Sleep loss

The effects of chronic sleep deprivation or cumulative minor sleep losses have been relatively under investigated. Little is known about the relationships among the size of the sleep deficit, its rate of accumulation, the amount and timing of optimum recovery sleep, and their effect on human performance and productivity. 

If the change in cortical electrical characteristics is permanent, why don t seizures occur all the time This is probably because the occurrence of an individual seizure depends upon an interplay of environmental and internal brain factors which from time to time result in loss of the normal mechanisms that contain and control abnormal neuronal firing. Some common factors are sleep loss and fatigue, but it is impossible to determine what sets off a particular seizure in most patients. 

Figure 3.2 Schematic representation of the mechanism of increasing noradrenahne levels in the brain associated with REM sleep loss, and the putative role and mechanism of action of these increased levels in the induction of altered...

Baghdoyan, H. A. (2006). Hyperalgesia induced by REM sleep loss a phenomenon in search of a mechanism. Sleep 29, 137-9. 

Horne, J. A. (1993). Human sleep, sleep loss and behaviour implications for the prefrontal cortex and psychiatric disorder. Br. J. Psychiatry 162,... 

Disturbances of sleep are typical of mood disorders, and belong to the core symptoms of major depression. More than 90% of depressed patients complain of impaired sleep quality [60], Typically, patients suffer from difficulties in falling asleep, frequent nocturnal awakenings, and early morning awakening. Not only is insomnia a typical symptom of depression but, studies suggest, conversely, insomnia may be an independent risk factor for depression. In bipolar disorders sleep loss may also be a risk factor for the development of mania. Hypersomnia is less typical for depression [61] and, in contrast to insomnia, may be related to certain subtypes of depression, such as seasonal affective disorder (SAD). 

Answer Zolpidem is the best choice. M. W. s inability to sleep well is probably the result of anxiety caused by several stresses in her life. She is a recent college graduate, has a new job, and has moved to a new town. These events constitute three stressors, which can induce anxiety and sleep loss. The sleep loss and anxiety are usually of relatively short duration. Zolpidem has a quick onset and a half-life of approximately 2.5 hours. If taken at bedtime, it should allow her to fall asleep quickly and sleep though most or all of the night. Its elimination is fast enough that it should not produce residual drowsiness during the day. A week-long trial of zolpidem should help M. W. overcome her sleep disturbance. 

Although society tolerates this sleep is for sissies attitude, scientists and medical professionals are trying hard to educate the public that chronic sleep loss is a serious health issue. It may seem like just some heavy eyelids during class here and a yawn there, but sleep deprivation is indeed very dangerous. Not only does it cause us to be irritable and less tolerant (and perhaps less pleasant to be around), but it also hampers our creative and analytical thinking, physical performance (we run and swim better and lift more weight when we are well-rested), and often leads to health problems like increased susceptibility to colds and infections. 

The Walter Reed Army Institute of Research s Department of Behavioral Biology has developed a field-deployable version of a commercial Psychomotor Vigilance Task (PVT) that has been widely used in sleep research. The software runs on handheld PDAs running the Palm Operating System (Palm OS). It is modeled after the simple reaction time task of Wilkinson and Houghton,57 as modified by Dinges and Powell.58 The Palm OS version incorporates additional stimulus, feedback, control, and data options developed by Dr. Thome. In laboratory studies, performance on the PDA task has been shown to be sensitive to time-on-task fatigue effects, sleep deprivation, and circadian variation.18 Field studies have utilized the PVT to measure the efficacy of caffeine gum as a sleep loss countermeasure. 

MAO Inhibitors. In contrast to the tricyclics, MAO inhibitors tend to produce CNS excitation, which can result in restlessness, irritability, agitation, and sleep loss. These drugs also produce some central and peripheral anticholinergic effects (e.g., tremor, confusion, dry mouth, urinary retention), but these effects tend to occur in a lesser extent than with the tricyclics (see Table 7-3). Because of the systemic MAO inhibition, excess activity at peripheral sympathetic adrenergic terminals may cause a profound increase in blood pressure, leading to a hypertensive crisis. This situation is exacerbated if other drugs that increase sympathetic nervous activity are being taken... 

The MSLT has been utilized in many studies to examine the effects of sleep deprivation on daytime sleepiness. As described earlier, Carskadon and Dement (11) performed the first MSLT study to test the effects of two nights of sleep loss in six young subjects. The scores fell to about 1 min at 0600 on the first night of sleep loss and remained at similarly low values throughout the sleep loss period. After one night of recovery sleep the scores remained significantly below baseline levels, which were not achieved until after the second recovery night. 

The effect of sleep deprivation on different age groups has also been tested using the MSLT. Sleep loss in young adolescents was assessed by examining the effects of one night s sleep loss in 12 subjects whose ages ranged from 11.7 to 14.6 years. MSLTs showed a marked reduction of sleep-onset latency from 0530... 

Dinges DF. Probing the limits of functional capability the effects of sleep loss on short-duration tasks. In Broughton RJ, Ogilvie R, eds. Sleep, Arousal and Performance. Cambridge MA Birkhauser-Boston, 1992 176-188. 

Carskadon MA, Dement WC. Sleep tendency an objective measure of sleep loss. Sleep Res 1977 6 200. 

Carskadon, MA, Dement WC. Effects of total sleep loss on sleep tendency. Percept Mot Skills 1979 48(2) 495-506. 

Carskadon MA, Harvey K, Dement WC. Sleep loss in young adolescents. Sleepl981 4(3) 299-312. 

Psychomotor Vigilance Performance Neurocognitive Assay Sensitive to Sleep Loss... 

Finally, a cognitive performance assay used repeatedly during sleep deprivation should have high test-retest reliability it should be demonstrated to be sensitive to a large proportion of the performance phenomena associated with sleep loss and it should have the capacity to reflect aspects of real world performance (i.e., ecological validity). 

V. Theories of How Sleep Loss Affects Cognitive Functions... 

For approximately two decades, the lapse hypothesis was the dominant theoretical explanation for the effects of sleep loss on cognitive performance. In their seminal monograph, Williams, Lubin, and Goodnow (43) reported that performance lapses on experimenter-paced RT tasks increased with increasing hours of wakefulness, and that while poorest performance worsened, subjects were still able to perform at almost optimum levels between lapse periods. Thus, the longer subjects remained awake, the more variable their performance became. Importantly, this was observed regardless of the type (simple vs. choice) or duration (10 vs. 30 min) of RT task, and whether or not subjects were provided with performance feedback. 

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