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Duan, Zhihao, Jinliang Xu, Han Ru y Menghui Li. "Classification of Driving Fatigue in High-Altitude Areas". Sustainability 11, n.º 3 (4 de febrero de 2019): 817. http://dx.doi.org/10.3390/su11030817.
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Driving fatigue is one of the main causes of traffic accidents. Thus, to prevent traffic accidents and ensure traffic safety, the properties of driving fatigue at the wheel must be determined. The Qinghai–Tibet Plateau in China is known for its high elevation, causing hypoxia, and presence of severely cold areas; all these easily lead to fatigue during driving. This, in turn, seriously affects the traffic safety on the high-altitude highway. Therefore, the factors leading to driving fatigue and the influence of high-altitude on driving fatigue affecting the driver must be further studied. In this study, we classified and quantified driving fatigue according to the driving fatigue degree. We determined three levels of driving fatigues (i.e., mild, moderate, and severe fatigues) to present their influence on drivers. Our study shows that in this high-altitude area, drivers became fatigued within a significantly shorter time.
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Palotai, Miklos, Michele Cavallari, Brian C. Healy y Charles RG Guttmann. "A novel classification of fatigue in multiple sclerosis based on longitudinal assessments". Multiple Sclerosis Journal 26, n.º 6 (23 de enero de 2020): 725–34. http://dx.doi.org/10.1177/1352458519898112.
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Background: Magnetic resonance imaging (MRI) studies of multiple sclerosis–related fatigue had limited reproducibility. Temporal fatigue fluctuations have not been considered. Objective: To investigate whether a novel group allocation that reflects temporal dynamics of fatigue improves our ability to detect fatigue-associated structural brain abnormalities. Methods: Patient stratification based on biennial fatigue assessments: sustained fatigue (SF, n = 29, fatigued at the latest ⩾2 assessments), one time-point fatigue (1F, n = 15, fatigued at the latest, but non-fatigued at the penultimate assessment), reversible fatigue (RF, n = 31, non-fatigued at the latest assessment, but reported fatigue previously), and never fatigued (NF, n = 54). Brain parenchymal fraction (BPF) and T2 lesion volume (T2LV) were compared between these groups and were derived using a conventional, single time-point fatigued versus non-fatigued stratification. Results: The SF versus NF stratification yielded improved power. SF ( p = 0.005) and RF ( p = 0.043) showed significantly higher T2LV than NF. T2LV showed no significant differences in SF versus 1F, SF versus RF, or 1F versus RF. Fatigued versus non-fatigued patients showed significantly higher T2LV ( p = 0.030). We found no significant differences in BPF between the groups. Conclusion: Taking into account temporal fatigue dynamics increases the statistical power with respect to T2LV and may improve characterization of brain pathological correlates of MS-related fatigue.
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Andreasen, AK, J. Jakobsen, T. Petersen y H. Andersen. "Fatigued patients with multiple sclerosis have impaired central muscle activation". Multiple Sclerosis Journal 15, n.º 7 (22 de mayo de 2009): 818–27. http://dx.doi.org/10.1177/1352458509105383.
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Background The pathogenesis of fatigue in multiple sclerosis (MS) is poorly understood. Objective To elucidate the role of central motor activation we hypothesized that patients with primary fatigue have impaired central motor function and increased fatigability as compared to secondary fatigued and non-fatigued patients. Methods Sixty patients with relapsing remitting MS and an Expanded Disability Status Scale score ≤ 3.5 were recruited and grouped as fatigued (Fatigue Severity Scale (FSS) ≥ 5.0) or non-fatigued (FSS ≤ 4.0). Nineteen patients were primary fatigued, 20 secondary fatigued and 21 non-fatigued. Maximal voluntary contraction, central activation and peripheral activation were determined by percutaneous twitch interpolation of the right quadriceps muscle. Results Maximal voluntary contraction was similar between groups but did relate to scores of fatigue. Peripheral activation was similar in all groups. Central activation was impaired in both groups of fatigued patients compared to non-fatigued patients being 0.96(0.05) in primary fatigued and 0.96(0.04) in secondary fatigued versus 0.99(0.1) in non-fatigued patients. The impairment of central motor activation was related to degree of fatigue in all patients. During fatiguing exercise there was a similar loss of strength, without any time differences between the three groups. Conclusion We conclude that impaired central motor activation is involved in MS-fatigue.
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Cauch-Dudek, K., S. Abbey, D. E. Stewart y E. J. Heathcote. "Fatigue in primary biliary cirrhosis". Gut 43, n.º 5 (1 de noviembre de 1998): 705–10. http://dx.doi.org/10.1136/gut.43.5.705.
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Background—Fatigue is a frequent and debilitating symptom in patients with primary biliary cirrhosis (PBC).Aims—To study fatigue in relation to sleep, depression, and liver disease severity.Methods—Patients with PBC completed validated self report questionnaires measuring fatigue, sleep quality, depression, and functional capacity. Verbally reported fatigue and observer rated measure of depression and ursodeoxycholic acid (UDCA) use were recorded. Liver biochemistry and tests to rule out metabolic causes of fatigue were performed.Results—Mean age of the 88 patients enrolled was 57 years; 86% were female and mean duration of disease was 6.6 years. Median bilirubin was 13 μmol/l (mean 18.6). Verbally reported fatigue (for more than six months) was present in 60 patients (68%). The self rated Fatigue Severity Score (FSS) correlated well with verbally reported fatigue (p=0.0001). The FSS did not correlate with age, duration of disease, serum bilirubin, Mayo Risk Score, or UDCA use, but correlation was seen with sleep quality. Fatigued patients had more sleep problems and higher depression scores than non-fatigued patients. Self rated depression was present in 28% (17/60) of fatigued compared with 4% (1/28) of non-fatigued patients.Conclusions—Long term fatigue affected 68% of the patients with PBC but it was not related to the severity of their liver disease. Poor sleep quality and depression were commonly associated with fatigue.
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Malekzadeh, Arjan, Wietske Van de Geer-Peeters, Vincent De Groot, Charlotte Elisabeth Teunissen, Heleen Beckerman y TREFAMS-ACE Study Group. "Fatigue in Patients with Multiple Sclerosis: Is It Related to Pro- and Anti-Inflammatory Cytokines?" Disease Markers 2015 (2015): 1–7. http://dx.doi.org/10.1155/2015/758314.
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Objective. To investigate the pathophysiological role of pro- and anti-inflammatory cytokines in primary multiple sclerosis-related fatigue.Methods. Fatigued and non-fatigued patients with multiple sclerosis (MS) were recruited and their cytokine profiles compared. Patients with secondary fatigue were excluded. Fatigue was assessed with the self-reported Checklist Individual Strength (CIS20r), subscale fatigue. A CIS20r fatigue cut-off score of 35 was applied to differentiate between non-fatigued (CIS20r fatigue≤34) and fatigued (CIS20r fatigue≥35) patients with MS. Blood was collected to determine the serum concentrations of pro-inflammatory cytokines (IL-1β, IL-2, IL-6, IL-8, IL-12p70, IL-17, TNFα, and IFN-γ) and anti-inflammatory cytokines (IL-4, IL-5, IL-10, and IL-13). We controlled for the confounding effect of age, gender, duration of MS, disease severity, type of MS, and use of immunomodulatory drugs.Results. Similar cytokine levels were observed between MS patients with(n=21)and without fatigue(n=14). Adjusted multiple regression analyses showed a single significant positive relationship, that of IL-6 with CIS20r fatigue score. The explained variance of the IL-6 model was 21.1%, once adjusted for the confounding effect of age.Conclusion. The pro-inflammatory cytokine interleukin-6 (IL-6) may play a role in the pathophysiology of primary fatigue in patients with MS.Trial Registrations.ISRCTN69520623,ISRCTN58583714, andISRCTN82353628.
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Martin, Tristan, Rosie Twomey, Mary E. Medysky, John Temesi, S. Nicole Culos-Reed y Guillaume Y. Millet. "The Relationship between Fatigue and Actigraphy-Derived Sleep and Rest–Activity Patterns in Cancer Survivors". Current Oncology 28, n.º 2 (10 de marzo de 2021): 1170–82. http://dx.doi.org/10.3390/curroncol28020113.
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Cancer-related fatigue can continue long after curative cancer treatment. The aim of this study was to investigate sleep and rest–activity cycles in fatigued and non-fatigued cancer survivors. We hypothesized that sleep and rest–activity cycles would be more disturbed in people experiencing clinically-relevant fatigue, and that objective measures of sleep would be associated with the severity of fatigue in cancer survivors. Cancer survivors (n = 87) completed a 14-day wrist actigraphy measurement to estimate their sleep and rest–activity cycles. Fatigue was measured using the Functional Assessment of Chronic Illness Therapy Fatigue Scale (FACIT-F). Participants were dichotomised into two groups using a previously validated score (fatigued n = 51 and non-fatigued n = 36). The participant’s perception of sleep was measured using the Insomnia Severity Index (ISI). FACIT-F score was correlated with wake after sleep onset (r = −0.28; p = 0.010), sleep efficiency (r = 0.26; p = 0.016), sleep onset latency (r = −0.31; p = 0.044) and Insomnia Severity Index (ISI) score (r = −0.56; p < 0.001). The relative amplitude of the rest–activity cycles was lower in the fatigued vs. the non-fatigued group (p = 0.017; d = 0.58). After treatment for cancer, the severity of cancer-related fatigue is correlated with specific objective measures of sleep, and there is evidence of rest–activity cycle disruption in people experiencing clinically-relevant fatigue.
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Moll, I., J. M. N. Essers, R. G. J. Marcellis, R. H. J. Senden, Y. J. M. Janssen-Potten, R. J. Vermeulen y K. Meijer. "Lower limb muscle fatigue after uphill walking in children with unilateral spastic cerebral palsy". PLOS ONE 17, n.º 12 (6 de diciembre de 2022): e0278657. http://dx.doi.org/10.1371/journal.pone.0278657.
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Fatigue during walking is a common complaint in cerebral palsy (CP). The primary purpose of this study is to investigate muscle fatigue from surface electromyography (sEMG) measurements after a treadmill-based fatigue protocol with increasing incline and speed in children with CP with drop foot. The secondary purpose is to investigate whether changes in sagittal kinematics of hip, knee and ankle occur after fatigue. Eighteen subjects with unilateral spastic CP performed the protocol while wearing their ankle-foot orthosis and scored their fatigue on the OMNI scale of perceived exertion. The median frequency (MF) and root mean square (RMS) were used as sEMG measures for fatigue and linear mixed effects model were applied. The MF was significantly decreased in fatigued condition, especially in the affected leg and in the tibialis anterior and peroneus longus muscle. The RMS did not change significantly in fatigued condition, while the OMNI fatigue score indicated patients felt really fatigued. No changes in sagittal kinematics of hip, knee and ankle were found using statistical non-parametric mapping. In conclusion, the current fatigue protocol seems promising in inducing fatigue in a population with CP with drop foot and it could be used to expand knowledge on muscle fatigue during walking in CP.
