Explicit Motor Imaging Abilities are Similar in Complex Regional Pain Syndrome, Chronic Limb Pain and Healthy Individuals: a cross sectional study

ABSTRACT Background Complex regional pain syndrome (CRPS) is a chronic pain condition characterised by peripheral and central sensory and motor dysfunction. Implicit motor imagery is known to be impaired in these patients, but evidence is still lacking for explicit motor imagery. Using a self-rated questionnaire, this study aims to compare explicit motor imagery abilities between individuals with CRPS, with chronic limb pain (CLP) and healthy controls and also examine differences between affected and unaffected limbs. Methods In this single-centre observational study, 123 participants were recruited (CRPS = 40, chronic limb pain, CLP = 40, and healthy individuals = 43). Participants completed the Movement Imagery Questionnaire - Revised Second (MIQ-RS) once for each body side. The total MIQ-RS score, and the kinesthetic and visual subscores were compared between groups and between the affected and unaffected sides. Results The MIQ-RS revealed no significant differences in explicit motor imagery abilities, neither between groups nor between the affected and unaffected side. Null Hypothesis Bayesian Testing on kinesthetic motor imagery abilities indicated a sevenfold likelihood of no differences between groups and a more than fivefold likelihood of no differences between sides. Conclusion CRPS and chronic limb pain individuals showed preserved explicit motor imagery abilities, notably on the pain side. The preservation of these abilities supports the recommendation of mental imagery therapy to improve motor function and relieve pain in chronic pain patients.