Parkinson’s Disease / 2012 / Article / Tab 1

Review Article

Bright Light Therapy in Parkinson's Disease: An Overview of the Background and Evidence

Table 1

Definitions of sleep terminology.


Sleep disturbanceSleep pattern divergent of what is considered to be normal as objectively measured, for example, by polysomnography.
Sleep disorderMedical disorder involving sleep, resulting in suffering or reduced functioning, including dyssomnias and parasomnias.
Sleep onset latencyTime interval between time of turning of the lights and onset of sleep.
Sleep efficiencyRatio of the time spent asleep to the amount of time spent in bed.
ChronotypeIndividual internal timing type regarding preferred time for mental and physical activity and sleep.
Homeostatic sleep driveDrive to sleep that gradually increases with prolonged wakefulness and decreases during sleep.
Sleep fragmentationDisrupted sleep cycle due to interruption of a sleep stage, as a result of the appearance of a lighter sleep stage or wakefulness.
Sleep phase advanceForward shift of the sleep/wake rhythm, as demonstrated by the time of the nocturnal elevation of plasma melatonin.
InsomniaSleep disorder comprising difficulty initiating and/or maintaining sleep or nonrestorative sleep for at least one month, resulting in significant distress and/or impaired daytime functioning
REM sleep behavior disorderParasomnia characterized by “acting out” of dreams during REM sleep due to absence of normally occurring muscle atonia.
Excessive daytime sleepinessParasomnia characterized by excessive sleepiness during the day, often with hypersomnia and the occurrence of sleep attacks.
Periodic limb movement disorderSleep disorder characterized by involuntary limb movements causing fragmented sleep.
Restless legs syndromeSyndrome characterized by unpleasant sensations in one or more limbs, exacerbated by rest and relieved with activity, paired with a strong urge to move the affected limbs, often with paresthesias or dysesthesias.