Objective: To develop a questionnaire to evaluate symptoms of complex regional pain syndrome type I (CRPS-I), fibromyalgia, and repetitive strain injury to determine the test-retest reliability and investigate concurrence in the clinical manifestations of CRPS-I and fibromyalgia.
Design: The Trauma Related Neuronal Dysfunction Symptoms Inventory (TSI) was developed by determining the content validity and the practical use of the questionnaire. Furthermore, the test-retest reliability was assessed on 2 identical questionnaires filled out within a 7-day interval by CRPS-I and fibromyalgia patients.
Setting: Outpatient pain clinic of a Dutch medical center.
Participants: CRPS-I (n=26; mean age, 54y) and fibromyalgia patients (n=42; mean age, 45.4y).
Interventions: Not applicable.
Main outcome measure: Test-retest reliability calculated with intraclass correlation (ICC).
Results: Reliability scores were good for the whole questionnaire, its categories, and domains (ICC>.75) for both CRPS-I and fibromyalgia patients. Sensory complaints (except for change in cold perception), motor complaints, and visceral complaints (diarrhea and incontinence) were reported by both CRPS-I and fibromyalgia patients. A change in cold perception, discoloration, change in skin temperature, change in sweating behavior, change in the severity of edema during exercise, and trophic changes of skin were reported significantly more often by CRPS-I patients, whereas complaints of the (upper and lower) back, constipation, urine retention, and experiencing a dry mouth were reported significantly more often by fibromyalgia patients.
Conclusions: The TSI is a reliable instrument with good content validity, which can be used in the evaluation of similarities and differences between CRPS-I and fibromyalgia. The systematic evaluation of symptoms of CRPS-I and potentially related illnesses may provide a better basis for future research into the underlying mechanism(s).