Background and aims
People with Complex Regional Pain Syndrome (CRPS) experience a diminished sense of ownership of their painful limb. Evidence of a reduction in pain when the affected limb is visually altered in size, suggests that targeting central processing by using visual illusions could restore coherence and reintegrate the disrupted limb representation.
We hypothesized that creating visual illusions via the MIRAGE system, a form of augmented virtual reality to change hand appearance, would improve ownership of the hand. Thirty nine patients with CRPS of one arm were randomly allocated to either a control or experimental group. While both hands were placed in the MIRAGE system, the experimental intervention involved digitally making visual changes to the affected hand according to the patient’s description of how they desired their hand to appear. The procedure was similar with controls except that no visual changes to hand appearance were made. Participants were exposed to the resultant image for one minute. Perceived ownership ratings of the hand were recorded pre and post intervention.
Twenty participants aged 51 (mean; SD=11) with disease duration of 50 months (mean; SD=2.5) reported a significantly improved sense of affected hand ownership post illusion when compared to controls (p = 0.02).
Changing the visual appearance according to how those with CRPS would like their affected hand to look improves ownership. These findings may be clinically useful for patients with CRPS.
Lewis, J., McCabe, C., & Newport, R. (2015, September). Changing appearance using visual illusions improves ownership of the painful hand in complex regional pain syndrome. Poster presented at European Pain Federation EFIC 9th Congress