{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T03:55:00Z","timestamp":1787025300338,"version":"build-2736575974"},"reference-count":50,"publisher":"Oxford University Press (OUP)","issue":"4","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2014,4,1]]},"abstract":"\n Background<\/jats:title>\n Both good physical and cognitive functioning have a positive influence on the execution of activities of daily living. Patients with chronic fatigue syndrome (CFS) as well as patients with fibromyalgia have marked cognitive deficits. Furthermore, a good physical and functional health status may have a positive impact on a variety of cognitive skills\u2014a link that has been observed in young and old individuals who are healthy, although evidence is limited in patients with CFS.<\/jats:p>\n <\/jats:sec>\n \n Objective<\/jats:title>\n The purpose of this study was to examine whether recovery of upper limb muscle function could be a significant predictor of cognitive performance in patients with CFS and in patients with CFS and comorbid fibromyalgia. Furthermore, this study determined whether cognitive performance is different between these patient groups.<\/jats:p>\n <\/jats:sec>\n \n Design<\/jats:title>\n A case-control design was used.<\/jats:p>\n <\/jats:sec>\n \n Methods<\/jats:title>\n Seventy-eight participants were included in the study: 18 patients with CFS only (CFS group), 30 patients with CFS and comorbid fibromyalgia (CFS+FM group), and 30 individuals who were healthy and inactive (control group) were studied. Participants first completed 3 performance-based cognitive tests designed to assess selective and sustained attention, cognitive inhibition, and working memory capacity. Seven days later, they performed a fatiguing upper limb exercise test, with subsequent recovery measures.<\/jats:p>\n <\/jats:sec>\n \n Results<\/jats:title>\n Recovery of upper limb muscle function was found to be a significant predictor of cognitive performance in patients with CFS. Participants in the CFS+FM group but not those in the CFS group showed significantly decreased cognitive performance compared with the control group.<\/jats:p>\n <\/jats:sec>\n \n Limitations<\/jats:title>\n The cross-sectional nature of this study does not allow for inferences of causation.<\/jats:p>\n <\/jats:sec>\n \n Conclusions<\/jats:title>\n The results suggest that better physical health status could predict better mental health in patients with CFS. Furthermore, they underline disease heterogeneity, suggesting that reducing this factor in future research is important to better understand and uncover mechanisms regarding the nature of diverse impairments in these patients.<\/jats:p>\n <\/jats:sec>","DOI":"10.2522\/ptj.20130367","type":"journal-article","created":{"date-parts":[[2013,12,21]],"date-time":"2013-12-21T00:52:12Z","timestamp":1387587132000},"page":"511-522","source":"Crossref","is-referenced-by-count":10,"title":["Can Recovery of Peripheral Muscle Function Predict Cognitive Task Performance in Chronic Fatigue Syndrome With and Without Fibromyalgia?"],"prefix":"10.1093","volume":"94","author":[{"given":"Kelly","family":"Ickmans","sequence":"first","affiliation":[{"name":"K. Ickmans, PT, MSc, Pain in Motion Research Group, Department of Human Physiology and Physiotherapy, Faculty of Physical Education and Physiotherapy, Vrije Universiteit Brussel, Brussels, Belgium; Pain in Motion Research Group, Division of Musculoskeletal Physiotherapy, Department of Health Care Sciences, Artesis University College, Antwerp, Belgium; and Pain in Motion Research Group, Department"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mira","family":"Meeus","sequence":"additional","affiliation":[{"name":"M. Meeus, PT, PhD, Pain in Motion Research Group, Division of Musculoskeletal Physiotherapy, Department of Health Care Sciences, Artesis University College; Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium; and Pain in Motion Research Group, Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health S"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Margot","family":"De Kooning","sequence":"additional","affiliation":[{"name":"M. De Kooning, PT, MS, Pain in Motion Research Group, Department of Human Physiology and Physiotherapy, Faculty of Physical Education and Physiotherapy, Vrije Universiteit Brussel; Pain in Motion Research Group, Department of Physical Medicine and Physiotherapy, University Hospital Brussels; and Department of Neurology, Faculty of Medicine, University of Antwerp."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Luc","family":"Lambrecht","sequence":"additional","affiliation":[{"name":"L. Lambrecht, MD, PhD, private practice of internal medicine, Ghent, Belgium."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nathalie","family":"Pattyn","sequence":"additional","affiliation":[{"name":"N. Pattyn, MD, PhD, Department of Human Physiology, Faculty of Physical Education and Physiotherapy, Vrije Universiteit Brussel, and VIPER Research Unit, Royal Military Academy, Brussels, Belgium."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jo","family":"Nijs","sequence":"additional","affiliation":[{"name":"J. Nijs, PT, PhD, Pain in Motion Research Group, Department of Human Physiology and Physiotherapy, Faculty of Physical Education and Physiotherapy, Vrije Universiteit Brussel, and Pain in Motion Research Group, Department of Physical Medicine and Physiotherapy, University Hospital Brussels. Mailing address: Vrije Universiteit Brussel, Faculty of Physical Education and Physiotherapy, Medical Campu"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","reference":[{"key":"2019123008281264500_B1","doi-asserted-by":"crossref","first-page":"953","DOI":"10.7326\/0003-4819-121-12-199412150-00009","article-title":"The chronic fatigue syndrome: a comprehensive approach to its definition and study","volume":"121","author":"Fukuda","year":"1994","journal-title":"Ann Intern Med"},{"key":"2019123008281264500_B2","doi-asserted-by":"crossref","first-page":"268","DOI":"10.1097\/01.PSY.0000033125.08272.A9","article-title":"Comorbid illness in women with chronic fatigue syndrome: a test of the single syndrome hypothesis","volume":"65","author":"Ciccone","year":"2003","journal-title":"Psychosom Med"},{"key":"2019123008281264500_B3","doi-asserted-by":"crossref","first-page":"381","DOI":"10.1002\/art.1780330311","article-title":"High frequency of fibromyalgia in patients with 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