Exploring symptom subgroups in patients with ME/CFS
Jonsjö M, Wicksell RK, Holmström L, Andreasson A, Ljungar I, Olsson GL
Dept. of Behavior Medicine, Karolinska University Hospital, Dept. of Physiology & Pharmacology; Dept. of Clinical Neuroscience; Dept. of Women's and Children's Health; Dept. of Neurobiology, Care Sciences and Society; Dept. of Clinical Sciences, Karolinska Institutet, Stockholm, Sweden
Background: It is still not clear whether the diagnosis Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) represents one single disease entity, as diagnosis depends on clinical case definitions. The heterogeneity and variation of symptoms across individuals indicate possible differences in the relations between symptoms, and their impact on fatigue, mood, functioning and quality of life. To advance the knowledge of the relative importance of different symptoms, the investigation of relations between symptoms among patients with ME/CFS would be of great value.
Objectives
The present study examines the relations between symptoms in patients diagnosed with ME/CFS, to identify possible symptom subgroups and their relations to functioning and quality of life.
Methods
Data was collected from 106 adults as part of the standard assessment at a tertiary specialist clinic for ME/CFS. All included patients fulfilled the 1994 CDC and 2003 Canadian criteria for ME/CFS and were thus included in this study. All participants presented with longstanding unexplained fatigue, post-exertional malaise and symptom increase after activity as well as prolonged recovery period after mental, physical or emotional effort.
Patients reported occurrence and severity of 14 different symptoms (Tender lymph nodes; Palpitations; Feverishness; Orthostatic dizziness; Irritable bowel; Sleep dysfunction; Numbness and paraesthesia; Joint pain; General pain; Body soreness; Difficulty concentrating; Memory problems; Chills and perspirations and; Headache). Symptoms were chosen based on the 2003 case definition (i.e. the Canadian criteria) and our clinical experience of the most commonly presented symptoms by patients. Data were analysed using principal component (PCA) and correlation analyses.
Results
The poster will present results from PCA as well as relationships between symptom subgroups and other clinical factors of importance. Principal component analyses suggested four clinically meaningful and statistically distinct subgroups of symptoms. Analyses of the relations between symptom subgroups and measures of fatigue, mood, functioning and quality of life showed large differences in strength, indicative of dif
ferences in impact of symptom subgroups.
Conclusions
The results from this study further the understanding of symptom relations. The identification of symptom subgroups could be a first step towards a more systematic approach in investigating possible differences in aetiology between patients, as well as tailoring treatments depending on illness profile.
Martin Jonsjö, PhD student.
Dept. of Physiology & Pharmacology, Karolinska Institutet
Behavior Medicine, Department of Anesthesiology & Intensive Care
P8:01, Karolinska University Hospital, SE-171 76 Stockholm, Sweden
