Reflex receptive fields in patients with acute and chronic low back pain ? a case-control study

M. MÜLLER; J. A. BIURRUN MANRESA; F. TREICHEL; O. K. ANDERSEN; L. ARENDT-NIELSEN; P. JÜNI; M. CURATOLO

Vienna

Congreso; 9th Congress of the European Pain Federation EFIC; 2015

European Pain Federation EFIC

Background and aim: Currently the transition from acute (ALBP) to chronic low back pain (CLBP) can only be predicted to a limited extent. Central hypersensitivity is a potential predictor. The area of Reflex Receptive Fields (RRF) is a novel method to assess central hypersensitivity. The RRF area denotes the area of the sole of the foot from which spinal nociceptive reflexes (NWR) can be elicited. We performed a case-control study measuring the RRF in patients with ALBP and CLBP. The aim was to evaluate the potential role of RRF in predicting the transition from ALBP to CLBP.Methods: NWR were evoked by electrical stimulation at ten spots of the foot sole. NWR were evoked by electrical stimulation at ten sites on the sole of the foot and the RRF was defined as the area from which a NWR could be evoked following a predefined detection criterion. We computed unadjusted and adjusted linear regression models to assess the effect of the RRF on chronic pain.Results: We studied 108 patients with ALBP and 111 patients with CLBP. The unadjusted linear regression suggests a smaller RRF in patients with CLBP (regression coefficient -0.02; 95%CI - 0.077-0.03; p=0.39). After adjustment for gender, age, pain intensity and depression, it decreased to -0.01 (95%CI -0.08-0.06); p=0.77.Conclusion: No difference in the RRF area could be detected in patients with acute and chronic low back pain. This suggests that RRF may not predict the transition from acute to chronic low back pain.