Maintenance of wakefulness test (MWT)

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A maintenance of wakefulness test or MWT is a study done to test the patients vigilance and ability to stay awake for extended periods during the day. This test is most commonly done for commercial drivers such as truck drivers, train drivers and those in occupations where sustained attention is vital.  

This may mean that your employer refers you to a sleep physician for this test if you are found to be high risk for a sleep disorder during a routine medical examination.

The test can involve a diagnostic sleep study the night before or your doctor may ask you to come to the sleep lab 90 minutes after waking up in the morning at home. During the MWT you will be asked to sit upright in bed (with the bed head positioned upright so that you are comfortable) and remain awake for 40 minutes in a dark quite room without any stimulation. This is done 4 times throughout the day at 2 hour intervals. If the patient falls asleep during the 40 minute trial, that trial is ended early and the time is recorded on the report. 

After the MWT the results of the test and management plan will be discussed with your sleep physician at your follow up appointment. If the patient falls asleep in multiple trials during the test, their sleep physician will likely recommend further testing for a sleep disorder and appropriate treatments for the day time sleepiness.