Assessment of day time functioning as an index of the adequacy of sleep can be made with

(C) Multiple Sleep Latency Test # Evaluation of Daytime Sleepiness:> While clinical evaluation of the complaint of excessive sleepiness is usually adequate, objective quantification is sometimes necessary.> Assessment of daytime functioning as an index of the adequacy of sleep can be made with the multiple sleep latency test (MSL.T), which involves repeated measurement of sleep latency (time to onset of sleep) under standardized conditions during a day following quantified nocturnal sleep.> The average latency across four to six tests (administered every 2 h across the waking day) provides an objective measure of daytime sleep tendency.> Disorders of sleep that result in pathologic daytime somnolence can be reliably distinguished with the MSLT.> In addition, the multiple measurements of sleep onset may identify direct transitions from wakefulness to REM sleep that are suggestive of specific pathologic conditions (e.g., narcolepsy).