A sleep study, also known as a polysomnogram (PSG), is an overnight test that records multiple streams of information to help doctors gauge how you sleep. The comprehensive and continuous recordings taken during the test include brain waves (EEG), oxygen saturation (SpO2), eye movements (EOG), respiratory effort, muscle activity (EMG) and heart rhythm (ECG). Based on the information from PSG sleep doctors are able to diagnose, or effectively rule out, many types of sleep disorders. Although the most common disorder seen is obstructive sleep apnea, we can also diagnose narcolepsy, hypersomnia, periodic limb movement disorder (PLMD), REM behavior disorder, and restless legs syndrome (RLS).
Once diagnosed with a sleep disorder, what are the next steps?
Once the test is completed, a registered sleep technician scores the entire study. The goal of the sleep study is to check for any sleep disorders that may be disturbing your sleep. We check and count all the breathing irregularities (called apneas, hypopneas, and respiratory-effort related arousals). Additionally we also count all the “Arousals” from sleep, cardiac rhythm abnormalities, leg movements, body position during sleep, and oxygen saturation during sleep. Once scored, the test recording and the scoring data is now completely reviewed usually by ABIM Sleep Medicine board-certified physicians.
The physician interpretation is done with the help of the patient’s medical history, a complete list of prescribed medications, and the sleep questionnaire provided. The doctor then writes a full report that is sent to your doctor. If you are diagnosed with sleep apnea your doctor can decide to start to on CPAP or have you come back for another sleep study to start on CPAP.