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Road, J., R. Vahi, P. del Rio y A. Grassino. "In vivo contractile properties of fatigued diaphragm". Journal of Applied Physiology 63, n.º 2 (1 de agosto de 1987): 471–78. http://dx.doi.org/10.1152/jappl.1987.63.2.471.
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The effects of fatigue on diaphragmatic contractility in vivo are unknown. In this study we used sonomicrometry to examine the velocity of shortening and lengthening and the amount of shortening in the fresh and fatigued canine hemidiaphragm (8 dogs) including the force generated. Fatigue was produced by epiphrenic stimulation of the left phrenic nerve; the right hemidiaphragm acted as the control. We found that 1) hemidiaphragmatic fatigue caused an increase in frequency with reduced tidal volume; 2) fatigue resulted in a near complete cessation of tidal shortening during spontaneous breathing; 3) there was an initial decrease in central activation (electromyogram) to the fatigued hemidiaphragm, an indication of central fatigue; 4) force-frequency curves showed a considerable and prolonged loss of the amount of shortening, velocity, and force generated by the fatigued hemidiaphragm during supramaximal stimulation, an indication of peripheral fatigue; and 5) during spontaneous breathing in the fatigued hemidiaphragm, tidal shortening remained reduced for up to 3 h, whereas in the right right hemidiaphragm tidal shortening and electromyographic activity did not change. We conclude that fatigue of a hemidiaphragm alters the spontaneous breathing pattern and produces profound modifications in its contractile properties without altering contralateral hemidiaphragmatic performance.
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Kumamoto, Tsuneo, Toshiaki Seko, Ryo Matsuda y Sayo Miura. "Repeated standing back extension exercise: Influence on muscle shear modulus change after lumbodorsal muscle fatigue". Work 68, n.º 4 (27 de abril de 2021): 1229–37. http://dx.doi.org/10.3233/wor-213452.
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BACKGROUND: In low back pain, multifidus muscle fibers reportedly exhibit increased stiffness. Low back pain was associated with lumbodorsal muscle fatigue. There is no report of using shear modulus to verify the mechanism of an immediate effect of exercise on low back pain. Here, temporary lumbodorsal muscle fatigue was created, simulating fatigue-related nonspecific low back pain. OBJECTIVE: To assess the effect of standing back extension exercise on fatigued lumbodorsal muscle based on the results of multifidus muscle elasticity measured using shear wave elastography. METHODS: Thirty-three healthy subjects were randomly divided into three groups. The subjects performed the Biering-Sorensen test as the fatigue-task of the lumbodorsal muscle before the standing back extension exercise. The fatigue-exercise group exercised five sets after completing the fatigue-task. The fatigue-non-exercise group remained standing for the same duration as the fatigue-exercise group without doing the exercise after the fatigue-task. The non-fatigue-exercise group exercised five sets of without performing the fatigue-task. As intra-group and inter-group factors, the shear modulus of the multifidus muscle was compared before and after the exercise. RESULTS: The shear modulus of the multifidus muscle after the standing back extension exercise was significantly lower in the fatigue-exercise group, and no significant decrease was observed in the fatigue-non-exercise and non-fatigue-exercise group. CONCLUSIONS: The standing back extension exercise improved the shear modulus of the fatigued multifidus muscle. Therefore, it was suggested that the change in the elasticity of fatigued muscle might lead to the prevention of low back pain caused by muscle fatigue.
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Barrios, Liliana, Rok Amon, Pietro Oldrati, Marc Hilty, Christian Holz y Andreas Lutterotti. "Cognitive fatigability assessment test (cFAST): Development of a new instrument to assess cognitive fatigability and pilot study on its association to perceived fatigue in multiple sclerosis". DIGITAL HEALTH 8 (enero de 2022): 205520762211177. http://dx.doi.org/10.1177/20552076221117740.
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Background Fatigue is a common symptom of many diseases, including multiple sclerosis. It manifests as a cognitive or physical condition. Fatigue is poorly understood, and effective therapies are missing. Furthermore, there is a lack of methods to measure fatigue objectively. Fatigability, the measurable decline in performance during a task, has been suggested as a complementary method to quantify fatigue. Objective To develop a new and objective measurement of cognitive fatigability and investigate its association with perceived fatigue. Methods We introduced the cognitive fatigability assessment test (cFAST), a novel smartphone-based test to quantify cognitive fatigability. Forty-two people with multiple sclerosis (23 fatigued and 19 non-fatigued, defined by the Fatigue Scale for Motor and Cognitive Functions) took part in our validation study. Patients completed cFAST twice. We used t-tests, Monte Carlo sampling, and area under the receiver operating characteristic curves to evaluate our approach using two sets of proposed metrics. Results When classifying fatigue, our fatigability metric Δresponse time has a mean area under the receiver operating characteristic curve of 0.74 (95% CI 0.64–0.84), making it the best performing metric for this task. Furthermore, Δresponse time shows a statistically significant difference between the fatigued and non-fatigued groups (t = 2.27, P = .03). Particularly, cognitively-fatigued patients decline in performance, while non-fatigued patients do not. Conclusions We introduce cFAST, a new instrument to quantify cognitive fatigability. Our pilot study provides evidence that cognitive fatigability assessment test produces a quantifiable drop in cognitive performance in a short period. Furthermore, our results indicate that cFAST may have the potential to serve as a surrogate for subjective cognitive fatigue. cFAST is significantly shorter than the existing fatigability assessments and does not require specialized equipment. Thus, it could enable frequent and remote monitoring, which could substantially aid clinicians in better understanding and treating fatigue.
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Stanzl-Tschegg, Stefanie E. "OS11W0385 Gigacycle fatigue and fatigue crack growth". Abstracts of ATEM : International Conference on Advanced Technology in Experimental Mechanics : Asian Conference on Experimental Mechanics 2003.2 (2003): _OS11W0385. http://dx.doi.org/10.1299/jsmeatem.2003.2._os11w0385.
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Sartain, S., M. McDonnell, M. Dingwall, C. Westoby, V. Katarachia, C. Davis, A. Heinson, S. Wootton y F. Cummings. "P359 Persistence of severe fatigue in adults with Crohn's disease in remission". Journal of Crohn's and Colitis 18, Supplement_1 (1 de enero de 2024): i764. http://dx.doi.org/10.1093/ecco-jcc/jjad212.0489.
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Abstract Background Fatigue is a frequent manifestation in patients with Inflammatory Bowel Disease (IBD), including those in remission. The persistence of fatigue over time in inactive disease is not well known. We aimed to determine the prevalence and continuation of severe fatigue at baseline and at 12 months follow-up in a cohort of patients with Crohn’s disease (CD) in remission. Methods Adult patients with CD in remission, defined by age ≥18 years, HBI <5 and faecal calprotectin <250mcg/g, were recruited to the INTICO2 observational study. Baseline assessment included SF36, FACIT-F and IBD Control patient-reported outcome measures. After 12 months in routine care, participants were invited to repeat FACIT-F. Severe fatigue was defined as scoring FACIT-F <30. Baseline data was analysed for factors associated with the persistence of severe fatigue at 12 months. Results A total of 198 patients were studied at baseline, of which 141 completed both baseline and 12-month assessments. The correlation between FACIT-F scores at baseline and 12 months was r = 0.79 (p < 0.001). Twenty-five (17.7%) patients were severely fatigued at both baseline and 12-month follow-up, and 99 (72.1%) were not severely fatigued at either time. Of the 34 patients severely fatigued at baseline, 9 (26.5%) were not severely fatigued at 12 months. From the 107 patients who were not severely fatigued at baseline, 12 (7.5%) became severely fatigued at 12 months. Participants with ongoing severe fatigue at baseline and 12 months had significantly worse SF36 Mental Health scores, 64 v 80 (p <0.001), and more night waking due to IBD, 32.0% v 7.1% (p = 0.011), at baseline assessment than those not severely fatigued at either assessment, see Table 1. Eight patients had a clinical disease flare during the 12-month follow-up period. Conclusion Most patients in this cohort in remission continued to have similar fatigue severity at 12-month follow-up. A higher proportion of severely fatigued patients at baseline improved at 12 months than non-severely fatigued patients at baseline developing severe fatigue at 12 months. Factors at baseline associated with persistent severe fatigue were worse mental health and poor sleep secondary to IBD. These may represent areas where intervention could improve reported fatigue levels in remission.
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Hernandez, Luis y Clayton Camic. "Fatigue-Mediated Loss of Complexity is Contraction-Type Dependent in Vastus Lateralis Electromyographic Signals". Sports 7, n.º 4 (2 de abril de 2019): 78. http://dx.doi.org/10.3390/sports7040078.
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The purpose of this study was to investigate the effect of fatigue status and contraction type on complexity of the surface electromyographic (sEMG) signal. Twelve females (mean age ± SD = 21.1 ± 1.4 years) performed three fatigue-inducing protocols that involved maximal concentric, eccentric, or isometric knee-extensor contractions over three non-consecutive sessions. Pre- and post-fatigue assessments were also completed each session and consisted of three maximal efforts for each type of contraction. Complexity of sEMG signals from the vastus lateralis was assessed using Sample Entropy (SampEn) and Detrended Fluctuation Analysis (DFA) as expressed using the scaling exponent α. The results showed that fatigue decreased (p < 0.05) sEMG complexity as indicated by decreased SampEn (non-fatigued: 1.57 ± 0.22 > fatigued: 1.46 ± 0.25) and increased DFA α (non-fatigued: 1.27 ± 0.26 < fatigued: 1.32 ± 0.23). In addition, sEMG complexity was different among contraction types as indicated by SampEn (concentric: 1.58 ± 0.22 > eccentric: 1.47 ± 0.27 and isometric: 1.50 ± 0.21) and DFA α (concentric: 1.27 ± 0.18 < isometric: 1.32 ± 0.18). Thus, these findings suggested sEMG complexity is affected by fatigue status and contraction type, with the degree of fatigue-mediated loss of complexity dependent on the type of contraction used to elicit fatigue.
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Calabrese, Massimiliano, Francesca Rinaldi, Paola Grossi, Irene Mattisi, Valentina Bernardi, Alice Favaretto, Paola Perini y Paolo Gallo. "Basal ganglia and frontal/parietal cortical atrophy is associated with fatigue in relapsing—remitting multiple sclerosis". Multiple Sclerosis Journal 16, n.º 10 (29 de julio de 2010): 1220–28. http://dx.doi.org/10.1177/1352458510376405.
