Individuals who have or are at risk for knee osteoarthritis (OA) and indicate experiencing high neuropathic-like pain, may have central pain sensitization, according to a study published in Pain Medicine.
In this subanalysis of a larger ongoing observational cohort study, researchers selected individuals self-identified as non-Hispanic black or non-Hispanic white between the ages of 45 and 85 years who screened positive for clinical knee OA (n=184). Participants underwent quantitative sensory testing (ie, heat and mechanical), with assessments of temporal summation of pain, and conditioned pain modulation. Questionnaires were given periodically to evaluate clinical pain, disability, and psychological functioning. Neuropathic-like pain characteristics were assessed using the painDETECT tool. The Western Ontario and McMaster Universities Osteoarthritis Index was used to measure lower extremity pain and function, and the Graded Chronic Pain Scale was used to evaluate global pain severity and pain-related interference.
Participants who were classified as having vs not having neuropathic-like pain features (n=32; 17.4%) were significantly younger, had higher body mass index, and reported greater pain over the past 6 months. Neuropathic-like pain was most frequently characterized as burning and pain attacks/electric shocks. There was a significant group difference in clinical pain in uncontrolled analyses and both analyses partially and fully controlled for covariates. Patients in the neuropathic-like pain group also reported significantly greater pain severity, stiffness, functional impairments related to knee OA on the Western Ontario and McMaster Universities Osteoarthritis Index, higher rates of pain catastrophizing, and more somatic symptoms, compared with participants classified as not having neuropathic pain. In unadjusted analyses, the neuropathic-like pain group exhibited lower heat pain tolerance than the non-neuropathic-like pain group.
Study limitations include its cross-sectional design.
”Overall, we found support for differences in central sensitization, clinical pain, and poorer psychological function in adults with or at risk for knee OA who have neuropathic-like pain symptoms,” concluded the study authors.
Terry EL, Booker SQ, Cardoso JS, et al. Neuropathic-like pain symptoms in a community-dwelling sample with or at risk for knee osteoarthritis [published online May 30, 2019]. Pain Med. doi: 10.1093/pm/pnz112