A sleep study is a test that is used to diagnose various sleep disorders, especially sleep apnea. It can be used to diagnose other sleep related disorders including periodic limb movements, parasomnias and also nocturnal seizures. Occasionally, sleep study at night is followed by daytime study called Multiple Sleep Latency Test (MSLT) used to diagnose narcolepsy.
Polysomnogram is an in-lab sleep study, that is done in the lab at the sleep center. In appropriate patients, home sleep study could be also be considered.
During the sleep study at the sleep center, you will be asked to arrive in the late evening. The room is usually like hotel room and has a separate bathroom. Technologist will apply electrodes on scalp, chest and legs using adhesive. These electrodes are connected by wires to computer. Electrodes on the scalp record brain wave activity. Others will record eye movement, muscle tone in your chin, heart rate, breathing movement, chest and abdominal movements that happen with breathing, and limb movements. A small clip will be placed on your finger or ear to monitor level of oxygen in your blood. The technologist will monitor recording during the study. If CPAP study is ordered, the technologist will put a mask and start trial of cpap.
After the study, the technologist will remove all the electrodes and you can leave the center. The data will further be analyzed by the sleep technologist and the sleep physician.
Sleep study is a noninvasive painless study. Occasionally skin irritation could be caused by the adhesive used to attach sensors on your skin.
You might be advised to avoid caffeine, taking naps in afternoon or to avoid other drinks or foods that can interfere with your sleep at night. Occasionally you might be advised to not take certain medications. Do not apply lotions, gels, colognes or sprays that can interfere with application of electrodes.