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Background: Fatigue is one of the most frequent symptoms suffered by patients affected by multiple sclerosis. The patho-physiological basis of multiple sclerosis-related fatigue remains to be elucidated. Objective: Our aim was to investigate whether a particular pattern of deep and/or cortical grey matter atrophy is associated with fatigue in patients with multiple sclerosis. Methods: A total of 152 patients with relapsing—remitting multiple sclerosis were evaluated with the Expanded Disability Status Scale, the Fatigue Severity Status Scale (FSS), the Modified Fatigue Impact Scale and the Beck Depression Inventory. The thalamic and basal ganglia volume and the regional cortical thickness were analysed by means of FreeSurfer. Results: Based on Fatigue Severity Status Scale score, patients were divided into fatigued (FSS ≥ 4, 71 patients, 46.6%) and non-fatigued (FSS < 4, 81 patients, 53.4%). A significant atrophy of striatum, thalamus, superior frontal gyrus and inferior parietal gyrus was observed in fatigued patients compared with non-fatigued patients. The cognitive domain of Modified Fatigue Impact Scale significantly correlated with the volume of the striatum and with the cortical thickness of the posterior parietal cortex and middle frontal gyrus (R = 0.51—0.61), while the physical domain of Modified Fatigue Impact Scale significantly correlated with striatum volume and superior frontal gyrus cortical thickness (R = 0.50—0.54). Conclusions: The regional analysis of deep and cortical grey matter atrophy suggests an association between the neurodegenerative process taking place in the striatum—thalamus—frontal cortex pathway and the development of fatigue in relapsing—remitting multiple sclerosis. The inclusion of the posterior parietal cortex as one of the best predictors of the Modified Fatigue Impact Scale cognitive domain suggests the major role of the posterior attentional system in determining cognitive fatigue in relapsing—remitting multiple sclerosis.
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Veauthier, C., H. Radbruch, G. Gaede, CF Pfueller, J. Dörr, J. Bellmann-Strobl, K.-D. Wernecke, F. Zipp, F. Paul y JP Sieb. "Fatigue in multiple sclerosis is closely related to sleep disorders: a polysomnographic cross-sectional study". Multiple Sclerosis Journal 17, n.º 5 (28 de enero de 2011): 613–22. http://dx.doi.org/10.1177/1352458510393772.
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Background: Sleep disorders can cause tiredness. The relationship between sleep disorders and fatigue in patients with multiple sclerosis (MS) has not yet been investigated systematically.Objective: To investigate the relationship between fatigue and sleep disorders in patients with MS.Methods: Some 66 MS patients 20 to 66 years old were studied by overnight polysomnography. Using a cut-off point of 45 in the Modified Fatigue Impact Scale (MFIS), the entire cohort was stratified into a fatigued MS subgroup ( n = 26) and a non-fatigued MS subgroup ( n = 40).Results: Of the fatigued MS patients, 96% ( n = 25) were suffering from a relevant sleep disorder, along with 60% of the non-fatigued MS patients ( n = 24) ( p = 0.001). Sleep-related breathing disorders were more frequent in the fatigued MS patients (27%) than in the non-fatigued MS patients (2.5%). Significantly higher MFIS values were detected in all (fatigued and non-fatigued) patients with relevant sleep disorders (mean MFIS 42.8; SD 18.3) than in patients without relevant sleep disorders (mean MFIS 20.5; SD 17.0) ( p < 0.001). Suffering from a sleep disorder was associated with an increased risk of fatigue in MS (odds ratio: 18.5; 95% CI 1.6–208; p = 0.018).Conclusion: Our results demonstrate a clear and significant relationship between fatigue and sleep disorders.
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Chou, Yun-Jen, Kord M. Kober, Ching-Hua Kuo, Kun-Huei Yeh, Tien-Chueh Kuo, Yufeng J. Tseng, Christine Miaskowski, Jin-Tung Liang y Shiow-Ching Shun. "A Pilot Study of Metabolomic Pathways Associated With Fatigue in Survivors of Colorectal Cancer". Biological Research For Nursing 23, n.º 1 (22 de julio de 2020): 42–49. http://dx.doi.org/10.1177/1099800420942586.
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Background: Over 30% of cancer survivors experience chronic fatigue. An alteration in energy metabolism is one of the hypothesized mechanisms for cancer-related fatigue (CRF). No studies have evaluated for changes in metabolic profiles in cancer survivors with CRF. The purpose of this pilot study was to evaluate for differences in metabolic profiles between fatigued and non-fatigued survivors of colorectal cancer (CRC). Methods: Survivors were recruited from the surgical outpatient department and the oncology clinic of a medical center in northern Taiwan. Fatigue was assessed using the Fatigue Symptom Inventory. Fasting blood samples were collected on the day the fatigue questionnaire was completed. Metabolomic profile analysis was performed using non-targeted, liquid chromatography/time-of-flight mass spectrometry. Fold change analyses, t-tests, and pathway analyses were performed to identify differences in metabolomic profiles between the fatigued and non-fatigued survivors. Results: Of the 56 CRC survivors in this study, 28.6% (n = 16) were in the fatigue group. Statistically significant differences in carnitine, L-norleucine, pyroglutamic acid, pyrrolidonecarboxylic acid, spermine, hydroxyoctanoic acid, and paraxanthine were found between the two fatigue groups. In addition, two pathways were enriched for these metabolites (i.e., glutathione metabolism, D-glutamine and D-glutamate metabolism). Conclusions: Findings from this pilot study provide preliminary evidence that two pathways that are involved with the regulation of ATP production and cellular energy (i.e., glutathione metabolism, D-glutamine and D-glutamate metabolism) are associated with fatigue in CRC survivors. If these findings are confirmed, they may provide new therapeutic targets to decrease fatigue in cancer survivors.
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Penedo, Tiago, Paula Favaro Polastri, Sérgio Tosi Rodrigues, Felipe Balistieri Santinelli, Elisa de Carvalho Costa, Luis Felipe Itikawa Imaizumi, Ricardo Augusto Barbieri y Fabio Augusto Barbieri. "Motor strategy during postural control is not muscle fatigue joint-dependent, but muscle fatigue increases postural asymmetry". PLOS ONE 16, n.º 2 (25 de febrero de 2021): e0247395. http://dx.doi.org/10.1371/journal.pone.0247395.
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The aim of this study was to investigate the effects of ankle and hip muscle fatigue on motor adjustments (experiment 1) and symmetry (experiment 2) of postural control during a quiet standing task. Twenty-three young adults performed a bipedal postural task on separate force platforms, before and after a bilateral ankle and hip muscle fatigue protocol (randomized). Ankle and hip muscles were fatigued separately using a standing calf raise protocol (ankle fatigue) on a step and flexion and extension of the hip (hip fatigue) sitting on a chair, at a controlled movement frequency (0.5Hz), respectively. In both experiments, force, center of pressure, and electromyography parameters were measured. The symmetry index was used in experiment 2 to analyze the postural asymmetry in the parameters. Our main findings showed that muscle fatigue impaired postural stability, regardless of the fatigued muscle region (i.e., ankle or hip). In addition, young adults used an ankle motor strategy (experiment 1) before and after both the ankle and hip muscle fatigue protocols. Moreover, we found increased asymmetry between the lower limbs (experiment 2) during the quiet standing task after muscle fatigue. Thus, we can conclude that the postural motor strategy is not muscle fatigue joint-dependent and a fatigue task increases postural asymmetry, regardless of the fatigued region (hip or ankle). These findings could be applied in sports training and rehabilitation programs with the objective of reducing the fatigue effects on asymmetry and improving balance.
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Damasceno, Alfredo, Benito Pereira Damasceno y Fernando Cendes. "Atrophy of reward-related striatal structures in fatigued MS patients is independent of physical disability". Multiple Sclerosis Journal 22, n.º 6 (3 de agosto de 2015): 822–29. http://dx.doi.org/10.1177/1352458515599451.
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Background: MRI studies have shown gray-matter abnormalities in fatigued multiple sclerosis (MS) patients. However, given that physical disability is highly correlated to MS fatigue, it is often difficult to disentangle its effect in these MRI findings. Objective: The objective of this research paper is to investigate gray-matter damage in mildly disabled MS patients, addressing which variables were better related to fatigue while controlling for physical disability and depression. Methods: Forty-nine relapsing–remitting MS (RRMS) patients and 30 controls underwent MRI (3T). Fatigue was assessed using the Fatigue Severity Scale (FSS). Multivariate logistic regression was performed to assess the contribution of clinical and MRI metrics to fatigue. Statistical analyses were performed controlling for disability and depression. Results: Fatigue was present in 22 (44.9%) patients. FSS score was highly correlated with EDSS ( p = 0.00001). Patients with fatigue had lower brain cortical and subcortical gray-matter volumes. However, after controlling for EDSS, only the caudate and the accumbens volumes remained statistically significant. Conclusions: Fatigued MS patients have a global cortical and subcortical gray-matter atrophy that seems largely related to higher physical disability. However, striatal structures involved in effort-reward functions exhibited smaller volumes in fatigued patients, independently of physical disability and depressive symptoms, supporting the theory of cortico-striatal network impairment in MS fatigue.
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Demers, K., B. C. Bongers, D. M. A. E. Jonkers, M. J. Pierik y L. P. S. Stassen. "P478 Fatigue, physical fitness, and physical activity in patients with inflammatory bowel disease". Journal of Crohn's and Colitis 18, Supplement_1 (1 de enero de 2024): i958—i959. http://dx.doi.org/10.1093/ecco-jcc/jjad212.0608.
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Abstract Background Fatigue is a common and debilitating symptom in patients with Inflammatory Bowel Disease (IBD) with a great impact on quality of life and work productivity. A better comprehension of the contributing factors to fatigue could potentially pave the way for more targeted and effective strategies for managing fatigue in IBD. Fatigue may be associated with lower levels of physical activity and reduced physical fitness. Yet, the interaction between these factors in IBD, measured with validated tests, is not fully understood. Therefore, this study aimed to investigate the association between fatigue and physical fitness and physical activity in patients with IBD. Methods Adult patients with IBD in remission or with mild-to-moderate clinical disease activity with an ASA Physical Status <III were eligible for inclusion. Fatigue was defined as a Checklist Individual Strength-fatigue subscale score ≥35. Patient and clinical characteristics were collected, including age, sex, body mass index, comorbidities, disease duration, disease location and behavior, clinical and biochemical disease activity, smoking status, previous intestinal resection, and medication use. Cardiorespiratory fitness was measured using cardiopulmonary exercise testing to assess the oxygen uptake at peak exercise (VO2peak). Muscular strength (peak torque at 60°/s) and endurance (fatigue rate as percentage decline in peak torque over 30 repetitions at 180°/s) of the knee extensor and flexor muscles were assessed using an isokinetic dynamometer. Objective physical activity data were collected continuously for seven consecutive days utilizing the MOX accelerometer, with activities categorized into sedentary, standing, light (LPA), moderate (MPA), and vigorous physical activity (VPA) levels. Results In total, 50 patients were included, with 17 being classified as fatigued. Fatigued patients had significantly higher BMIs, a higher frequency of clinical disease activity, and a higher prevalence of smoking (Table 1). They also exhibited significantly lower VO2peak (mean [±SD] 28.1 [±7.9] vs. 36.0 [±9.8] mL·kg-1·min-1, p=0.007) and higher knee extensor fatigue rate (mean [±SD] 39.0% [±8.8] vs. 31.1% [±10.4], p=0.010) compared to non-fatigued patients. There was no statistical significant difference in physical activity between fatigued and non-fatigued patients. Conclusion Although physical activity did not differ between patients with and without fatigue, fatigued patients exhibited lower cardiorespiratory fitness and knee extensor muscular endurance. A larger population is needed to further investigate the influence of patient and disease characteristics on this relationship to work towards more targeted and effective strategies for managing fatigue in patients with IBD.
