Background NSAIDs are widely used for therapy nociceptive pain in osteoarthritis (OA) patients. But in 27% - 61% case this treatment fails to reduce mean pain levels beyond minimal clinically important thresholds . Recent studies have demonstrated that chronic knee OA mechanisms besides nociceptive pain also include central sensitization (CS) (neuroplastic changes in the posterior horn) . CS characterized with neuropathic (NP) phenomena spontaneous and evoked (34% cases), referred hyperalgesia and neurophysiological changes (low pressure pain threshold).
Objectives to evaluate the efficacy of NSAID in patients with “clinical” CS.
Methods 40 women (age 55±75), II-III grade by Kellgren-Lawrence with chronic knee OA were included. Patients were divided in groups in accordance with the results of neuropathic test DN4 (screening test for CS): patients with positive DN4 (n=11) and patients with negative DN4 (n=29) and accordance with presence of spontaneous NP phenomena (for ex. burning, tingling, current rush): patients with spontaneous NP phenomena (n=29) and patients without spontaneous NP phenomena. Dynamic of OA severity by WOMAC (mm) and pain intensity by VAS (mm) were assessed between groups.
Results There was no difference between sociodemographic factors in groups. Statistically and clinically significant reduction in pain score after one-month treatment (n=20) in patients with negative DN4 score was seen (mean pain relief 26mm vs 17 mm, p<0,05). Significant decrease of WOMAC from baseline to final evaluation in patients without spontaneous NP phenomena (mean WOMAC redaction 315 mm vs 199 mm, p<0,05) was demonstrated.
Conclusions Patients with clinical signs of CS have suboptimal pain control. Targeting treatment including anticonvulsants or antidepressants to symptoms of CS in people with OA could lead to benefit.
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Dieppe PA, Ayis S, Clarke S, Simmons D, Williams S, Fallon 1022 Hochman et al M, et al. Quantitative sensory testing in osteoarthritis of the knee [abstract]. Osteoarthritis Cartilage 2008;16:S204
Disclosure of Interest None declared