LAUSR

Background: Despite no current knowledge of lesions or disease of the sensory nervous system in osteoarthritis (OA), subgroups of knee OA patients report neuropathic-like pain. The neuropathic-like pain component has been suggested to reflect central sensitization. Objectives: To describe the prevalence of neuropathic-like pain in persons with hand OA and explore whether neuropathic-like pain associate with peripheral and/or central sensitization. Methods: These cross-sectional analyses included 280 participants with hand OA from the Nor-Hand study. A modified PainDETECT questionnaire was used to characterize neuropathic-like hand pain (mPD-hand, 0-36 scale). We conducted quantitative sensory testing (QST) of pressure pain thresholds (PPT) and temporal summation (TS). Low PPTs at local sites (painful finger joint and non-painful finger joint) indicate peripheral and/or central sensitization, while low PPTs at extra-segmental sites (radioulnar joint, musculus trapezius and tibialis anterior) indicate central sensitization. TS, defined as an increase in pain ≥2 on a numeric rating scale (NRS, 0-10) during a repetition of ten punctate stimuli at the wrist, indicate central sensitization. Participants with painful hand OA (NRS of hand pain above the patient acceptable symptom score of ≥4), were categorized as having either nociceptive pain (mPD-hand ≤12) or neuropathic-like pain (mPD-hand score >12). We examined whether reporting nociceptive or neuropathic-like pain, as compared to no/mild pain (NRS hand pain below 4) was associated with QST results using regression analyses. Results: In this study sample, 88% were female, median age was 61 (IQR 57-66) years and 94% fulfilled the ACR criteria for hand OA. Median mPD-hand score was 8 (IQR 3, 13). Half of the participants (n=144, 51%) reported NRS pain ≥4, of whom 58 (40%) had neuropathic-like pain. Those with neuropathic-like pain reported higher mean (SD) NRS pain severity than persons with nociceptive pain (5.9 (1.6) vs 5.3 (1.5), p=0.01). We found that neuropathic-like pain was associated to higher pain sensitization reflected by lower PPT at the painful finger joint (Table), non-painful finger joint (beta -1.6, 95% CI -2.3, -0.9), radioulnar joint (beta -1.1, 95% CI -1.8, -0.4), trapezius (Table) and tibialis anterior (-1.0, 95% CI -1.8, -0.2) and presence of TS (Table). The associations between nociceptive pain and sensitization were weaker than the associations observed for neuropathic-like pain (Table).Abstract THU0418 –Table 1 Associations between neuropathic-like pain and quantitative sensory testing PPT painful finger joint1 PPT trapezius muscle1 Temporal summation2 Mean(SD) beta(95% CI) Mean(SD) beta(95% CI) N(%) OR(95% CI) No/Mild pain(n=136) 4.3 (2.1) 0.0 (ref.) 4.9 (2.1) 0.0 (ref.) 43 (32%) 0.0 (ref.) Nociceptive pain (n=86) 3.9 (1.7) -0.5 (-1.0, 0.1) 4.1 (1.9) -0.6 (-1.1, 0.0) 35 (41%) 1.3 (0.7, 2.4) Neuropathic-like pain (n=58) 2.9 (1.4) -1.6 (-2.2, -0.9) 3.6 (1.9) -0.9(-1.5, -0.2) 39 (67%) 3.8 (1.8, 8.2) 1Linear regression, 2logistic regression. Adjusted for age, sex, BMI, use of analgesics, level of education, sleep disturbance, Pain Catastrophizing Scale, the Hospital Anxiety and Depression Scale and radiographic hand OA severity (Kellgren-Lawrence sum score). Conclusion: Of persons with painful hand OA, 40% have a neuropathic-like pain component. Reporting neuropathic-like pain is associated with peripheral and central sensitization, indicated by low PPTs and presence of TS. Our results suggest that patients who report neuropathic-like symptoms are more likely to have sensitization-associated pain.  Disclosure of Interests: Pernille Steen Pettersen: None declared, Tuhina Neogi: None declared, Marthe Gløersen: None declared, Karin Magnusson: None declared, Hilde Berner Hammer Grant/research support from: AbbVie, Pfizer and Roche, Paid instructor for: AbbVie, Pfizer, UCB, Novartis, Roche, Speakers bureau: AbbVie, Pfizer, UCB, Novartis, Roche, Tore K. Kvien Grant/research support from: AbbVie, BMS, MSD, Pfizer, Roche and UCB., Consultant for: AbbVie, Biogen, BMS, Boehringer Ingelheim, Celgene, Celltrion, Eli Lilly, Hospira, Merck-Serono, MSD, Novartis, Oktal, Orion Pharma, Pfizer, Roche, Sandoz, Sanofi, Mylan and UCB, Speakers bureau: AbbVie, Biogen, BMS, Boehringer Ingelheim, Celgene, Celltrion, Eli Lilly, Hospira, Merck-Serono, MSD, Novartis, Oktal, Orion Pharma, Pfizer, Roche, Sandoz, Sanofi and UCB, Till Uhlig Consultant for: Grünenthal, Novartis, Speakers bureau: Grünenthal, Novartis, Ida Kristin Haugen Grant/research support from: ADVANCE research grant from Pfizer, Consultant for: Advisory board Abbvie