Research poster abstract:
Comparing post-exertional symptoms following serial exercise tests, by Lariel J Mateo, Lily Chu, S Stevens, J Stevens, CR Snell, Todd E Davenport, and J Mark Van Ness – Workwell Foundation Presentation, April 2018
Post-exertional malaise (PEM) is an exacerbation of symptoms that leads to a reduction in functional ability. Recognizing the triggers, onset, symptoms and duration of PEM is important for the diagnosis of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). PEM following serial exercise tests has not been examined.
To compare descriptions of symptoms by ME/CFS and control subjects after two maximal exercise tests, each separated by 24 hours.
Open-ended questionnaires were provided to 10 control subjects and 49 ME/CFS patients who underwent two maximal exercise tests, 24 hours apart. Each subject evaluated how they felt immediately after the first exercise test, before and immediately after the second exercise test, 24 hours after the second exercise test and in the week following the tests. Responses were analyzed and categorized by two reviewers, blinded to subject diagnosis.
Over the two days of testing, ME/CFS subjects reported an average of 15.4 p/m 7.7 symptoms compared to 5.5 p/m 1.8 in the control group. Following the tests, ME/CFS subjects reported an average of 5.0 p/m 2.8 symptoms compared to 0.1 p/m 0.3 in the control group. Among the ME/CFS subjects, fatigue, cognitive dysfunction, and sleep problems were reported with the greatest frequency. Out of the eighteen symptom categories, ME/CFS subjects reported seventeen at a higher frequency than control subjects.
The largest differences were observed in cognitive dysfunction, headache, light-headedness, muscle/joint pain and weakness. Other symptoms included decreased function, pain, flu-like and gastrointestinal symptoms. Forty-nine percent of ME/CFS subjects recovered within an average of 4.5 days while fifty-one percent had not recovered by day seven. In contrast, all but one control subject recovered within 1 day.
A standardized exertional stimulus produces prolonged and more diverse symptoms in ME/CFS subjects compared with those seen in control subjects. Understanding PEM more comprehensively may provide clues to the underlying pathophysiology of ME/CFS and lead to improved diagnosis and treatment.