Meredyth Evans

Meredyth Evans, PhD, Pediatric Psychologist at Ann & Robert H. Lurie Children's Hospital of Chicago, Illinois, USA.

Notable studies

• 2016, Are Myalgic Encephalomyelitis and chronic fatigue syndrome different illnesses? A preliminary analysis (FULL TEXT)

  Abstract - Considerable discussion has transpired regarding whether chronic fatigue syndrome is a distinct illness from Myalgic Encephalomyelitis. A prior study contrasted the Myalgic Encephalomyelitis International Consensus Criteria (ME-ICC; Carruthers et al., 2011) with the Fukuda et al. (1994) CFS criteria and found that the ME-ICC identified a subset of patients with greater functional impairment and physical, mental, and cognitive problems than the larger group who met Fukuda et al. (1994) criteria (Brown et al., 2013). The current study analyzed two discrete data sets and found that the ME-ICC identified more impaired individuals with more severe symptomatology.

• 2015, Test–retest reliability of the DePaul Symptom Questionnaire Abstract
• 2014, Examining case definition criteria for chronic fatigue syndrome and myalgic encephalomyelitis

  Abstract - Background: Considerable controversy has transpired regarding the core features of myalgic encephalomyelitis (ME) and chronic fatigue syndrome (CFS). Current case definitions differ in the number and types of symptoms required. This ambiguity impedes the search for biological markers and effective treatments. Purpose: This study sought to empirically operationalize symptom criteria and identify which symptoms best characterize the illness. Methods: Patients (n = 236) and controls (n = 86) completed the DePaul Symptom Questionnaire, rating the frequency and severity of 54 symptoms. Responses were compared to determine the threshold of frequency/severity ratings that best distinguished patients from controls. A Classification and Regression Tree (CART) algorithm was used to identify the combination of symptoms that most accurately classified patients and controls. Results: A third of controls met the symptom criteria of a common CFS case definition when just symptom presence was required; however, when frequency/severity requirements were raised, only 5% met the criteria. Employing these higher frequency/severity requirements, the CART algorithm identified three symptoms that accurately classified 95.4% of participants as patient or control: fatigue/extreme tiredness, inability to focus on multiple things simultaneously, and experiencing a dead/heavy feeling after starting to exercise. Conclusions: Minimum frequency/severity thresholds should be specified in symptom criteria to reduce the likelihood of misclassification. Future research should continue to seek empirical support of the core symptoms of ME and CFS to further progress the search for biological markers and treatments.

• 2013, Contrasting chronic fatigue syndrome versus myalgic encephalomyelitis/chronic fatigue syndrome. Abstract

Doctorate thesis

• 2015, Onset Patterns of Chronic Fatigue Syndrome and Myalgic Encephalomyelitis: A Mixed Method Approach - Meredyth Evans - DePaul University

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myalgic encephalomyelitis (M.E.) - A disease often marked by neurological symptoms, but fatigue is sometimes a symptom as well. Some diagnostic criteria distinguish it from chronic fatigue syndrome, while other diagnostic criteria consider it to be a synonym for chronic fatigue syndrome. A defining characteristic of ME is post-exertional malaise (PEM), or post-exertional neuroimmune exhaustion (PENE), which is a notable exacerbation of symptoms brought on by small exertions. PEM can last for days or weeks. Symptoms can include cognitive impairments, muscle pain (myalgia), trouble remaining upright (orthostatic intolerance), sleep abnormalities, and gastro-intestinal impairments, among others. An estimated 25% of those suffering from ME are housebound or bedbound. The World Health Organization (WHO) classifies ME as a neurological disease.

International Consensus Criteria (ICC) - A set of diagnostic criteria, based on the Canadian Consensus Criteria, that argued for the abandonment of the term "chronic fatigue syndrome" and encouraged the sole use of the term "myalgic encephalomyelitis".

cognition Thought processes, including attention, reasoning, and memory.