Multiple Sleep Latency Test

MSLT Scores
Minutes	Sleepiness
0-5	Severe
5-10	Troublesome
10-15	Manageable
15-20	Excellent

The Multiple Sleep Latency Test (MSLT) is a sleep disorder diagnostic tool. It used to measure the time it takes from the start of a nap period to the first signs of sleep. The test is based on the idea that the sleepier one is the faster they will fall asleep.

Additional recommended knowledge

Essential Laboratory Skills Guide

Daily Visual Balance Check

Daily Sensitivity Test

It can be used to test for narcolepsy, to distinguish between physical tiredness and true excessive daytime sleepiness, or to see if breathing disorder treatments are working. Its main purpose is to serve as an objective measure of sleepiness.

The test consists of four or five, twenty minute naps that are scheduled about two hours apart. The test is often done following an overnight sleep study. During the test things such as the patient's brain waves, EEG, muscle activity and eye movements are monitored and recorded. The entire test normally takes about 7 hours.

The MSLT may also be used more extensively to test sleepiness in a number of other research and diagnostic protocols.

History

The Multiple Sleep Latency Test was created in 1977 by sleep pioneer William C. Dement and Mary Carskadon. ^[1]^,^[2]^,^[3]^,^[4] It developed out of repeating a project done in 1970 by Dr. Dement called the 90-minute day.^[5] They informally called the 0-5 score range the twilight zone due to its indication of extreme physical and mental impairment.

Typical procedure

Preparation: On the day of the test the patient is asked to not take any stimulants such as tea, coffee, colas and chocolate.

Often a formal sleep study is done the night before.
Sometimes urine screening is done to make sure no substances exist in the subjects body that might interfere with sleep.
Patient may be asked to fill out a pre-test questionnaire
Electrodes are attached to the patient's head to record brain waves
Electrodes are attached by the eyes to record eye movement
Electrodes are attached to the chin to detect muscle tone
Heart beat may also be monitored
Patients are asked to perform simple tasks to test that the equipment is working properly
The patient is asked to nap for 20 minutes after which they are awoken
Nap process is repeated every two hours 4 or 5 times.
Patient may be asked to fill out a post test questionnaire

A neurologist or sleep specialist will review the results and inform the patient of the outcome.

References

^ Carskadon, M.A. and Dement, W.C. Sleep tendency: an objective measure of sleep loss. Sleep Research 6: 200, 1977.
^ Richardson GS, Carskadon MA, Flagg W, Van den Hoed J, Dement WC, Mitler MM. Excessive daytime sleepiness in man: multiple sleep latency measurement in narcoleptic and control subjects. Electroencephalogr Clin Neurophysiol. 1978 Nov;45(5):621–627.
^ Carskadon MA, Dement WC, Mitler MM, Roth T, Westbrook PR, Keenan S: Guidelines for the Multiple Sleep Latency Test (MSLT): a standard measure of sleepiness. Sleep 1986; 9:519–524
^ Thorpy MJ, Westbrook P, Ferber R, Fredrickson P, Mahowald M, Perez-Guerra F, Reite M, Smith P: The clinical use of the Multiple Sleep Latency Test. Sleep 1992; 15:268–276.
^ Carskadon, M.A. and Dement, W.C. Sleep studies on a 90-minute day. Electroencephalogr. Clin. Neurophysiol. 39: 145-155, 1975.

Category: Sleep

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Multiple_Sleep_Latency_Test". A list of authors is available in Wikipedia.