Diagnostic Polysomnogram (PSG): The PSG is the most common sleep study. The PSG monitors and records; EEG (brain waves that show what stage of sleep), EKG (heart/cardiac monitor), EMG (muscle activity including leg movements), airflow from the nose and mouth, breathing effort, body position, eye movements, chin muscle tension and oxygen levels during sleep. This study is used to determine if you have Obstructive Sleep Apnea (OSA) and/or other sleep disorders like RLS/PLMS (kicking at night), parasomnias (sleepwalking or RBD acting out of dreams), and other (more rare) sleep disorders.
Polysomnogram w/PAP Titration: The CPAP (or BiPAP or ASV) titration study is the second study for those patients with OSA. It’s mostly the same as a diagnostic PSG but adding a CPAP mask and machine that provides gentle positive air pressure. The air pressure is gradually raised (titrated) until OSA and usually snoring is eliminated.
Multiple Sleep Latency Test (MSLT): An MSLT is typically for patients with excess daytime fatigue and/or possible narcolepsy or other non-apnea sleep disorders. A diagnostic PSG is followed by four to five 20 minute naps spaced 2 hours apart. It’s used to measure a person’s excessive daytime sleepiness and is the diagnostic test for narcolepsy.
Maintenance of Wakefulness Test (MWT): The MWT begins with a PSG followed by a full day at the sleep lab to monitor a person’s ability to stay awake.