- Neil Freedman, MD
Neil Freedman, MD
- Head, Division of Pulmonary, Critical Care, Allergy and Immunology
- North Shore University Health System
It is important to detect excessive sleepiness – defined as sleepiness that occurs in a situation when an individual would usually be expected to be awake and alert – because it is associated with morbidity and increased mortality, and can be treated in many cases . However, self-reported sleepiness is generally subjective and imprecise, which has led to the development of tests to quantify an individual's sleepiness [2-5].
The multiple sleep latency test (MSLT) and the maintenance of wakefulness test (MWT) use objective measures to quantify sleepiness. In contrast, the Epworth sleepiness scale (ESS) and Stanford sleepiness scale (SSS) subjectively quantify sleepiness. Other modalities used to assess sleepiness include the Oxford SLEep Resistance (OSLER) test and pupillometry.
Here, methods for quantifying sleepiness are described, and each of the tests used to quantify sleepiness is discussed. A general approach to the epidemiology, etiology, clinical features and evaluation of excessive daytime sleepiness is discussed separately. (See "Approach to the patient with excessive daytime sleepiness".)
The following definitions are important for understanding the discussion that follows:
●Epoch – An epoch is a standard 30-second interval of a polysomnogram (PSG) to which a sleep stage is assigned. In special situations, an epoch can be longer or shorter.
- Littner MR, Kushida C, Wise M, et al. Practice parameters for clinical use of the multiple sleep latency test and the maintenance of wakefulness test. Sleep 2005; 28:113.
- Kribbs N, Getsy J, Dinges D. Investigation and management of daytime sleepiness in sleep apnea. In: Sleeping and Breathing, Saunders N, Sullivan C (Eds), Marcel Dekker, New York 1993. p.575.
- Mitler MM, Miller JC. Methods of testing for sleepiness [corrected]. Behav Med 1996; 21:171.
- Sangal RB, Mitler MM, Sangal JM. Subjective sleepiness ratings (Epworth sleepiness scale) do not reflect the same parameter of sleepiness as objective sleepiness (maintenance of wakefulness test) in patients with narcolepsy. Clin Neurophysiol 1999; 110:2131.
- Sangal RB, Sangal JM, Belisle C. Subjective and objective indices of sleepiness (ESS and MWT) are not equally useful in patients with sleep apnea. Clin Electroencephalogr 1999; 30:73.
- Carskadon MA, Dement WC, Mitler MM, et al. Guidelines for the multiple sleep latency test (MSLT): a standard measure of sleepiness. Sleep 1986; 9:519.
- Zwyghuizen-Doorenbos A, Roehrs T, Schaefer M, Roth T. Test-retest reliability of the MSLT. Sleep 1988; 11:562.
- Thorpy MJ. The clinical use of the Multiple Sleep Latency Test. The Standards of Practice Committee of the American Sleep Disorders Association. Sleep 1992; 15:268.
- Lumley M, Roehrs T, Asker D, et al. Ethanol and caffeine effects on daytime sleepiness/alertness. Sleep 1987; 10:306.
- Carskadon MA, Dement WC. Nocturnal determinants of daytime sleepiness. Sleep 1982; 5 Suppl 2:S73.
- Levine B, Roehrs T, Stepanski E, et al. Fragmenting sleep diminishes its recuperative value. Sleep 1987; 10:590.
- Carskadon MA, Dement WC. Multiple sleep latency tests during the constant routine. Sleep 1992; 15:396.
- Richardson GS, Carskadon MA, Orav EJ, Dement WC. Circadian variation of sleep tendency in elderly and young adult subjects. Sleep 1982; 5 Suppl 2:S82.
- Strohl K, Bonnie R, Findley L, et al. Sleep apnea, sleepiness and driving risk. American Journal of Respiratory and Critical Care Medicine 1999; 150:1463.
- Wyatt JK, Cajochen C, Ritz-De Cecco A, et al. Low-dose repeated caffeine administration for circadian-phase-dependent performance degradation during extended wakefulness. Sleep 2004; 27:374.
- Clodoré M, Benoit O, Foret J, Bouard G. The Multiple Sleep Latency Test: individual variability and time of day effect in normal young adults. Sleep 1990; 13:385.
- Czeisler CA, Zimmerman JC, Ronda JM, et al. Timing of REM sleep is coupled to the circadian rhythm of body temperature in man. Sleep 1980; 2:329.
