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Sleep Medicine Services

Maintenance Wakefulness Test (MWT)

The following MWT protocol should be adhered to by patients:

  • The MWT will be performed immediately following polysomnography recorded during the patient’s major sleep period.
  • The MWT consist of four 40 minute trials performed at two hours intervals, with the first trial beginning about 1.5 to 3 hours after the patient’s usual wake-up time.  You may expect to complete the final trial between 5 and 6 p.m.
  • The sleep technician will place electrodes on the scalp, left and right eye, chin, and heart for the recording.
  • Drug screening is usually performed on the morning of the MWT.
  • The use of tobacco, caffeine and other medications by the patient before and during the MWT should be discussed with the sleep physician.
  • A light breakfast will be provided at least one hour prior to the first trial, and a light lunch will be provided immediately after the termination of the noon trial.
  • The room should be maximally insulated from external light and a dim light source behind the patient’s head and out of his or her view should be used.
  • The patient should be seated in bed, with the back and head supported by a bed rest (bolster pillow) such that the neck is not uncomfortably flexed or extended.
  • Prior to each trial, the patient should use the restroom if necessary and make other adjustments for comfort.
  • The patient will be given standard instructions for bio-calibrations prior to each nap: 1) lie quietly with your eyes open for 30 seconds, 2) close both eyes for 30 seconds, 3) without moving your head, look to the right and then left, 4) blind your eyes slowly five times, and 5) clench or grit your teeth tightly together.
  • With each nap opportunity, the patient will be instructed as follow:  “Please sit still and remain awake for as long as possible.  Look directly ahead of you, and do not look directly at the light.”
  • Patients are not allowed to use extraordinary measures to stay awake such as slapping the face or singing.
  • Trials are ended when sleep occurs or after 40 minutes if no sleep occurs.