title: What is in a name? Comparing diagnostic criteria for chronic fatigue syndrome with or without fibromyalgia.
abstract: The current study had two objectives. (1) to compare objective and self-report measures in patients with chronic fatigue syndrome (CFS) according to the 1994 Center for Disease Control (CDC) criteria, patients with multiple sclerosis (MS), and healthy controls, and (2) to contrast CFS patients who only fulfill CDC criteria to those who also fulfill the criteria for myalgic encephalomyelitis (ME), the 2003 Canadian criteria for ME/CFS, or the comorbid diagnosis of fibromyalgia (FM). One hundred six participants (48 CFS patients diagnosed following the 1994 CDC criteria, 19 MS patients, and 39 healthy controls) completed questionnaires assessing symptom severity, quality of life, daily functioning, and psychological factors. Objective measures consisted of activity monitoring, evaluation of maximal voluntary contraction and muscle recovery, and cognitive performance. CFS patients were screened whether they also fulfilled ME criteria, the Canadian criteria, and the diagnosis of FM. CFS patients scored higher on symptom severity, lower on quality of life, and higher on depression and kinesiophobia and worse on MVC, muscle recovery, and cognitive performance compared to the MS patients and the healthy subjects. Daily activity levels were also lower compared to healthy subjects. Only one difference was found between those fulfilling the ME criteria and those who did not regarding the degree of kinesiophobia (lower in ME), while comorbidity for FM significantly increased the symptom burden. CFS patients report more severe symptoms and are more disabled compared to MS patients and healthy controls. Based on the present study, fulfillment of the ME or Canadian criteria did not seem to give a clinically different picture, whereas a diagnosis of comorbid FM selected symptomatically worse and more disabled patients.
authors.affiliation: Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium. mira.meeus@ugent.be.|Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium. mira.meeus@ugent.be.|Pain in Motion International Research Group, . mira.meeus@ugent.be.|Rehabilitation Sciences and Physiotherapy, Ghent University, Campus Heymans (UZ) 3 B3, De Pintelaan 185, Ghent, Belgium. mira.meeus@ugent.be.
authors.forename: Mira
authors.initials: M
authors.lastname: Meeus
authors.affiliation: Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium.|Pain in Motion International Research Group.|Departments of Human Physiology and & Rehabilitation Sciences, Faculty of Physical Education & Physiotherapy, Vrije Universiteit Brussel, Brussel, Belgium.|Department of Physiotherapy and Rehabilitation, University Hospital Brussels, Brussel, Belgium.
authors.forename: Kelly
authors.initials: K
authors.lastname: Ickmans
authors.affiliation: Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium.|Pain in Motion International Research Group.
authors.forename: Filip
authors.initials: F
authors.lastname: Struyf
authors.affiliation: Pain in Motion International Research Group.|Division of Occupational Therapy, Artesis Plantijn University College Antwerp, Antwerp, Belgium.|Rehabilitation Sciences, KU Leuven, Leuven, Belgium.
authors.forename: Daphne
authors.initials: D
authors.lastname: Kos
authors.affiliation: Private practice for internal medicine, Ghent, Belgium.
authors.forename: Luc
authors.initials: L
authors.lastname: Lambrecht
authors.affiliation: Department of Neurology, Faculty of Medicine, University and University Hospital Antwerp, Antwerp, Belgium.
authors.forename: Barbara
authors.initials: B
authors.lastname: Willekens
authors.affiliation: Department of Neurology, Faculty of Medicine, University and University Hospital Antwerp, Antwerp, Belgium.
authors.forename: Patrick
authors.initials: P
authors.lastname: Cras
authors.affiliation: Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium.|Pain in Motion International Research Group.|Departments of Human Physiology and & Rehabilitation Sciences, Faculty of Physical Education & Physiotherapy, Vrije Universiteit Brussel, Brussel, Belgium.|Department of Physiotherapy and Rehabilitation, University Hospital Brussels, Brussel, Belgium.
authors.forename: Jo
authors.initials: J
authors.lastname: Nijs
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002487:Centers for Disease Control and Prevention, U.S.; D003071:Cognition; D015897:Comorbidity; D003863:Depression / Q000523:psychology; D015673:Fatigue Syndrome, Chronic / Q000175:diagnosis* / Q000523:psychology; D005260:Female; D005356:Fibromyalgia / Q000175:diagnosis* / Q000523:psychology; D006801:Humans; D008297:Male; D009043:Motor Activity; D009103:Multiple Sclerosis / Q000150:complications*; D010147:Pain Measurement; D011788:Quality of Life; D020127:Recovery of Function; D057566:Self Report; D012720:Severity of Illness Index; D014481:United States; D055815:Young Adult
keywords: Chronic fatigue syndrome; Diagnosis; Fibromyalgia; Multiple sclerosis; Psychomotor performance; Symptom assessment