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Liu, Xinjing, Komal Kenkare, Shanshan Li, Varsha Desai, John Wong, Xun Luo, Lisa J. Wood, Yuming Xu y Qing Mei Wang. "Increased Th17/Treg Ratio in Poststroke Fatigue". Mediators of Inflammation 2015 (2015): 1–9. http://dx.doi.org/10.1155/2015/931398.
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Fatigue is a major debilitating symptom after stroke. The biological mechanisms underlying poststroke fatigue (PFS) are unknown. We hypothesized that PSF is associated with an alteration in the balance between Th17 and Treg cells. To test this hypothesis we assessed fatigue in 30 stroke survivors using the Fatigue Scale for Motor and Cognitive Functions (FSMC). Peripheral blood was collected for assessment of Th17 and Treg cell populations and measurement of interleukin-10 (IL-10). Participants were dichotomized into severe fatiguen=14and low-moderate fatiguen=16groups byK-mean cluster analysis of FSMC scores. There were no group differences in age, gender, stroke type, stroke severity, or time since stroke. Stroke survivors in the severe fatigue group reported greater anxietyp=0.004and depressionp=0.001than in the low-moderate fatigue group. The ratio of Th17 to Treg cells was significantly increased in the severe fatigue group relative to the mild-moderate fatigue groupp=0.035. Serum levels of IL-10 negatively correlated withTh17/Treg ratio (r=-0.408, p=0.025). Our preliminary findings suggest that an imbalance in the Th17/Treg ratio is associated with the severity of PSF.
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Griesbaum, M. G., T. Vogl, S. Andreu-Sánchez, S. Klompus, I. N. Kalka, S. Leviatan, H. M. van Dullemen et al. "P193 Fatigued patients with Inflammatory Bowel Disease exhibit distinct systemic antibody epitope repertoires". Journal of Crohn's and Colitis 18, Supplement_1 (1 de enero de 2024): i507—i508. http://dx.doi.org/10.1093/ecco-jcc/jjad212.0323.
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Abstract Background Patients with inflammatory bowel diseases (IBD) frequently experience fatigue, affecting up to 80% of those with active disease and approximately 50% with quiescent disease. The exact cause of IBD-associated fatigue is often unknown, making clinical management very challenging. In this study we aimed to explore whether patients with quiescent IBD reporting fatigue exhibit specific systemic antibody responses, which could provide insight into immune reactivities underlying fatigue. Methods Systemic antibody epitope repertoires were profiled in 327 patients with IBD (156 Crohn’s disease [CD]; 171 ulcerative colitis [UC]) leveraging phage-display immunoprecipitation sequencing (PhIP-Seq) against 344,000 rationally selected peptide antigens. Fatigue severity was assessed on a 10-point Likert scale, ranging from 1 (no fatigue) to 10 (highest fatigue severity). Quiescent IBD was defined as clinical (Harvey-Bradshaw Index [HBI] <5 or Simple Clinical Colitis Activity Index [SCCAI] <2.5) and biochemical remission (C-reactive protein [CRP] <5 mg/L) at time of sampling. Multivariable logistic regression analyses, allowing adjustment for potential confounding factors e.g. age, sex, and smoking, were performed to identify associations between fatigue and systemic antibody responses. Results A total of 105 different antibody-bound peptides were associated with fatigue (nominal P-value<0.05), albeit none passed adjustment for multiple comparisons. Among these antibodies, 50 (47.6%) were found to be less frequent in highly fatigued patients (fourth quartile, Q4), while 55 (52.4%) were identified as more frequent in highly fatigued patients compared to those with low fatigue scores (first quartile, Q1). Among highly fatigued patients, antibody responses were primarily directed towards viral antigens, notably several antigens from Epstein-Barr virus (EBV), as well as bacterial antigens, including functional proteins from Streptococcus and Staphylococcus species. Fatigued patients with CD exhibited elevated systemic antibody responses against allergens, Staphylococcus, Pseudomonas aeruginosa, and Shigella spp. Fatigued patients with UC showed higher frequencies of antibody responses against herpes simplex virus (HSV), influenza viruses, and few responses against allergens and Streptococcus bacteria. These results remained materially unchanged when repeating analyses in patients with quiescent IBD. Conclusion This study may suggest a potential role of viral antigens, particularly EBV, in the pathophysiology of fatigue in patients with IBD. However, larger confirmatory studies are needed to validate these findings. PhIP-Seq may represent a valuable strategy to approach the investigation of immune responses underlying complex symptoms such as fatigue.
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Borren, N., M. Long, J. van der Woude, R. Sandler y A. Ananthakrishnan. "P778 Longitudinal trajectory of fatigue in inflammatory bowel disease patients: a prospective study". Journal of Crohn's and Colitis 14, Supplement_1 (enero de 2020): S616—S617. http://dx.doi.org/10.1093/ecco-jcc/jjz203.906.
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Abstract Background Fatigue is a commonly reported and sometimes disabling symptom in patients with inflammatory bowel disease (IBD). Its prevalence, mechanism, and impact remain poorly understood. Using a large cohort of patients with IBD, we aimed to prospectively determine the trajectory of fatigue and to identify determinants and impact of incident and prevalent fatigue on patients with IBD. Methods This prospective study was nested within the IBD partners cohort, a validated internet-based cohort of patients with IBD. Participants were invited to prospectively complete questionnaires assessing fatigue status at baseline and subsequently after 6 and 12 months. Fatigue was assessed using the validated Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) score. A FACIT-F score of < 43 was defined as significant fatigue. We examined the trajectory and predictors of different courses of fatigue including incident fatigue (not fatigued as baseline but fatigued at 6 months) and resolved fatigue (fatigue at baseline but resolved on follow-up). Results A total of 2429 patients (1605 CD, 824 UC) completed baseline assessment among whom 1057 completed a second assessment at 6 months. First, we identified three distinct patterns of fatigue. Episodic fatigue defined as fatigue at any one (but not both) time point was the most common, affecting 1182 patients (57.0%). Persistent fatigue (at both baseline and follow-up) affected 33.5% (n = 695) while only 196 patients (9.5%) reported no fatigue at any time point (n = 196) (Figure). Patients that reported persistent or intermittent fatigue were more likely to have active disease (p < 0.001), be younger, (p < 0.001), report anaemia (p = 0.002) and low vitamin B12 levels (p < 0.001) and to have a prior diagnosis of depression, anxiety or sleep disorder (p < 0.001). Among patients who were not fatigued at baseline, 26% developed new fatigue at 6 months defined as incident fatigue). The strongest predictor of this being presence of sleep disturbance at baseline (OR 2.45, 95% CI 0.24–1.55) (Table). In contrast, only 12.3% of those with fatigue at baseline had symptom resolution by month 6. Resolution of fatigue was more common in those with UC (p = 0.03), quiescent disease at baseline (p = 0.006), not receiving biologic therapy at baseline (p = 0.016) and no sleep disturbance (p < 0.001), anxiety (p = 0.002) and depressive (p = 0.005) symptoms at baseline. Conclusion Our findings indicate three distinct trajectories of fatigue in patients with IBD with their distinct predictors. Importantly, 26% of patients developed new onset fatigue at 6 months demonstrating the substantial impact of this on patients with IBD.
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Asprusten, Tarjei Tørre, Maria Pedersen, Eva Skovlund y Vegard Bruun Wyller. "EBV-requisitioning physicians’ guess on fatigue state 6 months after acute EBV infection". BMJ Paediatrics Open 3, n.º 1 (febrero de 2019): e000390. http://dx.doi.org/10.1136/bmjpo-2018-000390.
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We assessed referring medical practitioner’s ability to predict chronic fatigue development in adolescents presenting with acute infectious mononucleosis. Compared with ‘not fatigued’ being predicted as ‘unsurely fatigued’ and ‘likely fatigued’ were both strongly associated with developing fatigue 6 months later (OR 2.5, 95% CI 1.16% to 5.47% and 3.2, 95% CI 1.19% to 8.61%, respectively, P=0.012). The positive and negative predictive values were 66% and 62%, respectively. Disentangling the physician’s intuition may be of interest in further investigations of risk factors and prophylactic factors for fatigue development.
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Contessa, Paola, Carlo J. De Luca y Joshua C. Kline. "The compensatory interaction between motor unit firing behavior and muscle force during fatigue". Journal of Neurophysiology 116, n.º 4 (1 de octubre de 2016): 1579–85. http://dx.doi.org/10.1152/jn.00347.2016.
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Throughout the literature, different observations of motor unit firing behavior during muscle fatigue have been reported and explained with varieties of conjectures. The disagreement amongst previous studies has resulted, in part, from the limited number of available motor units and from the misleading practice of grouping motor unit data across different subjects, contractions, and force levels. To establish a more clear understanding of motor unit control during fatigue, we investigated the firing behavior of motor units from the vastus lateralis muscle of individual subjects during a fatigue protocol of repeated voluntary constant force isometric contractions. Surface electromyographic decomposition technology provided the firings of 1,890 motor unit firing trains. These data revealed that to sustain the contraction force as the muscle fatigued, the following occurred: 1) motor unit firing rates increased; 2) new motor units were recruited; and 3) motor unit recruitment thresholds decreased. Although the degree of these adaptations was subject specific, the behavior was consistent in all subjects. When we compared our empirical observations with those obtained from simulation, we found that the fatigue-induced changes in motor unit firing behavior can be explained by increasing excitation to the motoneuron pool that compensates for the fatigue-induced decrease in muscle force twitch reported in empirical studies. Yet, the fundamental motor unit control scheme remains invariant throughout the development of fatigue. These findings indicate that the central nervous system regulates motor unit firing behavior by adjusting the operating point of the excitation to the motoneuron pool to sustain the contraction force as the muscle fatigues.
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Chung, Linda H., Damien M. Callahan y Jane A. Kent-Braun. "Age-related resistance to skeletal muscle fatigue is preserved during ischemia". Journal of Applied Physiology 103, n.º 5 (noviembre de 2007): 1628–35. http://dx.doi.org/10.1152/japplphysiol.00320.2007.
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During voluntary contractions, the skeletal muscle of healthy older adults often fatigues less than that of young adults, a result that has been explained by relatively greater reliance on muscle oxidative metabolism in the elderly. Our aim was to investigate whether this age-related fatigue resistance was eliminated when oxidative metabolism was minimized via ischemia induced by cuff (220 mmHg). We hypothesized that 1) older men ( n = 12) would fatigue less than young men ( n = 12) during free-flow (FF) contractions; 2) both groups would fatigue similarly during ischemia; and 3) reperfusion would reestablish the fatigue resistance of the old. Subjects performed 6 min of intermittent, maximal voluntary isometric contractions of the ankle dorsiflexors under FF and ischemia-reperfusion (IR) conditions. Ischemia was maintained for the first 3 min of contractions, followed by rapid cuff deflation and reperfusion for 3 additional minutes of contractions. Central activation, peripheral activation, and muscle contractile properties were measured at 3 and 6 min of contractions. Older men fatigued less than young men during FF ( P ≤ 0.02), ischemia ( P < 0.001), and reperfusion ( P < 0.001). During FF, activation and contractile properties changed similarly across age groups. At the end of ischemia, central ( P = 0.02) and peripheral ( P ≤ 0.03) activation declined more in the young, with no effect of age on the changes in contractile properties. Thus age-related fatigue resistance was evident during FF and IR, indicating that differences in blood flow and oxidative metabolism do not explain the fatigue resistance of old age.
