Sleep driving

The sleepiness associated with narcolepsy may result from impaired circadian influences (Broughton et al, 1998), particularly of the circadian alertness signal which contributes to the timing and consolidation of the sleep period (Dijk Czeisler, 1994 Edgar et al, 1993). Confirmatory data for this hypothesis was provided by Dantz et al. (1994), who, using a forced desynchrony protocol, showed that narcoleptic patients have a normal circadian pacemaker and homeostatic sleep drive, but a deficit in alertness associated with the circadian signal. Although results are more difficult to interpret in an animal with... 

The possibility that adenosine production was reduced or deficiently accumulated during wakefulness, which would explain the reduction in SWS, sleep fragmentation, and overall reduced sleep drive in the older animals, was also... 

Interaction of homeostatic sleep drive and endogenous circadian pacemaker Total sleep deprivation... 

VII. Sensitivity of PVT Performance to Neurobiological Causes of Elevated Sleep Drive... 

The theoretical and practical utility of any putative cognitive test of the effects of sleep deprivation must be grounded in its demonstrated sensitivity to known neurobiological sources of elevated sleep drive. The following sections review the sensitivity of the PVT to such factors. 

Changes in performance capability during continuous wakefulness can be conceptualized as a two-process interaction (33), derived from the two-process model of sleep regulation (54). Specifically, sleepiness and performance are influenced by the homeostatic sleep drive (producing monotonic increases in impairment) and by circadian rhythmicity (near 24-hr cycles) (33,58). Daily circadian modulation of neurocognitive performance has been consistently noted since the first studies of sleep deprivation and human performance (2,13). 

The interaction between endogenous circadian rhythmicity and homeostatic sleep drive results in a pattern in neurobehavioral functioning such that cognitive performance capability increases across the diurnal portion of each day (despite... 

As is well known, the sleep tendency at any moment is the net effect of the dynamic interplay of several factors. The main factors include homeostatic sleep drive, circadian influences on sleep propensity, and environmental and situational elements. Some investigators, e.g., Dinges and Kribbs (3), have categorized these factors as describing the state of sleepiness, adding that individual differences may also be important. 

Hoque R, Chesson AL Jr. Zolpidem-induced sleepwalking, sleep related eating disorder, and sleep-driving fluorine-18-flourodeoxyglucose positron emission tomography analysis, and a literature review of other unexpected clinical effects of zolpi-dem. J Clin Sleep Med 2009 5 471-6. 

Southworth MR, Kortepeter C, Hughes A. Nonbenzodiazepine hypnotic use and cases of sleep driving. Ann Intern Med 2008 148(6) 486-7. 

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