Sleep Diagnostic Studies
If you feel tired despite getting enough sleep or frequently wake feeling unrested, your SSM Health physician may order a sleep study to determine if you have a sleep disorder. Most sleep disorders can be easily treated, so a proper diagnosis can greatly improve your quality of life.
Types of Sleep Studies
SSM Health utilizes several sleep tests to diagnose sleep disorders.
- Sleep Apnea Evaluation or Polysomnogram
- Multiple Sleep Latency Test
- Maintenance of Wakefulness Test
Sleep Apnea Evaluation/Polysomnogram
The polysomnogram, or overnight sleep study, is the most common test utilized to analyze your sleep. The polysomnogram consists of at least 13 sensors that monitor different aspects of your sleep.
During the overnight sleep study, the sleep technician will count the number of times you stop breathing or demonstrate shallow breathing during your sleep. If that number is five events per hour or more, you may have sleep apnea. If you demonstrate moderate to severe sleep apnea during the initial part of the study, the technician will come into your room and start nasal Continuous Positive Airway Pressure (CPAP) therapy. During the remaining portion of the study, the technician will adjust the air pressure setting on the CPAP until the sleep apnea is treated.
Multiple Sleep Latency Test
The Multiple Sleep Latency Test (MSLT) is used to measure the time it takes from the start of a daytime nap period to the first signs of sleep. The test is based on the idea that the sleepier people are, the faster they will fall asleep.
It can be used to test for narcolepsy, to distinguish between physical tiredness and true excessive daytime sleepiness, or to see if sleep disorder treatments are effective. Its main purpose is to serve as an objective measure of sleepiness.
The test consists of four or five, 20-minute nap opportunities that are scheduled about two hours apart. The test is often done following an overnight sleep study and is performed in the same room as the overnight study. During the test, things such as brain waves, EEG, muscle activity and eye movements are monitored and recorded. Between naps, you are allowed to walk around the sleep lab, or watch TV in the room. The entire test typically takes about 7 hours.
Maintenance of Wakefulness Test
The Maintenance of Wakefulness Test (MWT) is used to measure how alert you are during the day. It shows whether or not you are able to stay awake for a defined period of time. This is an indicator of how well you are able to function and remain alert in quiet times of inactivity. The test consists of four 40-minute sessions in one of the sleep center bedrooms. You are asked to stay awake while the lights are very dim.
The MWT is used to see how well a sleep disorder patient is able to stay awake after starting treatment. It can also be used to help judge whether a patient is too tired to drive or perform other daily tasks. Sometimes the Federal Aviation Administration or Department of Transportation will require passing this test before a specialized license can be issued.
Restful sleep is critical to your overall health. Schedule an appointment with your SSM Health provider if you experience the symptoms of a sleep disorder. The sooner you have an accurate diagnosis, the sooner you can feel better and improve your quality of life.