Neuropathic component of low back pain in patients with ankylosing spondylitis

Objective: The aim of this cross sectional study was to evaluate frequency of neuropathic back pain in ankylosing spondylitis (AS) patients and to determine the relation with disease variables and occurrence of neuropathic pain. Methods: Fifty-eight AS patients who were not having any comorbid disease and/or using drugs that would cause neuropathy, were recruited to the study. Demographic properties and clinical characteristics (functional status and disease activity assessed by BASFI and BASDAI respectively, ESR, CRP) and quality of life determined by AS quality of life-QoL questionnaire, were recorded. The neuropathic property of back pain was assessed by both Leeds Assessment of Neuropathic symptoms and signs (LANSS) and Douleur Neuropathique 4 (DN4) scales. Results: 58 AS patients (17 female, 41 male) with a mean age of 45 +/- 18 years were included. 33 patients (56.9%) and 31 patients (53.4%) were defined as having neuropathic pain depending on the LANSS (scores > 12) and DN4 (scores > 4) questionnaire scores respectively. The mean score of LANSS scale was correlated with ASQoL, BASFI, BASDAI, and DN4; and the mean score of DN4 scale was correlated with ASQoL, BASFI and LANSS. The mean levels of BASFI and ASQoL scores were significantly higher in patients having neuropathic pain than in patients not having (p < .05). Conclusion: Neuropathic pain is common and determined in more than half of the patients with AS and related with functional status and quality of life. Diagnosis and treatment of neuropathic pain are warranted in order to increase functional ability and quality of life in patients suffering from AS.