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Buunk, A. M., F. F. Siebenga, M. C. A. Kramer, F. Gelens, F. Gelmers, S. E. Rakers, I. Bosma et al. "P01.08.B MENTAL FATIGUE IN PATIENTS WITH LOW-GRADE GLIOMA: ASSOCIATIONS WITH NEUROCOGNITIVE FUNCTIONING AND TUMOR CHARACTERISTICS". Neuro-Oncology 25, Supplement_2 (1 de septiembre de 2023): ii27—ii28. http://dx.doi.org/10.1093/neuonc/noad137.082.
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Abstract BACKGROUND Fatigue is a frequent consequence of low-grade glioma (LGG), but the causes are still barely understood. Specifically mental fatigue might be related to cognitive impairment such as mental slowness and decreased attention. Also, patients with greater tumor volumes or tumors in certain locations (such as the frontal cortex) might have more cognitive impairments and experience more fatigue. The aim of the present study was twofold: (1) to examine the relationship between mental fatigue and information processing speed and complex attention and (2) to investigate the associations between mental fatigue and tumor volume and location in patients with LGG. MATERIAL AND METHODS 124 patients with LGG (IDH mutated astrocytoma and oligodendroglioma grade 2 and 3) were included before the start of proton therapy. Different facets of fatigue, including mental fatigue, were measured after surgery, with a multidimensional fatigue scale, the Dutch Multifactor Fatigue Scale (DMFS). The Vienna Test System was used to examine simple information processing speed, response inhibition, and divided attention. Tumor location and tumor volume (radiation target volume) were scored on the pre-radiotherapy MRI scan. Descriptive statistics, Spearman’s correlations, and between group comparisons were performed. RESULTS 41% of patients with LGG reported severe mental fatigue. No significant differences were found in mean performance on simple information processing speed, response inhibition and divided attention between severely mental fatigued patients and non-severely mental fatigued patients. However, the percentage of patients with impaired divided attention was significantly higher in the severely mental fatigued group (39%) compared to the non-severely mental fatigued group (16.2%), χ2 = 7.6, p < 0.05. No significant relationships were found between mental fatigue and tumor volume and location. Also, tumor location was not related to neurocognitive functioning, but larger tumor volume was significantly associated with poorer performance on divided attention (r = -0.19, p < 0.05). CONCLUSION A high rate of mental fatigue was found in patients with LGG. Furthermore, a relationship between impaired divided attention and severe mental fatigue was found. This implies that patients may develop mental fatigue due to increased cognitive efforts to compensate for attentional deficits. This might be especially important in patients with larger tumors, considering the relationship between tumor volume and divided attention. The results stress the importance of neuropsychological assessment in this patient group before the start of adjuvant treatment, to timely offer individual rehabilitation.
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Andreasen, AK, E. Stenager y U. Dalgas. "The effect of exercise therapy on fatigue in multiple sclerosis". Multiple Sclerosis Journal 17, n.º 9 (5 de abril de 2011): 1041–54. http://dx.doi.org/10.1177/1352458511401120.
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Background: Fatigue occurs in the majority of patients with multiple sclerosis (MS) and therapeutic possibilities are few. Exercise therapy is a therapeutic option but no studies have systematically reviewed the existing literature evaluating the effect of exercise therapy on MS fatigue. Objective: To determine the effect of exercise therapy on MS fatigue by systematically reviewing the literature. Methods: A comprehensive literature search (PubMed, SweMed +, Embase, Cochrane, CINAHL, PEDro, Sport Discuss and Bibliotek.dk) was conducted. Results: Studies evaluating the effect of exercise therapy on MS fatigue show heterogeneous results and only few studies have evaluated MS fatigue as the primary outcome. The heterogeneous findings seem to be related to the selected study population, which in many studies are non-fatigued. Most studies that have included fatigued patients with MS show positive effects, although it is not clear whether any exercise modalities are superior to others because there are no comparative studies regarding different exercise interventions. Conclusion: Exercise therapy has the potential to induce a positive effect on MS fatigue, but findings are heterogeneous probably because many studies have applied non-fatigued study populations. Furthermore, only few studies have evaluated MS fatigue as the primary outcome measure, emphasizing the need for future studies within this field.
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Mao, Ping Li, Zheng Liu, Yang Li y Li Jia Chen. "Low Cycle Fatigue Behavior of As-Extruded AZ31 Magnesium Alloy". Materials Science Forum 686 (junio de 2011): 202–7. http://dx.doi.org/10.4028/www.scientific.net/msf.686.202.
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The investigation on fatigue behavior and fracture surfaces of fatigued specimens of as-extruded AZ31 magnesium alloy can provide a reliable theoretical foundation for both fatigue resistant design and reasonable application of magnesium alloys. Through total-strain-amplitude controlled fatigue tests and analysis on fracture surfaces of fatigued specimens, the behavior of cyclic stress response and fatigue life as well as fracture mechanism were identified for as-extruded AZ31 magnesium alloy. The experimental results show that the extruded AZ31 alloy exhibits significant cyclic strain hardening, the relation between elastic strain amplitude, plastic strain amplitude and reversals to failure can be described by Basquin and Coffin-Manson equations respectively. In addition, it has been found that fatigue cracks initiate and propagate in a transgranular mode.
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Luo, Ze Fu, Shi Ming Cui, Yan Zeng Wu y Qing Yuan Wang. "Super Long Life Fatigue Properties of Rail Steel U71Mn and U75V". Advanced Materials Research 690-693 (mayo de 2013): 1753–56. http://dx.doi.org/10.4028/www.scientific.net/amr.690-693.1753.
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Railway track steel, U71Mn and U75V were fatigued in this study, with the help of ultrasonic fatigue test system, to investigate the high cycle fatigue life behaviors. The results showed that the fatigue damage still occurs when the fatigue life exceeds 107, and the evolution of S-N curve showed a ladder type. This test showed that the traditional view of fatigue design and life prediction method were unable to meet the requirements of machinery and equipment working in gigacycle fatigue range, very high cycle fatigue behavior of fatigue has become a major challenge for researchers. The scanning electron microscope analysis of crack initiation was performed to clarify the mechanism of very high cycle fatigue failure.
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Jain, Saransh, Nuggehalli Puttareviyah Nataraja y Vijaya Kumar Narne. "The Effect of Subjective Fatigue on Auditory Processing in Musicians and Nonmusicians". Music Perception 39, n.º 3 (1 de febrero de 2022): 309–19. http://dx.doi.org/10.1525/mp.2022.39.3.309.
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We assessed fatigue's effect on temporal resolution and speech perception in noise abilities in trained instrumental musicians. In a pretest-posttest quasiexperimental research design, trained instrumental musicians (n = 39) and theater artists as nonmusicians (n = 37) participated. Fatigue was measured using a visual analog scale (VAS) under eight fatigue categories. The temporal release of masking measured the temporal resolution, and auditory stream segregation assessed speech perception in noise. Entire testing was carried out at two time-points: before and after rehearsal. Each participant rehearsed for five to six hours: musicians playing musical instruments and theater artists conducted stage practice. The results revealed significantly lower VAS scores for both musicians and nonmusicians after rehearsal, indicating that both musicians and nonmusicians were fatigued after rehearsal. The musicians had higher scores for temporal release of masking and lower scores for auditory stream segregation abilities than nonmusicians in the pre-fatigue condition, indicating musicians’ edge in auditory processing abilities. However, no such differences in the scores of musicians and nonmusicians were observed in the post-fatigue testing. The results were inferred as the music training related advantage in temporal resolution, and speech perception in noise might have been reduced due to fatigue. In the end, we recommend that musicians consider fatigue a significant factor, as it might affect their performance in auditory processing tasks. Future researchers must also consider fatigue as a variable while measuring auditory processing in musicians. However, we restricted the auditory processing to temporal resolution and speech perception in noise only. Generalizing these results to other auditory processes requires further investigation.
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Timmons, Shane y Ruth MJ Byrne. "Moral fatigue: The effects of cognitive fatigue on moral reasoning". Quarterly Journal of Experimental Psychology 72, n.º 4 (7 de mayo de 2018): 943–54. http://dx.doi.org/10.1177/1747021818772045.
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We report two experiments that show a moral fatigue effect: participants who are fatigued after they have carried out a tiring cognitive task make different moral judgements compared to participants who are not fatigued. Fatigued participants tend to judge that a moral violation is less permissible even though it would have a beneficial effect, such as killing one person to save the lives of five others. The moral fatigue effect occurs when people make a judgement that focuses on the harmful action, killing one person, but not when they make a judgement that focuses on the beneficial outcome, saving the lives of others, as shown in Experiment 1 ( n = 196). It also occurs for judgements about morally good actions, such as jumping onto railway tracks to save a person who has fallen there, as shown in Experiment 2 ( n = 187). The results have implications for alternative explanations of moral reasoning.
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Dominguese, David J., Jeff Seegmiller y B. Andrew Krause. "Alterations in Peak Ground-Reaction Force During 60-cm Drop Landings Caused by a Single Session of Repeated Wingate Anaerobic Tests". Journal of Sport Rehabilitation 21, n.º 4 (noviembre de 2012): 306–12. http://dx.doi.org/10.1123/jsr.21.4.306.
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Context:Lower extremity injury is prevalent among individuals participating in sports. Numerous variables have been reported as predisposing risk factors to injury; however, the effects of muscle fatigue on landing kinetics are unclear.Objectives:To investigate the effects of a single session of repeated muscle fatigue on peak vertical ground-reaction force (GRF) during drop landings.Design:Mixed factorial with repeated measures.Setting:Controlled laboratory.Participants:10 female and 10 male healthy recreational athletes.Intervention:Subjects performed 3 fatigued drop landings (60 cm) after four 20-s Wingate anaerobic tests (WATs) with 5 min of active recovery between fatigued conditions.Main Outcome Measures:Kinetic data of peak forefoot (F1) force, peak rear-foot (F2) force, and anteroposterior (AP) and mediolateral (ML) forces at both F1 and F2.Results:A significant main effect was observed in the nonfatigued and fatigued drop landings in respect to peak F2 force. The greatest significant difference was shown between the first fatigued drop-landing condition and the last fatigued drop-landing condition. No significant difference was observed between genders for all GRF variables across fatigue conditions.Conclusion:A single session of repeated conditions of anaerobic muscle fatigue induced by WATs caused an initial reduction in peak F2 force followed by an increase in peak F2 force across conditions. Muscle fatigue consequently alters landing kinetics, potentially increasing the risk of injury.
