Maintenance of Wakefulness Test (MWT)

The ability to stay awake might be taken for granted until you are called on to perform a task that requires full alertness. This is true for individuals in the line of works as airline pilots and truck or school bus drivers. Sleepiness for such individuals can lead to accidents.

The Maintenance of Wakerfullness Test (MWT) is a useful test of your ability to stay awake during the day, a time that you are expected to stay awake. Sometimes the MWT is used to evaluate response to treatment in individuals with narcolepsy, for example, who are taking stimulants or wake promoting agents.

During the MWT, you would be asked to undergo 4 trials, each lasting 40 minutes at 2 hour intervals. During the trial you will be sitting in a room (typically inside the sleep lab) with no stimulation (TV, reading or music) and you will be asked to “stay awake”. The doctor will then read your MWT results and assess if and how fast you fall asleep to determine whether it is abnormal.

Typically, you would have undergone a sleep study the night before to make sure you got enough sleep and you don’t have a major sleep disorder such as sleep apnea. Some sleep labs perform drug screening to take into account any drug effect on the result of the study.

The results of the study are interpreted by a sleep medicine doctor to determine the degree of sleepiness.