title: Problems in defining post-exertional malaise.
abstract: Post-exertional malaise (PEM) is a cardinal symptom of the illnesses referred to as Myalgic Encephalomyelitis (ME), Myalgic Encephalomyelitis/chronic fatigue syndrome (ME/CFS), and chronic fatigue syndrome (CFS). PEM is reported to occur in many of these patients, and with several criteria (e.g., ME and ME/CFS), this symptom is mandatory (Carruthers et al., 2003 , 2011 ). In the present study, 32 participants diagnosed with CFS (Fukuda et al., 1994 ) were examined on their responses to self-report items that were developed to capture the characteristics and patterns of PEM. As shown in the results, the slight differences in wording for various items may affect whether one is determined to have PEM according to currently used self-report criteria to assess CFS. Better understanding of how this symptom is assessed might help improve the diagnostic reliability and validity of ME, ME/CFS, and CFS.
authors.affiliation: a Center for Community Research, DePaul University , Chicago , Illinois , USA.
authors.forename: Leonard A
authors.initials: LA
authors.lastname: Jason
authors.forename: Meredyth
authors.initials: M
authors.lastname: Evans
authors.forename: Suzanna
authors.initials: S
authors.lastname: So
authors.forename: Jilian
authors.initials: J
authors.lastname: Scott
authors.forename: Abigail
authors.initials: A
authors.lastname: Brown
mesh_terms: D003937:Diagnosis, Differential; D004185:Disability Evaluation; D015444:Exercise / Q000502:physiology; D005221:Fatigue / Q000175:diagnosis* / Q000503:physiopathology; D015673:Fatigue Syndrome, Chronic / Q000145:classification* / Q000175:diagnosis* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D018763:Muscle Fatigue / Q000502:physiology; D005082:Physical Exertion / Q000502:physiology*; D015203:Reproducibility of Results; D057566:Self Report; D009626:Terminology as Topic
keywords: Myalgic Encephalomyelitis; Myalgic Encephalomyelitis/chronic fatigue syndrome; chronic fatigue syndrome; post-exertional malaise