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Donnelly, Elizabeth A., Paul Bradford, Matthew Davis, Cathie Hedges, Doug Socha y Peter Morassutti. "Fatigue and Safety in Paramedicine". CJEM 21, n.º 6 (13 de agosto de 2019): 762–65. http://dx.doi.org/10.1017/cem.2019.380.
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ABSTRACTObjectivesExtant research has established an empirical relationship between fatigue and safety-related outcomes. It is not clear if these findings are relevant to Canadian paramedicine. The purpose of this study was to determine if fatigue and shiftwork variables were related to safety outcomes in Canadian paramedics.MethodsA survey was conducted with ten paramedic services in Ontario with a 40.5% response rate (n = 717). Respondents reported levels of fatigue, safety outcomes (injury, safety compromising behaviours, and medical errors/adverse events), work patterns (types of shifts, hours worked weekly) and demographic characteristics. Univariate and logistic regression analyses were used to assess for significant differences.ResultsIn this sample, 55% of paramedics reported being fatigued at work. Fatigued paramedics were over twice as likely to report injuries, three times as likely to report safety compromising behaviors, and 1.5 times more likely to report errors/adverse outcomes. When controlling for fatigue, shift length variables did not consistently influence safety outcomes.ConclusionThese results create preliminary evidence of a relationship between fatigue and safety outcomes in Canadian paramedicine. While more research is needed, these findings point to the influence fatigue has on safety outcomes and provide an indication that fatigue mitigation efforts may be worthwhile.
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Johansson, S., C. Ytterberg, K. Gottberg, L. Widén Holmqvist y L. von Koch. "Use of health services in people with multiple sclerosis with and without fatigue". Multiple Sclerosis Journal 15, n.º 1 (enero de 2009): 88–95. http://dx.doi.org/10.1177/1352458508095730.
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Objective To explore and compare the use of health services in people with multiple sclerosis (MS) with and without fatigue. Methods Over a period of 30 months, the use of health services in 48 MS outpatients with persistent fatigue and 36 without fatigue was studied. Data were collected from a computerized register and by interviews, and analyzed with regard to disease severity categorized as mild or moderate/severe MS. Results Fatigued people with mild MS used more hospital outpatient care and primary care including rehabilitation, and a higher proportion had transportation service, compared with non-fatigued people with mild MS. In moderate/severe MS, the differences were that non-fatigued people used more occupational therapy in primary care and a higher proportion had salaried service. Regardless of MS severity, informal care was more common among fatigued people. Conclusions Overall, fatigued people with mild MS have more contacts with outpatient health care compared with non-fatigued people. There are few such differences in people with moderate/severe MS. The reasons for the differences in use between fatigued and non-fatigued people are not understood and need further exploration. Fatigued people more often receive informal care, thus support to caregivers are of particular importance if fatigue is present.
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Prinsen, Hetty, Jolanda de Vries, Foekje Stelma, Sasja Mulder, Carla Van Herpen, Jan Willem Leer, Lammy Elving, Gijs Bleijenberg y Hanneke W. M. Van Laarhoven. "Humoral and cellular immune response after influenza vaccination in patients with postcancer fatigue and patients with chronic fatigue syndrome." Journal of Clinical Oncology 30, n.º 15_suppl (20 de mayo de 2012): 9070. http://dx.doi.org/10.1200/jco.2012.30.15_suppl.9070.
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9070 Background: Postcancer fatigue (PCF) is a frequently occurring problem, impairing quality of life. Patients with chronic fatigue syndrome (CFS) also suffer from severe fatigue symptoms. We hypothesized that in fatigued patients (PCF and CFS) alterations in immune response could explain fatigue symptoms. Therefore, we examined whether the humoral and/or cellular immune response after influenza vaccination differed between fatigued patients and non-fatigued individuals and between PCF and CFS patients. Methods: PCF (n=15) and CFS patients (n=22) were vaccinated against influenza. Age and gender matched non-fatigued cancer survivors (n=12) and healthy controls (n=23) were included for comparison. Antibody responses were measured at baseline and at day 21 by a hemagglutination inhibition test. T cell responses were measured at baseline and at day 7 by a lymphocyte proliferation and activation assay. Results: Both patient groups developed seroprotection rates comparable to the accompanying control groups. Functional T cell reactivity was observed in all groups. Proliferation at baseline was significantly lower in fatigued patients compared to non-fatigued individuals. A significant increase in proliferation from baseline to day 7 was observed in fatigued patients, but not in controls. At day 7, proliferation was not significantly different between fatigued patients and non-fatigued individuals. CD4+CD127-FoxP3+ expression was significantly higher in PCF patients compared to non-fatigued cancer survivors. Conclusions: We observed a lower T cell proliferation at baseline in fatigued patients compared to non-fatigued individuals, suggesting a difference in the baseline state of the immune system between fatigued patients and non-fatigued individuals. Furthermore, the difference in CD4+CD127-FoxP3+ expression between PCF and CFS patients suggests subtle differences in immune state between these two fatigued patient groups. However, since humoral and cellular immune responses after vaccination did not differ significantly between fatigued patients and non-fatigued individuals, vaccination of fatigued patients (PCF and CFS) can be effective.
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Tsivouraki, Niki, Konstantinos Tserpes y Ioannis Sioutis. "Modelling of Fatigue Delamination Growth and Prediction of Residual Tensile Strength of Thermoplastic Coupons". Materials 17, n.º 2 (11 de enero de 2024): 362. http://dx.doi.org/10.3390/ma17020362.
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Thermoplastic composites are continuously replacing thermosetting composites in lightweight structures. However, the accomplished work on the fatigue behavior of thermoplastics is quite limited. In the present work, we propose a numerical modeling approach for simulating fatigue delamination growth and predicting the residual tensile strength of quasi-isotropic TC 1225 LM PAEK thermoplastic coupons. The approach was supported and validated by tension and fatigue (non-interrupted and interrupted) tests. Fatigue delamination growth was simulated using a mixed-mode fatigue crack growth model, which was based on the cohesive zone modeling method. Quasi-static tension analyses on pristine and fatigued coupons were performed using a progressive damage model. These analyses were implemented using a set of Hashin-type strain-based failure criteria and a damage mechanics-based material property degradation module. Utilizing the fatigue model, we accurately foretold the expansion of delamination concerning the cycle count across all interfaces. The results agree well with C-scan images taken on fatigued coupons during interruptions of fatigue tests. An unequal and unsymmetric delamination growth was predicted due to the quasi-isotropic layup. Moreover, the combined models capture the decrease in the residual tensile strength of the coupons. During the quasi-static tension analysis of the fatigued coupons, we observed that the primary driving failure mechanisms were the rapid spread of existing delamination and the consequential severe matrix cracking.
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Townsend, Liam, David Moloney, Ciaran Finucane, Kevin McCarthy, Colm Bergin, Ciaran Bannan y Rose-Anne Kenny. "Fatigue following COVID-19 infection is not associated with autonomic dysfunction". PLOS ONE 16, n.º 2 (25 de febrero de 2021): e0247280. http://dx.doi.org/10.1371/journal.pone.0247280.
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Background The long-term clinical and physiological consequences of COVID-19 infection remain unclear. While fatigue has emerged as a common symptom following infection, little is known about its links with autonomic dysfunction. SARS-CoV-2 is known to infect endothelial cells in acute infection, resulting in autonomic dysfunction. Here we set out to test the hypothesis that this results in persistent autonomic dysfunction and is associated with post-COVID fatigue in convalescent patients. Methods We recruited 20 fatigued and 20 non-fatigued post-COVID patients (median age 44.5 years, 36/40 (90%) female, median time to follow up 166.5 days). Fatigue was assessed using the Chalder Fatigue Scale. These underwent the Ewing’s autonomic function test battery, including deep breathing, active standing, Valsalva manoeuvre and cold-pressor testing, with continuous electrocardiogram and blood pressure monitoring, as well as near-infrared spectroscopy-based cerebral oxygenation. 24-hour ambulatory blood pressure monitoring was also conducted, and patients completed the generalised anxiety disorder-7 questionnaire. We assessed between-group differences in autonomic function test results and used unadjusted and adjusted linear regression to investigate the relationship between fatigue, anxiety, and autonomic test results. Results We found no pathological differences between fatigued and non-fatigued patients on autonomic testing or on 24-hour blood pressure monitoring. Symptoms of orthostatic intolerance were reported by 70% of the fatigued cohort at the time of active standing, with no associated physiological abnormality detected. Fatigue was strongly associated with increased anxiety (p <0.001), with no patients having a pre-existing diagnosis of anxiety. Conclusions These results demonstrate the significant burden of fatigue, symptoms of autonomic dysfunction and anxiety in the aftermath of COVID-19 infection, but reassuringly do not demonstrate pathological findings on autonomic testing.
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Rzepka, Michalina, Mateusz Toś, Michał Boroń, Katarzyna Gibas y Ewa Krzystanek. "Relationship between Fatigue and Physical Activity in a Polish Cohort of Multiple Sclerosis Patients". Medicina 56, n.º 12 (21 de diciembre de 2020): 726. http://dx.doi.org/10.3390/medicina56120726.
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Background and objectives: Fatigue is one of the most common and disabling symptoms of multiple sclerosis (MS). It can be defined as a subjective lack of physical and mental energy. The aim of this study was to evaluate the frequency and severity of fatigue in patients with MS and its relationship with overall physical activity and disease-related disability. Materials and Methods: The study included 100 patients with a clinical relapsing-remitting form of MS. Patients with severe depression were excluded. Neurological impairment was rated using the Expanded Disability Status Scale (EDSS). Fatigue was assessed using the Modified Fatigue Impact Scale (MFIS) and the Fatigue Severity Scale (FSS), with FSS scores greater than 36 indicating patients with fatigue. Physical activity was evaluated with the International Physical Activity Questionnaire (IPAQ) and categorized on three levels: low, moderate, and high, using standard metabolic equivalents (MET). Results: The average FSS and MFIS scores were (mean ± SD) 31.3 ± 15.2 and 30.1 ± 17.0, respectively. The mean EDSS score was 2.5 ± 1.5. 42%. Patients were classified as fatigued based on FSS. Fatigued patients had higher mean EDSS scores than non-fatigued (3.0 ± 1.6 vs. 2.2 ± 1.4, respectively, p = 0.002). Low, moderate, and high levels of physical activity were reported in 35%, 20%, and 45% of patients, respectively. Higher scores of fatigue in FSS and MFIS were inversely correlated with the intensity of physical activity (r = −0.38, p < 0.001 and r = −0.33, p < 0.001, respectively). Conclusions: In patients with MS, fatigue is a common symptom. Patients with lower physical activity and greater MS-related disability have a higher severity of fatigue, which negatively affects cognitive, psychosocial, and physical functioning.
