Types of Sleep Testing:
A referring doctor may perscribe one or more of the following types of studies to determine the best course of treatment for a patient suffering from a sleep disorder.
NPSG (nocturnal polysomnogram) - is the standard overnight sleep study used to assess many sleep disorders including, sleep apnea, insomnia, RLS, periodic limb movements, etc This type of study measures several physiological signals including respiratory effort, EKG (electrocardiogram-heart), EEG (electroencephalogram-brain), muscle movement, snoring, and oxygen levels.
MSLT (multiple sleep latency test) - is a study performed during the day after a NPSG test to determine a patient's level of sleepiness after waking up from a night's sleep. This type of study is typically a series of 5 timed tests, two hours apart during which we examine whether a patient falls asleep, to what level of sleep, and how quickly. This type of test can be used to diagnose narcolepsy or excessive daytime sleepiness.
MWT (maintenance wakefulness test) - is a study performed to determine whether the patient is able to remain awake in a sleep induced environment. This test is useful in determining the efficay of a sleep disorder treatment.
EEG Sleep Recording - is an NPSG performed with full EEG (electroencephalogram) recording. This study can be used to detect nocturnal seizures and other sleep disorders.
RBD (REM sleep behavioral disorder) - is a modified NPSG test with electrodes added to the arms and legs to detect movement during REM (rapid eye movement) sleep during which the muscles are typically immobile.
NPSG with End Tidal CO2 - is a modified NPSG test with the use of CO2 monitoring. This is a useful addition to a standard test which can detect conditions of obesity hypoventilation and Hypercapnia (CO2 retention).
CPAP Titration (continuous positive airway pressure) - a therapuetic study used to typically treat obstructive sleep apnea syndrome (OSAS). This study determines the variety of airway pressures that are most effective in eliminating sleep apneic events and also snoring.
Split Study - is a study which combines a 4 hour diagnostic test (NPSG type) and a 4 hour therapeutic test (CPAP) in the same night. This study enables patients with severe obstructive sleep apnea syndrome to be treated immediately.
Bi-Level Titration - is an alternative to a standard CPAP study used to treat patients that have high severe obstructive sleep apnea syndrome. Pressures are varied both on the inhalation and exhalation cycle which enables certain patients to breathe more comfortably during night sleep.