Neuropathic pain in rheumatoid arthritis

Objective: to identify the signs of neuropathic pain (NP) in patients with rheumatoid arthritis (RA) on the basis of the PainDETECT questionnaire and neurological examination.Patients and methods. A total of 208 RA patients (39 men and 169 women; mean age, 47.7 years) with chronic pain syndrome were examined. The patients underwent rheumatological and neurological examinations; NP was diagnosed using the PainDETECT questionnaire; inflammation severity (DAS28 index), pain intensity (VAS), affective disorders (HADS), and quality of life (EQ-5D) were assessed.Results and discussion. 172 (82.7%) patients had moderate and high disease activity according to the DAS28. The signs of possible and highly probable NP according to the PainDETECT questionnaire were detected in 29.8 and 26.9% of patients, respectively; they were significantly more likely to be detected in patients with more severe pain syndrome, clinically significant anxiety, and worse quality of life, but were unassociated with RA activity according to the DAS28. Somatosensory nervous system injury (polyneuropathy, tunnel syndromes, and cervical myelopathy) was found in 77.6% of patients with possible NP and in 80.4% with highly probable NP. In other patients, NP might be caused by central sensitization. Conclusion. In patients with a RA exacerbation, chronic pain syndrome is caused not only by an active inflammatory process in the joint area and adjacent tissues, but also by somatosensory nervous system injury and central sensitization