Pitch for International Association for the Study of Pain (IASP) 2021

Aims and Objectives. Complex Regional Pain Syndrome (CRPS) is a disorder of severe chronic pain in one or more limb(s). People with CRPS show altered body representations, as well as difficulty attending to their affected limb. These symptoms might be related; however, existing evidence is unclear. We hypothesized that if there were a body-related visuospatial attention bias, any attention bias away from the affected side should be larger for or limited to circumstances when the body representation is involved versus when this is not the case. Methods. People with CRPS (N=40), other pain (N=40), and pain-free controls (N=40) performed tasks of spatial attention, including free viewing, shape cancellation, temporal order judgement, and dot-probe. The degree to which different task versions involved body representation was manipulated by: (1) presenting stimuli nearer versus further away, (2) using body-related versus neutral stimuli, and (3) inducing mental rotation of body parts versus no mental rotation. Eye movements were recorded as a sensitive index of spatial attention. Results and Significance. We found no evidence for a (body-related) visuospatial attention bias in upper limb CRPS. Secondary analyses suggested a body-related visuospatial attention bias in lower limb CRPS. Our results add to growing evidence that there is no general visuospatial attention bias in CRPS.