Pain and other symptoms of CRPS can be increased by ambiguous visual stimuli - An exploratory study

Hall, Jane; Harrison, Simon; Cohen, Helen; McCabe, Candy; Harris, N.; Blake, David R.

Abstract

Background: Visual disturbance, visuo-spatial difficulties, and exacerbations of pain associated with these, have been reported by some patients with Complex Regional Pain Syndrome (CRPS). Aims: We investigated the hypothesis that some visual stimuli (i.e. those which produce ambiguous perceptions) can induce pain and other somatic sensations in people with CRPS. Methods: Thirty patients with CRPS, 33 with rheumatology conditions and 45 healthy controls viewed two images: a bistable spatial image and a control image. For each image participants recorded the frequency of percept change in 1 min and reported any changes in somatosensation. Results: 73% of patients with CRPS reported increases in pain and/or sensory disturbances including changes in perception of the affected limb, temperature and weight changes and feelings of disorientation after viewing the bistable image. Additionally, 13% of the CRPS group responded with striking worsening of their symptoms which necessitated task cessation. Subjects in the control groups did not report pain increases or somatic sensations. Conclusions: It is possible to worsen the pain suffered in CRPS, and to produce other somatic sensations, by means of a visual stimulus alone. This is a newly described finding. As a clinical and research tool, the experimental method provides a means to generate and exacerbate somaesthetic disturbances, including pain, without moving the affected limb and causing nociceptive interference. This may be particularly useful for brain imaging studies. © 2010 Published by Elsevier Ltd. on behalf of European Federation of International Association for the Study of Pain Chapters.

• Journal Article Type: Article
• Publication Date: Jan 1, 2011
• Deposit Date: Aug 9, 2010
• Publicly Available Date: Feb 10, 2016
• Journal: European Journal of Pain
• Print ISSN: 1090-3801
• Electronic ISSN: 1532-2149
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 15
• Issue: 1
• Pages: 17-22
• DOI: https://doi.org/10.1016/j.ejpain.2010.04.009
• Keywords: Complex Regional Pain Syndrome, somatosensory system, visual illusion, visual stimulus
• Public URL: https://uwe-repository.worktribe.com/output/985278
• Publisher URL: http://dx.doi.org/10.1016/j.ejpain.2010.04.009
• Contract Date: Feb 10, 2016