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Williams, Jay H., Christopher W. Ward, Espen E. Spangenburg y Reagan M. Nelson. "Functional aspects of skeletal muscle contractile apparatus and sarcoplasmic reticulum after fatigue". Journal of Applied Physiology 85, n.º 2 (1 de agosto de 1998): 619–26. http://dx.doi.org/10.1152/jappl.1998.85.2.619.
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This study examined the effects of fatigue on the functional aspects of the contractile apparatus and sarcoplasmic reticulum (SR). Frog semitendinosus muscles were stimulated to fatigue, and skinned fibers or a homogenate fraction was prepared from both fatigued and rested contralateral muscles. In fatigued fibers, maximal Ca2+-activated force of the contractile apparatus was unaltered, whereas maximal actomyosin-ATPase activity was depressed by 20%. The Ca2+ sensitivity of force was increased, whereas that of actomyosin-ATPase was not altered. Also, the rate constant for tension redevelopment was decreased at submaximal Ca2+ concentration. These latter findings suggest that fatigue slows the dissociation of force-generating myosin cross bridges. Ca2+ uptake and Ca2+-ATPase activity of the SR were depressed by 46 and 21%, respectively, in the fatigued muscles. Fatigue also reduced the rates of SR Ca2+ release evoked by AgNO3 and 4-chloro- m-cresol by 38 and 45%, respectively. During fatigue, the contractile apparatus and SR undergo intrinsic functional alterations. These changes likely result in altered force production and energy consumption by the intact muscle.
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Mgbekem, Mary A., Emilia J. Oyira, Regina Ella, Felicia Lukpata, Margaret Armon y Gabriel U. Ntamu. "Counseling fatigue of HIV/AIDS counselor in Calabar, Nigeria". Calabar Journal of Health Sciences 3 (4 de febrero de 2020): 16–24. http://dx.doi.org/10.25259/cjhs_6_2019.
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Objective: There is different perception of HIV/AIDS counselling fatique among counsellors of patients. This descriptive study assessed perceived HIV/AIDS counseling fatigue among HIV/AIDS counselors in Calabar, Nigeria. Materials and Methods: A total of 90 counselors were assessed using a 35-item questionnaire measuring a variety of counseling activities. Fatigue was ranked on a 5-point Likert-type scale. The counseling fatigue was categorized in five subscales: accessibility of clients for HIV Counseling and Testing (HCT), explains and facilitates, monitoring and follow through, trusting relationships, policies in counseling activities, and burnout responses. Results: The results showed that counselors’ perceptions on fatigue were mostly on accessibility of clients for HCT (Mean = 72.50, standard deviation [SD] = 6.124) with statistical significance of Chi-square calculated = 161.419, df = 5; P < 0.001, monitoring and follow through activities (mean = 71.80, SD = 11.23, Chi-square calculated = 31.223; df = 4; P < 0.001), and policies in counseling activities (mean = 66.0 SD = 9.62, (Chi-square calculated = 11.906, df = 6; P < 0.05). Explain and facilitate statistically and significantly correlated with age (r = 0.610, P = 0.000) and years of experience (r = 0.695, P = 0.000). Burnout responses were also statistically significant (Chi-square calculated = 144.000; df = 7; P < 0.001). Conclusion: Findings show HCT counseling activities generally cause fatigue for counselors, however, explain and facilitate counseling activities correlated with age (20–29 years) and years of experience (1–2 years) as these were found to be more fatigued among the participants. The years of experience correlation could be attributed to lack of formal HCT counseling training reported by 20 (20%). Further research is needed to explore counselors’ perceptions of HIV/AIDS counseling fatigue in different cultures.
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Borren, Nienke Z., William Tan, Francis P. Colizzo, Jay Luther, John J. Garber, Hamed Khalili, C. Janneke van Der Woude y Ashwin N. Ananthakrishnan. "Longitudinal Trajectory of Fatigue With Initiation of Biologic Therapy in Inflammatory Bowel Diseases: A Prospective Cohort Study". Journal of Crohn's and Colitis 14, n.º 3 (26 de agosto de 2019): 309–15. http://dx.doi.org/10.1093/ecco-jcc/jjz148.
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Abstract Backgrounds and Aims Fatigue is prevalent in patients with inflammatory bowel diseases [IBD]. Biologic therapy is effective in achieving symptomatic and endoscopic remission, but its impact on fatigue is less well established. Our aim is to define the longitudinal trajectory of fatigue over 1 year in patients initiating biologic therapy. Methods This prospective cohort enrolled patients diagnosed with Crohn’s disease [CD] or ulcerative colitis [UC] initiating biologic therapy with infliximab, adalimumab, ustekinumab, or vedolizumab. Fatigue was quantified using the seven-point fatigue question in the Short Inflammatory Bowel Disease Questionnaire [SIBDQ]. A score of ≤4 for this question was used to define fatigue. Multivariable regression models adjusting for relevant confounders examined the independent association between attaining clinical remission and resolution of fatigue. Results Our study included 326 patients [206 CD, 120 UC] initiating biologic therapy [144 anti-tumour necrosis factor, 129 vedolizumab, 63 ustekinumab]. A total of 61% of the included patients reported significant fatigue at baseline. This was associated with female gender, depressive symptoms, active disease, and disturbed sleep [p < 0.001]. Among the 198 patients who were fatigued at therapy initiation, 86 [70%], 55 [63%], and 44 [61%] remained fatigued at Week 14, 30, and 54, respectively. At each of these time points, achieving clinical remission was associated with lower likelihood of persistent fatigue. However, despite achieving remission, 35%, 30%, and 28% of patients experienced persistent fatigue at Week 14, 30, and 54, respectively. Conclusions Fatigue is common in IBD. Though biologic therapy improves fatigue parallel symptomatic improvement, a significant proportion continue to experience persistent fatigue up to 1 year.
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Jiang, Xinyue, Kanesan Muthusamy, Jian Chen y Xueliang Fang. "Scented Solutions: Examining the Efficacy of Scent Interventions in Mitigating Driving Fatigue". Sensors 24, n.º 8 (9 de abril de 2024): 2384. http://dx.doi.org/10.3390/s24082384.
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Fatigued driving threatens the safety of people’s lives and property. Scent countermeasures offer minimal disruption and high efficacy, making them a promising approach. The aim of this study was to explore the application of scent countermeasures in alleviating fatigued driving. This study explored changes in EEG frequency bands (alpha, beta, theta, and gamma) and the activity of EEG metrics (R(α/β), Rθ/(α+β) and R(α+θ)/(α+β)) in the temporal lobe during driving tasks, selected fatigued driving identifiers, and aided validation by investigating subjective fatigue with the Karolinska Sleepiness Scale (KSS). The EEG indicators all increased, with a significant increase in R(α/β). R(α/β) was combined with the KSS to explore the effects of three scents, peppermint, grapefruit, and lavender, on driving fatigue. The subjective questionnaire results indicated that all three scents significantly improved driving fatigue, with significantly lower levels of driving fatigue compared to the control group. The analysis of EEG signals revealed a significant decrease in R(α/β) after the implementation of scent countermeasures. Moreover, R(α/β) was found to be lower in all three odor intervention groups compared to the control group. All three scents were found to significantly alleviate driving fatigue. The grapefruit scent had a better timely effect in relieving driving fatigue and the lavender scent had a longer effectiveness. This study provides further exploration for the application of odor interventions to alleviate driving fatigue. This study provides a practical reference for drivers to use odors to avoid fatigue in order to improve road safety.
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Gobbi, C., MA Rocca, G. Riccitelli, E. Pagani, R. Messina, P. Preziosa, B. Colombo et al. "Influence of the topography of brain damage on depression and fatigue in patients with multiple sclerosis". Multiple Sclerosis Journal 20, n.º 2 (27 de junio de 2013): 192–201. http://dx.doi.org/10.1177/1352458513493684.
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Objectives: Involvement of selected central nervous system (CNS) regions has been associated with depression and fatigue in MS. We assessed whether specific regional patterns of lesion distribution and atrophy of the gray (GM) and white matter (WM) are associated with these symptoms in MS. Methods: Brain dual-echo and 3D T1-weighted images were acquired from 123 MS patients (69 depressed (D), 54 non-depressed (nD), 64 fatigued, 59 non-fatigued) and 90 controls. Lesion distribution, GM and WM atrophy were estimated using VBM and SPM8. Results: Gender, age, disease duration and conventional MRI characteristics did not differ between D-MS and nD-MS patients. Fatigued patients experienced higher EDSS and depression than non-fatigued ones. Lesion distribution and WM atrophy were not related to depression and fatigue. Atrophy of regions in the frontal, parietal and occipital lobes had a combined effect on depression and fatigue. Atrophy of the left middle frontal gyrus and right inferior frontal gyrus were selectively related to depression. No specific pattern of GM atrophy was found to be related to fatigue. Conclusions: Depression in MS is linked to atrophy of cortical regions located in the bilateral frontal lobes. A distributed pattern of GM atrophy contributes to the concomitant presence of depression and fatigue in these patients.
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Rinaldin, Carla D. P., Julia A. Oliveira, Caroline R. Souza, Daniel B. Coelho y Luis A. Teixeira. "Does footedness affect bilateral plantar flexor responses to sudden stance perturbations under unilateral lower leg muscular fatigue?" Brazilian Journal of Motor Behavior 17, n.º 5 (30 de septiembre de 2023): 186–92. http://dx.doi.org/10.20338/bjmb.v17i5.381.
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BACKGROUND: Analysis of performance asymmetries has indicated that the right and left cerebral hemispheres are specialized for specific functions of motor control. AIM: In the current investigation, we aimed to evaluate the effect of leg dominance on electrical activation of the plantar flexor muscles in responses to unanticipated stance perturbations in a state muscular fatigue of the dominant leg. METHOD: Fatigue was induced through ankle isometric contraction targeting 40% of maximum voluntary contraction. Muscle activation of the triceps surae of the dominant and non-dominant legs were compared in reactive responses to unanticipated load released from the trunk, leading to forward body sway. Muscular responses were analyzed in two states: pre-fatigue and fatigue of the triceps surae muscles of the dominant leg only. RESULTS: Analysis of magnitude of muscular activation for balance recovery following perturbations revealed fatigue-related compensatory activation in the lateral gastrocnemius muscle, as indicated by over-activation of the non-fatigued/non-dominant leg to compensate for the low muscular activation of the dominant/fatigued leg in the unilateral fatigue state. CONCLUSION: Compensatory behavior between the legs was not evident in the medial gastrocnemius and soleus muscles. Lack of effects related to leg dominance indicates that footedness did not affect automatic muscular responses either in the pre-fatigue or fatigue states.
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Wahyuni, Islah. "MANAGEMEN KELELAHAN SAAT PERSALINAN MENGGUNAKAN JUS SEMANGKA". Jurnal Ipteks Terapan 12, n.º 1 (31 de marzo de 2018): 19. http://dx.doi.org/10.22216/jit.2018.v12i1.2385.
