Separating Patients with SEID from Those with CFS in the French ME/CFS Association, with Some Thoughts on Nomenclature.
Campagne, Julien, Fornasieri, Isabelle, Andreani, Barbara et al. · Diagnostics (Basel, Switzerland) · 2022 · DOI
Quick Summary
Researchers surveyed French ME/CFS patients to see how many met the newer diagnostic criteria called SEID (Systemic Exertion Intolerance Disease), proposed in 2015. They found that about 84% of patients in the survey met SEID criteria, and certain symptoms like unrefreshing sleep, brain fog, and problems with blood pressure changes were especially useful for identifying SEID patients. However, most patients didn't strongly prefer the new SEID name over ME/CFS, suggesting the medical community should work with patients to find better terminology.
Why It Matters
This study demonstrates that the 2015 IOM/NAM SEID criteria are clinically useful for identifying the majority of ME/CFS patients, while highlighting the ongoing importance of patient perspectives in refining diagnostic definitions. It emphasizes that effective disease terminology requires collaborative input from both clinicians and the patient community.
Observed Findings
84% (150/178) of French ME/CFS association members met the newer SEID diagnostic criteria.
Unrefreshing sleep, cognitive disorders, and orthostatic intolerance were the most discriminating symptoms between SEID and non-SEID patients.
46% of respondents preferred the SEID terminology over CFS, while 39% considered it inappropriate.
Specific questionnaire items better identified SEID criteria than others, suggesting differential diagnostic utility.
15% of respondents had no opinion on nomenclature preferences.
Inferred Conclusions
The IOM/NAM SEID criteria successfully capture the majority of French ME/CFS patients and represent a meaningful diagnostic framework.
Certain symptom clusters—particularly neurological (cognitive) and autonomic (orthostatic) features—are key distinguishing characteristics of SEID.
Terminology matters to patients; future diagnostic criteria should be developed collaboratively with patient communities rather than by experts alone.
Pending discovery of specific biomarkers, ongoing dialogue between clinicians and patients is essential to establish universally acceptable disease terminology.
Remaining Questions
Why did the SEID terminology not gain stronger acceptance among patients, and what alternative terminology would be more acceptable to the ME/CFS community?
What This Study Does Not Prove
This study does not establish that SEID criteria are superior to previous ME/CFS definitions, nor does it validate SEID criteria against objective biomarkers—it only shows how many patients meet the criteria. The findings are not generalizable beyond French association members and cannot determine whether SEID and traditional ME/CFS represent distinct entities or a spectrum of the same condition.
How do SEID criteria compare to other proposed diagnostic frameworks (e.g., Fukuda, Canadian, ICC) in terms of specificity and clinical utility?
What biological mechanisms distinguish the symptom clusters (sleep, cognitive, autonomic) that best characterize SEID patients, and do they correlate with any objective biomarkers?
Do the patients who did not meet SEID criteria represent a different disease entity, less severe disease, or misdiagnosis?