The use of sleep studies in neurological practice

In recent years, sleep medicine has become a rapidly advancing field filled with exciting new discoveries. Many sleep disorders are diagnosed by clinical history alone. Sleep disorders such as sleep apnea, narcolepsy, periodic limb movement disorder, parasomnias, and nocturnal seizures usually require evaluation in the sleep laboratory. Sleep studies are used for diagnostic purposes, to assess disease severity, and to evaluate treatment efficacy. Sleep testing should be tailored to answer the specific clinical question at hand. This article reviews the techniques most commonly performed in the sleep laboratory and their indications, interpretation, and limitations. These include the polysomnogram, the multiple sleep latency test, and the maintenance of wakefulness test. The accurate interpretation of these studies requires a comprehensive sleep and medical history.