Investigation of Pain Modulation Phenotypes in Female Patients With Fibromyalgia

Fibromyalgia is characterized by altered pain processing mechanisms, including impaired descending pain inhibition and central sensitization. Although both mechanisms have been independently associated with symptom severity and functional impairment, their interrelationship and relative contributions to disease impact are not fully understood.

This study aims to examine the associations between conditioned pain modulation, central sensitization symptoms, and fibromyalgia impact. In particular, the study evaluates whether central sensitization symptoms act as a mediator in the relationship between impaired pain modulation and clinical disease burden. Participants with fibromyalgia are assessed using standardized clinical and psychological measures, including the Fibromyalgia Impact Questionnaire, Central Sensitization Inventory, and Hospital Anxiety and Depression Scale. Quantitative sensory testing is performed to evaluate conditioned pain modulation, pressure pain threshold, and temporal summation.Statistical analyses are conducted to explore bivariate associations and to identify independent predictors of fibromyalgia impact. A mediation framework is applied to assess whether central sensitization symptoms explain the relationship between pain modulation and clinical outcomes.