EMOTIONAL ALLODYNIA IN FIBROMYALGIA: PSYCHOMETRIC PROPERTIES OF THE AEQ AND CLINICAL CORRELATES – INTERIM ANALYSIS OF THE PEARL STUDY

A. Corriero¹, M. Giglio¹, A. Pilolla¹, S. Ambrosi¹, T. Petracca¹, T. Campanella¹, S. Mavaddati¹, F. Fornarelli¹, F. Galdini¹, C. Di Venosa¹, P. Trerotoli², F. Puntillo¹ | ¹Department of Interdisciplinary Medicine - Pain and ICU Section, University of Bari Aldo Moro, Italy; ²Department of Interdisciplinary Medicine - Statistics Section, University of Bari Aldo Moro, Bari, Italy

Introduction. The IASP defines pain as a sensory and emotional experience (1), yet affective hypersensitivity to low-intensity interpersonal stimuli is not routinely measured in clinical practice. We term this construct “emotional allodynia” (EA): a lowered threshold for disproportionate emotional distress in response to subtle relational cues (perceived unresponsiveness, loss of reciprocity), which appears particularly prominent in fibromyalgia and may contribute to the high burden of interpersonal distress and care dissatisfaction in these patients (2). Existing tools such as PCS, CSI, DERS, BDI-II, and STAI assess downstream emotional dysregulation but not this specific affective activation threshold. The Emotional Allodynia Questionnaire (AEQ), an 11-item 0–4 Likert scale, was designed to fill this gap.
Methods. STUDIO PEARL is an ongoing prospective observational study at a tertiary pain clinic (Policlinico Hospital, Bari, Italy; Ethics: 2451/CEL). Fibromyalgia patients are consecutively enrolled according to ACR 2016 criteria (3). We report an interim analysis on the first 128 participants (117 F, 11 M; age: 57.5±11.5 years). The assessment battery includes AEQ, PCS, CSI, BDI-II, DERS, STAI-Y1/Y2, and VAS. Psychometric analyses cover internal consistency (Cronbach’s α), factorial structure (EFA, CFA), convergent validity (Spearman’s ρ), and clinical phenotyping via AEQ×CSI median-split stratification.
Results. In the current sample, AEQ showed excellent internal consistency (α=0.917). EFA supported a unidimensional structure (KMO=0.90; Bartlett p<.001; loadings: 0.60–0.83; variance explained: 48.8%). The modified CFA model (EQ10–EQ11 residual covariance freed on theoretical grounds) yielded: CFI=0.929, TLI=0.909, RMSEA=0.095, SRMR=0.049. Mean AEQ total score was 17.9±10.4. Convergent validity was supported by Spearman correlations with DERS (ρ=0.617), PCS (ρ=0.603), STAI-Y2 (ρ=0.572), STAI-Y1 (ρ=0.523), BDI-II (ρ=0.517), and CSI (ρ=0.448; all p<.001). Exploratory post hoc AEQ×CSI median-split cross-tabulation suggested four preliminary clinical profiles (resilient, emotional allodynia, central sensitization, mixed) (Figure 1), which differed significantly across all psychometric measures (Kruskal–Wallis p<.001).
Conclusions. This interim analysis on 128 fibromyalgia patients suggests the AEQ has solid psychometric properties: α=0.917, acceptable factorial fit, and convergent correlations up to ρ=0.617 with DERS. The instrument appears to detect a relational-affective dimension that PCS, CSI, DERS, and STAI do not directly target. Enrollment is ongoing; test-retest reliability data are being collected and full validation results will be presented at study completion.