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Query: UMLS:C0015672 (fatigue)
 51,768 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study investigated the psychophysiological effects of sleep deprivation on auditory event-related potentials (AERPs) and their relationship with psychological parameters. Twenty-four subjects remained awake for 37 h under continuous surveillance. In the mornings and the evenings of 2 consecutive study days, AERPs were recorded and 4 self-rated scales (sleepiness, fatigue, anxiety, and mood) were quantified. The latencies of P300 and N200 were significantly prolonged (p < 0.001) and their amplitudes decreased (p < 0.05) as a consequence of sleep deprivation. However, the only significant change in N100 and P200 was an increase in the P200 amplitude (p < 0.05). The increase in the latencies of P300 and N200 were correlated with increased sleepiness (p < 0.05), and the increase in P200 amplitude was correlated with negative mood, anxiety, and fatigue (p < 0.05). Although the changes in P300 and N200 induced by sleep deprivation are due to sleepiness, which may slow cognitive processing and decrease the efficiency of mental processing, the increase in P200 may be related with increased anxiety, negative mood, and fatigue.
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PMID:Auditory event-related potentials and psychological changes during sleep deprivation. 1517 12

Electrocortical effects of long duration exercise on cognitive function were investigated by analyzing P300 amplitude and latency changes during a 3-h cycling exercise. P300 components were measured in 12 well-trained cyclists and blood glucose, cortisol, insulin, glycerol, and free fatty acids (FFAs) epinephrine and norepinephrine were analyzed. Results indicated that P300 components were affected by exercise with a temporary increase in amplitude between the 1st and the 2nd hour and an increase in latency after 2 h of exercise concomitant with some hormonal changes, including an increase in cortisol and epinephrine and a decrease in blood glucose. These findings suggest a combined effect of arousal and central fatigue on electrocortical indices of cognitive function during acute physical exercise.
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PMID:Effects of long duration exercise on cognitive function, blood glucose, and counterregulatory hormones in male cyclists. 1519 81

Whether mental performance is affected by slowly progressive moderate dehydration induced by water deprivation has not been examined previously. Therefore, objective and subjective cognitive-motor function was examined in 16 volunteers (8 females, 8 males, mean age: 26 yr) twice, once after 24 h of water deprivation and once during normal water intake (randomized cross-over design; 7-day interval). Water deprivation resulted in a 2.6% decrease in body weight. Neither cognitive-motor function estimated by a paced auditory serial addition task, an adaptive 5-choice reaction time test, a manual tracking test, and a Stroop word-color conflict test nor neurophysiological function assessed by auditory event-related potentials P300 (oddball paradigm) differed (P > 0.1) between the water deprivation and the control study. However, subjective ratings of mental performance changed significantly toward increased tiredness (+1.0 points) and reduced alertness (-0.9 points on a 5-point scale; both: P < 0.05), and higher levels of perceived effort (+27 mm) and concentration (+28 mm on a 100-mm scale; both: P < 0.05) necessary for test accomplishment during dehydration. Several reaction time-based responses revealed significant interactions between gender and dehydration, with prolonged reaction time in women but shortened in men after water deprivation (Stroop word-color conflict test, reaction time in women: +26 ms, in men: -36 ms, P < 0.01; paced auditory serial addition task, reaction time in women +58 ms, in men -31 ms, P = 0.05). In conclusion, cognitive-motor function is preserved during water deprivation in young humans up to a moderate dehydration level of 2.6% of body weight. Sexual dimorphism for reaction time-based performance is present. Increased subjective task-related effort suggests that healthy volunteers exhibit cognitive compensating mechanisms for increased tiredness and reduced alertness during slowly progressive moderate dehydration.
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PMID:Effect of water deprivation on cognitive-motor performance in healthy men and women. 1584 79

