Association of Central Sensitization With Chronic Pain and Quality of Life Measures in Endometriosis

INTRODUCTION: Endometriosis affects 10% of reproductive-aged women and is characterized by chronic pelvic pain. Central sensitization, defined by amplified central nervous system signaling and enhanced pain sensitivity, is a theoretical explanation for the interrelatedness of chronic pain conditions and may contribute to endometriosis-associated pain and its comorbidity with other such conditions. The Central Sensitization Inventory (CSI) is a validated tool used in chronic pain and endometriosis research; however, its correlation with endometriosis-specific pain and quality of life remains understudied. OBJECTIVE: Given the theoretical impact of central sensitization on pain processing, we explored the association of central sensitization and endometriosis-related quality-of-life measures, including pain, emotional well-being, and chronic pain comorbidities. Our primary objective was to assess the association between a measure of central sensitization and endometriosis-associated functioning, comparing central sensitization scores among people with endometriosis alone to those with additional chronic pain conditions. METHODS: This cross-sectional study recruited 51 participants aged 18-45 years assigned female at birth from the minimally invasive gynecologic surgery division at a large academic medical center with ICD-10 endometriosis diagnosis codes between April and September 2025, with recruitment ongoing and a goal sample size of 300. Participants reported previous diagnoses of fibromyalgia, temporomandibular disorder, migraine, irritable bowel syndrome, anxiety, and depression. Validated questionnaires assessed endometriosis-related functioning, pain, and central sensitization. Pearson’s correlation coefficients examined linear relationships between CSI and Endometriosis Health Profile (EHP-30) scores. T-tests assessed mean differences in central sensitization scores between individuals with endometriosis alone versus those with additional pain conditions. RESULTS: Fifty-one participants (mean age 31.7 years [SD=6.6]) were analyzed; 38 [70.4%] White, 10 [18.5%] Black or African American, 2 [3.7%] American Indian or Alaskan Native, and 5 [9.3%] mixed race or other). Mean CSI score was 54.7 (SD=18.7), with 40 participants (78.4%) scoring >40, indicating high central sensitization. CSI scores were highly correlated with EHP-30 control/powerlessness subscale (r=0.75). Other EHP-30 correlations ranged from r=0.58 (social support) to r=0.63 (pain and self-image), with emotional well-being at r=0.60. Central sensitization scores were significantly higher among people with chronic pain conditions, specifically among those with temporomandibular disorder (mean difference 15.0 points, 95% CI 2.8–27.2, n=11 vs n=40) and migraine/tension headache (mean difference 14.3 points, 95% CI 4.5–24.2, n=24 vs n=27). Differences were non-significant for fibromyalgia (n=7, p=0.064) and irritable bowel syndrome (n=13, p=0.084). CONCLUSIONS: In this preliminary analysis of people with endometriosis, we found high central sensitization scores with variation across comorbid chronic pain conditions. CSI scores demonstrated a strong positive correlation with endometriosis-related feelings of control and powerlessness while showing moderate correlations with other endometriosis-specific quality-of-life measures of pain, emotional well-being, social support, and self-image. These findings suggest central sensitization may significantly contribute to endometriosis-related quality-of-life impairment, warranting investigation into targeted interventions addressing central nervous system sensitization alongside traditional management.Figure 1