5 sessions of 20-minute naps. There is a 1 ½ to 2 hour “break” in between each nap session. We highly discourage any naps during these breaks in between sessions as they will probably affect and potentially invalidate your test results.
- Once each nap session begins, personal electronics will need to be turned off until the session concludes. You will be able to use your electronics during the breaks in between each session.
- The test wires will remain attached to your head and body throughout the day. Although you can walk around between naps, you will not be permitted to leave the building.
- After your 5th session, your study will be completed. There are instances where the study may end early (e.g. falling sleep outside of the scheduled naps).
- After the study has ended, the sleep tech will remove all wires and you will be done and free to go.