The aim of the present study was to establish the rate of fatigue and the relationship between fatigue, depression, and P300 in people with epilepsy. We compared Fatigue Severity Scale (FSS) and Beck Depression Inventory (BDI) scores and event-related potentials (ERPs) of people with epilepsy (n=73) with those of controls (n=31). The rate of fatigue was found to be 42.4%, and fatigue and depression were positively correlated. There was an interaction between fatigue and ERPs, but the effect of ERPs on fatigue was greater. While polytherapy was a major factor affecting ERPs, depression had no effect on ERPs in people with epilepsy. The data suggest that fatigue is an important finding and is strongly correlated with cognitive processes and depression. Polytherapy contributed to cognitive disturbances and, hence, fatigue, whereas depression had no effect on cognitive processes in people with epilepsy.
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PMID:The relationship between fatigue and depression, and event-related potentials in epileptics. 1651 27

To evaluate the value of visual and auditory P300 for predicting the response of multiple sclerosis-related fatigue to modafinil treatment, 33 patients were treated with 100 mg modafinil once daily for 4 weeks, following a 4-week baseline phase and an optional 8-week extension phase. The main clinical outcome parameter was a decrease in the fatigue visual analogue score (VAS) before and after 4 weeks of treatment. Patients with shorter auditory P300 latency at baseline were more likely to benefit from modafinil treatment. Auditory P300 latency predicted treatment response with a specificity of 76% and a sensitivity of 75% at a cut-off latency of 350 ms. Visual P300 latency could not be used to predict treatment response. Baseline auditory P300 latency predicted treatment response, whereas visual P300 latency did not. Clinical improvement did not correlate with changes in either visual or auditory P300.
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PMID:P300 and treatment effect of modafinil on fatigue in multiple sclerosis. 1713 67

It is well known that the amplitude and latency of P300 in event-related brain potentials (ERPs) evoked by performing the oddball paradigm reflect the extent of individuals' selective attention. The purpose of this study was to examine whether P300 is a reliable measure for evaluating mental fatigue. In addition to the measurement of auditory ERPs derived from Fz, Cz and Pz, the concentrations of lactic acid, cortisol in plasma and the reaction time of the oddball paradigm, which are believed to reflect fatigue, were measured. In an attempt to cause mental fatigue, 12 healthy college students (8 males, 4 females; 19.5 +/- 0.5 yr; mean +/- S.D.) were forced to perform a continuous addition task using the Uchida-Kreperin test paper for about 2 h. Before the task, the latencies of P300 in Fz, Cz and Pz were 295.6 +/- 8.7 msec, 298.8 +/- 8.5 msec and 297.5 +/- 7.2 msec (mean +/- S.D.), respectively, and after the task they were 312.6 +/- 11.2 msec, 314.6 +/- 10.1 msec and 315.8 +/- 8.7 msec, respectively. A significant difference in the latency before and after the task was detected (p<0.01). In all subjects, the latency of P300 was prolonged in all recording positions, Fz, Cz and Pz. In a control experiment where the continuous addition task was not loaded, a significant change of the latency was not detected. The amplitude of P300 didn't change significantly in all recording positions after the task. In the control experiment, the amplitude of P300 did not change significantly. On the other hand, the changes in the concentrations of lactic acid and cortisol and the reaction time were not induced by the continuous addition task. The prolongation of the latency of P300 would originate from a decline in brain function. In this study, a prolongation of the latency of P300 after the task was detected in all subjects. It is well known that the value of P300 changes with modification of the recording condition, therefore a recording of P300 under the same conditions is required for qualitative evaluation.
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PMID:[Effect of mental fatigue induced by repeated continuous calculation tasks on event-related brain potential (P300)]. 1793 59

