A polysomnogram is a sleep study which records a full night’s sleep, including your brain waves, heartbeat, breathing, and the movement of your limbs while sleeping. A polysomnogram usually includes:
- Electroencephalogram (EEG) which monitors brain waves
- Electro-oculogram (EOG) which monitors eye movements
- Electromyogram (EMG) monitors muscle activity
- Measurement of airflow through the nose and mouth
- Measurement of chest and abdominal movement
- Audio recording of snoring activity
- Video monitoring the patient during the sleep study
A CPAP Study establishes the correct equipment levels for CPAP therapy used to treat sleep apnea. CPAP stands for continuous positive airway pressure. If a patient shows signs of severe sleep apnea during their overnight sleep study, a CPAP study may be done the same night. This will determine the level of air pressure needed to prevent the collapse of the upper airway due to sleep apnea.
CPAP machines are designed to maintain enough air pressure to keep a patient’s airway open and allow them to sleep.
A BiPAP machine is a breathing apparatus that helps patients get more air into their lungs. BiPAP stands for bilevel positive airway pressure. A BiPAP machine allows one pressure to be set for inhaling and another for exhaling. A sleep physician determines whether or not a patient needs a CPAP or a BiPAP based on the type of sleep apnea and its severity. These machines are especially helpful for patients with neuromuscular disease, congestive heart failure, and lung disorders. Some BiPAP machines even adjust therapy levels while the patient sleeps to ensure they are receiving optimum air pressure for a comfortable, successful sleep experience.
A Multiple Sleep Latency Test or MSLT is performed primarily to measure sleep latency which is basically how long it takes you to fall asleep. There is a wide range of what would be considered normal sleep latencies. Sleep physicians know when this test is necessary and are able to gather needed information to diagnose and treat patients. MSLTs are especially helpful in diagnosing excessive daytime sleepiness and narcolepsy.
An MSLT, if required, is performed the day after undergoing a polysomnogram. During the test you will have scheduled naps at intervals throughout the day that are monitored by a sleep technician. Many physiological parameters are also monitored while you sleep. These include breathing, oxygen levels, muscle tone, and eye and extremity movements. An EEG and EKG are also done during this test.