Laterality judgment performance between people with chronic pain and pain-free individuals. A systematic review and meta-analysis.

Background: Treatment of chronic pain is challenging and there is often failure of recovery, with the need to look at different approaches in its management. Central mechanisms may contribute to chronicity (i.e. disturbance in body schema). Laterality judgment is dependent on body schema and can determine affected central mechanisms. Objective: This review aimed to determine whether there are laterality judgment differences between chronic pain and pain-free individuals. Methods: A search was done of various databases, using combinations of keywords, and reference lists of full-text articles. Articles were considered from inception until February 2018. Eighteen studies were included. Methodological quality was assessed by two reviewers using the JBI Critical Appraisal Checklist. Studies were analyzed broadly then divided into subgroups. A meta-analysis or narrative review was done. Results: There was high heterogeneity for broad outcome measures, complex regional pain syndrome (CRPS1), and upper limb pain. Analysis for accuracy in lower limb conditions showed a medium significant effect size (0.59) and significant 95%CI (0.11-1.07). Low back and cervical pain results could not be pooled into meta-analysis (due to different methods of reporting). Conclusions: Laterality judgment impairment was shown in CPRS1, upper limb pain, hand and wrist pain, carpal-tunnel syndrome, facial pain, knee osteoarthritis, and leg pain. No conclusions could be drawn in low back pain, due to the low-quality evidence and differing results. There was no impairment in whiplash-associated disorders and nonspecific cervical pain showed conflicting evidence.