We assessed daytime sleepiness using objective and subjective measures in women with severe premenstrual syndrome (PMS) compared with women without significant premenstrual symptoms. Nine women with severe PMS and eight controls (aged 18-40 years) completed a laboratory-based daytime protocol including the maintenance of wakefulness test (MWT), psychomotor vigilance task (PVT), quantitative waking electroencephalogram (EEG), auditory and visual event-related potentials (ERPs), and sleepiness and mood scales during the mid-follicular and late-luteal (premenstrual) phases of the menstrual cycle. In association with increased perceived sleepiness, fatigue and other premenstrual symptoms in the late-luteal phase, women with PMS performed more poorly on the PVT, with increased lapses and slower reaction times (P < 0.05), compared with the follicular phase and controls. However, there were no significant group or menstrual phase differences in latency to sleep on the MWT. Waking spectral EEG power and ERP measures also did not differentiate PMS women when symptomatic. Both groups of women displayed increased spectral power in the delta/theta frequencies (2-6 Hz) and fast alpha frequency (11-12 Hz) in the late-luteal phase relative to the follicular phase. Trait-like differences were apparent in that women with PMS had increased beta1 (12-16 Hz) power and smaller P300 amplitude than controls in both menstrual cycle phases. Our findings indicate that women with severe PMS are subjectively sleepy and fatigued, and show psychomotor slowing when symptomatic compared with when they are symptom-free and compared with controls. However, the ability to maintain wakefulness under soporific conditions, spectral properties of waking EEG and cognitive processing do not vary in synchrony with premenstrual symptoms.
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PMID:Daytime sleepiness, psychomotor performance, waking EEG spectra and evoked potentials in women with severe premenstrual syndrome. 1984 Feb 40

The post-lunch sleepiness is considered to be part of biological rhythm. Many people take nap as a countermeasure to this afternoon circadian nadir. The aim of the study is to investigate the effect of a short-term midday nap in different physical positions after a full night sleep on subjective and physiological measures. Thirty-six young healthy habitual nappers (18 men, 18 women) aged 18-23 participated in the study. They were randomly assigned to three experimental conditions: to nap in a seat (NS), to nap in a bed (NB) and no-nap (NN). Measures of subjective sleepiness, mood, fatigue, and P300 component were taken before and after a 20min nap. Results showed that sleepiness, fatigue, and mood for both NS and NB were improved after napping. Moreover, objective alertness was enhanced in NB relative to NS and NN, which showed the larger P300 amplitude after nap. The delta power during sleep stage 2 of NS was inferior to that of NB, which induced a lower alertness after the sitting nap. Consequently, the result demonstrated the function of delta wave during stage 2 on arousal level following the brief midday nap. In general, taking a nap in a seat is a way to subjective restoration but taking a nap in a bed benefits the habitual nappers subjectively and physiologically.
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PMID:Effects of physical positions on sleep architectures and post-nap functions among habitual nappers. 2006 78

The concept of burnout remains enigmatic since it is only determined by behavioral characteristics. Moreover, the differential diagnosis with depression and chronic fatigue syndrome is difficult. EEG-related variables in 13 patients diagnosed with burnout syndrome were compared with 13 healthy comparison subjects in order to explore the existence of neurobiological markers for burnout. Burnout patients showed reduced P300 amplitude, a lower alpha peak frequency and reduced beta power. These EEG-related differences in burnout patients differ from those described in the literature in depression and chronic fatigue patients. Our preliminary findings suggest that burnout might be considered as a separate clinical syndrome.
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PMID:EEG findings in burnout patients. 2046 15

A novel spatiotemporal filtering method for single trial estimation of event-related potential (ERP) subcomponents is proposed here. Unlike some previous works in ERP estimation [1], , the proposed method is able to estimate temporally correlated ERP subcomponents such as P3a and P3b. A new cost function is, therefore, defined which can deflate one of the correlated subcomponents. The method is applied to both simulated and real data and has shown to perform very well even in low signal-to-noise ratio situations. In addition, the method is compared to spatial principal component analysis and its superiority has been confirmed by using simulated signals. The approach can be especially useful in mental fatigue analysis where the relative variability of P300 subcomponents is the key factor in detecting the level of fatigue.
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PMID:A new spatiotemporal filtering method for single-trial estimation of correlated ERP subcomponents. 2092 28


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