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<em>The condition of fatigue during labor has received little attention for meditative intervention, so it is important in suppressing the adverse effects of fatigue during labor on the mother and fetus, and preventing the incidence of maternal and fetal mortality and morbidity. The purpose of the study to determine the handling of fatigue using watermelon juice in maternal mothers. Anaerobic fatigue was measured using blood lactic acid values, and Visual Analoque Scale-Fatique (VAS-F) quetioner from 68 respondents were divided into 2 groups: treatment and control group were selected concencutive sampling. Measurement of blood lactate level was performed 2x at before and after treatment. Data analysis was using univariate and bivariate by dependent T test. The results showed that there were significant differences between lactate levels before and after treatment and control group (.003). The VAS-Fatique analysis resulted the difference in fatigue experienced stage 1 (.015) and fatigue experienced 24 hour post partum (.001) is lower treatment group compared with the control group. In conclusion, watermelon juice is effective as fatigue handling in maternal mothers, it is recommended that watermelon juice be given to the mother during normal delivery</em>
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Gao, Yixiang, Maria Dietrich y Guilherme N. DeSouza. "Classification of Vocal Fatigue Using sEMG: Data Imbalance, Normalization, and the Role of Vocal Fatigue Index Scores". Applied Sciences 11, n.º 10 (11 de mayo de 2021): 4335. http://dx.doi.org/10.3390/app11104335.
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Our previous studies demonstrated that it is possible to perform the classification of both simulated pressed and actual vocally fatigued voice productions versus vocally healthy productions through the pattern recognition of sEMG signals obtained from subjects’ anterior neck. In these studies, the commonly accepted Vocal Fatigue Index factor 1 (VFI-1) was used for the ground-truth labeling of normal versus vocally fatigued voice productions. Through recent experiments, other factors with potential effects on classification were also studied, such as sEMG signal normalization, and data imbalance—i.e., the large difference between the number of vocally healthy subjects and of those with vocal fatigue. Therefore, in this paper, we present a much improved classification method derived from an extensive study of the effects of such extrinsic factors on the classification of vocal fatigue. The study was performed on a large number of sEMG signals from 88 vocally healthy and fatigued subjects including student teachers and teachers and it led to important conclusions on how to optimize a machine learning approach for the early detection of vocal fatigue.
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Kobayashi, Yukiyoshi, Yoshinao Kishimoto y Toshihisa Ohtsuka. "OS8-9 Simple Method for Fatigue Life Prediction Based on Fatigue Mechanism(Fatigue life prediction,OS8 Fatigue and fracture mechanics,STRENGTH OF MATERIALS)". Abstracts of ATEM : International Conference on Advanced Technology in Experimental Mechanics : Asian Conference on Experimental Mechanics 2015.14 (2015): 119. http://dx.doi.org/10.1299/jsmeatem.2015.14.119.
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Goklemez, Sencer, Saligan Leorey, Filip Pirsl, Seth M. Steinberg, Sandra A. Mitchell, Frances T. Hakim, Jeremy J. Rose et al. "Clinical Characterization and Cytokine Profile of Fatigue in Patients with Chronic Gvhd". Blood 134, Supplement_1 (13 de noviembre de 2019): 3282. http://dx.doi.org/10.1182/blood-2019-124055.
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Introduction Chronic graft-versus-host disease (cGVHD) is an autoimmune-like condition caused by allogeneic hematopoietic stem cell transplantation. It is the major cause of non-relapse mortality and morbidity after transplant. The majority of patients with cGVHD experience longstanding fatigue that is associated with decreased quality of life and impaired physical functioning. The pathophysiology and clinical characteristics of fatigue in cGVHD remain poorly understood and no effective treatments exist. Methods This cross-sectional study aimed to describe characteristics of fatigue experienced by patients with cGVHD using SF-36 self-report vitality scale as the primary outcome. 109 patients with fatigue and 72 patients without fatigue were prospectively enrolled and compared using a set of clinical, demographic and behavioral data along with 7 potential cytokine biomarkers of active cGVHD (IFN- γ, IL-6, CXCL-10, MCP-1, CXCL-9, BAFF, ST2). IFN- γ, IL-6, IP-10, and MCP-1 were assayed using V-PLEX by from Meso-ScaleDiscovery (MSD). The BAFF, CXCL9, and ST2 high sensitive assays were developed and customized for clinical testing using MSD electrochemiluminescence immunoassay technology with antibody pairs obtained from R&D Systems. A patient was considered fatigued if SF-36 vitality score was >10 points below the mean of the general population (<40). Results The median Lee cGVHD symptom scale energy score was 6 (1-12) in fatigued individuals as compared to 3 (0-9) in non-fatigued individuals (P=0.0001) suggesting internal validity of the primary endpoint definition. SF-36 MCS and PCS scores were also significantly lower in the fatigued group by 10 points (P=0.0001 for both). Several measures including walk velocity, human activity profile, SF-36 physical and mental health self-report scales were potential predictors of fatigue in univariate analysis (Table 1). Patients with increasing levels of joint involvement were more likely to be fatigued (72% vs 60% with any involvement, p= 0.0067 for increasing involvement score). In addition, fatigued individuals had higher Lee cGVHD symptom burden in skin, breathing, muscles and joints and mental domains. None of the tested cytokines showed significant association with fatigue, even after stratification for time elapsed after cGVHD diagnosis to study enrollment. However, BAFF was shown to decrease in a consistent manner when more time elapsed from cGVHD diagnosis to study enrolment (p=0.015). BAFF levels were significantly associated with NIH joint score, NIH skin score, intensity of immunosuppression and Karnofsky performance status, thus confirming the usefulness of BAFF as a marker of cGVHD activity or severity, but not fatigue. Similarly, none of standard clinical laboratory serum markers of inflammation (e.g. ESR, CRP, C3, C4, albumin) showed significant association with fatigue. Multivariable analysis revealed that NIH joint score (P=0.03), Lee symptom scale sleep (P=0.0004) and depression (P=0.03) questions and PG-SGA nutrition score (P=0.0007) were predictors of fatigue after adjusting for confounders. Antidepressant use or sleep medication use did not differ significantly between the 2 groups (p=0.63 and 0.51, respectively), although patients reporting depression and sleep problems were more likely to be in the fatigued group, thus delineating a potential area for intervention and increasing quality of life. After adjusting for NIH lung score and performance status, known poor predictors of survival in this patient population, fatigue was associated with a slight trend toward lower probability of survival, median 130.6 months vs. median not reached (p=0.074) for fatigued and non-fatigued respectively (HR: 1.45, CI 0.88 to 2.40). Conclusions These results demonstrate that the pathophysiology of fatigue in cGVHD may involve mechanisms other than those reflected by cytokine markers of inflammation known to be associated with disease activity or severity. Musculoskeletal and lung involvement as well as decreased functional performance and capacity are significant features of fatigued patients with cGVHD. Sleep, nutrition and depression may be important therapeutic targets in these patients affected by clinically significant fatigue. Further studies involving longitudinal follow-up and deeper studies of biology are imperative to better understand or treat fatigue in cGVHD patients. Disclosures No relevant conflicts of interest to declare.
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Ronchei, Camilla, Andrea Carpinteri, Giovanni Fortese, Daniela Scorza y Sabrina Vantadori. "Fretting High-Cycle Fatigue Assessment through a Multiaxial Critical Plane-Based Criterion in Conjunction with the Taylor’s Point Method". Solid State Phenomena 258 (diciembre de 2016): 217–20. http://dx.doi.org/10.4028/www.scientific.net/ssp.258.217.
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The critical plane-based multiaxial criterion originally proposed by the authors for plain fatigue is here applied to estimate the crack initiation life of fretting high-cycle fatigued structural components. Although fretting fatigue can be regarded as a case of multiaxial fatigue, the common multiaxial fatigue criteria have to be modified to account for the severe stress gradients in the contact zone. Therefore, the above criterion is used in conjunction with the Taylor’s point method to numerically estimate the fatigue life of Ti-6Al-4V and Al-4Cu specimens under cylindrical contacts.
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Samanta, Abir y Sabyasachi Mukherjee. "Surface Electromyography Based Core Muscle Fatigue Analysis During Repetitive Plank Using Multivariate Dimensionality Reduction Methods in Boys Aged 12-14". Teorìâ ta Metodika Fìzičnogo Vihovannâ 21, n.º 3 (25 de septiembre de 2021): 253–63. http://dx.doi.org/10.17309/tmfv.2021.3.09.
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The aims of the study were: 1. To analyse the discriminative power of neuromuscular components for classifying the pre and post muscle fatigued states. 2. To examine whether the modification of neural recruitment strategies become more/less heterogeneous due to fatigue. 3. To research the effect of Erector Spinae (ES) muscle activity collectively with Rectus Abdominis (RA) and External Oblique (EO) muscle activity to identify the reduced spine stability during fatiguing Plank.
Material and methods. Twelve boys (age – 12-14 years, height 148.75 ± 10 cm, body mass 38.9 ± 7.9 kg) participated in the study. Multivariate Discriminant Analysis (DA) and Principal Component Analysis (PCA) were applied to identify the changes in the pattern of the electromyographic signals during muscle fatigue. In DA the Wilks’ lambda, p-value, canonical correlation, classification percentage and structure matrix were used. To evaluate the component validity the standard limit for Kaiser-Meyer-Olkin (KMO) was set at ≥0.529 and the p-value of Bartlett’s test was ≤0.001. The eigenvalues ≥1 were used to determine the number of Principal Components (PCs). The satisfactory percentage of non-redundant residuals were set at ≤50% with standard value >0.05. The absolute value of average communality (x̄ h2) and component loadings were set at ≥0.6, ≥0.4 respectively.
Results. Standardized canonical discriminant analysis showed that pre and post fatigued conditions were significantly different (p = 0.000, Wilks’ lambda = 0.297, χ2 = 24.914, df=3). The structure matrix showed that the parameter that correlated highly with the discriminant function was ES ARV (0.514). The results showed that the classification accuracy was 95.8% between fatigued conditions. In PCA the KMO values were reduced [0.547Pre fatigue vs. 0.264Post fatigue]; the value of Bartlett’s sphericity test was in pre χ2 = 90.72 (p = 0.000) and post fatigue χ2 = 85.32 (p = 0.000); The Promax criterion with Kaiser Normalization was applied because the component rotation was non-orthogonal [Component Correlation Matrix (rCCM) = 0.520 Pre fatigue >0.3Absolute<0.357Post fatigue]. In pre fatigue two PCs (cumulative s2 – 80.159%) and post fatigue three PCs (cumulative s2 – 83.845%) had eigenvalues ≥1. The x̄ h2 increased [0.802 Pre fatigue vs. 0.838 Post fatigue] and the percentage of nonredundant residuals reduced [50% Pre fatigue vs. 44% Post fatigue] from pre to post fatigue.
Conclusions. The variability and heterogeneity increase in the myoelectric signals due to fatigue. The co-activity of antagonist ES muscle is significantly sensitive to identify the deteriorating spine stability during the fatiguing Plank. Highly correlated motor unit recruitment strategies between ES and RA, providing supportive evidence to the concept of shared agonist-antagonist motoneuron pool or “Common Drive” phenomenon during fatigue.