- International Classification of Sleep Disorders, 3rd ed, American Academy of Sleep Medicine, Darien, IL 2014.
- Aldrich MS, Chervin RD, Malow BA. Value of the multiple sleep latency test (MSLT) for the diagnosis of narcolepsy. Sleep 1997; 20:620.
- Goldbart A, Peppard P, Finn L, et al. Narcolepsy and predictors of positive MSLTs in the Wisconsin Sleep Cohort. Sleep 2014; 37:1043.
- Bonnet MH, Arand DL. Sleepiness as measured by modified multiple sleep latency testing varies as a function of preceding activity. Sleep 1998; 21:477.
- Bonnet MH, Arand DL. Arousal components which differentiate the MWT from the MSLT. Sleep 2001; 24:441.
- Bonnet MH, Arand DL. 24-Hour metabolic rate in insomniacs and matched normal sleepers. Sleep 1995; 18:581.
- Stepanski E, Zorick F, Roehrs T, et al. Daytime alertness in patients with chronic insomnia compared with asymptomatic control subjects. Sleep 1988; 11:54.
- Schneider-Helmert D. Twenty-four-hour sleep-wake function and personality patterns in chronic insomniacs and healthy controls. Sleep 1987; 10:452.
- Stepanski E, Zorick F, Roehrs T, Roth T. Effects of sleep deprivation on daytime sleepiness in primary insomnia. Sleep 2000; 23:215.
- Sangal RB, Thomas L, Mitler MM. Disorders of excessive sleepiness. Treatment improves ability to stay awake but does not reduce sleepiness. Chest 1992; 102:699.
- Hartse KM, Roth T, Zorick FJ. Daytime sleepiness and daytime wakefulness: the effect of instruction. Sleep 1982; 5 Suppl 2:S107.
- Mitler MM, Walsleben J, Sangal RB, Hirshkowitz M. Sleep latency on the maintenance of wakefulness test (MWT) for 530 patients with narcolepsy while free of psychoactive drugs. Electroencephalogr Clin Neurophysiol 1998; 107:33.
- Johns MW. A new method for measuring daytime sleepiness: the Epworth sleepiness scale. Sleep 1991; 14:540.
- Kendzerska TB, Smith PM, Brignardello-Petersen R, et al. Evaluation of the measurement properties of the Epworth sleepiness scale: a systematic review. Sleep Med Rev 2014; 18:321.
- Kapur VK, Baldwin CM, Resnick HE, et al. Sleepiness in patients with moderate to severe sleep-disordered breathing. Sleep 2005; 28:472.
- Hoddes E, Zarcone V, Smythe H, et al. Quantification of sleepiness: a new approach. Psychophysiology 1973; 10:431.
- Bennett LS, Stradling JR, Davies RJ. A behavioural test to assess daytime sleepiness in obstructive sleep apnoea. J Sleep Res 1997; 6:142.
- Rechtschaffen A, Kales A. A manual of standardized terminology: techniques and scoring system for sleep stages of human subjects, Brain Info. Serv./Brain Res. Int., UCLA; NIH Publ. 2040, Los Angeles, CA 1968.
- Priest B, Brichard C, Aubert G, et al. Microsleep during a simplified maintenance of wakefulness test. A validation study of the OSLER test. Am J Respir Crit Care Med 2001; 163:1619.
- Yoss RE, Moyer NJ, Hollenhorst RW. Pupil size and spontaneous pupillary waves associated with alertness, drowsiness, and sleep. Neurology 1970; 20:545.
- Lowenstein O, Feinberg R, Lowenfeld I. Pupillary movements during acute and chronic fatigue: a new test for the objective evaluation of tiredness. Invest Opthalmo 1963; 2:138.
- Wilhelm B, Wilhelm H, Lüdtke H, et al. Pupillographic assessment of sleepiness in sleep-deprived healthy subjects. Sleep 1998; 21:258.
- GENERAL APPROACH
- MULTIPLE SLEEP LATENCY TEST (MSLT)
- MAINTENANCE OF WAKEFULNESS TEST (MWT)
- EPWORTH SLEEPINESS SCALE (ESS)
- STANFORD SLEEPINESS SCALE (SSS)
- OSLER TEST
- SUMMARY AND RECOMMENDATIONS