Hall, J., Harrison, S., Cohen, H., McCabe, C., Harris, N. and Blake, D. R.
Pain and other symptoms of CRPS can be increased by ambiguous visual stimuli – an exploratory study.
European Journal of Pain, 15 (1).
Publisher's URL: http://dx.doi.org/10.1016/j.ejpain.2010.04.009
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 2 images: a bistable spatial image and a control image. For each image participants recorded the frequency of percept change in 1 minute 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.
|Uncontrolled Keywords:||Complex Regional Pain Syndrome, somatosensory system, visual illusion, visual stimulus|
|Faculty/Department:||Faculty of Health and Applied Sciences|
Professor C. McCabe
|Deposited On:||09 Aug 2010 12:57|
|Last Modified:||12 Aug 2013 19:28|
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